Annual/Termination Reports:

[02/25/2002] [01/02/2004] [01/03/2005] [01/19/2006]

Report Information

Participants

Mike Benson (NC),

Craig Canaday (TN)

Marc Cubetta (NC)

Charles Howell (TX)

Don Huber (IN)

Bonnie Ownley (TN)

Craig Rothrock (AR)

Ken Seebold (GA)

Greg Weidemann (AR)

Emily Gatch (TN) (guest)

Note: Travel to the meeting by both Bill Batson and Monica Elliott was halted by a security threat at the Atlanta Hartsfield airport (which shut down the airport for several hours, leading to the cancellation of their flights). Bill Batson subsequently faxed his results to Craig Rothrock in time for the meeting. Monica Elliott e-mailed her results to committee members after her return to Florida.

Brief Summary of Minutes

Craig Rothrock opened the meeting and introduced Greg Weidemann, the new administrative advisor for S-302. After a few opening remarks by Dr. Weidemann, Craig Rothrock reviewed the results of the regional trials forwarded by Bill Batson. Data presented included the effects of treatments on final cotton and snap bean stands over all sites, significant treatment effects at selected sites, and the related stability analyses. In her e-mailed reports, Monica Elliott outlined the protocols used for the regional trials to assay levels of bacterial and fungal biological control agents on cotton and snap bean seed and presented the 2001 results of her seed assays of these agents at the time of delivery to cooperators and at the time of planting.

Problems and possible changes to the regional trials were discussed. Many of the cooperators present expressed a desire to switch to a Roundup Ready (RR) cotton variety, though one problem with many of the current varieties is getting seed of the same variety for more than one year. Craig Rothrock thought that an appropriate RR cotton variety could be identified. Interactions between soil temperature, GB03, and Lorsban were noted. GB03 + Lorsban appeared better than GB03 alone in cool soils but not in warm soils. A desire for more yield data was expressed, as well as a desire to look at the effects of the biological control agents on more than one variety. Craig Canaday suggested a possible change to the snap bean protocol to evaluate two snap bean varieties, two bacterial and two fungal biocontrol agents, with and without chemical seed treatments, plus two additional Awild card@ entries (without chemical seed treatment) that would maintain the size of the current regional tests. No change in the crops used for the regional trials were desired. Other possible modifications included looking at interactions between biologicals and insecticides used as seed treatments and looking at sampling at different times for seedling diseases.

Cooperators expressed their appreciation to Bonnie Ownley for her work on attempting to get the grant for the regional project and to Monica Elliott for her work on getting project results published in Pest Management Science.

Individuals reported on their project-related research by objective and state.

NEW BUSINESS. It was decided that the proposed new protocol for evaluation of snap bean seed treatments (see above) should be taken to committee members not present at the Knoxville meeting before it is accepted for the 2002 tests. Craig Canaday will prepare a draft of the proposed 2002 snap bean protocol and send it to committee members for comment/approval. It was also decided that a RR variety should be selected for use in the 2002 evaluation of cottonseed treatments. Craig Rothrock will identify an appropriate variety.

By unanimous vote the committee offices of vice chairman (who has no duties) and secretary were combined. Don Huber was nominated for the new position for the 2002 meeting, the nomination was unanimously approved, and he accepted. Mike Benson and Marc Cubetta offered to host the 2002 meeting in North Carolina. The offer was unanimously accepted. Location and date(s) will be announced later.

Accomplishments

Please see accomplishments at: <a href="http://www.cals.ncsu.edu:8050/research/s302/2001_annual_report.htm">http://www.cals.ncsu.edu:8050/research/s302/2001_annual_report.htm</a>

Publications

Batson, Jr., W. E., Caceres, J., Benson, M., Cubeta, M. A., Elliott, M. L., Huber, D. M., Hickman, M. V., Keinath, A. P., Dubose, V., McLean, K. S., Ownley, B., Canaday, C., Rushing, K. W., and Kenny, D. S. 2001. Evaluation of biological seed treatments for control of the seedling disease complex of snap bean, 2000. Biological and Cultural Tests for Control of Plant Diseases, 2001: V81, 2 pp. http://www.scisoc.org.online/B&Ctests/2001/.<br /> <br><br /> <br>Batson, Jr., W. E., Caceres, J., Benson, M., Cubeta, M. A., Elliott, M. L., Huber, D. M., Hickman, M. V., McLean, K. S., Ownley, B., Newman, M., Rothrock, C. S., Rushing, K. W., Kenny, D. S., and Thaxton., P. 2001. Biological seed treatment evaluations for control of the seedling disease complex of cotton, 2000. Biological and Cultural Tests for Control of Plant Diseases, 2001: F12, 2 pp. http://www.scisoc.org.online/B&Ctests/2001/.<br /> <br><br /> <br>Elliott, M. L., Des Jardin, E. A., Batson, Jr., W. E., Caceres, J., Brannen, P. M., Howell, C. R., Benson, D. M., Conway, K. E., Rothrock, C. S., Schneider, R. W., Ownley, B. H., Canaday, C. H., Keinath, A. P., Huber, D. M., Sumner, D. R., Molsenbocker, C. E., Thaxton, P. M., Cubeta, M. A., Adams, P. D., Backman, P. A., Fajardo, J., Newman M. A., and Pereira., R. M. 2001. Viability and stability of biological control agents used for disease management on cotton and snap bean seeds. Pest Manag. Sci. 57:695-706.<br /> <br><br /> <br>Elliott, M., Des Jardin, E., Batson, Jr., W., Caceres, J., Brannen, P., Howell, C., Benson, M., Conway, K., Rothrock, C., Schneider, R., Ownley, B., Keinath, A., Huber, D., Summer, D., Molsenbocker, C., Thaxton, P., Cubeta, M., Adams, P., Backman, P., Fajardo, J., Newman, M., and Pereira., R. 2001. Tracking biological control agents on cottonseed from delivery to planting. Pages 65-74 in: D. M. Huber (ed.). Biocontrol in a New Millenium: Building for the Future on Past Experience. Proceedings Joint Regional Biological Control Conference, Oct. 26-29, 2000, Estes Park, CO.<br /> <br><p><br /> <br>Additional publications may be viewed at: <a href="http://www.cals.ncsu.edu:8050/research/s302/2001_annual_report.htm">http://www.cals.ncsu.edu:8050/research/s302/2001_annual_report.htm</a><br /> <br>

Impact Statements

Back to top

Report Information

Participants

SAES:

Alabama K. S. McLean*, J. W. Kloepper

Arkansas C. S. Rothrock

Florida M. L. Elliott*, L. E. Datnoff

Georgia K. W. Seebold

Indiana D. M. Huber

Kentucky J. W. Hendrix

Louisiana G. B. Padgett

Mississippi W. E. Batson*, R. E. Baird

North Carolina D. M. Benson* M. A. Cubeta

Oklahoma L. L. Singleton* K. E. Conway

South Carolina A. P. Keinath

Tennessee B. H. Ownley*, C. H. Canaday

Texas T. Isakeit

USDA ARS

Texas C. R. Howell

Admin Advisor

Arkansas G. J. Weidemann

CSREESR R. Nowierski
* Voting member in state

Brief Summary of Minutes

Accomplishments

Objective 1. Selection, optimization and regional evaluation of biological control agents to include application techniques and enhancement of biological control agents to control diseases caused by soilborne plant pathogens.<br /> <br><br /> <br>Ten states (Nine test sites) were involved in the Regional Cotton Trials (AL, AR, FL, GA, IN, LA, MS, NC, TN, and TX). The fourteen treatments evaluated on two cotton cultivars (Deltapine 451B/RR and Paymaster 1218 BG/RR) included: Bacillus subtilis MBI 600 (Subtilex), B. subtilis GB03 (Kodiak), B. pumilus GB34 (YieldShield), B. subtilis GB03+ B. amyloliquefaciens GB99 (Bio Yield), Trichoderma virens G6, and T. virens/T. koningii fusant TV-117, alone and in combination with Vitavax-PCNB+ Allegiance, and the fungicide and non-treated controls. Significant treatment effects were observed at 5 locations (AR, GA, LA, MS, NC); however, significant interactions between cultivar and treatment were only observed in NC. A potential negative impact was observed for treatments with Trichoderma virens isolate G-6 (AR, LA) and YieldShield (Bacillus pumilus GB34) (LA, NC). The biological plus fungicide combinations were usually not significantly different from the fungicide alone treatment.<br /> <br><br /> <br>Ten states (AL, AR, FL, GA, IN, MS, NC, SC, TN, and TX) participated in the Regional Snap Bean Trials coordinated by Craig Canaday (TN). Four biological control agents (Bacillus subtilis MBI 600 (Subtilex), B. subtilis GB03 (Kodiak), Bacillus licheniformis SB3086 (710-145F), and Trichoderma harzianum T-22 HC), with and without captan + streptomycin were evaluated as seed treatments on two snap bean cultivars (Bronco and Carlo). A significant increase in stand was observed overall only with the chemical seed treatment. Significant cultivar effects were observed at 4 locations (AR, IN, SC and TN) and biological treatment at one location (TX). A significant interaction for chemical and biological treatments was observed only in TX.<br /> <br><br /> <br>The cooperative effort of Southern Regional Project S-302 also determines the stability, population, and purity of the biological agents applied to the seed from time of seed delivery to test cooperators until the seed is actually planted. Populations of most bacterial agents on seed were stable for the 4-8 weeks from delivery to planting. The greatest variability in populations of biocontrol agents on seed was observed with the fungal treatment on cotton. The addition of fungicides significantly increased populations of bacterial agents, but decreased populations of fungal agents on both snap bean and cotton. No significant differences between cultivars were observed when treatments were averaged across all locations.<br /> <br><br /> <br>Other Research under Objective 1.<br /> <br>Various techniques for enhancing efficacy of biocontrol agents are being evaluated. Actigard, an induced systemic-resistance activator (ISR) was evaluated with three new bacterial strains antagonistic to Phytophthora crown and fruit rot (P. capsici) (GA) and with binucleate Rhizoctonia (BNA) against R. solani seedling disease of cotton (AR). Infestation of soil with nonpathogenic strains of BNR significantly suppressed seedling disease caused by R. solani in both greenhouse and field tests (AR). There was no significant benefit of the ISR, but the three strains of BNR were as effective as the fungicide treatment used for comparison. Placement and timing of the biocontrol agents were important enhancements for R. solani control. BioYield, another induced systemic resistance activator, with and without two Plant Growth-Promoting Rhizobacteria (PGPR), increased tomato yield and reduced the number of culls from buckeye rot depending on the harvest time and cultivar (TN). A phosphite compound (FNX-100) reduced Phytophthora crown and fruit rot in the greenhouse, but did not increase yields of field-grown squash (GA). Combinations of Trichoderma virens and T. harzianum effective against Pythium damping-off (preemergence) with fungicides active against Rhizoctonia solani (post-emergence damping-off) increased cotton stands 72 to 80 % (TX). The addition of abiotic factors such as Al and composted animal wastes to potting mixes improved biological control of Phytophthora diseases (NC). Fourteen of over 912 Bacillaceae isolates screened in vitro for activity against R. solani were selected for further testing in vivo (FL). A reduction in post-emergence damping-off of marigolds was observed when the bacteria were applied just prior to transplanting, but not at seeding time (FL). <br /> <br><br /> <br><br /> <br>Objective 2. Improve understanding of mechanisms and applicability of biological control agents across different cultivars, environments, and cropping systems. <br /> <br><br /> <br>Two Bacillus isolates selected for biocontrol of post-emergence dampingoff also restored the normal color to iron chlorosis Vinca plants independent of disease suppression (FL). As little as 50-60 ppm ferrous iron was found to inhibit germination of Exserohilum rostratum conidia and there was no inhibition with 200 PPM or more of ferric iron (FL). Glyphosate reduced Mn uptake and physiological efficiency, but increased take-all of wheat following glyphosate-resistant soybeans was indirect through modification of the soil microflora (IN). Combinations of PGPR with Beauveria bassiana biocontrol agent were evaluated to improve biocontrol efficacy (TN). Trichoderma appears to prevent pre-emergence damping-off caused by Pythium spp. by inactivating seed exudates that stimulate Pythium germination (TX). Increased Rhizoctonia observed when a wheat cover crop was used to prevent soil and moisture loss may necessitate fungicide applications to manage subsequent disease on vegetables (GA). Crop sequence and tillage influenced the availability of Mn for a subsequent crop and could account for the yield benefit of crop rotation for soybeans in a corn -soybeanwheat rotation and yield decline in no-till compared with fall chisel tillage programs (IN). A greater number of jumbo-grade onions were produced in Pyrenocheata terestris (pink root) infested soil by biofumigation with turnip and solarization, but solarization alone increased bacterial rots (sour skin and center rot) (GA). Soilarization decreased populations of Sclerotium rolfsii and Rhizoctonia solani, but not Pythium in soil (SC). Fusaria were the most sensitive fungal group to solarization. Populations of Rhizoctonia solani AG-3 from potato seed tubers are genetically diverse and research is determining the association of the M2 dsRNA and other dsRNA elements with population dynamics and virulence (NC). The Mn-oxidizing factor associated with virulence of Gaeumannomyces graminis var tritici (take-all) and Magnaporthe grisea (rice blast) is an extracellular protein approximately 50 kd size, but not manganese peroxidase or a common laccase (IN). Competition for organic matter is a possible mechanism for the interaction between the biocontrol fungus Laetisaria arvalis and Sclerotium rolfsii (OK).<br /> <br><br /> <br><br /> <br>IMPACT:<br /> <br><br /> <br>Pesticides in the environment, and public concern over food safety, have led scientists in Southern Regional Research Project S-302 to look at biological control as a central component of an ecologically based approach to Integrated Pest Management for plant diseases. A major deterrent to widespread adoption of biological control for soilborne plant diseases, however, has been the limited knowledge regarding activity and stability of potential biological control agents on multiple crops in diverse locations. This information is limited because biological control agents are initially discovered by university or USDA researchers and not by the agricultural industry. Development of large scale, multi-state evaluations of biocontrol agents are difficult for a single researcher or small company. This problem was solved through Cooperative research conducted by researchers in Alabama, Arkansas, Florida, Georgia, Indiana, Louisiana, Mississippi, North Carolina, South Carolina, Tennessee, and Texas under the auspices of Southern Regional Research Project S302. This project has demonstrated that several bacteria and fungi, either individually and in combination with standard seed treatment chemicals, are effective in reducing damping-off and seedling diseases of cotton and green beans across diverse environments and soil types. These early season crop diseases cost cotton growers between $9.78 (2001) and 19.46 (2002) million dollars annually in lost stand and replant costs. In addition to providing efficacy data on biocontrol agents, this research includes an analysis for stability and purity of the seed populations of these biological agents from time of seed delivery to planting in order to insure product quality and performance. The evaluation of potential biological agents for disease control in this manner provides new incentives for alternative controls of poorly managed soilborne plant diseases and helps understand inconsistent performance problems encountered with biological agents in the past.<br /> <br><br /> <br><br /> <br>WORK PLANNED FOR NEXT YEAR:<br /> <br><br /> <br>Work will continue on both project objectives. Regional testing of biological control agents on cotton and snap bean will continue to be the primary focus of the regional research effort. The modified protocol will evaluate the interactions between genotype, biological control agents (both bacterial and fungal), and chemical seed treatments. Researchers in several states will work together to better understand the mechanisms of biocontrol and the complex interactions between host, pathogen, biocontrol agent, and the environment.

