Brief Summary of Minutes of Annual Meeting

Objective 1-A: Efficacy of Dactylaria higginsii (DH), a bioherbicide agent for purple nutsedge (Cyperus rotundus), was evaluated in field trials with bell pepper and onion as crops. Application of DH at different days after nutsedge emergence as well as single, double, and triple applications improved crop yield and quality. However, DH?s efficacy must be enhanced (i.e., increased fungal virulence, secondary infection, and conidia survival) and/or must be applied more than twice in order to suppress purple nutsedge interference to acceptable levels (<10% yield loss). Higher levels of suppression of purple nutsedge and higher yields are likely if DH were applied under favorable weather conditions.

Objective 1-B: Phomopsis amaranthicola (PA) was evaluated as a post-emergence bioherbicide to control Amaranthus lividus in bell pepper (C. annuum) and A. dubius in Caribbean-bonnet pepper (C. frutescens) and eggplant (S. melongena). Pigweeds that survived infection by PA were allowed to interfere with the crops season-long. In eggplant and Caribbean-bonnet pepper, spraying PA 10 days after weed emergence (DAE) resulted in about 30% mortality in different population densities of A. dubius and yield-loss reductions of about 25% in pepper and 16% in eggplant, as compared to the untreated weedy crops. In the bell pepper experiment, the results were similar when using a Psyllium mucilloid or an agricultural oil (PCC-588) as a surfactant in the spraying mix. In bell pepper, two applications of PA (10 and 20 DAE) were more effective than one application (10, 20, 30, or 40 DAE) in suppressing A. lividus growth and interference with the crop. When PA was applied more than twice, improvements in pigweed control and pepper yield were negligible. Maximum weed mortality, growth suppression, and yield-loss reduction in these crops were obtained with 1 or 2 early applications of PA (10 DAE in eggplant and Caribbean-bonnet pepper and 10 and 20 DAE in bell pepper). Further enhancement in the efficacy of PA as a post-emergence bioherbicide is possible through the use of improved formulations.

Waterhemp (Amaranthus tuberculatus) is a late-emerging species that is well suited to no-till cropping systems and remedial postemergence weed control strategies. Populations of waterhemp have developed resistance to chemical herbicides including the ALS-inhibitors, the s-triazines, the diphenylethers, and glyphosate. Resistance to the ALS-inhibitor herbicides has been found in Illinois, Indiana, Iowa, Kansas, Michigan, Missouri, Ohio, and Wisconsin. Approximately 70% of the waterhemp in Illinois is resistant to ALS-inhibitor herbicides, and it is advised not to use these herbicides where waterhemp is present. An isolate of Microsphaeropsis amaranthi (MA) has been shown to be pathogenic to a wide range of Amaranthus spp. The potential to exploit the interactions between MA and chemical herbicides for the control of waterhemp was studied.

Disease expression by MA was greatest with a dew period of > 12 h and around 18°C. Younger plants were more susceptible to MA, and greater impact was achieved with the highest inoculum levels. When waterhemp plants at the 2-4 leaf stage were sprayed with different rates of glyphosate (0, 0.16, 0.32, and 0.63 kg ae ha^-1) and then with conidia of MA after 24 h, a strong interaction was seen between the herbicide and MA at the higher glyphosate rates. A similar level of control was achieved with either a manufacturer-recommended rate (X = 0.63 kg ae ha^-1) of glyphosate alone or 0.5X rate of glyphosate combined with MA.

By screening putative glyphosate-resistant populations of waterhemp from different accessions in Indiana, Illinois, Missouri, and Iowa, the most susceptible and the most resistant individuals were selected and cloned by vegetative propagation. A response between glyphosate and MA existed for both the susceptible and resistant clones, but in each case the interaction was only apparent with rates of glyphosate that caused visible plant damage alone ? approx 0.32 kg ae ha^-1 for the susceptible clone and approx 1.25 kg ae ha^-1 for the resistant clone.

