Brief Summary of Minutes of Annual Meeting

Not provided for a temination report.

Accomplishments: Objective 1. Determine the impact of cultural factors on the attrition of nematode populations. Cultural factors believed to affect H. glycines attrition are use of plant resistance, tillage, trap crops and overwinter survival. Selection pressure exerted by plant resistance in a19-year monoculture using PI 88788 source of resistance resulted in increased H. glycines reproduction however, there was no increase in reproduction in a line derived from Peking in the same study. Studies from multiple states found decreased H. glycines reproduction after four or more years with a susceptible soybeans monoculture. In at least one of these studies, yield also decreased suggesting that this would not be an economical management strategy. Tillage effects on H. glycines reproduction were continued both independent of and as a continuation of a previous North Central Soybean Research Program grant. Results mirrored the earlier findings of the North Central Soybean Research Program grant that effects on H. glycines reproduction was site specific. Findings in this grant were questioned due to the short duration of the grant study period and the documentation that the transition from tillage to no-tillage in terms of soil characteristics, both biotic and abiotic, takes a number of years. The findings in continued studies still indicate that the site may be more important that the number of years in no-tillage. Trap crops were explored in several locations as a way to further reduce the soil egg population density. It appeared that a one-year trap crop effect was not sufficient to reduce the egg population density and longer trap crop cultivation is not economical. Overwinter survival was the focus in numerous locations. Early literature on H. glycines survival reported 50% survival during non crop periods. This groups research results were not consistent with this figure. Overwinter survival studies explored cropping sequences, tillage, and egg population density effects. Initial indications were that overwinter survival was higher following corn than soybean but this appears to be site specific. In some cases overwinter survival was inversely related to fall population egg density. It was clear that the longer the time between soybean crops, the lower the soil egg population density with three to five years being the most commonly cited time frame of significant decrease, but this was also crop dependent. It was felt that results could be skewed by differences in sample timing in these studies. Other plant-parasitic nematodes of importance included in studies were Pratylenchus, Meloidogyne incognita, and Xiphinema. Soil food web studies in agricultural and non agricultural sites were conducted at some locations as part of continuing research into ecological niches and plant rhizosphere interactions. This is gathering information to substantiate that only through better understanding of rhizosphere interactions and a holistic approach to the nematode- plant interaction can plant parasitic nematodes be reduced in an environmentally sound program. Objective 2. Determine the biological factors responsible for the attrition of nematode populations. Biological attrition of H. glycines can be due to parasitism, production of toxic substances by other organisms either through metabolism or decay processes, or through lowered reproduction. Field soil from soybean fields in all participating states was examined for presence of fungal parasites of H. glycines second stage juveniles. Hirsutella was detected from soil submitted from three states. Studies continue on best method of delivery, effects of soil pH on parasitism with preliminary data indicating that extremes in pH inhibit parasitism. Tillage increased fungal parasitism. High numbers of bacteria were associated with H. glycines cysts in a separate study and investigations are underway to determine if any of the isolates are potential biological control organisms. NViro, a registered fertilizer, was researched by several participating states as a potential product for reduction of H. glycines. Early research indicates some negative effect on H. glycines. Experiments on the effects of volatiles from leaf extracts on H. glycines in laboratory experiments and field experiments with plastic mulch were conducted. Discrepancies between laboratory and field results were reported. Greenhouse studies on sex determination in H. glycines influenced by use of resistant plant material were conducted in one location. Adult sex ratios were found to be a function of the type of resistance (early or late) expressed by the host cultivar. No evidence of sex reversal was found. It was concluded that if sex is environmentally determined in H. glycines, influences other than plant resistance are responsible. Objective 3. Characterize and understand egg dormancy. Dormancy or the cessation of hatch is an interruption in the nematode life cycle. Temperature, root exudates and other compounds have been shown to affect hatch of H. glycines eggs. In this project, studies using the H. glycines hatch stimulant, zinc chloride, indicated the age of the eggs had an effect on egg hatch with higher hatch/greater response with younger eggs. Two separate studies indicated that hatch is density dependent with greater hatch at higher egg population densities. In field studies, no differences were seen between H. glycines egg hatch when the eggs originated in tilled or no-tillage plot treatments.