Publications

Refereed Journal Articles:<br /> <br>Broschat, T.K. and Elliott, M.L. 2003. Effects of iron source on iron chlorosis and Excerohilum leaf spot severity in Wodyetia bifurcata. Hort Sci. (In Press).<br /> <br><br /> <br>Bush, B.J., Carson, M.L., Cubeta, M.A., Hagler, W.M., and Payne, G.A. 2003. Infection and fumonisin production by Fusarium verticillioides in developing maize kernels. Phytopathology 93:(In Press).<br /> <br><br /> <br>Ceresini, P.C., Shew, H.D., Vigalys, R., Rosewich-Gale, U.L., and Cubeta, M.A. 2003. Detecting migration in populations of Rhizoctonia solani AG-3 from potato in North Carolina using multilocus genotype probabilities. Phytopathology 93:610-615.<br /> <br><br /> <br>Diab, H., Hu, S., and Benson, D.M. 2003. Suppression of Rhizoctonia solani on impatiens by enhanced microbial activity in composted swine waste amended potting mixes. Phytopathology 93:1115-1123.<br /> <br><br /> <br>Elliott, M.L., Guertal, E.A., and Skipper, H.D. 2003. Rhizosphere bacterial population flux in golf course putting greens in the Southeastern United States. HortTechnol.: (In Press).<br /> <br><br /> <br>Hanson, L.E. and Howell, C.R. 2003. Elicitors of plant defense responses from biological control strains of Trichoderma virens. Phytopathology 93:(In Press). <br /> <br><br /> <br>Hollowell, J.E., Shew, B.B., Wilcut, J.W., and Cubeta, M.A. 2003. Weed species as hosts of Sclerotinia minor in peanut fields. Plant Dis. 87:197-199.<br /> <br><br /> <br>Howell, C.R. 2003. Mechanisms employed by Trichoderma species in the biological control of plant diseases: The history and evolution of current concepts. Plant Dis. 87:4-10.<br /> <br><br /> <br>Hwang, J. and Benson, D.M. 2003. Expression of induced systemic resistance in poinsettia cuttings against Rhizoctonia stem rot by treatment of stock plants with binucleate Rhizoctonia. Biol. Control 27:73-80.<br /> <br><br /> <br>Keinath, A.P., Harrison, H.F., Marino, P.C., Jackson, D.M., and Pullaro, T.C. 2003. Increase in populations of Rhizoctonia solani and wirestem of collard with velvet bean cover crop mulch. Plant Dis. 87:719-725.<br /> <br><br /> <br>Books, Book Chapters and Review Articles:<br /> <br>Cubeta, M.A., Mozley, S.E., and Porter, D. 203. Laboratory Exercises with Zoosporic Fungi. Pp. 99-110. In: Trigiano and Windam (eds.). Zoosporic Fungi. CRC Press, Boca Raton, FL.<br /> <br><br /> <br>Mozley, S.E., Leander, C.E., Porter, D., and Cubeta, M.A. 2003. Concepts: Zoosporic fungi. Pp. 91-98. In: Trigiano and Windam (eds.) Zoosporic Fungi. CRC Press, Boca Raton, FL.<br /> <br><br /> <br>Payne, G.A. and Cubeta, M.A. 2003. Biology and Detection of Human and Plant Pathogenic Fungi. Elsevier (In Press).<br /> <br><br /> <br>Symposia and other published works:<br /> <br>Bates, G.D., Rothrock, C.S., and Rupe, J.C. 2003. Possible mechanism for resistance to Phytium spp. in the soybean cultivar Archer. Proc. 8th Intern. Cong. Plant Pathol. 2:330.<br /> <br><br /> <br>Huber, D.M. 2003. Nutrient-disease interactions in the take-all disease of cereals. Proc. Symposium on take-all, April 2003, Temuco, Chili.<br /> <br><br /> <br>Huber, D.M. 2003. The role of plant nutrition in disease. Proc. Symposium Relacao entre Nutricao de Plantas e Incidencia de Doencas, March, 2003, Piracicaba, SP, Brazil.<br /> <br><br /> <br>Keinath, A.P., DuBose, V.B., Cantrell, J.P., and May, W.H. III. 2003. Evaluating foliar-applied fungicides to control wirestem on heading Brassica vegetables. Fungic. Nematic. Tests. 58:V010.<br /> <br><br /> <br>Rosskopf, E.N., Yandoc, C.B., and Lamb, E.M. 2002. Evaluation of PCC1210 for control of Phytophthora capsici on pepper. Pp. 85.1-85.3. In: Proc. 2002 Ann. Intern. Res. Conf. Methyl Bromide Alternatives Emissions Reductions..<br /> <br><br /> <br>Abstracts:<br /> <br>Bates, G.D., Rothrock, C.S., and Rupe, J.C. 2003. Possible mechanism for resistance to Pythium spp. in the soybean cultivar Archer. Proc. 8th Intern. Cong. Plant Pathol. 2:330.<br /> <br><br /> <br>Benson, D.M. and Parker, K.C. 2003. Suppression of Pythium root rot in poinsettia with swine waste and binucleate Rhizoctonia fungi. Phytopathology 93:S8.<br /> <br><br /> <br>Cubeta, M.A., Ceresini, P.C., Shew, H.D., Cody, B.R., Boerema, M.E., Lakshman, D.K., and Tavantzis, S.M. 2003. Occurrence of the M2 dsRNA in populations of Rhizoctonia solani AG-3 from potato and soil. Proc. Intern. Cong. Plant Pathol. Pp. 110.<br /> <br><br /> <br>Fichtner, E.J., Benson, D.M., Diab, H., and Shew, H.D. 2003. Suppression of Phytophthora parasitica in composted swine waste. Phytopathology 93:S26.<br /> <br><br /> <br>Gonzalez, D., Cubeta, M.A., and Vilgalys, R. 2003. Molecular systematics of Rhizoctonia phylogenetically integrates anamorphs into Ceratobasidiaceae. Proc. Intern. Cong. Plant Pathol. Pp. 29.<br /> <br><br /> <br>Howell, C.R. 2003. Pre-emergence damping-off of cotton seedlings. Workshop: Cotton Seedling Diseases. Proc. Beltwide Cotton Conf., National Cotton Assoc. America.<br /> <br><br /> <br>Howell, C.R., Puckhaver, L.S., and Stipanovic, R.D. 2003. Biocontrol of cotton pre-emergence seedling disease by metabolism of pathogen germination inducers. Phytopathology 93:S37.<br /> <br><br /> <br>Jia, Y., Singh, P., Cartwright, R.D., Lee, F.N., Rothrock, C.S., Eizenga, G.C., and Rutger, J.N. 2003. Characterization of isolate diversity in the rice sheath blight pathogen Rhizoctonia solani. Phytopathology 93:S40.<br /> <br><br /> <br>Keinath, A.P. and Smith, J.P. 2003. Effects of winter cover crops on populations of Rhizoctonia and Fusarium in bulk soil. Phytopathology 93:S43.

Impact Statements

1. Pesticides in the environment, and public concern over food safety, have led scientists in Southern Regional Research Project S-302 to look at biological control as a central component of an ecologically based approach to Integrated Pest Management for plant diseases. A major deterrent to widespread adoption of biological control for soilborne plant diseases, however, has been the limited knowledge regarding activity and stability of potential biological control agents on multiple crops in diver

Back to top

Report Information

Participants

Benson, Mike (mike_benson@ncsu.edu)NC; Canady, Craig (ccanaday@utk.edu)TN;Elliott, Monica (melliott@ufl.edu)FL; Huber, Don (huber@btny.purdue.edu) IN; Keinath, Anthony (tknth@clemson.edu)SC; Ownley, Bonnie (bownley@utk.edu)TN; Padgett, Boyd (bpadgett@agctr.lsu.edu)LA; Rothrock, Craig (rothrock@uark.edu)AR; Seebold, Kenneth (kseebold@tifton.cpes.peachnet.edu)GA; Weidemann, Greg (gweidema@uark.edu)AR

Brief Summary of Minutes

Craig Canaday hosted the meeting at the West Tennessee Experiment Station, Jackson, TN. The meeting convened November 6 at 8:20 with a welcome from Craig Canaday.

Greg Weidemann addressed the group concerning the renewal of the project. He explained the process for renewal. He also explained the differences, advantages, and benefits of a Regional Project and a Coordinating Committee. Greg recommended the group continue as a regional project.

Monica reviewed handout from Robert Nowierski, CSREES representative, and initiated the administrative meeting. Kenny Seebold volunteered to serve as secretary for 2005. The meeting site and arrangements were discussed by the group. There was discussion to meet with the Western regional group and potential meeting sites for 2005 included Estes Park; Hendersonville, NC; camp near Orlando; and Washington D.C. Monica agreed to contact the chair of the Western group to discuss the details.

Craig Canaday led a discussion on the Regional Snap Bean project. Twelve seed treatments were evaluated (six biological treatments, both with and without chemical seed treatments) on cultivars Bronco and Hialeah. Disease pressure was good at all locations except Mississippi. Three chemical reference treatments were added, but performance was not uniform across locations. He noted some biologicals may be promising, but that the best biological varied with state and with cultivar. This may be due to differences in cultivar susceptibility to root rot with Bronco being more susceptible than Hialeah. In two states (AR and TX), disease incidence was greater with some biological agents than on non-treated seed. This may be due to the carriers (molasses and yeast) used with some biological agents. A planting date effect was noted in the Tennessee trials (only participating state with multiple planting dates). It was concluded biologicals may be most beneficial in cultivars possessing some genetic resistance to root rots, when used in combination with seed treatment chemicals, or in scenarios where moderate disease pressure occurs. Other discussion included changing the method for statistical analysis using PROC MIX.

Monica Elliott reported on isolations from biological treatments for snap bean and cotton. When biological organisms were used in combination with chemicals there was an increase in bacteria recovered relative to non-chemical treatments. However, the addition of captan was not consistent and did not result in an increase. Monica noted biological organisms were stable on cotton.

Bill Batson was not able to attend. Therefore, Craig Rothrock reported on the results from the biological cotton seed treatments. Fourteen treatments were evaluated on two cultivars (DP 451BR and PM 1215BR). There was less disease pressure observed for DP 451BR compared to PM 1215BR. Statistical analysis revealed no location by treatment interaction; therefore results were summarized across locations. Plant stands were lowest in the non-treated control. Stands in cotton treated with Vitavax-PCNB were greater than the non-treated control. The addition of a biological organism to Vitavax-PCNB did not improve the efficacy of Vitavax-PCNB alone. The addition of Trichoderma to Chloroneb-Allegiance did not improve the efficacy of Chloroneb-Allegiance alone. Kodiak biological treatment did improve stand relative to the non-treated control. Craig noted that the current chemical standards were likely to change in the future.

Craig Rothrock and Bill Batson have agreed to summarize the results of the biological cotton seed treatment tests from the past years. Intentions are to evaluate the efficacy of the biological treatments, as well as, the effect of cultivars and environment. Craig and Bill will have a rough draft in the near future.

The group discussed the direction of the new project. Since interest in biologicals for seedling disease management in cotton is decreasing, it was suggested an emphasis on vegetable transplants may be warranted. Other ideas included increasing emphasis on the impact of cultural practices on seedling disease management. Several members (Seebold, Ownley, and Canaday) are already working with these crops. Tentative plans were made to explore these areas.

State reports were given by members of the group. Monica Elliott (FL) reported BioYield and Beauveria bassiana inhibited germination of geranium. Craig Canaday (TN) reported on interactions among tomato cultivars Celebrity, Florida 47, Mountain Fresh, and Spitfire with BioYield Concentrate and BioYield Flowable. The cultivars responded differently to these products indicating a possible cultivar effect. Mike Benson (NC) reported on using Beauveria bassiana to protect impatiens from Rhizoctonia and increase heat tolerance. In another study evaluating liquid and solid formulations of BioYield he found no difference in plant populations, but larger plants were noted with the solid formulation. Mike reported Botanigard, a commercial strain of B. bassiana, was phytotoxic to impatiens. In heat tolerance studies with vinca treated with B. bassiana Mike reported the following: (1) plants survived in all heat regimes (40, 43, 44, 46, 48 C exposed for 4 hr) five weeks after seeding; (2) vinca treated with B. bassiana isolate 11-98 at 107 CFUs grew best; (3) Botanigard isolate of B. bassiana did not adversely affect growth; and (4) Botanigard suppressed flowering by 50%.

Bonnie Ownley (TN) reported using brassica mulches to inhibit isolates of Gaeumanannomyces and Fusarium. She also reported on previous work evaluating various formulations of Beauveria for pathogen and insect control in cotton. Boyd Padgett (LA) reported on previous studies evaluating the influence of tillage and cover crops on cotton seedling disease. Excessive rains inhibited germination in conventionally-tilled plots and fungicides did not improve stand. Kenny Seebold (GA) reported on using an isolate of Pseudomonas fluorescens containing a gene for type III secretion system (T3SS) for managing gummy stem rot and Phytophthora crown rot in watermelon. Examining control of Phytophthora capsici, he reported Actigard provided some control, and evaluations of biocontrol agents provided similar control as tebuconazole. He will continue work with pepper and squash. Craig Rothrock (AR) updated the group on continuing work with binucleate Rhizoctonia for managing cotton seedling disease. Binucleates improved stand over the non-treated control and performed as well as some fungicides. Binucleates were associated more with the hypocotyls than the roots. Trichoderma produced inconsistent results and Actigard was phytotoxic to cotton.

Discussion was then directed at the RCU2 objective of the project. Craig Canaday (TN) commented on association among pre-plant applications of S-metolachlor and increased seedling disease compared to seedling disease where pre-emergence applications were used for snap bean production. Kenny Seebold (GA) reported that using solarization (8-10 weeks, 42-45C) reduced Phoma and increased yields in 2003 for onion; however, conflicting results with sour skin were obtained in 2004. Work with bio-mulches will continue. Tony Keinath (SC) observed reduced germination of sclerotia (Sclerotium rolfsii) using solarization. Effects decreased as depth of burial increased. In another experiment he reported no effects from two bio-fumigants (canola and mustard). Don Huber (IN) reported that glyphosate reduced manganese uptake in soybean. Deficiency can be corrected with foliar Mn applications. Other reported effects of glyphosate included: (1) reduced Mn uptake, (2) immobilization of Mn, (3) reduced root nodulations and N fixation, (4) increased drought stress, (5) earlier maturity, (6) more susceptibility to diseases, and (7) changes in soil microflora (rhizobium, fusaria, disease predisposition). He reported Corynesporum on dead ragweed roots and reduced growth on adjacent soybean plant sprayed with glyphosate. This was not observed on soybean plants 18 inches away.