Objective 1-C: Torpedograss (Panicum repens) is susceptible to three indigenous fungi, Drechslera gigantea, Exserohilum longirostratum, and E. rostratum. The feasibility of using these fungi as a bioherbicide mixture was tested under field conditions. An experiment was designed (randomized split-plot design; three replicates per main-plot and sub-plot treatments) and done twice at a site with dense, uniform growth of torpedograss. The main-plot treatments were: 1) chemical herbicide, imazapyr (Arsenal) at 64 oz per acre, 2) mowing, once, and 3) not mowed, no chemical herbicide applied. The sub-plot treatments were: 1) the bioherbicide mixture in an emulsion (30% Sunspray 6E in water, spores of each fungus at 1:1:1 v/v, final total spore concentration 1x10^6 per ml; BHE), 2) control emulsion only (E), and 3) untreated torpedograss (U). The chemical herbicide treatment was applied aerially (Trial 1), or manually (Trial 2), and the bioherbicide mixture with a CO2-propelled backpack sprayer set at 20 psi pressure. The bioherbicide was reapplied twice (Trial 1) or once (Trial 2) at three to five weeks after the initial application (WAI). At different time intervals, healthy plant species present every 10 cm along a diagonal transect of 3.5 m in each plot were counted. Chemical herbicide application killed all plant species present at the site by 19 weeks after chemical application (WAC) (Trial 1) or 8 WAC (Trial 2), compared to plots not treated with chemical. The BHE treatment provided maximum level of damage severity on both mowed and unmowed torpedograss (70-72% (Trial 1); 60-65% (Trial 2)), and was safe to the native plant species present. In both mowed and no treatment (unmowed) plots at 8 WAI (Trial 1) and 9 WAI (Trial 2), torpedograss population was significantly reduced, when treated with the bioherbicide mixture in emulsion. Simultaneously, numbers of total native plant species censused increased. The chemical control (nonselective) of torpedograss lasted for about 6 months, and bioherbicidal control (selective) for 7 to 9 months without any significant regrowth of torpedograss. Thus, the bioherbicide agents have potential to be used in integrated management of torpedograss.

Objective 1-D: A strain of Myrothecium verrucaria (MV) isolated from sicklepod in Louisiana shows strong bioherbicidal activity against a wide range of weed species across a number of plant families. Grasses (Poaceae), sedges (Cyperaceae), and a range of tree species associated with kudzu in the southeast appear to be relatively resistant/immune to MV.

Members of the genus Myrothecium are known producers of a variety of toxic secondary metabolites with biological activity against plants, fungi, nematodes, and mammals. The spectrum of biological activity of some secondary metabolites is known. To separate the biological activity of spores versus culture filtrate, cultures of MV were harvested, and the different treatments prepared as follows: 1) ?Washed Spores?: Spores were separated from culture filtrate by centrifuging four times at 4,000 g for 5 minutes and resuspending in water, 2) ?Cell-free Filtrate?: Crude filtrate centrifuged once at 4,000 g for 5 min and then filtered sequentially through 5.0 ?m and then 0.45 ?m millipore filters. Absence of fungal material was verified by plating onto PDA ? no growth observed, 3) ?Crude Filtrate?: Untreated harvest from PDA plates containing live fungus and its metabolites. The effect of MV was dominated by toxins with little effect of fungal infection per se, although infection was a significant factor in Chenopodium album (lambsquarters).

A range of dilutions of washed spores (0, 10^4, 10^5, 10^6, 10^7, and 10^8) and a range of dilutions of cell-free filtrate (0, 0.01%, 0.1%, 1%, 10%, and 100% concentration of original filtrate) were prepared and applied to hemp sesbania (Sesbania axaltata) and lambsquarters in a factorial design. The impact of MV conidia upon hemp sesbania was very small at all concentrations tested. Conidia of MV caused significant biomass reductions in lambsquarters at concentrations higher than 10^6 conidia ml^-1. In contrast, large biomass reductions were caused by culture filtrates, and this effect increased directly with increasing concentration.

Objective 1-E: Pseudomonas syringae pv. tagetis (PST), is being considered as a biological control agent of Canada thistle (Cirsium arvense). It produces tagetitoxin, an inhibitor of RNA polymerase that causes chlorosis of developing shoot tissues. While the mode-of-action of tagetitoxin is well known, little is known of the genes required for the production of the toxin. In an attempt to identify the genes required for tagetitoxin production, a strain, EB037, isolated from common ragweed was mutagenized using Tn5, and 17 nontoxigenic mutants were identified. DNA sequences of affected genes were obtained and BLAST searches conducted which demonstrated homologies to genes in other P. syringae pathovars.