Workshops Held by NC 215 Cyst nematode identification workshop 2000 Dorylaim workshop 2001 Standardization of procedures for extraction of soybean cyst nematode 2002 Identification of Freeliving Nematodes (Secrenentea) 2003 Ecological Techniques for Soil Microfauna 2004 Computation of Nematode Community Analysis 2004 (at Society of Nematologists Annual Meeting) Publications: Atibalentja, N., G.R. Noel, P.A. Donald, H. Melakeberham, T.R. Anderson, S. Chen, J. Faghihi, J.M. Ferris, C.R. Grau, D.E. Hershman, A.E. MacGuidwin, T.L. Niblack, R.D. riggs, W.C. Stienstra, G.L. Tylka, and T.W. Welacky. 2001. Soybean yield and population dynamics of Heterodera glycines in the Midwestern U.S. and Ontario, Canada. APS/SON Annual Meeting, Salt Lake, UT. Phytopathology 91:S130. Bekal, S., K.N. Lambert, and T.L. Niblack. 2002. Polymorphism of the newly cloned chorismate mutase of the soybean cyst nematode, Heterodera glycines, among the virulent and avirulent resistance-breaking inbred lines. Phytopathology 92:S7. Bird, G.W. 2000. Nematodes and Soil Quality. Pp. 84-94 (in) Michigan Field Crop Pest Ecology and Management, Cavigelli, M.A., S.R. Deming, L.K. Probyn, and D.R. Mutch (eds) MSU, Est Bulletin E-2704. 108 pp. Buckelew, L.D., L.P. Pedigo, H.M. Mero, M.D.K. Owen, and G.L. Tylka. 2000. Effects of weed management systems on canopy insects in herbicide-resistant soybeans. Journal of Economic Entomology 93:1437-1443. Charlson, D.V. and G.L. Tylka. 2003. Heterodera glycines cyst components and surface disinfestants affect H. glycines hatching. Journal of Nematology. 35:458-464. Chen, J.J., and S.Y. Chen. 2001. Mycoflorae in cysts, females and eggs of the soybean cyst nematode in Minnesota. Phytopathology 91:S15. (Abstr.) Chen, S. Y. and F. J. Chen. 2003. Fungal parasitism of Heterodera glycines eggs as influenced by egg age and pre-colonization of cysts by other fungi. Journal of Nematology. 35:271-277. Chen, S.Y. and D.W. Dickson. 2000. A technique for detecting viability of second-stage juvenile of Heterodera glycines. Journal of Nematology 32:117-121. Chen, S.Y., D.W. Dickson, and D.J. Mitchell. 2000. Viability of Heterodera glycines exposed to fungal filtrates. Journal of Nematology 32:190-197. Chen, S.Y., J. Charnecki, J.F. Preston, and D.W. Dickson. 2000. Extraction and purification of Pasteuria spp. endospores. Journal of Nematology 32:78-84. Chen, S.Y., X.Z. Liu, and F.J. Chen. 2000. Hirsutella minnesotensis sp. nov.-a new pathogen of the soybean cyst nematode. Mycologia 92:819-824. Chen, S.Y., P.M. Porter, C.D. Reese, L.D. Klossner, and W.C. Stienstra. 2001. Evaluation of pea and soybean as trap crops for managing Heterodera glycines. Journal of Nematology. 33:214-218. Chen, S.Y., W.C. Stienstra, W.E. Lueschen, and T.R. Hoverstad. 2001. Response of Heterodera glycines and soybean cultivar to tillage and row spacing. Plant Disease. 85:311-316. Colgrove, A.L., and T.L. Niblack. 2002. AFLP markers associated with virulence of Heterodera glycines on resistant soybean. Phytopathology 92:S16. Colgrove, A.L., G.S. Smith, J.A. Wrather, R.D. Heinz, and T.L. Niblack. 2002. Lack of predictive value in Heterodera glycines race testing. Plant Disease 86:1101-1108. Da Rocha, M.R., T.R. Anderson, and T.W. Welacky. 2001. Abnormal males of Heterodera glycines from roots of resistant soybean cultivars. APS/SON Annual Meeting, Salt Lake, UT. Phytopathology 91:S132. Donald. P.A., K. A. Sudduth and N. R. Kitchen 2001. Mapping soybean cyst nematode field variability. Journal of Nematology 33:255. Donald, P.A., K A. Sudduth, N. R. Kitchen.2002.Heterodera glycines distribution within a field in no-till production over time. Proceedings of the Fourth International Nematology Congress. Tenerife, Spain June 2002. page 264 Donald,P.A., J.A. Wrather, and G. Shannon. 