Nematode Thresholds and Damage Levels for California Crops Howard Ferris
Some of those involved…. Dan Ball Larry Duncan Pete Goodell Joe Noling Diane Alston Sally Schneider Lance Beem
Thresholds by field plot South Coast Field Station USDA Shafter Tulelake
Thresholds by transect Imperial and Coachella Valleys Ventura County Tulare County
Seinhorst Damage Function Y=m+(1-m)z (P i -T) Y=relative yield m=minimum yield Z=regression parameter P i =population level T=tolerance level Based on preplant population levels – measured or predicted from overwinter survival rates
Case Study on Cotton CultivarSoilLocation(T)oleranceZm SJ2loamy sandsouth SJV Deltapineloamy sandimperial SJ2, SJ5, SJ-C1l. sand/s. loamsouth SJV average (all) average (SJV) SJ2(-FOV)sandy loamsouth SJV SJ2(+FOV)sandy loamsouth SJV
Meloidogyne incognita, J2/250 cc soil Expected % yield loss at different preplant nematode densities CultivarSoilLocationThreshold SJ2loamy sandsouth SJV Deltapineloamy sandimperial SJ2, SJ5, SJ-C1l. sand/s. loamsouth SJV average (all) average (SJV) SJ2(-FOV)sandy loamsouth SJV SJ2(+FOV)sandy loamsouth SJV Case Study on Cotton
Damage Function Parameters for Selected Crops Crop(T)oleranceZm Bell Pepper Cantaloupe Carrot Chile Pepper Cotton Cowpea Potato Snapbean Squash Sugarbeet Sweetpotato Tomato
Thresholds and Expected Yield Loss Meloidogyne incognita, J2/250 cc soil; adjusted for extraction efficiency Expected % yield loss at different preplant nematode densities CropThreshold Bell Pepper Cantaloupe Carrot Chile Pepper Cotton Cowpea Potato Snapbean Squash Sugarbeet Sweetpotato Tomato
Expected Damage Meloidogyne chitwoodi; summer crop potato; Klamath Basin Fall population levels; adjusted for extraction efficiency Expected % tuber blemish at different fall nematode densities J2/250 cc % Blemish
Thresholds and Expected Yield Loss CultivarSoilLocation(T)oleranceZm US-H9clayImperial US-H9loamSJV/Idaho Heterodera schachtii, eggs/100g soil Sugarbeets CultivarSoilLocationThreshold US-H9clayImperial US-H9loamSJV/Idaho Expected % yield loss at different preplant nematode densities Data from P.A. Roberts
Optimized Discrete Model
Annual Population Change (Host Crop) Pi1 Pi1 * (Pi2/Pi1)
Annual Population Change (Non-host) Pi(t) Pi(t+x) Pi1 Pi2 Pi3
Years After Planting Host Crop Pi(t+x)
Perennial Crop Considerations
Year DD AUC LU LT NU NT Year DD AUC LU LT NU NT Year DD AUC LU LT NU NT
Some References Benedict, J.H., K.M. El-Zik, L.R. Oliver, P.A. Roberts, and L.T. Wilson Economic injury levels for cotton pests. Chapter 6. In: Integrated Pest Management Systems and Cotton Production. R.E. Frisbie, K.M. El-Zik, and L.T. Wilson (eds.). John Wiley and Sons, New York. Pp Cooke, D. A., and I. J. Thomason The relationship between population density of Heterodera schachtii, soil temperature, and sugarbeet yields. Journal of Nematology 11: Duncan, L. W. and H. Ferris Effects of Meloidogyne incognita on cotton and cowpeas in rotation. Proceedings of the Beltwide Cotton Production Research Conference: Ferris, H Probability range in damage predictions as related to sampling decisions. Journal of Nematology 16: Ferris, H Population assessment and management strategies for plant-parasitic nematodes. Agricultural, Ecosystems and Environment 12(1984/85): Ferris, H., D. A. Ball, L. W. Beem and L. A. Gudmundson Using nematode count data in crop management decisions. California Agriculture 40: Ferris, H., H. L. Carlson and B. B. Westerdahl Nematode population changes under crop rotation sequences: consequences for potato production. Agronomy Journal 86: Ferris, H., P. B. Goodell and M. V. McKenry Sampling for nematodes. California Agriculture 35: Goodell, P.B., M. A. McClure, P. A. Roberts, and S. H. Thomas Nematodes. In: Integrated Pest Management for Cotton in the Western Region of the United States. 2nd edition. Univ. of California Publ. No Pp Roberts, P.A. and G.D. Griffin The economic feasibility of management alternatives. In: Quantifying Nematode Control. G.D. Griffin and P.A. Roberts (eds.). Western Regional Research Publication #149, Utah State University Press, Logan, UT. Pp Roberts, P.A. and I.J. Thomason Sugarbeet Pest Management: Nematodes. Univ. of California Special Publ. No pages.
References Burt, O. R. and H. Ferris Sequential decision rules for managing nematodes with crop rotations. J. Nematology 28: Chen, J., J.R. Carey and H. Ferris Comparative demography of isogenic populations of Caenorhabditis elegans Expt. Gerontology 36: Ferris, H Nematode economic thresholds: derivation, requirements and theoretical considerations. J. Nematology 10: Ferris, H Density-dependent nematode seasonal multiplication and overwinter survivorship: a critical point model. J. Nematology 17: Hsin, H. and C. Kenyon Signals from the reproductive system regulate the lifespan of C. elegans. Nature 399: Kim D.G. and H. Ferris Relationship between crop losses and initial population densities of Meloidogyne arenaria in winter-grown oriental melon in Korea. J. Nematology (subm.) Noling, J.W. and H. Ferris Nematode-degree days, a density-time model for relating epidemiology and crop losses in perennials. J. Nematology 19: Seinhorst, J.W The relationship between nematode density and damage to plants. Nematologica 11: Seinhorst, J.W The relationship between population increase and population density in plant parasitic nematodes. II. Sedentary nematodes. Nematologica 13: Somers, J.A., H.H. Shorey and L.K. Gaston Reproductive biology and behavior of Rhabditis pellio (Schneider) (Rhabditida:Rhabditidae). J. Nematology 9: More information: