NC226: Development of Pest Management Strategies for Forage Alfalfa Persistence

(Multistate Research Project)

Status: Inactive/Terminating

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SAES-422 Reports

Annual/Termination Reports:

[05/03/2002] [05/12/2003] [03/10/2004]

Date of Annual Report: 05/03/2002

Report Information

Annual Meeting Dates: 02/26/2002 - 02/27/2002
Period the Report Covers: 10/01/2000 - 09/01/2001

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Brief Summary of Minutes

Minutes Attachment:

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Accomplishments

Objective 1. To Elucidate Mechanisms By Which Biotic Agents Interact With Abiotic Factors to Limit Stand Persistence of Forage Alfalfa Reports were received from three states for Objective 1. In Indiana, the persistence of alfalfa plants in response to varying levels of phosphorus and potassium was studied. Forage yield components have been measured during the 5 year study. The number of shoots per plant did not differ among the treatments, however, mass per shoot increased as phosphorus and potassium fertility improved. While potassium fertility did not affect plant persistence, increased phosphorus fertility reduced plant density. These plots will be re-sampled during 2002. In Michigan, patterns of soil properties of 5 production fields were related to patterns of potato leafhopper densities and alfalfa yield. Most correlations found during the first year of the study did not continue into the second year, however, alfalfa weevil and potato leafhopper were negatively correlated to plant height. Soils with higher organic matter are able to hold more moisture, which leads to taller plants, and greater insect pressure leads to stunted plants. In Ohio, a controlled environment study demonstrated the importance of potato leafhopper injury on root growth and TNC accumulation. In addition, Ohio reported on a field persistence study in which plant loss was greater at two spring-seeded sites compared to a fall-seeded site. Plants and soil were sampled to related plant mortality to root pathogens. Objective 2. To Enhance Alfalfa Persistence Through Improved Plant Resistance to Key Pests by Conventional Breeding and Genetic Engineering Approaches Six states reported studies under Objective 2. Four states reported on studies examining performance of potato leafhopper (PLH) resistant alfalfa cultivars, including Maryland, Michigan, Ohio, Minnesota, and Virginia. In field studies where yields were reported, resistant cultivars usually had higher forage yield than check cultivars when PLH populations were high and insecticide was not applied, but insecticide treatment usually increased yield of all varieties (only Virginia reported there were no significant differences in seasonal yield). In the seeding year, Ohio reported a significant reduction in PLH population growth in field plots of a resistant cultivar as compared with a susceptible cultivar, and insecticide treatment in the highly resistant cultivar was not economically justified in any of the three harvests but was justified in all three harvests of the susceptible cultivar. Maryland reported that equivalent exposure to PLH resulted in less impact on photosynthesis in resistant cultivars or clones as compared with susceptible cultivars or clones, suggesting that resistant germplasm exhibit tolerance to PLH. Michigan reported that during peak PLH density crude protein, maturity, and yields were greater in the resistant cultivars compared to the susceptible cultivars. The Ohio and Maryland data suggests the need for an adjustment in the economic action thresholds for resistant cultivars, based on lower PLH population growth rate and the tolerance mechanism. Maryland reported the presence of glandular-hairs in PLH-resistant cultivars does not appear to negatively affect the density of other sap feeders; the assemblages of other sap feeders appear largely random. Ohio and Virginia reported on infestations of alfalfa weevil in their studies evaluating PLH-resistant cultivars. The PLH-resistant cultivars showed no reduction in alfalfa weevil densities compared with standard cultivars, and in fact, Virginia noted an increase in alfalfa weevil density in one PLH-resistant cultivar at two locations. Ohio concluded that PLH-resistant cultivars showed no resistance to alfalfa weevil and alfalfa weevil damage. Three states reported on plant pathogen studies under Objective 2. Kentucky is conducting field screenings for Sclerotinia crown and stem rot and allowing private companies to make selections of surviving plants for their breeding programs. Ohio completed a greenhouse study investigating the interaction between PLH and Fusarium crown rot in alfalfa. The lack of any significant Fusarium x PLH x population interaction indicated that the nature of the effects of Fusarium were additive. Wyoming reported a survey of brown root rot (BRR) presence in alfalfa, a pathogenicity study of fungal isolates of BRR, and that progress is being made in breeding for BRR resistance in alfalfa. Objective 3. To Identify and Enhance Biological and Cultural Control Measures that Reduce Pest Populations and Improve Forage Alfalfa Persistence Three states reported any work in 2001 on biological and cultural control measures of pest populations. Both Illinois and Minnesota worked with alfalfa blotch leafminers (ABLM). In Illinois, ABLM was detected in 14 of 20 counties sampled north of Interstate Highway 80 in early May. Highest incidence found approximately one fly per sweep and 95% of stems displaying pinhole feeding. However, there were never more than 25% damaged trifoliolate leaves on a single stem. Samples collected in July displayed much lower adult populations, with only 4 of 68 counties having adults present and populations never exceeded 0.2 flys per sweep. A degree-day model has been developed and independently validated for ABLM; the phenological stage that ABLM populations were in during the two sampling periods will be determined retrospectively. In addition, parasitoids were collected from the sweep samples to determine whether biological control agents may have accompanied the invasion of ABLM in Illinois. No Dacnusa dryas have been found, and efforts to identify potential Chrysocharis liriomyzae are underway. In Minnesota, D. dryas has been released and has become established while C. liriomyzae has become established on its own. ABLM densities were so low in Minnesota in 2001 that surveys were not attempted. Virginia continues to compare densities of natural enemies of alfalfa weevil in treated and untreated glandular-haired and non-glandular-haired alfalfa at two locations. Bathyplectes anurus was the predominant parasitoid found at both locations, representing 81% and 91% of the total parasitoids reared from AW larvae at the Piedmont and southwestern sites, respectively. No differences in rates of parasitization or of fungal infection due to variety were found at either location. Glandular-hairs did not appear to impede overall parasitization of AW larvae by Bathyplectes spp. females. Objective 4. To Integrate Control Measures with Decision-Making Guidelines for Adoption by Specific States/Regions Two states provided reports on Objective 4. In Maryland, a web site, "Potato Leafhopper as a Pest of Alfalfa", is being developed in conjunction with leafhopper specialists. The site focuses on identification, biology, and management of the insect. This effort is intended as a model for the development of other pest web sites as part of NC-226. In Michigan, patterns of potato leafhopper densities were determined within two alfalfa fields to test for optimum scouting protocols. They determined that intensive sampling is not economically feasible, thus decision-making is best conducted on a whole field basis instead of on a treatment zone basis.

Publications

Publications: Indiana Noquet, C., J.C. Avice, A. Ourry, J.J. Volenec, S.M. Cunningham and J. Boucaud. 2001. Effects of environmental factors and endogenous signals on N uptake, N partitioning and taproot vegetative storage protein accumulation in Medicago sativa. Aust. J. Plant Physiol. 28:279-288. Cunningham, S.M., J.A. Gana, J.J. Volenec, and L.R. Teuber. 2001. Winter hardiness, root physiology, and gene expression in successive fall dormancy selections from ‘Mesilla‘ and ‘CUF 101‘ alfalfa. Crop Sci. 41:1091-1098. Shibli, R.A., D.M. Haagenson, S.M. Cunningham, W.K. Berg, and J.J. Volenec. 2001. Cryopreservation of alfalfa (Medicago sativa L.) cells by encapsulation-dehydration. Plant Cell Rpt. 20:445-450. Ourry, A., J.H. McDuff, J.J. Volenec, and J.P. Gaudillere. 2001. Nitrogen traffic during plant growth and development. p. 255-273. In P.J. Lea and J.F. Morot-Gaudry (eds.), Plant Nitrogen. Springer-Verlag, Berlin. Noquet, C., J.C. Avice, A. Ourry, J.J. Volenec, and J. Boucaud. 2001. Effects of photoperiod, low temperature, and N nutrition on VSP accumulation in taproots of alfalfa. Proc. Int. Grassl. Congress (in press). Gana, J.A., S.M. Cunningham, and J.J. Volenec. 2001. Allele-specific expression of a cold acclimation-responsive gene family in alfalfa buds and taproots. Abstr. #726. Amer. Soc. Plant Biol. Annual Meeting. http://www.rycomusa.com/aspp2001/public/P45/0694.html Haagenson, D.M., S.M. Cunningham, and J.J. Volenec. 2001. Water relations and dehydrin gene expression in roots of contrasting alfalfa cultivars during cold acclimation. Abstr. #387. Amer. Soc. Plant Biol. Annual Meeting. http://www.rycomusa.com/aspp2001/public/P33/0690.html. Berg, W. K., S.M. Cunningham, B.C. Joern, K.D. Johnson, and J.J. Volenec. 2001. Relationship of soil and tissue P and K concentrations on and alfalfa yield and persistence. Agron. Abstr. (CD-ROM) TSNo. s04-cunningham152819P. Berg W.K., S.M. Cunningham, B.C. Joern, K.D. Johnson, and J.J. Volenec. 2001. P and K effects on root physiology and persistence of field-grown alfalfa. Agron. Abstr. (CD-ROM) TSNo. c02-volenec153842-P. Maryland Fick, G.W., W.O. Lamp, and M. Collins. Integrated pest management in forages. In Forages: The Science of Grassland Agriculture, R.F. Barnes, D.A. Miller, and C.J. Nelson (eds.), 6th ed. Iowa State Univ. Press. (In press) Lamp, W.O., G.R. Nielsen, B. Quebedeaux, and Z. Wang. 2001. Potato leafhopper (Homoptera: Cicadellidae) injury disrupts basal transport of 14C-labelled photoassimilates in alfalfa. Journal of Economic Entomology 94: 93-97. Michigan Leep, R.H., J. R. Andresen and P. Jeranyama. 2001."Fall Dormancy and Snow Depth Effects on Winterkill of Alfalfa." Agron. J. 93, Pgs. 1142-1148. ASA, Madison, WI. Leep, R.H., Dietz, T. and Doo-Hong Min. 2001. Perennial Legume and Grass Forage Variety Selection in Michigan. Michigan State University. Available at http://www.msue.msu.edu/fis/extension_documents/extpub01.pdf Minnesota Heimpel, G.E. and F. Meloche. 2001. Biological control of alfalfa blotch leafminer (Diptera: Agromyzidae) in Ontario: status and ecology of parasitoids 20 years after introduction (Hymenoptera: Braconidae and Eulophidae). Great Lakes Entomologist (in press). Sheaffer, C.C., N.P. Martin, J.G. Jewett, J. Halgerson, R.D. Moon, and G.R. Cuomo. 2000. Sampling requirements for forage quality characterization of rectangular hay bales. Agron. Journal. 92:64-68. Pennsylvania None reported Ohio Venkatesh, R., R.M. Sulc, S.K. Harrison, J.D. Metzger, K.A. Diedrick, and R.B. Hammond. 2001. Volatile compounds from alfalfa clones differing in potato leafhopper resistance. Agronomy Abstracts. Barta, A.L., R.M. Sulc, M.J. Ogle, and R.B. Hammond. 2001. Abiotic stress effects on potato leafhopper injury in alfalfa. Agronomy Abstracts. Sulc, R.M., E.V. Santen, K.D. Johnson, C.C. Sheaffer, D.J. Undersander, L.W. Bledsoe, D.B. Hogg, and H.R. Willson. 2001. Glandular-haired cultivars reduce potato leafhopper damage in alfalfa. Agron. J. 93:1287-1296. Sulc, R.M., J.S. McCormick, L.H. Rhodes, D.J. Barker, and R.B. Hammond. 2001. Ohio forage performance trials. Horticulture & Crop Science Series 195. Ohio State University. Available at http://www.ag.ohio-state.edu/~perf/. Cox, J. J. 2001. Effects of potato leafhopper injury and Fusarium crown rot on three alfalfa populations. M. S. Thesis, The Ohio State University, Columbus. 119 pp. South Dakota None reported Wisconsin None reported Wyoming Hollingsworth, C.R., F.A. Gray, R.W. Groose and C.W. Mims. 2001. Morphological responses of Canadian and U.S.A. isolates of Phoma sclerotioides to different growth media, temperatures and light. MYCOTAXON 81:331-339 (In Press) Gray, F.A., C.R. Hollingsworth and D.W. Koch. 2001. Occurrence of brown root rot of alfalfa in the continental United States. Joint Meeting of the Canadian Phytopathological Society and the Pacific Division of the American Phytopathological Society. June 18-21, 2000. Victoria, B.C. Phytopathology 91, No. 6 (Supplement) S184. Hollingsworth, C.R., F.A. Gray, R.W. Groose, D.W. Koch and T.E. Heald. 2001. Development of a protocol for identifying alfalfa, Medicago sativa ssp. sativa reaction to infection by Phoma sclerotioides causal organism of brown root rot. Phytopathology 91, No. 6 (Supplement) S39. Larsen, R.C., G.J. Vandemark, M.A. Gritsenko, C.R. Hollingsworth, and F.A. Gray. 2001. PCR-based SCAR markers for the detection and identification of Phoma sclerotioides - the cause of brown root rot disease of alfalfa. Phytopathology 91, No. 6 (Supplement) S53. Larsen, R.C., G.J. Vandemark, F.A. Gray and M. Gritsenko. 2001. PCR-based markers for the identification of Phoma sclerotioides infecting alfalfa. Phytopathology 91, Vol. 6 (Supplement) S186. Gray, F.A., C.R. Hollingsworth, D.W. Koch and R.W. Groose. 2001. A preliminary test for characterizing alfalfa cultivars for brown root rot resistance. Presented at the Joint Western Society of Crop Science/Western Alfalfa Improvement Conference Meeting, Tucson, AZ, June 11-13, 2001. Virginia Kuhar, T. P., R. R. Youngman, and C. A. Laub. 2001. Alfalfa weevil (Coleoptera: Curculionidae) phenology with its host crop and parasitoids in Virginia. J. Entomol. Sci. 36: 352-365.

Impact Statements

1.To elucidate mechanisms by which biotic agents interact with abiotic factors to limit stand persistence of forage alfalfa
2.To enhance alfalfa persistence through improved plant resistance to key pests by conventional breeding and genetic engineering approaches
3.To identify and enhance biological and cultural control measures that reduce pest populations and improve forage alfalfa persistence
4.To integrate control measures with decision-making guidelines for adoption by specific states/regions.

Date of Annual Report: 05/12/2003

Report Information

Annual Meeting Dates: 02/25/2003 - 02/26/2003
Period the Report Covers: 10/01/2001 - 09/01/2002

Participants

Participants Attachment:

Attachment

Brief Summary of Minutes

Minutes Attachment:

Attachment

Accomplishments

Objective 1. To Elucidate Mechanisms By Which Biotic Agents Interact With Abiotic Factors to Limit Stand Persistence of Forage Alfalfa Results from Ohio and Indiana indicate that death of alfalfa plants is primarily occurring during the growing season instead of over winter. This is in sharp contrast to the generally accepted belief that winter killing is the primary reason alfalfa stands decline over time. Ohio data indicates that pathogenic fungi (Fusarium spp.) may contribute to stand decline in summer. Indiana data show that nutrient imbalance (high P levels without K fertilization) accelerates stand decline. Starch, protein and amino acid concentrations are lower in roots of plants grown in high-P soils without K fertilizer. Low levels of these root reserves may be contributing to poor alfalfa persistence. Objective 2. To Enhance Alfalfa Persistence Through Improved Plant Resistance to Key Pests by Conventional Breeding and Genetic Engineering Approaches A total of five states reported on studies examining the potential of plant resistance to key pests in alfalfa, including Maryland, Michigan, Minnesota, Ohio, Virginia, and Wyoming. The majority of the studies tested the efficacy of newer glandular-haired, potato leafhopper resistant alfalfa cultivars. Virginia, using the second-generation glandular-haired variety Pioneer 54H69, continued to observe no differences in PLH densities between the resistant variety and a susceptible cultivar. In contrast, other states reported clear-cut differences. Michigan continued with a variety trial that included resistant varieties and found two PLH-resistant lines with higher yields than the check under increased PLH populations. Ohio, in large plot studies using a recently released variety, Pioneer 54H91, found significant reductions in both PLH adult and nymph densities. They showed that insecticide treatment, while justified for a susceptible cultivar 7 of 8 summer harvests, was justified for the resistant cultivar only 3 of the 8 times. Maryland began field studies also using this newer line, 54H91, and found that during one harvest with heavier PLH pressure, that there was a significant reduction in yield with the susceptible cultivar compared with no yield loss in the resistant variety. Virginia also reported on infestations of alfalfa weevil in their plots with PLH-resistant cultivars. Variety had no effect on densities of alfalfa weevil. Overall, results from numerous locations are demonstrating the improvement in the PLH-resistant cultivars. Minnesota continued studies on the impact of possible resistant sources, including glandular-haired cultivars, on the alfalfa blotch leafminer, Agromyza frontella. They did not discern any significant differences in the percentage of stems with at least one trifoliolate damaged by the leafminer. They concluded that with the lack of resistance against the leafminer (and also poor insecticide performance), there is a need for greater work with beneficial parasitoids for a promising control strategy. Wyoming reported on resistance for plant diseases. They have continued to develop selection and breeding methods for increasing resistance to brown root rot, Phoma slerotioides. This effort has resulted in an increase in brown root rot resistance in half-sib family lines compared to their parent variety. Progress is also being made toward the development of a standard protocol for evaluating alfalfa lines for resistance to brown root rot. Ohio reported on a multi-state effort to evaluate performance of alfalfa varieties developed across six decades. Results suggest forage yield has increased over the past five decades, and that improvements in disease resistance are correlated with the higher yields and stand density as alfalfa stands age. Objective 3. To Identify and Enhance Biological and Cultural Control Measures that Reduce Pest Populations and Improve Forage Alfalfa Persistence Two states conducted research on biological and cultural control of insects in alfalfa during 2002. Virginia compared densities of natural enemies in treated and untreated glandular-haired and non-glandular-haired alfalfa at two sites. B. anurus represented 97% and 99% of the total parasitoids collected at the Piedmont and southwestern sites, respectively. Variety had no effect on rates of parasitization at either site nor did spray regime at the southwestern site despite reduced populations of AW larvae in treated plots. A sample date by spray regime interaction was found at the Piedmont site in 2002. However, the effect of spray regime on each sample date revealed no significant differences in rates of parasitization between spray regimes. Thus, glandular trichomes on 54H69 did not appear to impede overall biological control of AW larvae by Bathyplectes spp. females. Variety had no effect on rates of fungal infection by Z. phytonomi at the southwestern site. A sample date by variety interaction was significant for rates of fungal infection at the Piedmont site. However, the effect of variety on each sample date revealed no significant differences in rate of fungal infection between varieties. Minnesota scientists evaluated two European parasitoid species released in Ontario during the late 1970‘s to control alfalfa blotch leafminer, Agromyza frontella. In 1999, both D. dryas and C. liriomyzae were parasitizing first-generation A. frontella in Ontario. The combined parasitism rate for both species as revealed by larval dissections was 97.5% by the end of the first A. frontella generation. Of the adult parasitoids reared, 86% were D. dryas and 14% were C. liriomyzae. By the end of the first A. frontella generation, 86% of parasitized hosts contained at least one unencapsulated parasitoid and could therefore produce an adult parasitoid, and 12% of parasitized hosts escaped parasitism by containing only encapsulated parasitoids. The sex ratio of D. dryas was even at emergence, but strongly female-biased in sweep samples from the field. Egg loads of D. dryas females were all greater than zero and as high in the field as our highest laboratory estimates, suggesting that egg availability does not limit fitness under the conditions that we observed in the field. Objective 4. To Integrate Control Measures with Decision-Making Guidelines for Adoption by Specific States/Regions Two states provided reports on Objective 4. In Maryland, a web site, Potato Leafhopper as a Pest of Alfalfa, is being developed in conjunction with leafhopper specialists. The site focuses on identification, biology, and management of the insect. This effort is intended as a model for the development of other pest web sites as part of NC-226. In Michigan, patterns of potato leafhopper densities were determined within two alfalfa fields to test for optimum scouting protocols. They determined that intensive sampling is not economically feasible, thus decision-making is best conducted on a whole field basis instead of on a treatment zone basis. Usefulness of Findings The overall goal of the multistate project is to address a critical concern of farmers: the significant reduction in alfalfa stand life caused by pests and other factors. The lack of persistence significantly reduced profit associated with alfalfa, the principal forage component of a wide variety of agricultural production and conservation systems. In addition, the project plans to use the web site as a means to extend current information on the status of alfalfa pests and their management. Work Planned for Next Year Research will continue on each objective. Some of the original field studies are now focusing on the more critical final years during the lifespan of an alfalfa stand. An outline for a synthesis publication on integrating concepts of alfalfa persistence has been prepared, and work on this publication will continue during 2003. In addition, the website will be expanded to provide pest information beyond potato leafhopper.