On Sunday, November 7, the meeting was called to order at 8:30 am. The remainder of the meeting was directed toward defining new objectives for the project. It was agreed to terminate the snap bean and cotton biological seed treatment studies. The group has two years to write the new project. Tentative objectives were: 1) Evaluate biological seed treatments and biological drenches in tomato, broccoli and vinca. Pilot tests will be conducted this upcoming year. Bonnie Ownley, Craig Canaday, Tony Keinath, Kenny Seebold and Mike Benson will develop protocols. 2) Study the genetic diversity of pathogenic Rhizoctonia populations in two different cropping systems  probably with soybean, as it is more widely grown throughout the U.S., and an ornamental nursery plant species. Craig Rothrock will develop objective addressing genetic diversity in pathogenic Rhizoctonia populations. 3) Effects of cultural practices on ecological and genetic diversity of soilborne pathogens and indigenous mircroflora using mulches, herbicides, amendments, and long-term tillage. This objective may increase participation from the North Central region. The objective to address organic transition and changes it may have on soil diversity would be combined with objective 3.

Accomplishments

Objective 1. Selection, optimization and regional evaluation of biological control agents to include application techniques and enhancement of biological control agents to control diseases caused by soilborne plant pathogens.<br /> Regional Seed Treatment Trials:<br /> Nine states (eight test sites) were involved in the Regional Cotton Trials (AL, AR, FL, GA, LA, MS, NC, TN, and TX) coordinated by Bill Batson. The biological treatments evaluated on two cotton cultivars (Deltapine 451B/RR and Paymaster 1218 BG/RR) included: Bacillus subtilis MBI 600 (Subtilex), B. subtilis GB03 (Kodiak), B. pumilus GB34 (YieldShield), B. subtilis GB03+ B. amyloliquefaciens GB99 (BioYield), Trichoderma virens G6, T. virens/T. koningii fusant TV-117, and Trichoderma harzianum (T-22). The Bacillus treatments were evaluated alone and in combination with Vitavax-PCNB+ Allegiance. The Trichoderma treatments were evaluated in combination with Chloroneb + Allegiance. Other treatments were nontreated control and chemical treatments alone. Significant cultivar and seed treatment effects were observed at 5 locations (AL, AR, GA, MS and NC); however, significant interactions between cultivar and treatment were only observed in AR and NC. Statistical analysis revealed no location by treatment interaction; therefore results were summarized across locations. Plant stands were lowest in the non-treated control. Stands in cotton treated with Vitavax-PCNB were greater than the non-treated control. The addition of a biological organism to Vitavax-PCNB did not improve the efficacy of Vitavax-PCNB alone. The addition of Trichoderma to Chloroneb-Allegiance did not improve the efficacy of Chloroneb-Allegiance alone. Kodiak biological treatment used alone did significantly improve stand count relative to the non-treated control.<br /> Nine states (eight test sites) (AL, AR, FL, GA, MS, NC, SC, TN, and TX) participated in the Regional Snap Bean Trials coordinated by Craig Canaday. Four biological control agents (Bacillus subtilis MBI 600 (Subtilex), B. subtilis GB03 (Kodiak), Bacillus licheniformis SB3086 (710-145F), and Trichoderma harzianum T-22 HC), with and without captan + streptomycin, were evaluated as seed treatments on two snap bean cultivars (Bronco and Hialeah). Additional treatments were nontreated control and captan + streptomycin used alone. A significant increase in stand was observed overall only with the chemical seed treatment. Significant cultivar effects were observed at all locations except AL. Compared to the non-treated control, T-22 significantly improved stands of Bronco in TN (April planting) and of Hialeah in TX. A significant increase over non-treated seed in stands of Bronco was also observed with MBI600 in TN (May planting). The addition of a biological treatment to the chemical control treatment resulted in significant increases in stand over the chemical only treatment in NC (for Hialeah with MBI 600 ) and Texas (for Hialeah with GB03, MBI 600 and T-22).<br /> The cooperative effort of Southern Regional Project S-302 also determines the stability, population, and purity of the biological agents applied to the seed from time of seed delivery to test cooperators until the seed is actually planted. For snap bean cv Hialeah, more variation in biological seed populations throughout the planting period were observed for MB1600 alone and 710-145F with a chemical seed treatment. For snap bean cv Bronco, more variation in biological seed populations was observed for the treatment mixture of GB03 and T-22. When compared across both cultivars and all planting dates, the addition of chemical seed treatments to the bacterial biological treatments significantly increased the seed population of the biological. The reverse was true when the biological was the fungus T. harzianum. For cotton seed, the seed populations of the biologicals was very stable on both cultivars (DPI 451 and PM 1218) except for BioYield (B. pumilus GB34 and B. amyloliquefaciens GB99) without the addition of chemical seed treatments.<br /> <br /> Objective 2. Improve understanding of mechanisms and applicability of biological control agents across different cultivars, environments, and cropping systems.<br /> In Texas seed treatment of DP 451 B/RR, a seedling disease susceptible cotton cultivar, with preparations of P and Q strains of Trichoderma virens, has shown that P strains are ineffective as biocontrol agents, while Q strains give good disease control. In an effort to determine what characteristics make the strains of one group biocontrol effective and the other not, the strains of the two groups were assayed for pathogenicity to cotton seedlings in non infested soil, phytotoxin production, lytic enzyme activity, induction of phytoalexins in cotton roots, and metabolism of pathogen propagule stimulants released by germinating seedlings. The results indicated the P strains were indeed pathogenic to the susceptible cultivar in non infested soil, whereas the Q strains were not. Both P and Q strains synthesized the phytotoxin viridiol on certain substrates, and mutant of P strains deficient for viridiol production were still pathogenic to cotton. This indicates that viridiol production was not active in the disease syndrome. Both groups of strains were equally capable of synthesizing lytic enzymes such as cellulase, polygalacturonase, and protease, so this could not account for differences in pathogenicity. Assay of P and Q strains for metabolism of germination stimulants also indicated that both were equally capable of metabolizing these compounds. Therefore, this phenomenon could not be responsible for the observed differences. However, when the strains in the two groups were compared for the capacity to induce phytoalexin synthesis in cotton radicles, the P strains proved to be only weak inducers of the terpenoids hemigossypol and desoxyhemigossypol in cotton roots, whereas Q strains were very active inducers of the phytoalexins. These results indicate that although both P and Q strains are low grade pathogens of susceptible cotton cultivars, induction of high concentrations of phytoalexins in cotton roots by Q strains suppresses their further development in the cotton root and subsequent infection by other pathogens. Failure of the P strains to induce phytoalexin synthesis allows them to parasitize the cotton root, destroy root tissue and ultimately kill the seedling.<br /> <br /> Solarization studies were conducted in GA and SC. In GA soils with a history of 10 years of onion production were solarized using clear plastic (3.0 mil thickness) for a minimum of 10 wks in mid-summer in Tifton, Georgia in 2002-2004. In 2003, total yield, mean bulb weight, and number of jumbo grade onions were significantly higher and the severity of pink root, caused by Phoma terrestris, was significantly lower in solarized plots. In 2004, trends were similar for total yield, mean bulb weight, number of jumbo grade bulbs, but were not significantly different. <br /> A three-year project on soil solarization was continued in SC. Treatments included solarization for one, two, or three summers with or without cropping immediately after solarization. Plots were solarized for 10 weeks from early June to mid-August. Population dynamics of Pythium spp. differed between solarized and nonsolarized soil. Sclerotia of Sclerotium rolfsii did not germinate in response to methanol and did not cause any lesions on snap bean stems 2 months after burial at 5 cm in solarized soil. Viability and virulence also were reduced 1 month after burial. Sclerotia buried at 15 cm were not affected significantly by solarization.<br /> <br /> The effects of brassica mulches or meal on soilborne pathogens were evaluated in SC and TN. In SC, Brassica cover crops were incorporated one month prior to transplanting seedless watermelon cv. Tri-X 313. At 41 days after incorporation, soil populations of Fusarium, as determined by dilution plating on Komadas medium, did not differ among treatments except that populations in fumigated plots were lower than in plots cropped to brassicas. <br /> In TN the effects of Brassica spp. mulches or meal on growth of several isolates of Gaeumannomyces graminis var. tritici (Ggt) and Fusarium spp. were studied to determine if inhibition was fungicidal. Exposure of fungal pathogens to mulches of canola and Dwarf Essex rape inhibited growth of the pathogens but mycelial growth resumed following removal of the mulch treatments. In contrast, growth of Ggt and Fusarium spp. did not resume following exposure to mustard meal and mulch, indicating that these treatments were fungicidal. Phytotoxicity of mustard mulch to wheat seedlings and the efficacy of mustard mulch for suppression of take-all caused by Ggt was evaluated. Treatment of soil containing Ggt-infected roots with mustard mulch significantly reduced take-all disease severity in the subsequent wheat planting in two tests. <br /> <br /> In IN research has established that manganese oxidation is a virulence factor for the wheat take-all pathogen, Gaeumannomyces graminis, and other plant pathogens. Culture assays and spectrophotometric analysis of crude culture extracts derived from Gaeumannomyces support the involvement of a multi-copper oxidase such as laccase, and possibly other extracellular oxidative enzymes, in manganese oxidation, which reduces the plants ability to respond to infection by the pathogen. Twelve putative laccase genes were found in Magnaporthe grisea, a fungus closely related to Gaeumannomyces graminis, and we found strong expression of lcc 15 under manganese oxidizing conditions. Two genes with homology to manganese peroxidase also were identified in Magnaporthe grisea, and targeted deletion of these two genes resulted in greatly reduced virulence. It appears that there are at least two separate enzymes involved in manganese oxidation by these fungi that could influence their virulence and rhizosphere interactions via biological control.<br /> <br /> Common sources of Mn fertilizers (sulfate, carbonate, and oxide salts) are immobilized by glyphosate, and herbicidal efficacy is also reduced. It was observed in IN that there was an increase in take-all of wheat following glyphosate resistant soybeans and increased colonization of necrotic soybean roots by Corynespora. Application of Mn a few days prior to, at the same time, or within a few days after the application of glyphosate has not been efficiently translocated by soybean plants. Tank-mixing the micronutrient with the glyphosate can reduce herbicidal efficacy from 5-50% on specific weed species. The glyphosate formulation can be as important as micronutrient source in these interactions, with the potassium salt being less interactive with micronutrients than other herbicide formulations. Unlike most inorganic sources of micronutrients, specific nutrient chelates or micronutrient complexes (amino acid or protein complexes) are compatible with glyphosate and readily translocated to new soybean tissue from tank-mix combinations. Although increased translocation of micronutrients in compatible micronutrient-glyphosate formulations was observed with soybeans grown on a nutrient sufficient soil, no additional yield increase was observed to indicate that excess micronutrient availability is of little value in increasing yield.<br />

Publications

Refereed Journal Articles:<br /> Abad, J.A., Moyer, J.W., Kennedy, G.G., Holmes, G.A., and Cubeta, M.A. 2004. An epidemic of Tomato spotted wilt virus on potato in eastern North Carolina. Amer. J. Potato Res. (accepted).<br /> <br /> Bush, B.J., Carson, M.L., Cubeta, M.A, Hagler, W.M., and Payne, G.A. 2003. Infection and fumonisin production by Fusarium verticillioides in developing maize kernels. Phytopathology 94:88-93.<br /> <br /> Ceresini, P.C., Shew, H.D. Vilgalys, R., U.L. Rosewich-Gale and Cubeta, M.A. 2003. Detecting migration in populations of Rhizoctonia solani AG-3 from potato in North Carolina using multilocus genotype probabilities. Phytopathology 93:610-615.<br /> <br /> Elliott, M. L., E. A. Guertal, and H. D. Skipper. Rhizosphere bacterial population flux in golf course putting greens in the Southeastern United States. HortScience 39:1754-1758.<br /> <br /> Fichtner, E. J., Benson, D. M., Diab, H. G. and Shew, H. D. 2004. Abiotic and biological suppression of Phytophthora parasitica in a horticultural medium containing composted swine waste. Phytopathology 94:780-788.<br /> <br /> Harrison, H. F., Jackson, D. M., Keinath, A. P., Marino, P. C., and Pullaro, T. C. 2004. Broccoli production in cowpea, soybean, and velvetbean cover crop mulches. HortTechnology 14:484-487.<br /> Hollowell, J.E., Shew, B.B., Wilcut, J.W., and Cubeta, M.A. 2003. Weed species as hosts of Sclerotinia minor in peanut fields. Plant Dis. 87:197-199.<br /> Ownley, B.H., B.K. Duffy, and D.M. Weller. 2003. Identification and manipulation of soil properties to improve biological control performance of phenazine-producing Pseudomonas fluorescens. Appl. Environ. Microbiol. 69: 3333-3343<br /> Technical Articles:<br /> Batson, Jr., W.E., Caceres, Elliott, M.L., Huber, D.M., Hickman, M.V., McLean, K.S., Ownley, B., Newman, M., Padgett, G.B., Rushing, K.W., Kenny, D.S., Rothrock, C.S., Seebold, K., and Thaxton, P. 2003. Biological seed treatment evaluations for control of the cotton seedling disease complex, 2001. Biological and Cultural Tests for Control of Plant Disease Vol. 18:F002 (electronic).<br /> <br /> Batson, Jr., W.E., Caceres, Benson, M., Cubeta, M.A., Elliott, M.L., Isakeit, T., McLean, K.S., Padgett, G.B., Rothrock, C.S., and Seebold, K. 2003. Evaluation of selected biological seed treatments for cotton seedling disease control, 2002. Biological and Cultural Tests for Control of Plant Disease Vol. 18:F003 (electronic).<br /> <br /> Batson, Jr., W.E., Caceres, J., Benson, M., Cubeta, M.A., Elliott, M.L., Huber, D.M., Hickman, V., Keinath, A.P., Dubose, V., McLean, K.S., Ownley, B., Canaday, C., Rothrock, C.S., and Seebold, K. 2003. Evaluation of biological seed treatments for control of the seedling disease of snap bean, 2001. Biological and Cultural Tests for Control of Plant Disease Vol. 18:V029 (electronic).<br /> <br /> Books, Book Chapters and Review Articles:<br /> Cubeta, M.A., Mozley, S.E., and Porter, D. 2003. Laboratory Exercises with Zoosporic Fungi. In Plant Pathology Laboratory Exercises and Concepts. CRC Press, eds. Trigiano and Windam, pp. 99-110.<br /> <br /> Mozley, S.E., Leander, C.E., Porter, D, and Cubeta, M.A. 2003. Concepts:Zoosporic fungi. In Plant Pathology Laboratory Exercises and Concepts. CRC Press, eds. Trigiano and Windam, pp. 91-98.<br /> <br /> Symposia and other published works:<br /> Canaday, C. H., Results of 2003 Snap Bean Research, A Report for the Snap Bean Meeting, March 29, 2004, Crossville, TN, 13 pp.<br /> <br /> Canaday, C. H., BioYield Formulation Evaluations, a presentation with handouts for the Annual Convention of the Tennessee Fruit and Vegetable Association, Dec. 12-14, 2004, Nashville, TN.<br /> <br /> Canaday, C. H. and J. E. Wyatt, Increases in the incidence of snap bean seedling diseases associated with preplant incorporation of S-metolachlor, Annual Meeting of the Southern Division of the American Phytopathological Society, Tulsa, OK, Feb. 15-17, 2004.<br /> <br /> Gitaitis, R.D., Sanders, F.H., and Seebold, K.W. 2004. Development of a Screening Procedure to Identify Bacteria with Biocontrol Activity. Pages 80-81 in: Proceedings of the 2004 Southeast Regional Vegetable Conference, Savannah, Georgia, January 9-11. W.T. Kelley, ed. University of Georgia Cooperative Extension Service, 124 pp.<br /> Whitford, F., Cain, S., Alderson, K., Huber, D.M., Beaty, J., Biehle, D., Miller, R., Kemper, A., and Blessing, A. 2004. Rural Security Planning, Protecting Family, Friends, and Farm. PPP-64. Purdue University Cooperative Extension Service, West Lafayette, IN 47907.<br /> Abstracts:<br /> Abad, J.A., Speck, J., New, S., Kennedy, G., Cubeta, M.A., and Moyer, J.W. 2003. An epidemic of Tomato spotted wilt virus (TSWV) in North Carolina:first report of TSWV affecting potato and cabbage in North America. Phytopathology 93:S1-S2.<br /> <br /> Breeden, T.S., B.H. Ownley, D.R. West, and C.E. Sams. 2003. Brassica juncea inhibits soilborne pathogens. Phytopathology 93:S11.<br /> <br /> Charlton, N.D., Tavantzis, S.M., and M.A. Cubeta. 2004. Genetic diversity of double stranded RNA mycoviruses in a population of Rhizoctonia solani anastomosis group 3 (AG-3). Inoculum 55:11. (Supplement to Mycologia).<br /> Cubeta, M.A., Ceresini, P.C., Shew, H.D., Cody, B.R., Boerema, M.E., Lakshman, D.K. and Tavantzis. S.M. 2003 . Occurrence of the M2 dsRNA in populations of Rhizoctonia solani AG-3 from potato and soil. International Congress of Plant Pathology, pp. 110.<br /> <br /> Gonzalez, D., Cubeta, M.A., and Vilgalys, R. 2003. Molecular systematics of Rhizoctonia phyloenetically integrates anamorphs into Ceratobasidiaceae. International Congress of Plant Pathology pp. 29 <br /> Pickens, K., D.R. West, B.H. Ownley, and C.E. Sams. 2003. Brassica crops inhibit Fusarium graminarium and F. equiseti in culture. Southern Branch Am. Soc. Agron. Abstract of Tech. papers, p 24.<br /> <br /> Thompson, I.A., Huber, D.M., Schulze, D.G., and Guest, C.A. 2004. Fungal manganese oxidation in a saturated soil. Phytopathology 94:S<br /> <br /> Theses:<br /> Thompson, I.A. 2004. Manganese Oxidation in Plant Pathogenic Fungi. Ph.D. thesis, Purdue University, West Lafayette, IN 47907.<br /> <br />