Gene sequences from two of the mutants, Tox-9 and Tox-10, were used to develop the PCR protocols that can distinguish PST from closely related Pseudomonads, including those that produce toxins that cause apical chlorosis symptoms. The Tox-9 mutant has a mutation in a gene with homology to exbB, which codes for an auxiliary protein in the TonB/ExbD/ExbB, a membrane-transport system involved in iron transport. The mutation does not affect the growth rate of the mutant, which is identical to the wild-type strain in iron-rich or iron-deficient media. What role iron plays in tagetitoxin production is unknown. The Tox-10 mutant has a mutation in a gene with homology to asnB, which codes for an asparagine synthetase. Growth of the Tox-10 mutant with or without asparagine is comparable to that of the wild-type strain, indicating that this strain is not an asparagine auxothroph. Although growth is stimulated by the addition of asparagine to the growth medium, toxin production in Tox-10 is not restored. Additional experiments are planned to examine the effect of other nitrogenous amino acids and amine donors on tagetitoxin production. Knowledge of the genes required for tagetitoxin production may enable development of toxin over-producing strains. The production gene cluster may also be useful in modifying other bacterial weed pathogens with the ability to produce tagetitoxin, which may increase the efficacy of the weed pathogens.

Objective 3: Control of purple and yellow nutsedge (C. rotundus and C. esculentus) continues to be ranked as one of the greatest problems facing growers in the southern United States. It has been shown that the competitive ability of nutsedge can be significantly decreased with the application of the fungus, DH. A field experiment was designed to use the fungus as a component in an integrated approach to pest management as an alternative to methyl bromide fumigation. A tomato production system utilizing multiple treatment combinations was conducted using fallow season treatment as the main plot and production practice as the sub-plot treatment. Fallow season treatments of D. higginsii, glyphosate, and disk fallow were implemented in summer, followed by a fall tomato crop. Significant disease incidence was seen in the fungus-treated plots and no significant difference was found in tomato yield or nutsedge density in the following production season. Tomato yield from fumigant/fungus-treated plots was similar to yields in the fumigant/herbicide-treated plots.

Objectives 4 and 5: No new reports.

Anderson, K.I., and Hallett, S.G. 2003. Host Range of Myrothecium verrucaria isolated from sicklepod. Proc. NCWSS annual meeting, Louisville, KY.

Anderson, K.I., and Hallett, S.G. 2003. The role of phytotoxins in the herbicidal activity of Myrothecium verrucaria. Proc. NCWSS annual meeting, Louisville, KY.

Boyetchko, S.M., Peng, G., Sawchyn, K., Byer, K., Chandramohan, S. and Charudattan, R. 2003. Evaluation of variable temperature regimes on bioherbicidal activity of non-indigenous fungal pathogens for biological control of green foxtail. Abstracts of the XII Int. Symp. on Biol. Control of Weeds, April 28-May 2, 2003, Canberra, Australia (Abstr.).

Chandramohan, S., Charudattan, R., DeValerio, J.T., and Hanlon, C. 2003. A bioherbicide system to manage invasive torpedograss in Lake Okeechobee. Abstract, 8th Biennial Meeting of the Florida Phytopathological Society, May 5-7, 2003, Ft. Pierce, FL.

Chandramohan, S., Charudattan, R., DeValerio, J.T., and Hanlon C. 2003. Role of a Multiple Bioherbicide System in the Integrated Management of Torpedograss; Florida Exotic Plant Pest Council Annual Meeting, June 5, 2003. Abstract.

Chandramohan, S., Charudattan, R., DeValerio, J.T., and Hanlon, C. 2003. Field trials of a bioherbicide system for integrated management of torpedograss. 7th International Conference on the Ecology and Management of Alien Plant Invasions, November 3-7, 2003, Ft. Lauderdale, FL. p. 16 (Abstr.).

Chandramohan, S., Charudattan, R., Yandoc, C.B., and Mills, A. 2003. Biological Control of Cogongrass with a Mixture of Fungal Pathogens. Abstract, The 18th Annual Regional Phosphate Conference, Oct 16-17, 2003, Lakeland, Florida, pp 39-40.

Chandramohan, S., Duchrow, M.J., Shine, J.M., Jr., Rosskopf, E.N., and Charudattan, R. 2003. Field-trials of a multiple-pathogen bioherbicide system with potential to manage guineagrass in Florida sugarcane. J. Am. Soc. Sugarcane Technol. 23: 101 (Abstr.).

Charudattan, R. 2003a. Biological control of weeds with pathogens used as bioherbicides. In: Pages 89-95, Proceedings of the First Latin-American Short Course on Biological Control of Weeds. June 24-28, 2002, Montelimar, Nicaragua. J. Medal, H. Norambuena, and D. Gandolfo, editors. University of Florida, Institute of Food and Agricultural Sciences, Gainesville. (In Spanish; translated by the editors).