Publications

Publications: Indiana Justes, E., P. Thiebeau, J-C. Avice, G. Lemaire, J.J. Volenec, and A. Ourry. 2002. Influence of summer sowing dates, N fertilization and irrigation on autumn VSP accumulation and dynamics of spring regrowth in alfalfa (Medicago sativa L.). J. Exp. Bot. 53:111-121. Volenec, J.J., S.M. Cunningham, D.M. Haagenson, W.K. Berg, B.C. Joern, and D.W. Wiersma. 2002. Physiological genetics of alfalfa improvement: past failures and future prospects. Field Crops Res. 75:97-110. Haagenson D.M., S.M. Cunningham, B.C. Joern and J.J. Volenec. 2003. Autumn defoliation effects on alfalfa winter survival, root physiology, and gene expression. Crop Sci. (in press). Cunningham S.M., P. Nadeau, Y. Castonguay, S. Leberge and J.J. Volenec. 2003. Raffinose and stachyose accumulation, galactinol synthase expression, and winter injury of contrasting Medicago sativa germplasms. Crop Sci. (in press). Haagenson D.M., S.M. Cunningham and J.J. Volenec. 2003. Root physiology of less fall dormant, winter hardy alfalfa selections. Crop Sci. (in press). Berg, W. K. , S. M. Cunningham, S. M. Brouder, B. C. Joern, KD Johnson and JJ Volenec. 2002. Phosphorus and potassium effects on alfalfa shoot regrowth and root physiology. American Society of Agronomy Annual Meeting. Indianapolis, IN. Agron. Abstr. C02-cunningham133504-poster. Berg, W. K. , S. M. Howard, S. M. Cunningham, S. M. Brouder, B.C. Joern, K.D. Johnson and J.J. Volenec. 2002. Phosphorus and potassium impact on alfalfa yield component responses and herbage nutrient concentrations. American Society of Agronomy Annual Meeting. Indianapolis, IN. Agron. Abstr. S04-cunningham092229-poster. Berg, W. K. , S. M. Cunningham, S. M. Howard, S. M. Brouder, B.C. Joern, K.D. Johnson and J.J. Volenec. 2002. How should you manage phosphorus and potassium fertility to enhance alfalfa yield and persistence? American Society of Agronomy Annual Meeting. Indianapolis, IN. Agron. Abstr. A09-cunningham100644-oral. Maryland Fick, G.W., W.O. Lamp, and M. Collins. 2003. Integrated pest management in forages. In Forages: The Science of Grassland Agriculture, R.F. Barnes, D.A. Miller, and C.J. Nelson (eds.), 6th ed. Iowa State Univ. Press. Michigan None reported. Minnesota Heimpel, G.E. & F. Meloche. 2001. Biological control of alfalfa blotch leafminer (Diptera: Agromyzidae) in Ontario: status and ecology of parasitoids 20 years after introduction (Hymenoptera: Braconidae and Eulophidae). Great Lakes Entomologist 34: 17-26. Ohio Barta, A. L., R.M. Sulc, R. M., M.J. Ogle, and R.B. Hammond. 2002. Interaction between flooding or drought stress and potato leafhopper injury in alfalfa. Online. Plant Health Progress doi:10.1094/PHP-2002-0502-01-RS. Barta, A.L., and R.M. Sulc. 2002. Interaction between waterlogging injury and irradiance level in alfalfa. Crop Sci. 42: 1529-1534. Nutter, F.W. Jr., J. Guan, A.R. Gotlieb, L.H. Rhodes, C.R. Grau, and R.M. Sulc. 2002. Quantifying alfalfa yield losses caused by foliar diseases in Iowa, Ohio, Wisconsin, and Vermont. Plant Dis. 86:269-277. Diedrick, K.A., R.M. Sulc, R.B. Hammond, and J.S. McCormick. 2002. Reduced insecticide rates and host plant resistance for controlling potato leafhopper in alfalfa. Agronomy Abstracts. Diedrick, K.A., R.M. Sulc, R.B. Hammond, an A.L. Barta. 2002. Growth stage effects on alfalfa response to potato leafhopper injury. Agronomy Abstracts. Barta,A.L., R.M. Sulc, and M.J. Ogle. 2002. Alfalfa plant loss in relation to time after establishment and environment. Agronomy Abstracts. Lamb, J.F.S., C.C. Sheaffer, P.C. St. Amand, E.C. Brummer, L.H. Rhodes, M. Sulc, and D.J. Undersander. 2002. Comparing yield and forage quality of alfalfa cultivars released from the 1940‘s through the 1990‘s. In Proc. 38th North American Alfalfa Improvement Conf., Sacramento, CA, WI. 27-31 July 2002. Available online at http://www.naaic.org/Meetings/National/2002meeting/2002NAAICAbstracts.html Ariss, J.J., L. H. Rhodes, R. M. Sulc, and R. B. Hammond. 2002. Effects of potato leafhopper injury and Fusarium crown rot on three alfalfa populations. In Proc. 38th North American Alfalfa Improvement Conf., Sacramento, CA, WI. 27-31 July 2002. Available online at http://www.naaic.org/Meetings/National/2002meeting/2002NAAICAbstracts.html McCormick, J.S., R.M. Sulc, L.H. Rhodes, D.J. Barker, and R.B. Hammond. 2002. Ohio forage performance trials, 2002. Horticulture & Crop Science Series 195. Ohio State University. _ pp. Available at www.oardc.ohio-state.edu/forage2002. South Dakota None reported. Wisconsin None reported. Wyoming Gray, F. A., C. R. Hollingsworth and D. W. Koch. 2002. Biology and management of stand-decline diseases of irrigated alfalfa in the western U.S., pp 47-52. In, Proceedings of the Western Alfalfa & Forage Conference, 12-13 December. Reno, NV. Larsen, R. C., C. R. Hollingsworth, G. J. Vandemark, M. A. Gritsenko and F. A. Gray. 2002. A rapid method using PCR-based SCAR markers for the detection and identification of Phoma sclerotioides, the cause of brown root rot disease of alfalfa. Plant Disease 86:928-932. Gray, F. A. and G. D. Griffin. 2002. Plant parasitic nematodes of alfalfa in the United States. 2002. Proceedings of the 28th North American Alfalfa Improvement Conference (In Press). Hollingsworth, C. R., F. A. Gray, D. W. Koch, R. W. Groose and T. E. Heald. 2002. Distribution and incidence of brown root rot (Phoma sclerotioides) of alfalfa in Wyoming U.S.A. Canadian Journal of Plant Pathology (accepted). Gray, F. A., C. R. Hollingsworth and R. W. Groose. 2002. Brown root rot resistance, Phoma sclerotioides (G. Preuss ex Sacc.) In, Standard Tests to Characterize Alfalfa Cultivars. North American Alfalfa Improvement Conference publication. C. C. Fox, R. Berberet, F. A. Gray, C. R. Grau, D. L. Jessen and M. A. Peterson, eds. 1991, 3rd Edition. (accepted). Virginia Dellinger, T. A., R. R. Youngman, and C. A. Laub. 2003. Recovery of Oomyzus incertus (Hymenoptera: Eulophidae), a larval parasitoid of Hypera postica (Coleoptera: Curculionidae), in Virginia. J. Entomol. Sci. 38: 141-142.