Impact Statements

1. Pesticides in the environment, and public concern over food safety, have led scientists in Southern Regional Research Project S-302 to look at biological control and cultural control practices as central components of an ecologically based approach to Integrated Pest Management for plant diseases. Identification of biological controls or combinations of biologicals and chemicals that reduce losses due to seedling diseases will provide alternative management strategies for growers and reduce depe

Back to top

Report Information

Participants

Brief Summary of Minutes

Accomplishments

RCU 1. Selection, optimization and regional evaluation of biological control agents to include application techniques and enhancement of biological control agents to control diseases caused by soilborne plant pathogens.<br /> Biological control agents were evaluated on cotton seed from 2001 to 2004 in ten states (AL, AR, FL, GA, IN, LA, MS, NC, TN, TX). Seedling disease pathogens (predominately Rhizoctonia, Pythium, or Fusarium) were present at each location. Treatments evaluated included several species of Bacillus, Beauveria, Stenotrophomonas and Trichoderma alone and in combination with standard chemical fungicides. The performance of these products varied across years and locations; however, several treatments with B. subtilis were effective against seedling disease pathogens in 3 of 4 years. In most tests, the addition of biological control agents to chemical standards did not improve efficacy relative to chemical standards alone.<br /> Biological agents for control of soilborne pathogens of snap bean were evaluated in fields naturally infested with Rhizoctonia solani, Pythium spp., Fusarium spp. and Macrophomina phaseolina. Snap bean seed, with and without a chemical seed treatment of captan + streptomycin, were treated with several biological agents: B. subtilis (GB03 or MBI600), B. licheniformis (SB3086), and Trichoderma harzianum (Rifai strain KRL-AG2 = T-22) and distributed to cooperators in AL, AR, FL, GA, MS, NC, SC, TN, and TX for regional evaluation in 2002, 2003, and 2004. Significant treatment effects were observed in Tennessee only in the 2004 test. In that trial, stands of Bronco snap bean were greater than the untreated control when treated with GB03, T-22, or GB03 + T-22, with and without chemical seed treatment. Yields with T-22 in an April planting (cool soil) were greater than all other biological seed treatments and the chemical standard. Stands and yields of Hialeah in 2004 were unaffected by biological seed treatments in both the cool and warm soil plantings. <br /> Populations of most bacterial agents on seed were stable for the 4-8 weeks from delivery to planting. The greatest variability in populations of biocontrol agents was observed with the fungal treatment on cotton. The addition of fungicides significantly increased populations of bacterial agents, but decreased populations of fungal agents on both snap bean and cotton. <br /> <br /> Arkansas <br /> Bi-nucleate Rhizoctonia isolates were evaluated for their ability to control seedling disease caused by Rhizoctonia solani on cotton. These fungi are frequently isolated from cotton. In addition to their biological control potential, the influence of cultural practices, such as cover crops, is being examined for their influence on soil populations of this group of fungi. Infestation of soil with nonpathogenic strains of BNR significantly suppressed seedling disease caused by R. solani in both greenhouse and field tests. <br /> <br /> Florida<br /> The impact on the development of geranium, marigold, or vinca seed treated with Beauveria bassiana and Bacillus spp. was examined in vitro. Microbial isolates used were (B. bassiana Botanigard, B. bassiana 11-98, BioYield strain A, BioYield strain B). BioYield Flowable is a commercial product composed of Paenobaciullus macerans GB122 and B. amyloliquefaciens GB99. Negative interactions on seed germination and radicle length were observed due to the microbial treatments, but the effects were not consistent among or within plant species. When used individually, no microbial treatments used with geranium seed increased or decreased radicle length significantly from the water control. However combinations of fungal and bacterial strains did decrease radicle length. For marigold seed, no significant differences were observed in one trial but a negative response was observed when Bacillus BY-A and B. bassiana 11-98 were combined and when the mixture of Bacillus isolates and B. bassiana Botanigard were combined. Significant differences were observed in both trials using vinca seed, but there was little consistency between trials. In Trial 1, all treatments containing B. bassiana had significantly shorter radicles compared to the control, except where B. bassiana 11-98 was paired with Bacillus isolate BY-B. However, in Trial 2 no treatment had significantly shorter radicles than the control.<br /> <br /> Georgia<br /> Four non-pathogenic strains of Pseudomonas fluorescens containing genes for the type III secretion system (T3SS) were identified in Georgia using PCR. These strains exhibited activity against gummy stem blight (GSB) and Phytophthora crown rot (PCFR). Two strains used in this study, R6 and R10, exhibited antibiotic activity in vitro against P. irregulare and D. bryoniae, while strains R8 and B20 tested positive for the T3SS (R8 also exhibited in vitro activity against fungal pathogens). Systemic acquired resistance may have been involved in reducing PCFR and GSB severity with stains R8 and B20. These bacterial biological control agents performed as well against the GSB as tebuconazole or acibenzolar-S-methyl. The biological control agents tested in this study could be used potentially to reduce fungicide inputs.<br /> <br /> North Carolina<br /> A peat-moss based potting mix was amended with either of two composted swine wastes CSW1 and CSW2 at rates from 4 to 20% (v/v) and evaluated for suppression of pre-emergence damping-off of impatiens caused by R. solani. Higher rates of microbial activity were observed with increasing rates of CSW1 amendment than with CSW2. Microbial biomass carbon and nitrogen also were higher in CSW1-amended mix than the CSW2-amended mix at seeding and at emergence. The results suggest that enhanced microbial activity and functional and structural diversity of stable compost were responsible for the suppression of pre-emergence damping-off of impatiens caused by R. solani.<br /> <br /> Poultry waste compost, an uncomposted swine waste, swine waste compost, and composted cow manure with and without Trichoderma hamatum (T382) were amended at rates of 4 to 16% into a pine bark potting mix to evaluate suppression of Phytophthora root rot caused by Phytophthora cinnamomi. Azaleas (Rhododendron obtusum Hinodegiri) in mixes infested with P. cinnamomi developed foliar symptoms of Phytophthora root rot beginning in July and progressed over the summer. Manure did not suppress Phytophthora root rot compared to pine bark mix only. Microbial respiration was greatest in uncomposed swine waste and composted swine waste. Microbial carbon also was higher in the mixes amended with manures, but the nature of microorganisms contributing to these increases is unknown at present.<br /> The genetic diversity of 162 isolates of R. solani anastomosis group 3 (AG-3) was examined using somatic compatibility and DNA based (AFLP and PCR-RFLP) genetic markers. Results suggest that populations of R. solani AG-3 from soil in North Carolina (NC) and potato seed tubers from northern production areas in the US (Maine and Wisconsin) and Canada are genetically diverse. The soil population of R. solani AG-3 from NC had a structure that included both clonality and recombination. Five of the most predominant clones found in NC soil were also identified on potato tuber samples (seed population) originating from northern potato seed production areas. The relative contribution of one-way migration (unidirectional) of R. solani AG-3 on infested potato seed tubers originating from production areas in Canada, Maine and Wisconsin (source population) to the genetic diversity and structure of populations of R. solani AG-3 in North Carolina soil (recipient population) was identified as an important component for long distance dispersal of the pathogen. Unidirectional migration of R. solani AG-3 also provides an efficient mechanism to introduce new alleles and double stranded RNA (dsRNA) elements into recipient soil populations in NC.<br /> Isolates (115) of R. solani AG-3 from source and recipient soil populations were assayed for the presence of a 3.6 kb dsRNA element (M2) with reverse transcription polymerase chain reaction (RT-PCR), and approximately 48% possessed the M2 dsRNA. The sequence of the M2 dsRNA was determined for 35 isolates to assess their genetic diversity and to reconstruct their genealogical history. Approximately 120,000 nt have been sequenced; the largest sequence database of a fungal virus from a field population of a filamentous fungus. There are at least two divergent lineages of the M2 dsRNA with distinct histories of mutation and recombination. Research is ongoing to determine if M2 dsRNA can be transmitted via hyphal fusion between different R. solani AG-3 genotypes. Based on preliminary results M2 dsRNA transmission occurs between specific pairs of R. solani AG-3 isolates in the laboratory. This approach will be used to assess the role of dsRNA viruses in the saprophytic and parasitic activity of R. solani AG-3.<br /> Pythium root rot in poinsettia caused by P. aphanidermatum and P. ultimum was suppressed when composted swine waste and binucleate Rhizoctonia fungi were amended to a peat moss based potting mix. Poinsettia top weight of Freedom Red and Angelica White was increased 30 and 36%, respectively. Apparently, the BNR fungi utilized the compost as a food base to antagonize Pythium and/or the effect of beneficial organisms in the compost was additive to the effect of BNR fungi. <br /> Control of Phytophthora may be enhanced by combining abiotic factors such as aluminum (Al) with biological factors such as beneficial microorganism in composted animal wastes amended to potting mixes. Sporangia production by P. parasitica was 60% less on day 0 in a peat moss potting - composted swine waste medium treated with a pH 4 solution. Exchangeable Al levels decreased over time, and abiotic suppression was only observed at >2 µM Al/g medium. Sporangia production in unsteamed medium was reduced by 50% on vinca leaf disks buried on days 6, 13, and 21, but not day 0. Al-amendment of a CSW amended potting medium enhanced suppression of P. parasitica and occurred before biological suppression developed.<br /> Bioyield and growth promotion in bedding plants. Experiments were conducted with Bioyield (Paenobacillus macerans GB122 and Bacillus amyloliquefaciens GB99) and impatiens (Impatiens wallerana Super Elfin White) to determine the optimal rate and formulation of Bioyield for impatiens germination and growth. There was a slight inhibition (8-10%) in seedling emergence and stand establishment with either formulation of Bioyield compared to the untreated control. Leaf widths were 124 to 132% larger on seedlings in potting mix amended with Bioyield compared to the untreated control. The slight inhibition of seed germination and emergence in impatiens was off-set by an increased growth response once seedlings emerge.<br /> Beauveria biocontrol. Impatiens Super Elfin White and vinca (Catharanthus roseus) Peppermint Cooler seeds were coated with cultures of Beauveria bassiana strain 11-98 (B. Ownley, UTenn) or with Botanigard, a commercial formulation of B. bassiana (B. Ownley, UTenn). Seed populations of 10x3 and 10x5 cfu, were coated to compare population effect. <br /> Impatiens. Botanigard with or without Bioyield was highly phytotoxic to impatiens seed germination and emergence, particularly at the high population rate of seed treatment. Compared to the untreated, infested control, strain 11-98 did not improve stand count of impatiens, although the standard fungicide, Medallion did. Severe post-emergence damping-off occurred between day 26 and day 49 when trays were moved to a hand-watered bench and even Medallion failed to control Rhizoctonia post-emergence damping-off. <br /> Vinca. Botanigard at the high seed population rate was phytotoxic to vinca germination and emergence as stand counts in over two runs for Botanigard-treated seed were lower (P=0.05) than counts in the infested, untreated control. Strain 11-98 of B. bassiana did not improve stand count compared to the untreated infested control. Addition of Bioyield amendment to the potting mix did not improve stand counts of vinca in combination with either Beauveria strain. Drenching the potting mix with Medallion resulted in excellent stand counts that were not different (P=0.05) than the non-infested control. <br /> Heat tolerance studies. Five week old vinca seedlings were placed at a heat stress temperature in a growth chamber for 4 hours then returned to the bench and observed for growth and flowering. The five temperatures of exposure were 40, 42, 44, 46 and 48 C. Vinca treated with strain 11-98 of B. bassiana regardless of fungal concentration grew better growth after exposure to high temperatures than the untreated check at ambient temperature. The largest effect was a suppression of initial flowering in vinca treated at all temperatures including greenhouse ambient (31 C) with Botanigard at both the 105 and 106 cfu rates. The suppression of flowering by Botanigard is consistent with the inhibition of seed germination and emergence observed in the damping-off experiments.<br /> <br /> Oklahoma<br /> In competitive colonization experiments, Laetisaria arvalis colonized 80 to 83% of the seeds compared to 17 to 20% for Sclerotium rolfsii, suggesting competition for organic matter as a possible mechanism for the interaction between these two fungi.<br /> Canterbury bells, Campanula medium L. 'Champion Blue' seeds were primed using calcined clay at 68 C for 1,3, and 5 days at water potentials (Q) of 2.5, 2.0, 1.8, or 1.6 MPa. Priming did not affect total germination percentage (97%). Germination was fastest after priming with a matrix Q of 1.8 0r 1.6 MPa for 5days. Time to 50% germination was longer when seeds were primed for 1 day regardless of matrix Q compared to the unprimed seeds. Germination uniformity decreased (T 10 90 increased) as Q increased. Although a curvilinear relationship existed between T 10 90 and priming duration, T 10 90 did not differ between unprimed seeds and seeds in any priming treatment except those primed for 3 days with 15% moisture ( 1,8 MPa).<br /> <br /> Tennessee<br /> Biopesticides applied to seed singly or combined with chemical pesticides or other biopesticides were tested for control of cotton seedling diseases. Cotton was direct-seeded into no-till soil at Milan, TN; disease pressure from Rhizoctonia solani, Thielaviopsis basicola, Fusarium spp. and Alternaria solani was high. Treatment differences plant stand occurred in two of four years. In 2002, stands of Delta Pine 50 were greatest with combinations of Bacillus spp. and chemical seed treatments. In 2004, on Delta Pine 451 B/RR and Paymaster 1218 BG/RR, Bacillus and chemical seed treatment combinations had the highest plant stands.<br /> Fungicide soybean seed treatments supplemented with biological control agents GB03 or Bacillus pumilus (GB34) were evaluated. Stands and yields were lowest with an in-furrow spray of azoxystrobin, both with and without biological agents. Average yield of an April no-till planting of maturity group III soybeans in a field previously planted to cotton for the last 10-12 years was increased over 570 kg/ha with an in-furrow granular formulation of Bradyrhizobium japonicum.<br /> Three formulations of plant growth-promoting rhizobacteria (PGPR), Bacillus amyloliquefaciens (GB99), and Paenobacillus macerans (GB122) had no observable effects on the incidence or severity of tomato diseases in two field tests. However, early marketable tomato yields of Celebrity were increased by 28% with the addition of PGPR + chitosan to the potting soil at 28g PGPR product /1000 plants, but a higher rate of PGPR (183 g / 1000 plants) failed to increase early yields . Early yields of Mt. Spring, Mt. Fresh, Florida 47, and Spitfire were not affected by PGPR.<br /> <br /> RCU II. Improve understanding of mechanisms and applicability of biological control agents across different cultivars, environments, and cropping systems.