Charudattan, R. 2003b. http://plantpath.ifas.ufl.edu/s1001/main.htm
Multistate Research Project S-1001, Jason Mesmer, webmaster

Charudattan, R., Elliott, M.S., DeValerio, J.T., Jennings, E.W., Speed, S., and Horrell, J. 2003. Techniques for field application of Tobacco mild green mosaic tobamovirus. Abstracts, Florida Weed Sci. Soc. Annu. Meet. Feb 25, 2003.

Charudattan, R. 2003. Biological Control of Tropical Soda Apple with Tobacco Mild Green Mosaic Tobamovirus: A Case of Augmentation Strategy. Florida Exotic Plant Pest Council Annual Meeting, June 5, 2003. Abstracts, Florida Weed Sci. Soc., Feb. 25-26, 2003, Apopka, FL.

Charudattan, R. 2003c. Bioherbicides: Their Role in Addressing Emerging Needs in Weed Control. 8th SICONBIOL, Sao Pedro, SP, Brazil, June 26, 2003. P 45.

Charudattan, R., Elliott, M., DeValerio, J., Hiebert, E., and Pettersen, M., 2003. Tobacco mild green mosaic virus: A virus-based bioherbicide. Bioherbicide Workshop, Feb. 1, 2003, Christchurch, New Zealand.

Charudattan, R., Elliott, M., DeValerio, J., Hiebert, E., and Pettersen, M., 2003. Biological control of the noxious weed Solanum viarum by tobacco mild green mosaic tobamovirus. Poster, Proceedings of the 8th International Congress of Plant Pathology, Christchurch, New Zealand, 2003.

Charudattan, R., Elliot, M.S., DeValerio, J., and Horrell J. 2003. Tobacco mild green tobamovirus, a bioherbicide for tropical soda apple (Solanum viarum): Host range and field application methods. Phytopathology 93 (Suppl.): S15 (Abstr.).

Coelho, L., Charudattan, R., Pitelli, R., den Breeyen, A. and Tessmann, D. 2003. Host specificity of Uredo eichhorniae and taxonomic relationship of rust fungi that infect plants in the Pontederiaceae. Poster, Proceedings of the 8th International Congress of Plant Pathology, Christchurch, New Zealand, 2003.

Elliott, M.S., Horrell, J., and Charudattan, R. 2003. An extensive host-range study of Tobacco mild green mosaic tobamovirus, a biological control agent for tropical soda apple, Solanum viarum Dunal. Abstracts, Florida Weed Sci. Soc., Feb. 25-26, 2003, Apopka, FL.

Elliott, M.S., DeValerio, J.T., Horrell, J., and Charudattan, R. 2003. Tobacco mild green mosaic tobamovirus: Host range and field efficacy as a biocontrol agent for tropical soda apple. Abstract, 8th Biennial Meeting of the Florida Phytopathological Society, May 5-7, 2003, Ft. Pierce, FL.

Horrell, J., Hiebert, E., and Charudattan, R. 2003. Host-virus interaction in the tropical soda apple-Tobacco mild green mosaic tobamovirus system: A model. Abstract, 8th Biennial Meeting of the Florida Phytopathological Society, May 5-7, 2003, Ft. Pierce, FL.

Kong, H., Blackwood, C., Buyer, J., Gulya, T. J., Jr., and Lydon, J. 2003. The genetic characterization of Pseudomonas syringae pv. tagetis based on the 16S-23S rDNA intergenic spacer regions. Weed Sci. Soc. Am. Abstracts. 43:29.

Kong, H., Patterson, C.D., Zhang, W., Takikawa, S., Suzuki, A., and Lydon, J. 2003. PCR protocol for the identification of Pseudomonas syringae pv. tagetis based on genes required for tagetitoxin production. Biol. Control (In press.)

Morales-Payan, J.P., Charudattan, R., DeValerio, J.T., and Stall, W.M. 2003. Surfactants affect the efficacy of the mycoherbicide Phomopsis amaranthicola to suppress Amaranths lividus in bell pepper (Capsicum annuum). Abstracts, South. Weed Sci. Soc. 2003.

Morales-Payan, J.P., Charudattan, R., DeValerio, J.T., and Stall, W.M. 2003. Phomopsis amaranthicola affects the interference of the weed Amaranthus dubius with eggplant and pepper. Abstract, 8th Biennial Meeting of the Florida Phytopathological Society, May 5-7, 2003, Ft. Pierce, FL.

