Nematode Thresholds and Damage Levels Annual and Perennial Crops
Sources of Data Ferris et al, 1970s and 1980s Roberts et al, 1980s Cooke and Thomason, 1970s Some Constraints to Early Adoption Availability of inexpensive nematicides Development of resistant varieties in some crops Publication of thresholds in arcane format
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
Mesocriconema xenoplax
Bacterial canker of Prunus
Mesocriconema Mesocriconema xenoplax
Mesocriconema
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.