<br /> <br /> Arkansas<br /> The ability of winter cover crops (fallow, wheat, hairy vetch, and Indian mustard (Brassica juncea cv. Fumus) to suppress soilborne pathogens was examined in a cotton field with a history of reniform nematode and seedling diseases. Telone II was applied in strips on either side of cover crops prior to planting cotton for comparison. Telone had the greatest seedling response (plant weight) three weeks after planting. The cover crops were similar to winter fallow. Telone increased plant height, node number, and height of first fruiting node. Mustard had among the lowest fruiting nodes each year compared to other treatments. Mustard increased effective sympodia both years and Telone increased sympodia in 2005 compared to the other treatments.<br /> Cotton yields were hand harvested from mapped plants in 2005 and yield increase was 83% for mustard, 36% for Telone and 33% for vetch compared to winter fallow. Reniform populations were suppressed by a mustard cover crop and reproduction was suppressed on cotton roots at the end of the season, but not by Telone or the cover crops. Mustard generally decreased Thielaviopsis basicola, Rhizoctonia solani, and Pythium spp. compared to the other cover crops for the at-cotton-planting soil sample.<br /> Soil suppressiveness or conduciveness was examined for eight soils that varied in soil textural characteristics or cropping histories for the cotton seedling disease pathogens R. solani, Pythium spp. and T. basicola using marked or unique strains of the pathogens. Soils did not differ for R. solani or Pythium spp. in recovery of these pathogens from cotton seedlings. For T. basicola, sandy soil was found to be least conducive or most suppressive to this pathogen. In addition, a sandy clay soil and a field with a history of cotton production, but in corn the last three seasons, were moderately suppressive. These results may help explain why this pathogen is not universally present in cotton fields. <br /> The soybean cultivar Archer reported to be flood tolerant is significantly more resistant than the most commonly grown soybean cultivar in Arkansas, Hutcheson, to Pythium ultimum, P. aphanidermatum, P. vexans, and P. irregulare; having less stand loss and reductions in root weight in infested soil. Archer or high quality seed had greater stands and less root discoloration than Hutcheson or low quality seed in soil infested with these Pythium spp. Root discoloration was positively and percent stand negatively correlated to the quantity of sugars or organic acids in seed exudates. Seed exudates from Archer have fewer carbohydrates and more proteins than exudates from Hutcheson. Zoospores and oospores of P. aphanidermatum were more attracted to seed exudates of Hutcheson, suggesting a role for exudates in disease susceptibility. However, when the pathogen was placed in direct contact with the seed or injected into the hypocotyls of seedlings the resistance in the cultivar Archer was still observed compared to Hutcheson. Archer has the Rps gene 1k for resistance to Phytophthora stem and root rot. Using differential lines and isolines, it was demonstrated that Rps 1k also confers resistance to Pythium seed and root rot. This research suggests that cultivars with 1k should be effective in managing Pythium seed and root rot in the field.<br /> GIS research in Arkansas to examine population distribution of Thielaviopsis basicola in a growers field revealed populations of the pathogen vary greatly in the field. Population levels of the T. basicola were correlated positively with the occurrence of the root-knot nematode and finer textured soils.<br /> <br /> Georgia<br /> The effects of solarization and biofumigation on soilborne pathogens of sweet onion were evaluated in soils with a 10 year history of onion production (Tifton, GA). In 2002-2004, fields were harrowed, bedded and covered with clear plastic (3.0 mil thickness) for at least 10 wks in mid-summer. In 2003, total yield, mean bulb weight, and number of jumbo grade onions were significantly higher and the severity of pink root, caused by Phoma terrestris was significantly lower in solarized plots. In 2004, trends were similar but not significant for total yield, mean bulb weight, number of jumbo grade bulbs. Number of small grade bulbs and pink root severity were significantly lower in solarized plots in 2004. Significantly fewer bulbs with Fusarium basal rot occurred in solarized plots in 2003, but no differences were observed in 2004 because of low disease. Solarization had a long-term impact on reducing populations of soil saprophytes (cfu/g of soil) in both years. Solarization significantly reduced the weed populations, particularly yellow nutsedge, in 2004. No impact on bacterial diseases were observed in the 2002-2003 season, but a second year of solarization reduced the number of colony-forming-units of Burkholderia cepacia per gram soil a thousand fold in the 2003-2004 season. Although not significant, solarized plots yielded a lower percentage of onions with sour skin in 2004, a stark contrast from the results obtained in 2003.<br /> ProPhyt and foliar fungicides for control of P. capsici on summer squash were evaluated in 2004 as a continuation of work in 2003 funded by the IR-4 Project. Below normal May rainfall caused conditions that were not conducive for development and spread of Phytophthora crown and fruit rot (PCFR) despite overhead irrigation. Disease spread beyond inoculated plants in each plot was not observed until after heavy rains in early June. By 11 June, disease severity and losses in the untreated check were high; therefore, disease was assessed, but yield was not taken due to significant levels of virus-infected fruit in plots. Significant suppression of PCFR was observed in plots treated with ProPhyt. Where ProPhyt was not applied, all fungicides significantly reduced disease as compared to the untreated check. Omega 500SC (1.5 pt/A), applied three times on a 7-day schedule, reduced the severity of PCFR 77%. No differences were observed between fungicides plus ProPhyt and ProPhyt applied alone. ProPhyt for PCFR suppression allow fewer applications and lower rates of a conventional fungicide. Testing under conducive conditions for PCFR development and spread is needed.<br /> <br /> Indiana<br /> Five years of research in Indiana has focused on the unique aspects of the four components of the plant disease diamond (plant, pathogen, abiotic environment, and biotic environment) as encompassed in the two objectives. The focus has been on developing a unifying concept for several diseases to understand them and target specific components for more effective control. This Multiple Component Analysis of the diseases provided understanding of those factors that should be changed to synergize Plant Growth Regulation and biological control mechanisms. Nutritional sufficiency of the plant is important for resistance and tolerance to soilborne diseases. Abiotic environmental conditions influence nutrient availability (pH, temperature, moisture, etc.) and specific activity in the biotic environment (oxidizing/reducing, mineralizing, immobilizing organisms) influence disease severity through their effect on nutrient sufficiency of the plant and as inhibitors of pathogen or synergists to pathogen virulence and activity. Glyphosate herbicide is toxic to Mn reducing organisms and stimulates synergistic Mn oxidizing organisms in the rhizosphere to exacerbate Mn deficiency and suppress plant resistance of wheat to take-all and soybeans to Corynespora root rot. Heavy weed infestation increases the translocation of glyphosate into the soil and further increases root rot through the immobilization of Mn in the soil. Biological control agents proposed for control of take-all are all manganese reducing organisms and increase the availability of manganese for plant uptake to partially offset the effects of the pathogen. The most effective disease control is by cultural conditions that inhibit the pathogens virulence factor responsible for manganese oxidation. There is about three times the available (readily available) manganese following corn than after wheat or soybean in the rotation. This could account for the reduced take-all of wheat observed when wheat follows corn compared with glyphosate-resistant soybean. We have also found that high soil saturation that predisposes wheat to take-all can enhance manganese oxidation by soilborne fungi and bacteria. The most effective biological control is by those cultural conditions that inhibit the manganese oxidizing virulence factor of the pathogen. Closely associated soil organisms or crop sequence with certain crops such as oats that produce inhibitory compounds in their root exudates were observed to operate by this mechanism. Several nitrification inhibitors used to reduce leaching and denitrification losses of fertilizer nitrogen also were shown to suppress manganese oxidation in soil and reduce disease severity. <br /> <br /> Tennessee<br /> High and low rates of biocontrol bacteria (Bacillus subtilis GB03 and B. subtilis GB07) were applied separately or in combination with chemical pesticide to seed of two snap bean cultivars Bacillus populations on root samples from 2.5-week-old seedlings were not affected by cultivar. High rates of bacteria were not reduced by simultaneous seed treatment with chemical pesticides, but populations of B. subtilis GB03 applied at low concentration were lowered by some pesticides.<br /> In previous studies, Beauveria bassiana, applied as a seed treatment, provided significant protection of tomato seedlings against damping-off disease caused by Rhizoctonia solani. A mycelial form of the fungus, produced by a fermentation process, also increased seedling survival in Rhizoctonia-infested soil mix. Using ITS primers and polymerase chain reaction, B. bassiana was shown to be an endophyte of tomato seedlings grown from seed treated with B. bassiana. <br /> Pseudomonas fluorescens 2-79 protects wheat against take-all caused by Gaeumannomyces graminis var. tritici (Ggt); protection in soil varies from site to site. To evaluate the relative importance of 28 soil properties on take-all suppression, seeds were treated with 2-79, [produces antibiotic phenazine-1-carboxylate, PCA+], or mutants with PCA+ and PCA- phenotypes, and planted in ten soils with known physical and chemical properties. Sixteen soil properties were correlated with disease suppression. Biocontrol activity of PCA+ strains was positively correlated with ammonium-nitrogen, percent sand, soil pH, sodium, sulfate-sulfur, and zinc; biocontrol was negatively correlated with cation-exchange capacity (CEC), exchangeable acidity, iron, manganese, percent clay, percent organic matter (OM), percent silt, total carbon, and total nitrogen. Principal component factor analysis of the 16 soil properties identified a three-component solution that accounted for 87 percent of the variance in disease rating (biocontrol). A model was identified with step-wise regression analysis that included six key soil properties: ammonium-nitrogen, CEC, iron, percent silt, soil pH, and zinc. As predicted by the regression model, the biocontrol activity of 2-79 was improved by amending a soil low in Zn with 50 mg zinc-EDTA/g soil. Addition of OM (as wheat straw) at rates typical of high OM soils, significantly reduced biocontrol activity of 2-79, thus confirming the negative correlation of OM with disease suppression.<br /> The effects of Brassica spp. mulches or meal on growth of several isolates of Ggt and Fusarium spp. isolated from diseased wheat roots were studied to determine if inhibition was fungicidal. Exposure of fungal pathogens to mulches of canola and Dwarf Essex rape inhibited growth of the pathogens but mycelial growth resumed following removal of the mulch treatments. In contrast, growth of Ggt and Fusarium spp. did not resume following exposure to mustard meal and mustard mulch, indicating that these treatments were fungicidal. To evaluate phytotoxicity of mustard Florida Broadleaf mulch to wheat seedlings and the efficacy of mustard mulch for suppression of take-all, soil containing wheat roots infected with Ggt or healthy roots were covered with mustard mulch for 5 days. Mulch was not applied to controls. Wheat seeds were planted and disease severity and shoot height were assessed after 28 days. Soil containing Ggt-infected roots with mustard mulch significantly reduced take-all disease severity in the wheat seedlings in two tests. In one test, height of seedlings from mustard mulch-treated soil was reduced. <br /> The effects of seed treatment with endophytic Beauveria bassiana and heat stress on growth of Celebrity, Mountain Spring, and Trust tomato were evaluated by exposing 2-wk-old plants from seed treated with log 6 conidia per seed of isolate 11-98 or BotaniGard (B. bassiana isolate GHA) to heat (no heat, 40, 42, 44, 46, 48C) for several hours. At 6 wk, seedling height of all cultivars was reduced by 48C treatment; effect of seed treatment differed among cultivars and length of heat exposure. Trust seedlings were transplanted to a hydroponics greenhouse to evaluate effects of seed treatment and heat stress on yield. Yield of Grades 1 and 2 fruit was not affected; yield of Grades 3, 4, 5 was greatest with isolate 11-98 seed treatment and 46C heat treatment. Yield of culls increased as temperature increased. Numbers of cull fruit were greatest with BotaniGard seed treatment.<br /> Interactions between GB03 or MBI600 (Bacillus subtilis), planting date, seed treatment chemicals, and herbicide application method were evaluated in snap bean fields naturally infested with Rhizoctonia solani, Macrophomina phaseolina, Pythium spp., Fusarium spp., Phytophthora nicotianae var. parasitica, Sclerotinia sclerotiorum, and Sclerotium rolfsii. Root colonization by B. subtilis 2-3 wk after planting appeared independent of the rate of B. subtilis applied. Populations of B. subtilis colonizing roots were inversely correlated with damping-off losses. Treating seed with captan + chlorpyrifos + metalaxyl + streptomycin significantly reduced root colonization by B. subtilis while captan + streptomycin and chloroneb + metalaxyl + streptomycin did not. Acceptable stands and yields were achieved only when the biological agents were used in combination with chemical seed treatments. Treating seed only with GB03 or MBI 600 significantly reduced snap bean yields. Root colonization by B. subtilis was not affected by foliar sprays of a SAR inducer (harpin protein) or by differences in potash form (sulfate versus muriate) or potash application time (fall versus before planting in spring). When applied as a preemergence herbicide in warm soils, S-metolachlor led to more rapid emergence, more vigorous seedlings, higher stands, taller plants, and yield increases that were 15-30% greater than those achieved with preplant incorporation (PPI) of the herbicide. Use of B. subtilis did not ameliorate the effects of PPI. When planted in cool soils (April), supplementing seed treatment fungicides with GB03 reduced the incidence of seedling diseases and increased snap bean stand, height, and yield. When planted in warm soils (May or August), no significant effects were observed with GB03 use. <br /> <br /> A factorial field experiment for control of soilborne pathogens and insect pests of Tennessee staked tomato was performed in 2003 and 2004. Treatments were a transplant drench of imidacloprid followed with standard pesticide sprays, seeds treated with a commercial formulation of Beauveria bassiana [Bbcom], seeds treated with B. bassiana isolate 1198 [Bb1198], and an untreated control. Treatments were evaluated with and without PGPR added to the transplant potting mixes. PGPR did not affect incidences of Sclerotinia stem rot or southern blight. Severity of foliar diseases (early blight + Septoria leaf spot) was highest with the Bb1198 + PGPR combination. Foliar diseases were lowest with pesticides + PGPR. The combination of Bbcom with PGPR led to the highest early yields for both cultivars and increased yields to levels comparable to those with pesticide use. Overall yields were highest with pesticides + PGPR and were significantly higher than with Bbcom + PGPR. Overall yields were lowest with the combination of Bb1198 + PGPR. In other tomato tests, adding PGPR to transplant mixes led to taller plants one month after transplanting and to 8-32% increases in early tomato yields compared to control transplants. Growth and yield benefits with PGPR were found to be cultivar specific and varied also with PGPR formulation. PGPR had no observable effects on the incidence of buckeye rot.<br />