2003. Targeting soil sample collection of Meloidogyne incognita in southern Missouri soybean fields for management of yield losses. Journal of Nematology 35(3):334. Edson, C., S.S. Swinton, J. Nugent, G.W. Bird, A. Coombs, and D. Epstein. 2003. Cherry orchard floor management: Opportunities to Improve Profit and Stewardship. Michigan State University Extension, Bulletin E-2890. 6 pp. Faghihi, J. and J.M. Ferris. 2000. An efficient new device to release eggs from Heterodera glycines. Journal of nematology. 32: 411-413. Fallick, J.B., W.D. Batchelor, G.L. Tylka, T.L. Niblack, J.O. Paz. 2002. Coupling soaybean cyst nematode damage to CROPGRO-Soybean. Transactions of the American Society of Agricultural Engineers 45:433-441. Gavassoni, W.L., G.L. Tylka, and G.P. Munkvold. 2000. Relationship between tillage and spatial patterns of Heterodera glycines. Phytopathology. 91:534-545. Jackson, T.A., T.L. Niblack, and G.S. Smith. 2002. Effects of Heterodera glycines population levels on Fusarium solani f. sp. Glycines colonization of near-isogenic soybean lines differing in resistance to each pathogen. Phytopathology 92:S38. Landis, J.N., J.E. Sanchez, G.W. Bird, C.E. Edson, R. Issacs, R. H. Helnert, A.M. C. Schilder, and S.M. Swinton (Eds). 2002 Fruit Crop Ecology and Management. MI State University Ext. Bull. E-2759. E. Lansing, MI 101 pp. Liu, S.F. and S.Y. Chen. 2001. Nematode hosts of the fungus Hirsutella minnesotensis. Phytopathology 91:S138. (Abstr.) Liu, S.F. and S.Y. Chen. 2001. Sporulation of Hirsutella minnesotensis growing from second-state juveniles of Heterodera glycines. Phytopathology 91:S138. (Abstr.) Liu, X.Z. and S.Y. Chen. 2000. Parasitism of Heterodera glycines by Hirsutella spp. In Minnesota soybean fields. Biological Control 19:161-166. Liu, X.Z. and S.Y. Chen. 2001. Nutritional requirement of Hirsutella minnesotensis. Phytopathology 91:S118. (Abstr.) Liu, X.Z. and S.Y. Chen. 2001. Screening isolates of Hirsutella species for biocontrol of Heterodera glycines. Biocontrol Science and Technology 11:151-160. Liu, X.Z. and S.Y. Chen. 2002. Nutritional requiements of the nematophagous fungus Hirsutella rhossiliensis. Biocontrol science and technology.12:381-393. Liu, X.Z. and S.Y. Chen. 2003. Nutritional requirements of Pochonia chlamydospora and ARF18, fungal parasites of nematode eggs. Journal of invertebrate pathology. 83:10-15. Long, J.H., Jr. and T.C. Todd. 2001. Effect of crop rotation and cultivar resistance on seed yield and the soybean cyst nematode in full-season and double-cropped soybean. Crop Science. 41:1137-1143. Melakeberhan, H., G.W. Bird, and A.L. Jones. 2001. Soil pH Affects Nutrient Balance in Cherry Rootstock Leaves. HortScience 36:916-917. Niblack, T.L. 2002. The HG Type test for genetically diverse populations of the soybean cyst nematode. Proceedings of the China & International Soybean Conference & Exhibition 2002:61-62. Niblack, T.L., P.R. Arelli, G.R. Noel, C.H. Opperman, J.H. Orf, D.P. Schmitt, J.G. Shannon, and G.L. Tylka. 2002. A revised classification scheme for genetically diverse populations of Heterodera glycines. Journal of Nematology. 34:279-288. Niblack, T.L., R.D. Riggs, J. Wang, and R.D. Heinz. 2002. Further characterization of the HG Type classification test for soybean cyst nematode field populations. Phytopathology 92:S59. Nutter, F.W., Jr., G.L. Tylka, J. Guan, A.J.D. Moreira, C.C. Marrett, T.R. Rosburg, J.P. Basart, and C.S. Chong. 2002. Use of remote sensing to detect soybean cyst nematode-induced plant stress. Journal of Nematology. 