Impact Statements

Date of Annual Report: 03/10/2004

Report Information

Annual Meeting Dates: 02/24/2004 - 02/25/2004
Period the Report Covers: 10/01/2002 - 09/01/2003

Participants

Jennifer Ariss Ohio State University
Department of Plant Pathology
Columbus, OH 43210 614-688-5395 ariss.6@osu.edu ;;

Wayne Bailey University of Missouri
1-87 Agriculture Building
Columbia, MO 65211 573-882-2838 baileyw@missouri.edu ;;

Fred A. Gray University of Wyoming
Department of Plant Sciences
Laramie, WY 82071 307-766-3995 fagray@uwyo.edu ;

Robin Groose University of Wyoming
Department of Plant Sciences
Laramie, WY 82071 307-766-3151 groose@uwyo.edu ;;

Ron Hammond OARDC- Ohio State University
Entomology Department
Wooster, OH 44691 330-263-3727 hammond.5@osu.edu ;;

Leon Higley University of Nebraska
202 PI Building
Lincoln, NE 68583-0816 402-472-8689 ;;

Tom Hunt University of Nebraska
Haskell Ag. Lab
Concord, NE 68728 402-584-2863 thunt2@unl.edu ;;

Monte Johnson Waterfront Centre
800 9th Street, S.W.
Washington, DC 20024 202-401-1108 mpjohnson@csrees.usda.gov ;;

Bill Lamp University of Maryland
Department of Entomology
4112 Plant Sciences Building
College Park, MD 20742 301-405-3959 lamp@umd.edu ;;

Phil Larsen University of Minnesota
College of Agriculture, Food and
Environmental Sciences
St. Paul, MN 55108 612-625-1999 phill@umn.edu ;;

Lanny Rhodes Ohio State University
Department of Plant Pathology
Columbus, OH 43210 614-292-7717 ;;

Jeff Volenec Purdue University
Department of Agronomy
915 W. State Street
West Lafayette, IN 47907-2054 765-494-8071 jvolenec@purdue.edu;;

Brief Summary of Minutes

NC-226 Meeting Minutes

Development of Pest Management Strategies for Forage Alfalfa Persistence

Embassy Suites

Lincoln, Nebraska

February 24-25, 2004

Tuesday, February 24

At 1:05 pm, Leon Higley commenced the meeting, with 10 in attendance (see separate list of attendees; Robin Groose and Fred Gray arrived within 30 minutes and Wayne Bailey arrived Wednesday morning). Leon apologized that because of urgent business, he would need to leave the meeting early that day, and part of the next morning. All members present introduced themselves.

At 1:10, Phil Larsen provided comments as the Administrative Advisor. Because our request last year for an extension of NC-226 was declined, he suggested that we request the formation of an NCT committee, to serve the function of exploration of a new committee with a different title and set of objectives. He stated that the procedure was relatively simple and that we had plenty of time. A letter should be written by at least two members of NC-226 with approval from two experiment stations to the North Central Research Association (NCRA). The request will be considered by the Multistate Committee, a subset of NCRA, who will then make a recommendation to NCRA at the July meeting asked, with a starting date of October 1 (just after the termination of NC-226). An NCT committee would last 1-2 years, and have three objectives: 1) study and recommend a new project (or not), 2) prepare justification and scope for a new project, and 3) prepare the multistate project outline. Ron Hammond asked if an NCR committee could be the recommendation. Phil answered that it could, and that an NCR would serve as an information exchange committee, perhaps to develop a specific publication. Bill Lamp asked if a list of participants for the NCT committee is needed. Phil answered that no, only 2 or more individuals with approval of two experiment stations. When asked about funding for travel to NCT meetings, Phil answered that usually funds are provided.

Phil added that changes in the naming of committees are being considered, including NCR to NCIEG (North Central Information Exchange Group) and NCT to NCDC (North Central Development Committee). Finally, Phil stated that as of July he will be going on phased retirement, and this would be the last meeting with this group.

At 1:35, Monte Johnson provided comments as the USDA Representative. This is Monte?s second year on NC-226. He provided and reviewed a packet of materials, including the National Animal and Plant Diagnostic Laboratory Networks, PSEP Newsletter, Land Grant Institutions, IPM Programs, and Budget Proposal. He specifically mentioned that invasive species is a grant opportunity, and there was discussion of the other IPM grant programs, including Crops At Risk (CAR) to help support the efforts of a new committee.

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Bill Lamp, as Secretary for the meeting, stated that reports and publication lists can still be submitted to him for inclusion in the NC-226 report. Send them to lamp@umd.edu.

Leon then initiated a discussion of possible directions for a new project. Dates were discussed for submission (see end of minutes for final decision). Each state stated how they feel about a new project.

Ohio (Ron Hammond and Lanny Rhodes) stated that forage work is decreasing, but the value of this project has been the multidisciplinary nature of the work. Collaborative research is therefore needed to address the problems on the 26 million acres of alfalfa being grown nationwide. Funding would be needed. Changes are underway at Universities away from forage research.

Wyoming (Fred Gray) agreed that money would be necessary for their participation, but pests are important in the persistence of forage stands.

Nebraska (Leon Higley and Tom Hunt) stated that applied answers to growers questions are needed in alfalfa pest management. However, Leon stated that his lab will be focusing on larger picture questions on insect feeding injury and plant physiology. Alfalfa would be a good system, in part, because of the multiple species of aphids that attack the crop. The theme of this work is stress physiology.

Phil, who had left to make a phone call, reported on specific procedures for submitting a new multistate proposal. (This information is reported at end of minutes as part of final discussions.)

Indiana (Jeff Volenec) plans to continue its forage work, including hardiness and survival, genetic and biochemical aspects of persistence, fertility effects, and functional genomics. Basically, Jeff reported a need to understand the forage plant.

Maryland (Bill Lamp) reported that his lab is going different directions, but would be interested in pursuing novel aspects of plant physiological, biochemical, and gene expression changes associated with potato leafhopper.

After a brief break, Jeff began reports from each state on research during 2003. Their comprehensive study of P and K management continues, finally resulting in the death of alfalfa plots that were planted in 1997. Persistence appears to need both P and K in balance, and applications of P alone caused death of plants. Mass per shoot appears to be best correlated with yield among the yield components, suggesting that rapid regrowth after harvest permits higher yields. Shoots per area became important as a factor only as of 2003. Plants are dying in summer, not winter, although the specific cause of death is elusive. Root constituent changes in part respond to K. He reported on some preliminary work on gene expression, suggesting that stressed plants have more variation in RNA.

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Bill Lamp then reported on two studies related to persistence of alfalfa and potato leafhopper injury. In the first, potato leafhopper injury during the establishment year after spring-seeding did not affect yield components on the first harvest of the second year. This suggests that leafhopper injury during establishment does not affect persistence. In the second study, yield components of resistant and susceptible cultivars are being compared. During the establishment year, no differences were detected in plant density, but during the summer of the second year, there was greater mortality of plants in the susceptible cultivar. This study is continuing during 2004.

The meeting was adjourned at 5:10 pm.

Wednesday, February 26

The meeting commenced at 8:05 am. Robin Groose gave a presentation on the genetic changes in alfalfa over time, especially with regard to brown root rot resistance. Using information from Russelle (2001), published in American Scientist, Robin described the historical sources of alfalfa germplasms. He provided data to suggest that alfalfa yields are increasing with time, although they appear more variable in recent years. He also cited Volenec et al. (2002) which showed no relationship between year of release and first harvest, however the relationship between year of release and fourth harvest has been increasing in recent years. He further suggested that the lack of response of yield to the development of multiple pest resistance germplasm could be from the ?Red Queen Hypothesis? (with regard to Alice running faster and faster just to stay in place). Based upon his and Fred Gray?s work with brown root rot, there is evidence of resistance in some old varieties such as Ranger and OK49, which have survived in abandoned plots since 1992. He created a new cultivar with resistance, using the set theory for cultivar synthesis.