Publications

Refereed Journals Articles:<br /> <br /> Abad, J.A., Moyer, J.W., Kennedy, G.G., Holmes, G.A., and Cubeta, M.A. 2005. An epidemic of Tomato spotted wilt virus on potato in eastern North Carolina. Amer. J. Potato Res. 82:101-107.<br /> <br /> Bosma, T. L., Cole, J.C.. Conway, K.E., and Dole, J.M.2002. Solid Matrix Priming Enhances Canterbury Bells Seed germination. Hort Technology 12: 268 270. <br /> <br /> Broschat, T.K., and Elliott, M.L. 2005. Effects of iron source on iron chlorosis and Excerohilum leaf spot severity in Wodyetia bifurcata. HortScience 40:218-220.<br /> <br /> Broschat, T.K., and Elliott, M.L. 2005. A key to common landscape palm disorders and diseases in the continental United States. PALMS 49:143-148.<br /> <br /> Bush, B.J., Carson, M.L., Cubeta, M.A, Hagler, W.M., and Payne, G.A. 2003. Infection and fumonisin production by Fusarium verticillioides in developing maize kernels. Phytopathology 94:88-93.<br /> <br /> Ceresini, P.C., Shew, H.D., Vigalys, R., Rosewich-Gale, U.L., and Cubeta, M.A. 2003. Detecting migration in populations of Rhizoctonia solani AG-3 from potato in North Carolina using multilocus genotype probabilities. Phytopathology 93:610-615.<br /> <br /> Ceresini, P.C., Shew, H.D. Vilgalys, R., and Cubeta, M.A. 2002. Genetic diversity of Rhizoctonia solani AG-3 from potato and tobacco in North Carolina. Mycologia 94:437-449.<br /> <br /> Ceresini, P.C., Shew, H.D. Vilgalys, R., Rosewich, U.L., and Cubeta, M.A. 2002. Genetic structure of populations of Rhizoctonia solani AG-3 on potato in eastern North Carolina Mycologia 94:450-460.<br /> <br /> Conway, K.E., Mereddy, R., Kahn, B.A., Wu, Y., Hallgren, S.W., and Wu, L. 2001. Beneficial effects of solid matrix Chemo - priming in okra, Plant Dis. 85:535-537.<br /> <br /> Diab, H., Hu, S., and Benson, D.M. 2003. Suppression of Rhizoctonia solani on impatiens by enhanced microbial activity in composted swine waste amended potting mixes. Phytopathology 93:1115-1123.<br /> <br /> Elliott, M.L. 2005. Survival, growth and pathogenicity of Gaeumannomyces graminis var. graminis with different methods of long-term storage. Mycologia 97:901-907.<br /> <br /> Elliott, M.L., Guertal, E.A., and Skipper, H.D. 2004. Rhizosphere bacterial population flux in golf course putting greens in the Southeastern United States. HortScience 39:1754-1758.<br /> <br /> Elliott, M.L., and Broschat, T.K. 2002. Effects of a microbial inoculant on plant growth and rhizosphere bacterial populations of container-grown plants. HortTechnology 12:222-225.<br /> <br /> Elliott, M.L., Des Jardin, E.A., Batson, Jr., W.E., Caceres, J., Brannen, P.M., Howell, C.R., Benson, D.M., Conway, K.E., Rothrock, C.S., Schneider, R.W., Ownley, B.H., Canaday, C.H., Keinath, A.P., Huber, D.M., Sumner, D.R., Molsenbocker, C.E., Thaxton, P.M., Cubeta, M.A., Adams, P.D., Backman, P.A., Fajardo, J., Newman M.A., and Pereira., R.M. 2001. Viability and stability of biological control agents used for disease management on cotton and snap bean seeds. Pest Manag. Sci. 57:695-706.<br /> <br /> Farnham, M.W., Keinath, A.P., and Smith, J.P. 2001. Characterization of Fusarium <br /> yellows resistance in collard. Plant Dis. 85:890-894. <br /> <br /> Fichtner, E.J., Benson, D.M., Diab, H.G. and Shew, H.D. 2004. Abiotic and biological suppression of Phytophthora parasitica in a horticultural medium containing composted swine waste. Phytopathology 94:780-788.<br /> <br /> Gonzalez, D, Carling, D., Kuninaga, S., Vilgalys, R., and Cubeta, M.A. 2001. Ribosomal DNA systematics of Ceratobasidium and Thanatephorus with Rhizoctonia anamorphs. Mycologia 93:1138-1150.<br /> <br /> Guest, C.A., Schulze, D.G., Thompson, I.A., and Huber, D.M. 2002.Correlating manganese XANES spectra with extractable soil manganese. Soil Sci. Soc. Amer. J. 66:1172 1181.<br /> <br /> Hanson, L.E. and Howell, C.R. 2003. Elicitors of plant defense responses from biological control strains of Trichoderma virens. Phytopathology 94:171-176. <br /> <br /> Hanson. L.E. and Howell, C.R. 2001. Biological control efficacy and other characteristics of protoplast fusants between Trichoderma koningii and T. virens. Mycological Research.<br /> <br /> Harrison, H.F., Jackson, D.M., Keinath, A.P., Marino, P.C., and Pullaro, T.C. 2004. Broccoli production in cowpea, soybean, and velvetbean cover crop mulches. HortTechnology 14:484-487.<br /> <br /> Hollowell, J.E., Shew, B.B., Wilcut, J.W., and Cubeta, M.A. 2003. Weed species as hosts of Sclerotinia minor in peanut fields. Plant Dis. 87:197-199.<br /> <br /> Hollowell, J.E., Shew, B.B., Wilcut, J.W., and Cubeta, M.A. 2003. Weed species as hosts of Sclerotinia minor in peanut fields. Plant Dis. 87:197-199.<br /> <br /> Honeycutt, E.W. and Benson, D.M. 2001. Formulation and delivery of binucleate Rhizoctonia spp. for biocontrol of pre-emergence damping-off caused by Rhizoctonia solani on impatiens. Plant Dis. 85:1241-1248.<br /> <br /> Howell, C.R. 2001. Cotton seedling pre-emergence damping-off incited by Rhizopus oryzae and Pythium spp. and its biological control with Trichoderma spp. Phytopathology 92:177-180.<br /> <br /> Howell, C.R. 2003. Mechanisms employed by Trichoderma species in the biological control of plant diseases: The history and evolution of current concepts. Plant Dis. 87:4-10.<br /> <br /> Hwang, J. and Benson, D.M. 2003. Expression of induced systemic resistance in poinsettia cuttings against Rhizoctonia stem rot by treatment of stock plants with binucleate Rhizoctonia. Biol. Control 27:73-80.<br /> <br /> Hwang, J. and Benson, D.M. 2002. Biocontrol of Rhizoctonia stem and root rot of poinsettia with integrated application of Burkholderia cepacia and binucleate Rhizoctonia. Plant Dis 86:47-53.<br /> <br /> Hwang, J., Chilton, W.S., and Benson, D.M. 2002. Pyrrolnitrin production by Burkholderia cepacia and biocontrol of Rhizoctonia stem rot of poinsettia. Biol Control 25:56-63.<br /> <br /> Hwang, J., and Benson, D.M. 2001. Biocontrol of Rhizoctonia stem and root rot of poinsettia with integrated application of Burkholderia cepacia and binucleate Rhizoctonia. Plant Dis. 86:47-53.<br /> <br /> Keinath, A.P., Harrison, H.F., Marino, P.C., Jackson, D.M., and Pullaro, T.C. 2003. Increase in populations of Rhizoctonia solani and wirestem of collard with velvet bean cover crop mulch. Plant Dis. 87:719-725.<br /> <br /> Keinath, A.P., and Farnham, M.W. 2001. Effect of wirestem severity on survival and <br /> head production of transplanted broccoli and cabbage. Plant Dis. 85:639-643.<br /> <br /> Kirkpatrick, M.T., Rothrock C.S. and Rupe, J.C. 2006. The effect of Pythium ultimum and soil flooding on two soybean cultivars. Plant Dis. (In press).<br /> <br /> Kirkpatrick, M.T., Rupe, J.C., and Rothrock, C.S. 2006. Soybean response to flooded soil conditions and the association with soilborne plant pathogenic genera. Plant Dis. (In press).<br /> <br /> Kubikova, E., Moore, J.L., Ownley, B.H., Mullen, M.D., and Augé, A.M. 2001. Mycorrhizal impact on osmotic adjustment in Ocimum basilicum L. during a lethal drying episode. J. Plant Physiol. 158:1227-1230.<br /> <br /> Ownley, B.H., Duffy,B.K., and Weller, D.M. 2003. Identification and manipulation of soil properties to improve biological control performance of phenazine-producing Pseudomonas fluorescens. Appl. Environ. Microbiol. 69: 3333-3343<br /> <br /> Poag, P.S., Popp, M., Rupe, J., Dixon, B., Rothrock, C., and Boger, C. 2005. Economic evaluation of soybean fungicide seed treatments. Agronomy J. (In press).<br /> <br /> Sheng, X., Yang, F., Zheng, Q., Wei, Y., Halsey, M.E., and Huber, D.M. 2001. Efficacy of MON65500 for controlling take-all of irrigated spring wheat in Northcentral China. J. Crop Protect. 20:345-349.<br /> <br /> Thompson, I.A., Huber, D.M., and Schulze, D.G. 2005. Evidence of the involvement of a multi-copper oxidase in Mn oxidation by Gaeumannomyces graminis var tritici. Phytopathology 95: (In press). <br /> <br /> Wangsomboondee, T., Groves, C.T., Shoemaker, P.B., Cubeta, M.A. and Ristaino, J.B. 2002. Phytophthora infestans populations from tomato and potato in North Carolina differ in genetic diversity and structure. Phytopathology 92:1189-1195.<br /> <br /> Abstracts<br /> <br /> Abad, J.A., Speck, J., New, S., Kennedy, G., Cubeta, M.A., and Moyer, J.W. 2003. An epidemic of Tomato spotted wilt virus (TSWV) in North Carolina:first report of TSWV affecting potato and cabbage in North America. Phytopathology 93:S1-S2.<br /> <br /> Bates, G.D., Rothrock, C.S., and Rupe, J.C. 2003. Possible mechanism for resistance to Pythium spp. in the soybean cultivar Archer. Proc. 8th Intern. Cong. Plant Pathol. 2:330.<br /> <br /> Benson, D.M. and Parker, K.C. 2003. Suppression of Pythium root rot in poinsettia with swine waste and binucleate Rhizoctonia fungi. Phytopathology 93:S8.<br /> <br /> Benson, D.M., Hu, S., and Diab, H. 2002. Conventional vs. organic systems for disease suppressive potting mixes. ERCERIM Conf. and Potomac Div. APS. March 3-6, Williamsburg, VA.<br /> <br /> Breeden, T.S.,Ownley, B.H., West, D.R., and Sams, C.E. 2003. Brassica juncea inhibits soilborne pathogens. Phytopathology 93:S11.<br /> <br /> Breeden, T.S., Ownley, B.H., West, D.R., and Sams, C.E. 2002. Growth of Gaeumannomyces graminis var. tritici is inhibited by Brassica spp. mulches. Phytopathology 92:S9.<br /> <br /> Breeden, T.S., West, D.R., Ownley, B.H., and Sams, C.E. 2002. Brassica species inhibit take-all fungus of wheat. Agronomy Abstracts.<br /> <br /> Ceresini, P.C., Shew, H.D., Vilgalys, R., James, T., and Cubeta, M.A. 2001. Lack of gene flow between populations of Rhizoctonia solani AG-3 from potato and tobacco suggests they constitute genetically distinct groups within AG-3. Phytopathology 91:S105 (Abstract).<br /> <br /> Ceresini, P.C., Shew, H.D., Vilgalys, R., Rosewich, U.L., and Cubeta, M.A. 2001. Detecting migration using multilocus genotypes and its effect of gene flow in populations of Rhizoctonia solani AG-3 from potato in North Carolina. Phytopathology 91:S105 (Abstract).<br /> <br /> Charlton, N.D., Tavantzis, S.M., and Cubeta, M.A. 2005. The genetic diversity of dsRNA mycoviruses in a population of the soil fungus Rhizoctonia solani AG-3, Proceedings of the International Union of Microbiological Sciences, American Society for Microbiology (In Press).<br /> <br /> Charlton, N.D., Tavantzis, S.M., and Cubeta, M.A. 2005. Genetic diversity of double stranded RNA mycoviruses in a population of Rhizoctonia solani anastomosis group 3 (AG-3). Inoculum 56:15. (Supplement to Mycologia).<br /> (Abstr.)<br /> <br /> Charlton, N.D., Tavantzis, S.M., and Cubeta, M.A. 2005. Genetic diversity of double stranded RNA mycoviruses in a population of Rhizoctonia solani anastomosis group 3 Phytopathology 95:S18.<br /> <br /> Charlton, N.D., Tavantzis, S.M., and Cubeta, M.A. 2004. Genetic diversity of double stranded RNA mycoviruses in a population of Rhizoctonia solani anastomosis group 3 (AG-3). Inoculum 55:11. (Supplement to Mycologia).<br /> Cheng, M.W., Levy, M., Schulze, D.G., and Huber, D.M. 2005. Mn transition states during infection and early pathogenesis in rice blast relative to resistance and susceptibility. Phytopathology 95:S19.<br /> Copes, W, Rinehart, T., and Cubeta, M.A. 2005. Genetic, pathogenic and phenotypic characterization of Rhizoctonia spp. isolated from container-grown azalea in the southern United States. Phytopathology 95:S21.<br /> Cubeta, M.A., Ceresini, P.C., Shew, H.D., Cody, B.R., Boerema, M.E., Lakshman, D.K. and Tavantzis. S.M. 2003 . Occurrence of the M2 dsRNA in populations of Rhizoctonia solani AG-3 from potato and soil. International Congress of Plant Pathology, pp. 110. <br /> Cubeta, M.A., Ceresini, P.C., Shew, H.D., Cody, B.R., Boerema, M.E., Lakshman, D.K., and Tavantzis, S.M. 2003. Occurrence of the M2 dsRNA in populations of Rhizoctonia solani AG-3 from potato and soil. Proc. Intern. Cong. Plant Pathol. Pp. 110.<br /> Cubeta, M.A., Ceresini, P.C., and Shew, H.D. 2001. The contribution of population biology and genetics for developing seed certification programs and managing Rhizoctonia disease of potato. Amer. J of Potato Res. (Abstract)<br /> Cubeta, M.A., Sermons, D.N. and Cody, B.R. 2001. Mycelial interactions of Sclerotinia minor. Phytopathology 91:S19. (Abstract)<br /> Diab El-Arab, H.G., Hu, S., and Benson, D.M. 2002. Suppression of Rhizoctonia pre-emergence damping-off of impatiens by enhanced microbial activity in potting mix amended with composted swine waste. Phytopathology 92:S19.<br /> <br /> Dodds, D.M., Hickman, M.V., and Huber, D.M. 2002. Micronutrient uptake by isogenic glyphosate tolerant and normal corn. Proc. Weed Sci. Soc. Amer. 42:2.<br /> <br /> Elmer, W.H. and Huber, D.M. 2002. Manipulating host plant nutrition to alter biocontrol activity. Phytopathology 92:S98.<br /> <br /> Fichtner, E.J., Benson, D.M., Diab, H., and Shew, H.D. 2003. Suppression of Phytophthora parasitica in composted swine waste. Phytopathology 93:S26.<br /> <br /> Greene, S.E., K.D. Gwinn, D.J. Trently, S.L. Hamilton, and Ownley, B.H. 2002. Monarda didyma and control of damping off of tomato. Phytopathology 92:S31.<br /> <br /> Gonzalez, D., Cubeta, M.A., and Vilgalys, R. 2003. Molecular systematics of Rhizoctonia phyloenetically integrates anamorphs into Ceratobasidiaceae. International Congress of Plant Pathology pp. 29 <br /> Gonzalez, D., Cubeta, M.A., and Vilgalys, R. 2003. Molecular systematics of Rhizoctonia phylogenetically integrates anamorphs into Ceratobasidiaceae. Proc. Intern. Cong. Plant Pathol. Pp. 29.<br /> <br /> Gwinn, K., Greene, S., Ownley, B., Wills, Jr., J., and Honea, G. 2005. Bioactive natural products and selected biopesticides for control of Pythium disease in hydroponically-grown tomatoes. Phytopathology 95:S38.<br /> <br /> Gwinn, K. Greene, S., Ownley, B., Wills, Jr., J., and Honea, G. 2005. Integration of biopesticides for control of Pythium disease in hydroponically-grown greenhouse tomatoes. Phytopathology 95:S38.<br /> <br /> Hickman, M.V., Dodds, D.M., and Huber, D.M. 2002. Micronutrient interactions reduce glyphosate efficacy on tall fescue. Weed Sci. Soc. Amer. 42:18.<br /> <br /> Hickman, M.V., Huber, D.M., and Dodds, D.M. 2002. Residual effects of glyphosate on yield and take all of wheat. Proc. Weed Sci. Soc. Amer. 42:6.<br /> <br /> Howell, C.R. 2003. Pre-emergence damping-off of cotton seedlings. Workshop: Cotton Seedling Diseases. Proc. Beltwide Cotton Conf., National Cotton Assoc. America.<br /> <br /> Howell, C.R., Puckhaver, L.S., and Stipanovic, R.D. 2003. Biocontrol of cotton pre-emergence seedling disease by metabolism of pathogen germination inducers. Phytopathology 93:S37.<br /> <br /> Howell, C.R., Hanson, L.E., Puckhaber, L.S. and Stipanovic, R.D. 2001. Phenotypic characteristics of protoplast fusants of Trichoderma virens and T. longibrachiatum. Phytopathology 91:S95 (Abstract).<br /> <br /> Huber, D.M. and Cheng, M.W. 2005. Association of severe Corynespora root rot of soybean with glyphosate-killed ragweed. Phytopathology 95:S45.<br /> <br /> Huber, D. M., Schnelle, K., Young, J., Leuck, J.D., and Thompson, I.A. 2001. Stalk rot of corn relative to N rate, form and kernel sink sufficiency. Phytopathology 91:S41(Abstract).<br /> <br /> Hwang, J., and Benson, D.M. 2001. Resistance of poinsettia cultivars against Rhizoctonia stem rot induced by binucleate Rhizoctonia. Phytopthology 91:S41 (Abstract).<br /> <br /> Hwang, J., and Benson, D.M. 2001. Role of pyrrolnitrin produced by Burkholderia cepacia in biocontrol of Rhizoctonia stem rot of poinsettia. Phytopathology 91:S41 (Abstract).<br /> <br /> Jia, Y., Singh, P., Cartwright, R.D., Lee, F.N., Rothrock, C.S., Eizenga, G.C., and Rutger, J.N. 2003. Characterization of isolate diversity in the rice sheath blight pathogen Rhizoctonia solani. Phytopathology 93:S40.<br /> <br /> Keinath, A.P. and Smith, J.P. 2003. Effects of winter cover crops on populations of Rhizoctonia and Fusarium in bulk soil. Phytopathology 93:S43.<br /> <br /> Keinath, A.P. and Harrison, H.F. 2002. Increase in populations of Rhizoctonia solani and wirestem of collard after a velvetbean cover crop. Phytopathology 92: S150.<br /> <br /> McBeath, J.H., su, B., and Huber, D.M. 2005. Heavy metal sequestration potential of Trichoderma atroviride. Phytopathology 95:S67.<br /> <br /> Ownley, B., Breeden, T., West, D. and Sams, C. 2005. Take-all of wheat is reduced by incorporating Brassica juncea mulch into soil infested with Gaeumannomyces graminis var. tritici. Phytopathology 95:S78.<br /> <br /> Ownley, B.H., and Duffy, B.K. 2002. Identifying and manipulating soil factors that influence biocontrol. Phytopathology 92:S98.<br /> <br /> Pickens, K., West, D.R., Ownley, B.H., and Sams, C.E. 2003. Brassica crops inhibit Fusarium graminearum and F. equiseti in culture. Southern Branch Am. Soc. Agron. Abs of Tech papers, p 24.<br /> <br /> Pagani, M.C., Moussa, E.M., Tavantzis, S.M, Cubeta, M.A., and Carbone, I. 2005. Analysis of Gene Cluster Organization within the Quinic/Shikimic acid Pathway in Filamentous Fungi. Mid-Atlantic State Mycology Conference Proceedings. (in press).<br /> <br /> Smith, W.C., Schulze, D.G., and Huber, D.M. 2005. Crop rotation and sequence influence on manganese availability. CSM-SSSA Proceedings, Madison, WI.<br /> <br /> Pickens, K., West, D.R., Ownley, B.H., and Sams, C.E. 2003. Brassica crops inhibit Fusarium graminarium and F. equiseti in culture. Southern Branch Am. Soc. Agron. Abstract of Tech. papers, p 24.<br /> <br /> Seebold, K.W., Gitaitis, R.D., and Sanders, F.H. 2004. Biological control of gummy stem blight on watermelon and Phytophthora crown rot on summer squash with bacteria. Phytopathology 94:S94.<br /> <br /> Seth, D., Ownley, B.H., Pereira, R., and Canaday, C.H. 2001. Effect of application method and inoculum form of Beauveria bassiana on Rhizoctonia damping-off in tomato. Phytopathology 91:S81(Abstract) .<br /> <br /> Sullivan, M., Shew, H.D., Melton, T., and Cubeta, M.A. 2005. Molecular characterization of races 0 and 1 of Phytophthora parasitica var. nicotianae using amplified fragment length polymorphisms. Phytopathology 95:S101.<br /> <br /> S.M.C. Njoroge, Toler, J.E., and Keinath, A.P. 2005. Pythium spp. inoculum density and disease development under different soil solarization strategies in South Carolina. Phytopathology 95:S76.