Nematode Thresholds and Damage Levels for California Crops Howard Ferris
Dec 19, 2015
Nematode Thresholdsand
Damage Levelsfor
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 StationUSDA ShafterTulelake
Thresholds by transectImperial and Coachella Valleys
Ventura CountyTulare County
Seinhorst Damage Function
• Y=m+(1-m)z(Pi-T)
• Y=relative yield• m=minimum yield• Z=regression parameter• Pi=population level• T=tolerance level
• Based on preplant population levels – measured or predicted from overwinter survival rates
0
0.2
0.4
0.6
0.8
1
1.2
0 2 4 6 8
Ln (Pi+1)R
elat
ive
Yie
ld
Case Study on Cotton
Cultivar Soil Location (T)olerance Z m
SJ2 loamy sand south SJV 65 0.998 0.55
Deltapine loamy sand imperial 50 0.9972 0.65
SJ2, SJ5, SJ-C1 l. sand/s. loam south SJV 55 0.999 0.48
average (all) --------------------- ------------- 57 0.998 0.56
average (SJV) --------------------- ------------- 60 0.9985 0.52
SJ2(-FOV) sandy loam south SJV 55 0.9966 0.54
SJ2(+FOV) sandy loam south SJV 55 0.9847 0.38
Meloidogyne incognita, J2/250 cc soil
Expected % yield loss at different preplant nematode densities
Cultivar Soil Location Threshold 20 50 100 200 500
SJ2 loamy sand south SJV 25 0 5 15 27 41
Deltapine loamy sand imperial 19 0 7 16 26 34
SJ2, SJ5, SJ-C1 l. sand/s. loam south SJV 21 0 4 10 19 37
average (all) --------------------- ------------- 22 0 6 15 27 40
average (SJV) --------------------- ------------- 23 0 5 12 24 41
SJ2(-FOV) sandy loam south SJV 21 0 10 23 37 45
SJ2(+FOV) sandy loam south SJV 21 0 42 59 62 62
Case Study on Cotton
Damage Function Parameters for Selected Crops
Crop (T)olerance Z m
Bell Pepper 65 0.9978 0.87
Cantaloupe 10 0.9972 0.40
Carrot 0 0.99 0.6
Chile Pepper 39 0.9934 0.70
Cotton 57.5 0.9976 0.6
Cowpea 22 0.9816 0.96
Potato 18 0.99 0.49
Snapbean 14 0.9978 0.57
Squash 0 0.9898 0
Sugarbeet 0 0.9955 0.89
Sweetpotato 0 0.99375 0.47
Tomato 41.8 0.99934 0.47
Thresholds and Expected Yield Loss
Meloidogyne incognita, J2/250 cc soil; adjusted for extraction efficiency
Expected % yield loss at different preplant nematode densities
Crop Threshold 1 2 5 10 20 50 100 200
Bell Pepper 25 0 0 0 0 0 2 5 8
Cantaloupe 4 0 0 1 3 7 17 30 46
Carrot 0 1 2 5 9 16 29 37 40
Chile Pepper 15 0 0 0 0 3 14 24 30
Cotton 22 0 0 0 0 0 6 15 27
Cowpea 52 0 0 0 0 0 0 6 8
Potato 7 0 0 0 4 15 34 47 51
Snapbean 5 0 0 0 1 3 10 18 29
Squash 0 3 5 12 23 41 74 93 100
Sugarbeet 0 0 0 1 1 2 5 8 10
Sweetpotato 0 1 2 4 8 15 30 43 51
Tomato 16 0 0 0 0 0 3 7 14
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 1 2 5 10 20 50 100 200 500
% Blemish 3 4 5 7 8 12 15 18 25
Thresholds and Expected Yield Loss
Cultivar Soil Location (T)olerance Z m
US-H9 clay Imperial 100 0.99886 0
US-H9 loam SJV/Idaho 300 0.99976 0
Heterodera schachtii, eggs/100g soil
Sugarbeets
Cultivar Soil Location Threshold 50 100 200 500 1000
US-H9 clay Imperial 100 0 0 11 37 64
US-H9 loam SJV/Idaho 300 0 0 0 5 15
Expected % yield loss at different preplant nematode densities
Data from P.A. Roberts
Optimized Discrete Model
Annual Population Change (Host Crop)
0
20000
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0 500 1000 1500 2000Pi1
Pi1
* (
Pi2
/Pi1
)
Annual Population Change (Non-host)
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1400
0 500 1000 1500 2000Pi(t)
Pi(t
+x)
Pi1
Pi2
Pi3
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1600
0 1 2 3 4 5 6 7 8
Years After Planting Host Crop
Pi(t
+x)
Population Convergence
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0 5 10 15Year
Po
pu
lati
on
Le
vel
0NHR
2NHR
4NHR
6NHR
Optimum Rotation Length
-200
-100
0
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0 1 2 3 4 5 6 7 8 9 10
Years of Non-host
Ave
. An
nu
al R
etu
rns
($
)
Perennial Crop Considerations
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0 200 400 600 800 1000 1200 1400 1600 1800 2000 2200
Days
Mes
ocric
onem
a xe
nopl
ax
Lovell
Nemaguard
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Degree-Days
Mes
ocric
onem
a xe
nopl
ax
Year 1
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0 1000 2000 3000DD
AU
C LU
LT
NU
NT
Year 2
02000400060008000
1000012000
0 1000 2000 3000DD
AU
C LU
LT
NU
NT
Year 3
05000
1000015000200002500030000
0 1000 2000 3000DD
AU
C LU
LT
NU
NT
Some ReferencesBenedict, J.H., K.M. El-Zik, L.R. Oliver, P.A. Roberts, and L.T. Wilson. 1989. 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. 121-153.