34:222-231. Paz, J.O., W.D. Bachelor, and G.L. Tylka. 2001. A modeling approach to quantify the effects of spatial soybean yield limiting factors. Transactions of the ASAE. 44:1329-1334. Paz, J.O., W.D. Bachelor, and G.L. Tylka. 2001. Method to use crop growth models to estimate potential return for variable-rate management in soybeans. Transactions of the ASAE. 44:1335-1341. Perry, R.N., J. Beanne, C.C. Marett, and G.L. Tylka. 2002. Comparison of the rate of embryogenic development of Globodera rostochiensis and G. pallida using flow cytometric analysis. Nematology. 4:553-555. Pike, S., R. Heinz, T. Walk, C. Jones, G.A. Kraus, W. Gassmann, A.J. Novacky, and T.L. Niblack. 2002. Is change in electrical potential or pH a hatching signal for Hetrodera glycines? Phytopathology 92:456-463. Riga, E., T. Welacky, J. Potter, T. Anderson, E. Topp, and A Tenuta. 2001. The impact of plant residues on the soybean cyst nematode, Heterodera glycines. Can. J. Plant Pathol. 23:168-173. Riggs, R.D., T.L. Niblack, R. Kinloch, and A.E. MacGuidwin. 2002. Overwinter survival of Heterodera glycines. Journal of Nematology 33:219-226. Sanchez, J.E., T.C. Willson, R.J. Zoppolo, D. Stefanelli, and G.W. Bird. 2002. The Soil. Pp21-28 (in) Fruit Crop Ecology and Management, Landis, J.A., J.E. Sanchez, G.W. Bird, C.E. Edson, R. Issace, R.H. Lehnert, A.M. C. Schilder, and S.M. Swinton (eds). MI State Univ. Ext. Bull. E-2759. E. Lansing, MI 101 pp. Sanchez. J.E., C.E. Edson, G.W. Bird, M.E. Whalon, T.C. Willson, R.R. Harwood, K. Kizilkaya, J.E. Nugent, W. Klein, A. Middleton, T.L. Loudon, D.R. Mutch, and J. Scrimger. 2003. Orchard floor and nitrogen management influences soil and water quality and tart cherry yields. Journal American Society Horticultural Science. 128:277-284. Smith, G.J., W.J. Wiebold, T.L. Niblack, P.C. Scharf, and D.G. Blevins. 2001. Macronutrient concentrations of soybean infected with soybean cyst nematode. Plant and Soil. 235:21-26. Tenuta, A.U., T.W. Welacky, T.R. Anderson. 2001. The spread of soybean cyst nematode in Ontario, 1987-2000. APS/SON Annual Meeting, Salt Lake, UT. Phytopathology 91:S87. Todd, T.C., J.H. Long, and T.R. Oakley. 2000. Effects of maturity and determinancy in soybean on host-parasite relationships of Heterodera glycines. Supplement to Journal of Nematology 32:584-590. Todd, T.C., J.H. Long, Jr., and T.R. Oakley. 2003. Density-dependent multiplication and survival rates in Heterodera glycines. Journal of Nematology 35:98-103. Venkatesh, R., S.K. Harrison, and R.M. Riedel. 2000. Weed Hosts of Soybean Cyst Nematode (Heterodera glycines) in Ohio. Weed Tech. 14:156-160. Wang, J., P.A. Donald, T.L. Niblack, G.W. Bird, J. Faghihi, J.M. Ferris, D.J. Jardine, C. Grau, P.E. Lipps, A.E. Mac Guidwin, H. Melakeberhan, G.R. Noel, P. Pierson, R.M. Reidel, P.R. Sellers, W.C. Stienstra, T.C. Todd, G.L. Tylka, and D.S. Wysong. 2000. Soybean cyst nematode reproduction in the north central United States. Plant Disease 84:77-82. Welacky, T.W. and E. Topp. 2001. Control of soybean cyst nematode, Heterodera glycines, with lime-stabilized municipal biosolids. APS/SON Annual Meeting, Salt Lake, UT. Phytopathology 91:S145. Welacky, T.W., T.R. Anderson, A.U. Tenuta. 2001. Reduction of soil populations of soybean cyst nematode (Heterodera glycines) by crop rotation with non-hosts and varietal resistance. APS/SON Annual Meeting, Salt Lake, UT. Phytopathology 91:S145. Y. Xu, S. Bekal, A. Colgrove, and T.L. Niblack. 2002. Infraspecific variation of ITS rDNA among geographical isolates of the soybean cyst nematode Heterodera glycines. Phytopathology 92:S88.