Fred Gray then described the development of a protocol for screening brown root rot (BRR). Seeds are planted in the summer, inoculated in the fall, and evaluated in the spring. He used ATCC and #2 as standard isolates for comparison to new germplasms. He added that the survey of BRR now can be done by soil testing.

Leon Higley then described research in his lab on aphid systems of injury. He suggests that there is a common mechanism of injury in spite of varying toxins, etc., that is associated with the blocking of starch loading in the mesophyll. If this mechanism is found to be true, then each aphid species is not unique in their injury, and screening for resistance should not be on the basis of mesophyll structure and function. Rather, the impact of injury on primary metabolism and synthesis should be determined. Furthermore, time course studies should be started soon after injury because of rapidly cascading effects.

Lanny Rhodes then introduced a discussion of the ?Decades Trial?, involving a number of states and the selection of old and new varieties for concurrent comparisons. He and Jennifer Ariss are especially interested in comparing disease resistance. Jennifer then continued by describing her research, which overall seems to suggest that the

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modern varieties had less disease (e.g., anthracnose, fusarium wilt) than older varieties, although some older varieties (e.g. Ranger) do show resistance. In addition, the more recent releases generally show greater ground cover as of fall 2003, more total yield from 99-03, and fewer diseased stems based on number per plot. She is now testing disease resistance versus persistence by selection. She cross-pollinated six varieties to produce new clones, and these clones will be tested against standard protocols.

Jeff Volenec asked how they might explain the performance of the old variety, Vernal, which fell in the middle of the set of those tested in spite of low ratings for disease resistance. He asked if there has been actual improvement, and suggested that rather than selecting for multiple disease resistance, there should be selection for yield and persistence.

Wayne Bailey described two studies in progress at Missouri. One is being conducted with Jerry Nelson on leafhopper tolerance and alfalfa persistence as affected by potassium fertility. He said they have found no yield drag associated with the new glandular-haired varieties. Potassium effects are starting now in year two of the study. The second study with Dr. Blevins is investigating the relationship between boron fertility and alfalfa persistence.

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t 10:05, a brief break was taken.

The remainder of the morning was devoted to discussion of a future project. Bill Lamp started by displaying key words/phrases, then adding as the discussion continued:

I. Cropping Systems

a. Alfalfa

b. Forage legumes (This was decided as our focus.)

c. Other legumes

d. Forages ? grasses, legumes

e. Dairy industry

II. Changing Agronomic Practices and Environments

a. Organic production

b. Round-up Ready cultivars

c. Nontarget organisms

d. Fertility effects

e. Pesticides

f. Irrigation

g. Rotation

III. Topics related to persistence

a. Plant death

b. Stand persistence

c. Root constituents

d. Protein dynamics

e. Gene expression

f. Root-shoot interactions

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g. Pest interactions

IV. Issues

a. Molecular and physiological changes

b. Functional genomics

c. Global warming and changing pest complex

d. Invasive plant and insect pest species

e. Nitrogen fixation

f. Complex interactions

g. Abiotic and biotic stresses/tolerance

h. Mechanisms

i. Functional biology

j. Sustainability

V. Project features

a. Multidisciplinary

b. Private industry involvement

c. Both basic and applied foci

d. Standard protocol across states (not needed)

e. Standardized plant testing

f. Shared collaboration on specific research

g. Funding, e.g. SARE, Organic Transition

h. National in scope (not just NC region)

i. Application of new skills and tools

We developed a tentative title for the new project of, ?Impact of Changing Practices on Stress Tolerance within Forage Legumes.? As determined before, Jeff Volenec will host the next meeting in Indianapolis in February 2005. The dates for project development are as follows:

1. July, 2004: Request NCT committee formation to last from Oct. 1, 2004 to Sept. 30, 2006 from NCRA.

2. Fall, 2004: Prepare proposal to fund workshop to develop details of issues, to be held October, 2005.

3. February, 2005: Initial NCT meeting to finalize title and objectives, scope, justification, and general methods; plans for workshop (if funded).

4. October, 2005: Hold workshop, if funded.

5. December, 2005: Submit proposal to NCRA, to be reviewed by NCA committee during January, 2006.

6. March, 2006: Proposal reviewed by NCRA.

7. October, 2006: Start of new multistate project.

Leon Higley concluded the meeting at 11:30. The group thanked Leon for his hospitality. Also, they thanked Phil Larsen for his contributions to the project.

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Accomplishments

Accomplishments and Impacts: Objective 1. To Elucidate Mechanisms By Which Biotic Agents Interact With Abiotic Factors to Limit Stand Persistence of Forage Alfalfa Results from Ohio and Indiana continue to indicate that death of alfalfa plants is primarily occurring during the growing season instead of over winter. This is in sharp contrast to the generally accepted belief that winter killing is the primary reason alfalfa stands decline over time. Large variation in plant size exists between seeding date and fertility treatments, and this results in the few large plants present in plot contributing disproportionately to total forage yield. Missouri data indicate that plant losses in summer are exacerbated by potato leafhopper infestation irrespective of potassium (K) fertilizer application. Application of phosphate (P) without K fertilizer resulted in complete stand losses in Indiana. Starch, protein and amino acid concentrations are lower in roots of plants grown in high-P soils without K fertilizer. Low levels of these root reserves may be contributing to poor alfalfa persistence. Wyoming data indicates that brown rot fungi (Phoma sclerotioides ) contribute to stand decline, and that winter stress is a necessary component of disease development. Objective 2. To Enhance Alfalfa Persistence Through Improved Plant Resistance to Key Pests by Conventional Breeding and Genetic Engineering Approaches A total of five states reported on studies examining the potential of plant resistance to key pests in alfalfa. Maryland conducted studies to test for effects of leafhopper injury on alfalfa establishment. Experiments were established in two fields. Results indicated no significant effect of injury on the yield components of alfalfa cultivars, suggesting that alfalfa is tolerant of long-term leafhopper injury during the establishment year, with no long-term effects on persistence in subsequent years. The second year of a field study quantified and compared the yield components of a locally adapted, susceptible alfalfa cultivar and a leafhopper resistant cultivar. Results indicate a declining plant density especially in the susceptible cultivar during 2003 in comparison to the susceptible cultivar. Michigan is conducting studies to evaluate new commercial resistant varieties for PLH damage (hopper burn) and alfalfa yield. In the trial planted in 2000 all resistant varieties were not significantly different in yield or hopper burn from the non-resistant varieties for cut 2 but were significantly lower in hopper burn than the non resistant varieties in cut 3. Resistant varieties were significantly higher yielding and lower in hopper burn than non-resistant varieties in the trial established in 2001 Minnesota conducted studies to assess the potential for tolerance or resistance among alfalfa cultivars to the alfalfa leafminer. They found no significant differences in leaf mining damage to trifoliolates among the 86 entries, or among glandular-haired and traditional commercial varieties. The low levels of resistance to A. frontella among glandular-haired commercial alfalfa varieties and numerous experimental entries of M. sativa germplasm, confirms the need for alternative A. frontella management strategies such as biological control and possible manipulation of harvest schedules. Ohio continued field plot trials in 2003 in west-central Ohio to evaluate yield and persistence of glandular-haired alfalfa varieties with resistance to potato leafhopper. Across trials under heavy PLH pressure, insecticide treatment was economically justified for the susceptible cultivar in 11 of the 14 summer harvests but in only 6 of the 14 harvests for the resistant cultivar. These results demonstrate the improvement in PLH-resistance with recently developed glandular-haired cultivars. Virginia conducted a study to compare pest densities of alfalfa weevil and potato leafhopper in treated and untreated glandular-haired and non-glandular haired alfalfa. Differences in yields and forage quality between varieties were rarely significant and often inconsistent. Based on our study, we recommend that growers considering investing in glandular-haired alfalfa should wait until seed companies substantially improve the level of PLH resistance in these varieties, which will probably be achieved within a few years, as ?third-generation? varieties are commercially available now. Wyoming reported on resistance for plant diseases. They continue towards the development of a brown root rot resistant variety, as well as, a standard protocol for alfalfa breeders for use in evaluating alfalfa lines for reaction to this root rot pathogen. The standard protocol for brown root rot for the North American Alfalfa Improvement Conference publication, ?Standard Tests to Characterize Alfalfa Cultivars," is nearing completion. Progress is being made in the field evaluation of the brown root rot resistant cultivar developed in Wyoming. Objective 3. To Identify and Enhance Biological and Cultural Control Measures that Reduce Pest Populations and Improve Forage Alfalfa Persistence Illinois provided the only report for this objective. A survey of the alfalfa blotch leafminer and its natural enemies was completed. They concluded that the leafminer is not a serious threat to alfalfa production at this time although its major parasitoids were not detected. Objective 4. To Integrate Control Measures with Decision-Making Guidelines for Adoption by Specific States/Regions