Cooke, D. A., and I. J. Thomason. 1979. The relationship between population density of Heterodera schachtii, soil temperature, and sugarbeet yields. Journal of Nematology 11:124-128.
Duncan, L. W. and H. Ferris. 1983. Effects of Meloidogyne incognita on cotton and cowpeas in rotation. Proceedings of the Beltwide Cotton Production Research Conference: 22-26.
Ferris, H. 1984. Probability range in damage predictions as related to sampling decisions. Journal of Nematology 16:246-251.
Ferris, H. 1985. Population assessment and management strategies for plant-parasitic nematodes. Agricultural, Ecosystems and Environment 12(1984/85):285-299.
Ferris, H., D. A. Ball, L. W. Beem and L. A. Gudmundson. 1986. Using nematode count data in crop management decisions. California Agriculture 40:12-14.
Ferris, H., H. L. Carlson and B. B. Westerdahl. 1994. Nematode population changes under crop rotation sequences: consequences for potato production. Agronomy Journal 86:340-348.
Ferris, H., P. B. Goodell and M. V. McKenry. 1981. Sampling for nematodes. California Agriculture 35:13-15.
Goodell, P.B., M. A. McClure, P. A. Roberts, and S. H. Thomas 1997. Nematodes. In: Integrated Pest Management for Cotton in the Western Region of the United States. 2nd edition. Univ. of California Publ. No. 3305. Pp. 103-110.
Roberts, P.A. and G.D. Griffin. 1994. 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. 23-49.
Roberts, P.A. and I.J. Thomason. 1981. Sugarbeet Pest Management: Nematodes. Univ. of California Special Publ. No. 3272. 32 pages.
References
Burt, O. R. and H. Ferris. 1996. Sequential decision rules for managing nematodes with crop rotations. J. Nematology 28:457-474.
Chen, J., J.R. Carey and H. Ferris. 2001. Comparative demography of isogenic populations of Caenorhabditis elegans Expt. Gerontology 36:431-440.
Ferris, H. 1978. Nematode economic thresholds: derivation, requirements and theoretical considerations. J. Nematology 10:341-350.
Ferris, H. 1985. Density-dependent nematode seasonal multiplication and overwinter survivorship: a critical point model. J. Nematology 17:93-100.
Hsin, H. and C. Kenyon. 1999. Signals from the reproductive system regulate the lifespan of C. elegans. Nature 399:362-366.
Kim D.G. and H. Ferris. 2001. 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. 1987. Nematode-degree days, a density-time model for relating epidemiology and crop losses in perennials. J. Nematology 19:108-118.
Seinhorst, J.W. 1965. The relationship between nematode density and damage to plants. Nematologica 11:137-154.
Seinhorst, J.W. 1967. The relationship between population increase and population density in plant parasitic nematodes. II. Sedentary nematodes. Nematologica 13:157-171.
Somers, J.A., H.H. Shorey and L.K. Gaston. 1977. Reproductive biology and behavior of Rhabditis pellio (Schneider) (Rhabditida:Rhabditidae). J. Nematology 9:143-148.
More information:http://plpnemweb.ucdavis.edu/nemaplex