<br /> <br /> Thompson, I.A., Xu, J.R., Huber, D.M., and Schulze, D.G. 200. Investigations of manganese oxidation by two plant pathogenic fungi.. Phytopathology 95:S166.<br /> <br /> Thompson, I.A., Huber, D.M., Schulze, D.G., and Guest, C.A. 2004. Fungal manganese oxidation in a saturated soil. Phytopathology 94:S<br /> <br /> Thompson, I.A., Li, L., Huber, D.M., and Schulze, D.G. 2002. Mn oxidation in plant pathogenic fungi. Phytopathology 92:S80.<br /> <br /> Thompson, I.A., Huber, D.M., and Schulze, D.G. 2001. Investigation and characterization of the Mn oxidizing factor from Gauemannomyces graminis var. tritici. Phytopathology 91:S88 (Abstract).<br /> <br /> <br /> State Publications:<br /> <br /> Canaday, C.H., and Ownley, B.H. 2002. Effects of snap bean cultivars, seed treatment chemicals, and Bacillus subtilis on snap bean seedling diseases, growth, and yield. Pages 16-23 in 2001 Vegetable Initiative Progress Rpt., University of Tennessee Pub. No. E11-6515-01-001-02.<br /> <br /> Canaday, C.H. and Reddick, B.B. 2002. Evaluation of an IPM Program and SAR Inducers for Control of Viral Diseases of Summer Squash, pp. 125-129 In: 2001 Vegetable Initiative Progress Report, Univ. of Tennessee Publication No. E11-6515-01-001-02.<br /> <br /> Canaday, C.H. and Wyatt, J.E. 2002. Evaluation of Tomato Varieties with TSWV Resistance, pp. 157-161 In: 2001 Vegetable Initiative Progress Report, Univ. of Tennessee Publication No. E11-6515-01-001-02.<br /> <br /> Canaday, C.H., Wyatt, J.E., and Tyler, D.D. 2002. Effects of Different Fertilizers and Continuous No-Till Production on Diseases, Growth, and Yield of Staked Tomato, pp. 130-139 In: 2001 Vegetable Initiative Progress Report, Univ. of Tennessee Publication No. E11-6515-01-001-02.<br /> <br /> Canaday, C.H. 2001. Evaluation of seed treatment chemicals, Bacillus subtilis, and seed adjuvants on snap bean seedling diseases, plant growth, and estimated yields at West Tennessee Experiment Station, 2000. Pages 125-129 in: 2000 Vegetable Initiative Progress Report, Univ. of Tennessee Publication No. E11-6515-01-001-01.<br /> <br /> Canaday, C.H. and Ownley, B.H. 2001. Effects of seed treatment chemicals and Bacillus subtilis on snap bean seedling diseases, growth, and yield at the West Tennessee Experiment Station, 2000. Pages 210-214 in: 2000 Vegetable Initiative Progress Report, Univ. of Tennessee Publication No. E11-6515-01-001-01.<br /> <br /> Ownley, B. H., Seth, D., Hamilton, C., and Dee, M.. 2002. Effects of plant-growth-promoting rhizobacteria on biomass, flowering, and yield of field tomatoes, 2001, KES. Pages 153-156 in: 2001 Vegetable Initiative Progress Rpt., University of Tennessee Pub. No. E11-6515-01-001-02.<br /> <br /> Rothrock, C.S., Sealy, R.L., and Winters, S.A. 2001. The importance of seedling disease problems in rice. Pages 149-154 in: B. R. Wells Rice Research Studies 2000. R. J. Norman and J. -F. Meullenet, eds. Arkansas Agricultural Experiment Station Research Series 485.<br /> <br /> Seth, D., and Ownley, B.H. 2002. Evaluation of tomato cultivars for susceptibility to Rhizoctonia damping-off, 2001, KES. Pages 162-166 in: 2001 Vegetable Initiative Progress Rpt., University of Tennessee Pub. No. E11-6515-01-001-02.<br /> <br /> Proceedings<br /> <br /> Canaday, C.H. and Ownley, B.H. 2001. Effects of seed treatment chemicals on root colonization by Bacillus subtilis and subsequent effects on snap bean seedling diseases, growth, and yield. Pages 31-35 in: D. M. Huber (ed.). Biocontrol in a New Millenium: Building for the Future on Past Experience. Proceedings Joint Regional Biological Control Conference, Oct. 26-29, 2000, Estes Park, CO.<br /> <br /> Elliott, M., Des Jardin, E., Batson, Jr., W., Caceres, J., Brannen, P., Howell, C., Benson, M., Conway, K., Rothrock, C., Schneider, R., Ownley, B., Keinath, A., Huber, D., Summer, D., Molsenbocker, C., Thaxton, P., Cubeta, M., Adams, P., Backman, P., Fajardo, J., Newman, M., and Pereira. 2001. Tracking biological control agents on cotton seed from delivery to planting. Proc. Joint Regional Biological Control Conf., Biocontrol in a New Millennium: Building for the Future on Past Experience, Estes Park, CO, October 26-29. Pp. 65-74.<br /> <br /> Elliott, M., Des Jardin, E., Batson, Jr., W., Caceres, J., Brannen, P., Howell, C., Benson, M., Conway, K., Rothrock, C., Schneider, R., Ownley, B., Keinath, A., Huber, D., Summer, D., Molsenbocker, C., Thaxton, P., Cubeta, M., Adams, P., Backman, P., Fajardo, J., Newman, M., and Pereira., R. 2001. Tracking biological control agents on cottonseed from delivery to planting. Pages 65-74 in: D. M. Huber (ed.). Biocontrol in a New Millenium: Building for the Future on Past Experience. Proceedings Joint Regional Biological Control Conference, Oct. 26-29, 2000, Estes Park, CO.<br /> <br /> Gwinn, K. D., S. Greene, D. J. Trently, B. H. Ownley, and S. L. Hamilton. 2003. Monarda: A new control strategy. Proceedings of the Southern Nurserymans Association Research Conference 48:208-211.<br /> <br /> Howell, C.R. 2001. Pythium aphanidermatum and cotton seedling and root disease. Proceedings Beltwide Cotton Conferences. National Cotton Council. Anaheim, CA.<br /> <br /> Huber, D.M. 2005. Take-all: the disease and its control. October 25, 2005, Rothamstead Experimental Station, Harpenden, UK.<br /> <br /> Huber, D.M. 2005. Nutrient-Disease Interactions. October 27, Phosyn, York, UK.<br /> <br /> Huber, D.M. 2005. Challenges in providing micronutrient sufficiency. October 28, Phosyn, York, UK.<br /> <br /> Huber, D.M., 2001. Biocontrol in a New Millennium: Building for the Future on Past Experience. Proceedings Joint Regional Biological Control Conference, Estes Park, CO, October 26-29, 2000.<br /> <br /> Huber, D.M. 2001. Biological control:expanding the peaks of our understanding. Pages 14-26 in: D. M. Huber (ed.). Biocontrol in a New Millenium: Building for the Future on Past Experience. Proceedings Joint Regional Biological Control Conference, Oct. 26-29, 2000, Estes Park, CO.<br /> <br /> Huber, D.M., Hugh-Jones, M.E., Rust, M.K., Sheffield, S.R., Simberloff, D., and Taylor, C.R. 2001. Invasive Pest Species:Impacts on Agricultural Production, Natural Resources, and the Environment. Issue Paper No. 20. Council for Agricultural Science and Technology, Ames, IA.<br /> <br /> Huber, D.M., Thompson, I.A., Schulze, D.G., and Hickman, M.V. 2001. Understanding the ecology of Gauemannomyces for biocontrol of take-all. Pages113-116 in: D. M. Huber (ed.). Biocontrol in a New Millenium: Building for the Future on Past Experience. Proceedings Joint Regional Biological Control Conference, Oct. 26-29, 2000, Estes Park, CO.<br /> <br /> Padgett, G.B. 2003. The influence of tillage practices, cover crops, and in-furrow fungicide applications on cotton seedling disease epidemics and Rhizoctonia populations. 6th Annual National Conservation Tillage Cotton & Rice Conference Proceedings. pp. 24-26, Houston, TX, January 23&24, 2003. MidAmerica Farm Publications.<br /> <br /> Padgett, G.B., and Rea, W. 2002. Effects of cover crop, tillage system, and soil-applied fungicide on cotton seedling disease epidemics. Proceedings APS Southern Division Meeting. Orlando, FL, February 3-5.<br /> <br /> Smith, W.C., Schulze, D.G., and Huber, D.M. 2005. Crop rotation and sequence influence on manganese availability. CSM-SSSA Proceedings, Madison, WI.<br /> <br /> Smith, W.C., Schulze, D.G., and Huber, D.M. 2005. Influence of crop rotation and sequence on manganese availability. ASA Proceedings, Madison, WI.<br /> <br /> Theses and Dissertations<br /> <br /> Breeden, Thomas S. 2005. Biological Control of Wheat Pathogens with Brassica spp. M.S. Thesis. The University of Tennessee, Knoxville.<br /> <br /> Ceresini, P.C. 2001. Population biology and genetics of Rhizoctonia solani anatomosis group 3 (AG-3). Ph.D. Thesis, N. C. State University, pp.<br /> <br /> Honeycutt, E.R. 2001. Formulation and delivery of binucleate Rhizoctonia spp. for biocontrol of pre-emergence damping-off caused by Rhizoctonia solani on impatiens. M. S. Thesis, N. C. State University, 42 pp.<br /> <br /> Hwang, J.S. 2001. Integrated application of binucleate Rhizoctonia and Burkholderia cepacia for control of Rhizoctonia stem rot of poinsettia. Ph.D. Thesis, N. C. State University, 88 pp.<br /> <br /> Leckie, B.M. 2002. Effects of Orally Administered Beauveria bassiana Mycelia and Metabolites on Helicoverpa zea; and Detection of Endophytic B. bassiana in Tomato Plants using ITS Primers. M.S. Thesis. The University of Tennessee, Knoxville.<br /> <br /> Thompson, I.A. 2004. Manganese Oxidation in Plant Pathogenic Fungi. Ph.D. thesis, Purdue University, West Lafayette, IN 47907.<br /> <br /> Book Chapters<br /> <br /> Benson, D.M. 2000. Inoculum density. Pages 579-581 in: The Encyclopedia of Plant Pathology. O. C. Maloy and T. D. Murray, eds. John Wiley & Sons, New York. <br /> <br /> Benson, D.M. 2000. Inoculum potential. Pages 581-582 in: The Encyclopedia of Plant Pathology. O. C. Maloy and T. D. Murray, eds. John Wiley & Sons, New York. <br /> <br /> Benson, D.M. 2000. Population density. Pages 796 in: The Encyclopedia of Plant Pathology. O. C. Maloy and T. D. Murray, eds. John Wiley & Sons, New York. <br /> <br /> Cubeta, M.A., Mozley, S.E., and Porter, D. 2003. Laboratory Exercises with Zoosporic Fungi. In Plant Pathology Laboratory Exercises and Concepts. CRC Press, eds. Trigiano and Windam, pp. 99-110.<br /> <br /> Evans, I., Solberg, E., and Huber, D.M. 2001. Deficiency diseases. Pages 295-302. in: The Encyclopedia of Plant Pathology. O. C. Maloy and T. D. Murray, eds. John Wiley & Sons. New York.<br /> <br /> Keinath, A.P., Cubeta, M.A., and Langston, D. 2005. Cabbage Disease, Ecology and Control. In Encyclopedia of Pest Management, ed., David Pimentel, Markel-Dekker, (In Press)<br /> <br /> Mozley, S.E., Leander, C.E., Porter, D, and Cubeta, M.A. 2003. Concepts:Zoosporic fungi. In Plant Pathology Laboratory Exercises and Concepts. CRC Press, eds. Trigiano and Windam, pp. 91-98.<br /> <br /> Mozley, S.E., Leander, C.E., Porter, D., and Cubeta, M.A. 2003. Concepts: Zoosporic fungi. Pp. 91-98. In: Trigiano and Windam (eds.) Zoosporic Fungi. CRC Press, Boca Raton, FL.<br /> <br /> Ownley, B. H. and Windham, M. 2003. Biological control of plant pathogens. Pages 323-332 in: Plant Pathology: Concepts and Laboratory Exercises. R. Trigiano, M. Windham, and A. Windham, eds., CRC Press, Boca Rotan, FL.<br /> <br /> Ownley, B. H. 2002. Biological control of tobacco diseases. Pages 111-130 in: Biological Control of Major Crop Plant Diseases. S. Gnanamanickam, ed., Marcel Dekker, NY.<br /> <br /> Payne, G.A. and Cubeta, M.A. 2005. Biology and Detection of Human and Plant Pathogenic Fungi. In Microbial Forensics, pp. 109-130. Eds. R.G. Breeze, B. Budowle and S.E. Schutzer, Elsevier, London, UK. 425 pp.<br /> <br /> Rothrock, C.S. 2001. Phytophthora collar rot. Pages 235-237 in: The Encyclopedia of Plant Pathology. O. C. Maloy and T. D. Murray, eds. John Wiley & Sons, New York.<br /> <br /> Rothrock, C.S. 2001. Pythium root rot. Pages 841-842 in: The Encyclopedia of Plant Pathology. O. C. Maloy and T. D. Murray, eds. John Wiley & Sons, New York. <br /> <br /> Rothrock, C.S. 2001. Take-all. Pages 1007-1008 in: The Encyclopedia of Plant Pathology. O. C. Maloy and T. D. Murray, eds. John Wiley & Sons, New York.<br /> <br /> Other Activities<br /> <br /> Canaday, C.H., Wyatt, J.E., Bohac, J., and Smith, J.R. 2002, Field evaluation of bean cultivars and lines for resistance to Rhizoctonia, 2001. Biol. and Cult. Tests 17:V02. <br /> <br /> Dodds, D.M., Hickman, M.V., and Huber, D.M.. 2002. Comparison of micronutrient uptake by glyphosate resistant and non glyphosate resistant soybeans. NC Weed Sci. Soc. 57.<br /> <br /> Howell, C.R. and Hanson, L.E. 2001. Elicitor protein produced by Trichoderma virens that induces resistance response in plants. U.S. Patent 6,242,420.<br /> <br /> Huber, D.M., Hugh-Jones, M.E., Rust, M.K., Sheffield, S.R., Simberloff, D., and Taylor,C.R. 2002. Invasive Pest Species: Impacts on Agricultural Production, Natural Resources, and the Environment. Issue Paper No. 20. Council for Agricultural Science and Technology, Ames, IA.<br /> <br /> Technical Articles:<br /> <br /> Batson, Jr., W.E., Caceres, J., Benson, M., Cubeta, M.A., Elliott, M.L., Isakeit, T., McLean, K.S., Padgett, G.B., Rothrock, C.S., and Seebold, K. 2003. Evaluation of selected biological seed treatments for cotton seedling disease control, 2002. Biological and Cultural Tests for Control of Plant Disease Vol. 18:F003 (electronic).<br /> <br /> Batson, Jr., W.E., Caceres, J., Elliott, M.L., Huber, D.M., Hickman, M.V., McLean, K.S., Ownley, B., Newman, M., Padgett, G. Boyd, Rushing, K.W., Kenny, D.S., Rothrock, C.S., Seebold, K., and Thaxton, P. 2003. Biological seed treatment evaluations for control of the cotton seedling disease complex, 2001. Biological and Cultural Tests for Control of Plant Diseases, 2003: Report No. 18:F002. <br /> <br /> Batson, Jr., W.E., Caceres, J., Benson, M., Cubeta, M.A., Elliott, M.L., Huber, D.M., Hickman, M.V., McLean, K.S., Ownley, B., Newman, M., Rothrock, C.S., Rushing, K.W., Kenny, D.S., and Thaxton. P. 2001. Biological seed treatment evaluations for control of the seedling disease complex of cotton, 2000. Biological and Cultural Tests for Control of Plant Diseases, 2001: F12. <br /> <br /> Batson, Jr., W.E., Caceres, J., Benson, M., Cubeta, M.A., Elliott, M.L., Huber, D.M., Hickman, M.V., Keinath, A.P., Dubose, V., McLean, K.S., Ownley, B., Canaday, C., Rothrock, C.S, and Seebold, K. 2003. Evaluation of biological seed treatments for control of seedling disease of snap bean, 2002. Biological and Cultural Tests for Control of Plant Diseases, 2003: Report No. 18:V029. <br /> <br /> Batson, Jr., W.E., Caceres, J., Benson, M., Cubeta, M.A., Elliott, M.L., Huber, D.M., Hickman, V., Keinath, A.P., Dubose, V., McLean, K.S., Ownley, B., Canaday, C., Rothrock, C.S., and Seebold, K. 2003. Evaluation of biological seed treatments for control of the seedling disease of snap bean, 2001. Biological and Cultural Tests for Control of Plant Disease 18:V029.<br /> <br /> Batson, Jr., W.E., Caceres, J., Benson, M., Cubeta, M.A., Elliott, M.L., Huber, D.M., Hickman, M.V., Keinath, A.P., Dubose, V., McLean, K.S., Ownley, B., Canaday, C., Rushing, K.W., and Kenny, D.S. 2001. Evaluation of biological seed treatments for control of the seedling disease complex of snap bean, 2000. Biological and Cultural Tests for Control of Plant Diseases, 2001: V81. <br /> <br /> Gitaitis, R.D., Sanders, F.H., and Seebold, K.W. 2004. Development of a Screening Procedure to Identify Bacteria with Biocontrol Activity. Pp. 80-81 in: Proceedings of the 2004 Southeast Regional Vegetable Conference. University of Georgia Cooperative Extension Service. 124 pp.<br /> <br /> Seebold, K.W. 2003. Control of Phytophthora capsici on Yellow Squash with Organic Amendments and Biological Agents. Page 69 in: Proceedings of the 2003 Georgia Vegetable Conference. University of Georgia Cooperative Extension Service. 108 pp.<br /> <br /> Symposia and other published works:<br /> <br /> Bates, G.D., Rothrock, C.S., and Rupe, J.C. 2003. Possible mechanism for resistance to Phytium spp. in the soybean cultivar Archer. Proc. 8th Intern. Cong. Plant Pathol. 2:330.<br /> <br /> Canaday, C.H., Results of 2003 Snap Bean Research, A Report for the Snap Bean Meeting, March 29, 2004, Crossville, TN, 13 pp.<br /> <br /> Canaday, C.H., BioYield Formulation Evaluations, a presentation with handouts for the Annual Convention of the Tennessee Fruit and Vegetable Association, Dec. 12-14, 2004, Nashville, TN.<br /> <br /> Canaday, C.H. and Wyatt, J.E. Increases in the incidence of snap bean seedling diseases associated with preplant incorporation of S-metolachlor, Annual Meeting of the Southern Division of the American Phytopathological Society, Tulsa, OK, Feb. 15-17, 2004.<br /> <br /> Gitaitis, R.D., Sanders, F.H., and Seebold, K.W. 2004. Development of a Screening Procedure to Identify Bacteria with Biocontrol Activity. Pages 80-81 in: Proceedings of the 2004 Southeast Regional Vegetable Conference, Savannah, Georgia, January 9-11. W.T. Kelley, ed. University of Georgia Cooperative Extension Service, 124 pp.<br /> <br /> Huber, D.M. 2005. Plant nutrition, GMO crops and plant diseases. PP 41-44. XIII Congreso Latinoamericano de Fitopatologia and III Taller de la Asociacion Argentina de Fitopatologos, 19-22 April, 2005, Cordoba, Argentina. <br /> <br /> Huber, D.M. 2005. Nutrient interactions for disease control. Jornada de Actualizacion sobre Diagnostico y Manejo de Enfermedades de la Cana de Azacur (Conference on the Diagnostics and Management of diseaes of Sugar Cane). April 24-25, 2005, Tucuman, Argentina.<br /> <br /> Huber, D.M. 2005. The roles of sulfur in nutrient disease interactions. International Workshop: Crosstalks between Metabolic Pathways involving Sulphur in Plants. October 21-23, Braunschweig, Germany.<br /> <br /> Huber, D.M. 2005. The role of nitrogen and sulfur in disease reduction. International Symposium on the relationship between mineral nutrition and disease severity in plants. February 28, 2005, Potafos, Piracicaba  SP, Brazil.<br /> <br /> Huber, D.M. 2003. Nutrient-disease interactions in the take-all disease of cereals. Proc. Symposium on take-all, April 2003, Temuco, Chili.<br /> <br /> Huber, D.M. 2003. The role of plant nutrition in disease. Proc. Symposium Relacao entre Nutricao de Plantas e Incidencia de Doencas, March, 2003, Piracicaba, SP, Brazil.<br /> <br /> Keinath, A.P., DuBose, V.B., Cantrell, J.P., and May, W.H. III. 2003. Evaluating foliar-applied fungicides to control wirestem on heading Brassica vegetables. Fungic. Nematic. Tests. 58:V010.<br /> <br /> Rosskopf, E.N., Yandoc, C.B., and Lamb, E.M. 2002. Evaluation of PCC1210 for control of Phytophthora capsici on pepper. Pp. 85.1-85.3. In: Proc. 2002 Ann. Intern. Res. Conf. Methyl Bromide Alternatives Emissions Reductions..<br /> <br /> Whitford, F., Cain, S., Alderson, K., Huber, D.M., Beaty, J., Biehle, D., Miller, R., Kemper, A., and Blessing, A. 2004. Rural Security Planning, Protecting Family, Friends, and Farm. PPP-64. Purdue University Cooperative Extension Service, West Lafayette, IN 47907.<br />