Morales-Payan, J.P., Charudattan, R., DeValerio, J.T., and Stall, W.M. 2003. Effect of surfactants on the efficacy of the potential mycoherbicide Phomopsis amaranthicola to control Amaranthus lividus. Abstract, 8th Biennial Meeting of the Florida Phytopathol. Soc., May 5-7, 2003, Ft. Pierce, FL.

Morales-Payan, J.P., Charudattan, R., Stall, W.M. and DeValerio, J.T. 2003. Suppression of purple nutsedge (Cyperus rotundus) in bell pepper (Capsicum annuum) with the potential bioherbicide Dactylaria higginsii. Abstracts, South. Weed Sci. Soc. 2003.

Morales-Payan, J.P., Charudattan, R., Stall, W.M., DeValerio, J. 2003. Surfactants affect the efficacy of the potential mycoherbicide Phomopsis amaranthicola to control livid amaranth (Amaranthus lividus L.) in cilantro (Coriandrum sativum). Abstracts, pp245-246, APS Caribbean and Southern Divisions joint meeting, South Padre Island, Texas, April 6-11, 2003.

Morales-Payan, J.P., Charudattan, R., Stall, W.M., DeValerio, J. 2003. Effect of surfactants for Phomopsis amaranthicola, a potential mycoherbicide, on the competitiveness of livid amaranth (Amaranthus lividus L.) with bell pepper (Capsicum annuum). Abstracts, p246, APS Caribbean and Southern Divisions joint meeting, South Padre Island, Texas, April 6-11, 2003.

Morales-Payan, J.P., Charudattan, R., Stall, W.M., and DeValerio, J. 2003. Evaluation of surfactants for the potential bioherbicide Phomopsis amaranthicola to control livid amaranth (Amaranthus lividus L.) in basil (Ocimum basilicum). Proc. Southern Region Am. Soc. Hort. Sci. 2003 (Abstr.).

Morales-Payan, J.P., Charudattan, R., Stall, W.M., and DeValerio, J.T. 2003. Phomopsis amaranthicola as a postemergence bioherbicide in pepper (Capsicum annuum and C. frutescens) and eggplant (Solanum melongena). Abstracts of the XII Int. Symp. on Biol. Control of Weeds, April 28-May 2, 2003, Canberra, Australia (Abstr.).

Morales-Payan, J.P., Charudattan, R., Stall, W.M., and DeValerio, J.T. 2003. Dactylaria higginsii as a postemergence bioherbicide for purple nutsedge (Cyperus rotundus) in bell pepper (Capsicum annuum). Abstracts of the XII Int. Symp. on Biol. Control of Weeds, April 28-May 2, 2003, Canberra, Australia (Abstr.).

Morales-Payan, J.P., Charudattan, R., Stall, W.M., and DeValerio, J.T. 2003. Efficacy of Dactylaria higginsii to suppress purple nutsedge (Cyperus rotundus) in pepper (Capsicum annuum) is affected by some surfactants. Phytopathology 93 (Suppl.): S63 (Abstr.).

Morales-Payan, J. P., Stall, W. M., Charudattan, R., DeValerio, J. T. 2003. Competitiveness of livid amaranth (Amaranthus lividus) with basil (Ocimum basilicum) as affected by Phomopsis amaranthicola applied with different surfactants. HortScience 38(5):770.

Morales-Payan, J. P., Stall, W. M., Charudattan, R., DeValerio, J. T. 2003 Integrating plant growth regulators and a mycoherbicide to enhance the competitive ability of bell pepper with the weed livid amaranth. Plant Growth Regul. Soc. Am. 31(2):34.

Rosskopf, E.N., Yandoc, C.B., Kadir, J.B., and Charudattan, R. 2003. Evaluation of Dactylaria higginsii as a component in an integrated approach to pest management. Abstracts of the XII Int. Symp. on Biol. Control of Weeds, April 28-May 2, 2003, Canberra, Australia (Abstr.).

Rosskopf, E., Yandoc, C., DeValerio, J., Kadir Jr., and Charudattan, R. 2003 Evaluation of the bioherbicidal fungus Dactylaria higginsii as a component of an IPM approach to pest management in tomato. Phytopathology 93 (Suppl.): S75 (Abstr.).

Semidey, N., Charudattan, R., Morales-Payan, J.P., DeValerio, J.T. 2003 Response of Cyperus rotundus and Allium cepa to Dactylaria higginsii in Puerto Rico. XVI Congreso Latinoamericano de Malezas y el XXIV Congreso Nacional de la Asociación Mexicana de la Ciencia de la Maleza, Nov. 10-12, 2003, Manzanillo, Colima, Mexico.

Teuton T., Brecke B., Unruh J. B., Chandramohan S., Charudattan C., Stiles C., Miller G., Weinbrecht J., and Trenholm L. 2003 Tropical Signalgrass Management in Warm-Season Turf: Signal Pathogens. Florida Turf Digest, March/April 2003: 18-22.

Yandoc, C., Rosskopf, E., and Charudattan. R. 2003 Effect of selected pesticides on Dactylaria higginsii, a potential bioherbicide for purple nutsedge. Phytopathology 93 (Suppl.): S92 (Abstr.).

Zhang, W., Sulz, M., Mykitek, T., Li, X., Yanke, L. J., Kong, H., Buyer, J. S., and Lydon, J. 2003. Characterization of the bacterial strain from Canada that causes white-color disease in Canada thistle (Cirsium arvense (L.) Scop.). Weed Sci. Soc. Am. Abstracts 43:28.

Smith, D.A., and Hallett, S.G. 2003. Compatibility of the candidate bioherbicide Microsphaeropsis amaranthi with herbicides and adjuvants in tank mixture. Proceedings of the BCPC International Congress: Crop Science and Technology, Glasgow, UK, pp. 615-618.

Smith, D.A., and Hallett, S.G. 2003. Interactions between Microsphaeropsis amaranthi and glyphosate products for the control of waterhemp (Amaranthus tuberculatus). Proc. NCWSS annual meeting, Louisville, KY, 12/03.

Smith, D.A., and Hallett, S.G. 2003. Measurement of glyphosate resistance in waterhemp from across the Midwest. Proc. NCWSS annual meeting, Louisville, KY, 12/03.

Chandramohan, S. and Charudattan, R. 2003. A multiple-pathogen strategy for bioherbicidal control of several weeds. Biocontrol Sci. Technol. 13: 199-205.

Fennimore, S. A., and Jackson, L. E. 2003. Organic amendments and tillage effects on vegetable field weed emergence and seedbanks. Weed Technol. 17:42-50.

Fennimore, S.A., and Jackson, L.E. 2003. Effects of organic amendments and reduced tillage on weed emergence and seedbanks in a California vegetable field. Seedbanks: Dynamics, Determination and Management. Aspects of Appl. Biol. 69:107-112.

Jackson, L.E., Ramirez, I., Yokota, R., Fennimore, S.A., Koike, S.T. Henderson, D., Chaney, W.E., and Klonsky, K. 2003. Scientists, growers assess trade-offs in use of tillage, cover crops and compost. Calif. Agric. 57:48-54.

Morales-Payan, J.P., Stall, W.M., Shilling, D.G., Charudattan, R., Dusky, J.A., and Bewick, T.A. 2003. Above- and belowground interference of purple and yellow nutsedge (Cyperus spp.) with tomato. Weed Sci. 51:181-185.

Robinson, M. J., Lydon, J., and Murphy, C. A. Influence of Pseudomonas syringae pv. tagetis infection on sunflower leaf ascorbic acid relations. International Journal of Plant Sciences (in press).

Shabana, Y.M., Cuda, J.P., and Charudattan, R. 2003. Evaluation of Pathogens as Potential Biocontrol Agents of Hydrilla. J. Phytopathol. 151:1-7.

Shabana, Y.M., Cuda, J.P., and Charudattan, R. 2003. Combining plant pathogenic fungi and the leaf-mining fly, Hydrellia pakistanae, increases damage to hydrilla. J. Aquat. Plant Manage. 41:76-81.

Smith, DA, and SG Hallett. 2003. Compatibility of the candidate bioherbicide Microsphaeropsis amaranthi with herbicides and adjuvants in tank mixture. Proceedings of the BCPC International Congress: Crop Science and Technology, Glasgow, UK, pp. 615-618.

Smith, DA, and SG Hallett. 2003. Interactions between Microsphaeropsis amaranthi and glyphosate products for the control of waterhemp (Amaranthus tuberculatus). Proc. NCWSS annual meeting, Louisville, KY, 12/03.

Smith, DA, and SG Hallett. 2003. Measurement of glyphosate resistance in waterhemp from across the Midwest. Proc. NCWSS annual meeting, Louisville, KY, 12/03.