Publications

Publications: Illinois Lundgren, J. G., K. L. Steffey and R. N. Wiedenmann. 2004. The distribution and prevalence of the alfalfa blotch leafminer (Diptera: Agromyzidae) in Illinois. Great Lakes Entomologist, in press. Indiana Haagenson D.M., S.M. Cunningham, B.C. Joern and J.J. Volenec. 2003. Autumn defoliation effects on alfalfa winter survival, root physiology, and gene expression. Crop Sci. 43:1340-1348. Cunningham S.M., P. Nadeau, Y. Castonguay, S. Leberge and J.J. Volenec. 2003. Raffinose and stachyose accumulation, galactinol synthase expression, and winter injury of contrasting Medicago sativa germplasms. Crop Sci. 43:562-570. Haagenson D.M., S.M. Cunningham and J.J. Volenec. 2003. Root physiology of less fall dormant, winter hardy alfalfa selections. Crop Sci. 43:1441-1447. Kalengamaliro N.E., S.M. Cunningham and J.J. Volenec. 2003. Growth, sugar accumulation, and dark respiration of suspension cell cultures derived from contrasting alfalfa cultivars. Plant Cell Tiss. Organ Cult. 72:163-171. Meuriot, F., J.-C. Avice, M.-L. Decau, J.-C. Simon, P. Laine, J.J. Volenec, and A. Ourry. 2003. Accumulation of N reserves and vegetative storage protein (VSP) in taproots of non-nodulated alfalfa (Medicago sativa L.) are affected by mineral N availability. Plant Sci. 165:709-718. Meuriot, F., C. Noquet, J.-C. Avice, J.J. Volenec, S.M. Cunningham, T.G. Sors, S. Caillot, and A. Ourry. 2003. MeJA reduces N uptake, changes N partitioning, stimulates VSP storage in taproots of Medicago sativa L. and induces expression of a 32 kDa genes, a VSP with chitinase activity. Physiol. Plantarum 120:113-123. Noquet, C., F. Meuriot, J.-C. Avice, A. Ourry, S.M. Cunningham, and J.J. Volenec. 2003. Short-day photoperiod induced changes in N uptake, N partitioning and accumulation of vegetative storage proteins in two Medicago sativa L. cultivars. Func. Plant Biol. 30:853-8. Berg, W.K., S.M. Cunningham, S.M. Brouder, B.C. Joern, K.D. Johnson, and J.J. Volenec. 2003. Phosphorus and potassium effects on alfalfa yield components, physiology, and stress tolerance. Amer. Soc. Agron. Meeting, Denver, CO. Berg W.K., S.M. Brouder, B.C. Joern, K.D. Johnson, and J.J. Volenec. 2003. Enhancing alfalfa production through improved potassium management. Better Crops. 87:8-11. Berg W.K., S.M. Brouder, B.C. Joern, K.D. Johnson, and J.J. Volenec. 2003. Improved phosphorus management enhances alfalfa production. Better Crops. 87:20-23. Berg, W.K., S.M. Cunningham, S.M. Brouder, B.C. Joern, K.D. Johnson, and J.J. Volenec. 2003. The impact of phosphorus and potassium nutrition on alfalfa root carbon and nitrogen pools following defoliation. Agron. Abstr.: C02-berg700438-poster. Berg, W.K., S.M. Cunningham, S.M. Brouder, B.C. Joern, K.D. Johnson, and J.J. Volenec. 2003. Phosphorus and potassium effects on alfalfa yield components, physiology, and stress tolerance. Agron. Abstr.: A09-berg559158-oral. Howard, S.M., W.K. Berg, S.M. Cunningham, S.M. Brouder, B.C. Joern, K.D. Johnson, and J.J. Volenec. 2003. Phosphorus and potassium fertilizer effects on soil nutrient concentration, and their impact on alfalfa yield components. Agron. Abstr.: S04-howard133968-poster. Al-Hadid, K., S.M. Cunningham, and J.J. Volenec. 2003. Characterization of defoliation-responsive genes in Medicago sativa. Agron. Abstr.: C02-al-hadid977857-poster. Milton, A., T. Henderson, S.M. Cunningham, J.J. Volenec, and J.A. Gana. 2003. Allele structure of the ROOTCAR1 locus in populations of diploid and tetraploid alfalfa (Medicago sativa L.). Annu. Meeting of the Amer. Soc. Plant Biol. Honolulu, HI., Abstr. No. 211. Cunningham, S.M., W.K. Berg, S.M. Brouder, B.C. Joern, K.D. Johnson, K. Dalton and J.J. Volenec. 2003. Phosphorus and potassium effects on alfalfa (Medicago sativa L.) root physiology during post-defoliation shoot regrowth. Annu. Meeting Amer. Soc. Plant Biol. Honolulu, HI., Abstr. No. 433. Volenec, J.J., S.F. Abu Qamar, and S.M. Cunningham. 2003. Phosphate nutrition effects on growth, phosphate transporter expression, and physiology of alfalfa (Medicago sativa L.). Annu. Meeting Amer. Soc. Plant Biol. Honolulu, HI., Abstr. No. 434. Maryland Lamp, W.O. 2003. Persistence of Alfalfa as Impacted by Insect Pests. University of Maryland Integrated Pest Management 2002 Progress Report. Lamp, W., J.J. Volenec, W.K. Berg, A.L. Barta, R.B. Hammond, L.H. Rhodes, R.M. Sulc, J. Ariss, R. Leep, P. Vincelli, T. Denlinger, C. Laub, and R. Youngman. 2003. Development of pest management strategies for forage alfalfa persistence. Proceedings of the Fourth National Integrated Pest Management Symposium. Indianapolis, IN. April 8-10, 2003. Michigan Leep, R., Dietz, T., and Min, D. 2003. Alfalfa Variety Trial Results. http://www.msue.msu.edu/fis/ Lamp, W., Volenc, J., Berg, W. K., Barta, A. L., Hammond, R. B., Rhodes, L. H., Sulc, R. M., Ariss, J., Leep, R., Vincelli, P., Denlinger, T., Laub, C., and Youngman, R. 2003. Development of Pest Management Strategies for Forage Alfalfa Persistence. Proceedings of the Fourth National Integrated Pest Management Symposium. Indianapolis, IN. April 8-10, 2003. Caddel, J., Undersander, D., Anderson, B., Brummer, E. C., Hansen, J., Joos, D., Johnson, K., Kallenbach, R., Leep, R., Meyer, D., Owens, V., Roozeman, K., Sheaffer, C., Spitalieri, R., Sulc, R. M., and Todd, R. 2003. Reporting CAIC Variety Tests in Crop Management on the Web. Proceedings of Central Alfalfa Improvement Virtual Conf. 21-22 July 2003. Minnesota Heimpel, G.E. & F. Meloche. 