Impact Statements

1. Research generated from the Southern Regional Research Project S-302 has provided information on potential biological control agents that can be used alone or in combination with chemical fungicides for managing soilborne diseases in various field crops, vegetables, and ornamentals. Identification of biological controls or combinations of biologicals and chemicals that reduce losses due to seedling diseases will provide alternative management strategies for growers and reduce dependence on chemical treatments alone, thus reducing the risk of pathogen resistance.
2. Regional testing has also provided data generated over numerous environmental scenarios which could not be achieve at a single locations. This is important with growing concern over pesticides in the environment, and public concern over food safety.
3. Identification of biologicals, such as binucleate Rhizoctonia, antibiotic-producing bacteria or bacteria with Type III secretion systems, provided new sources for development of biocontrol agents. Cultural controls such as in-furrow applications of meal prepared from Brassica spp., or cropping schemes that incorporate Brassica mulches into soil have the potential to be effective, economical alternative management strategies to chemical treatments for protection of plants against soilborne pathogenic fungi.
4. The potential role of glyphosate and Mn deficiency for increasing take-all in wheat and Corynespora root rot in soybean was demonstrated. This has implications for using Roundup in field crops. Using solarization and heat culture for managing diseases and weeds in vegetable and ornamental crops will provide producers with environmentally-friendly alternatives. Research has also been initiated to determine to role of dsRNA viruses in the saprophytic and parasitic activity of R. solani AG-3.

Back to top