2001. Biological control of alfalfa blotch leafminer (Diptera: Agromyzidae) in Ontario: status and ecology of parasitoids 20 years after introduction (Hymenoptera: Braconidae and Eulophidae). Great Lakes Entomol. 34: 17-26. (published in 2003). R.C. Venette, W. D. Hutchison, E.C. Burkness and C.C. Sheaffer. Evaluation of experimental and glandular-haired alfalfa cultivars for tolerance to alfalfa blotch leafminer (Diptera: Agromyzidae) in Minnesota. Great Lakes Entomol. (submitted, 12/03). Hutchison, W.D., E. Cullen. 2003. Cowpea Aphids on Alfalfa in Wisconsin and Minnesota. MN Vegetable IPM Newsletter. VegEdge: 5(6): 2 pp. On-line: http://www.vegedge.umn.edu/mnvegnew/vol5/808cow.htm Hutchison, W.D., E. Burkness, R. Koch, S. Wold, K. Bennett. 2003. Spring Insect Updates -Potato Leafhopper. MN Vegetable IPM Newsletter. VegEdge: 5(1): 2 pp.; http://www.vegedge.umn.edu/mnvegnew/vol5/526mag.htm Nebraska Madsen, R. A., T. E. Hunt, and L. G. Higley. 2004. Simulated clover leaf weevil injury and alfalfa yield and quality. Agron. J. 96: 224-228. Ohio Sulc, R.M., R.B. Hammond, L.H. Rhodes, and H. Willson. 2003. Glandular-haired alfalfa: a new integrated pest management tool. p. 22-23. In NC IPM for our environment, for our future, NC Region IPM Grants Program 1998-2000. Sulc, R.M., J.S. McCormick, L.H. Rhodes, D.J. Barker, and R.B. Hammond. 2003. Ohio forage performance trials, 2003. Horticulture and Crop Science Series 195. Ohio State Univ. Available at http://www.ag.ohio-state.edu/~perf/. Sulc, R.M., K.D. Johnson, C.C. Sheaffer, D.J. Undersander, and E.V. Santen. 2004. Forage quality of potato leafhopper resistant and susceptible alfalfa cultivars. Agron. J. (in press). Lamb, J.S., C.C. Sheaffer, E.C. Brummer, L.H. Rhodes, R.M. Sulc, and D.J. Undersander. 2003. Comparing forage yield and quality of alfalfa cultivars released from the 1940‘‘s through the 1990‘‘s. Abstract no. C06-lamb771003-oral, Agronomy Abstracts. [CD-ROM computer file]. ASA, Madison, WI. Lamp, W., J.J. Volenec, W.K. Berg, A.L. Barta, R.B. Hammond, L.H. Rhodes, R.M. Sulc, J. Ariss, R. Leep, P. Vincelli, T. Denlinger, C. Laub, and R. Youngman. 2003. Development of pest management strategies for forage alfalfa persistence. Proceedings of the Fourth National Integrated Pest Management Symposium. Indianapolis, IN. April 8-10, 2003. Caddel, J., D. Undersander, B. Anderson, E.C. Brummer, J. Hansen, D. Joos, K.D. Johnson, R. Kallenbach, R. Leep, D. Meyer, V. Owens, K. Roozeman, C.C. Sheaffer, R. Spitalieri, R.M. Sulc, and R. Todd. 2003. Reporting CAIC Variety Tests in Crop Management on the Web. Proceedings of Central Alfalfa Improvement Virtual Conf. 21-22 July 2003. Sulc, R.M., E. Santen, K.D. Johnson, C.C. Sheaffer, and D. Undersander. 2003. Forage quality of glandular-haired and standard alfalfa cultivars. p. 1 In Forage Progress Vol. 1, April 2003. American Forage & Grassland Council, Geogetown, TX. Available online at http://www.afgc.org/afgcforageprogressapril2003.pdf. Ariss, J., L.H. Rhodes, R.B. Hammond, and R.M. Sulc. 2003. Influence of potato leafhopper injury on Fusarium crown rot development in three alfalfa varieties. Am. Path. Soc. Meeting. August 9-13. Charlotte, NC. South Dakota No publications reported. Virginia Dellinger, T. A. 2003. Combined roles of glandular-haired alfalfa and natural enemies in alfalfa pest management in Virginia. Ph.D. Dissertation, Virginia Tech, Blacksburg, VA. Dellinger, T. A., R. R. Youngman, and C. A. Laub. 2003. Recovery of Oomyzus incertus (Hymenoptera: Eulophidae), a larval parasitoid of Hypera postica (Coleoptera: Curculionidae), in Virginia. J. Entomol. Sci. 38: 141-142. Wisconsin Grau, C.R. 2004. Influence of alfalfa brown root rot on winterkill. Proceedings of the 2004 Wisconsin Fertilizer, Aglime, and Pest Management Conference 43:270-274. Wyoming Gray, F.A. and D.W. Koch. 2004. Alfalfa disease management. University of Wyoming, College of Agriculture, Cooperative Extension Service publication, B-1136, 35pp. (on-line at www.uwyo.edu/ces/plantsci.htm, in press). Gray, F.A., C.R. Hollingsworth, C.J. Reedy, L.B. Powers, D.E. Legg, and R.W. Groose. 2004. Pathogenicity of 14 isolates of Phoma sclerotioides pathogenic to alfalfa. Phytopath. Abstr. (in press). Hollingsworth, C.R., F.A. Gray, and D.W. Koch. 2003. Distribution and incidence of brown root rot of alfalfa in Wyoming, U.S.A. Can. J. Plant Path. 25:215-217. Hollingsworth, C.R., R.W. Groose, and F.A. Gray. 2003. Comparative disease reactions of cycle 0 and cycle 1 alfalfa following inoculation with Phoma sclerotioides. Phytopath. 93:S36.