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ARS Home » Southeast Area » Tifton, Georgia » Crop Protection and Management Research » Research » Publications at this Location » Publication #224490
Title: Considering field physical characteristics in assessing risk and delineating nematode management zones

Author
item Davis, Richard
item ORTIZ, B - UNIV OF GA
item PERRY, C - UNIV OF GA
item Sullivan, Dana
item KEMERAIT, B - UNIV OF GA
item VELLIDIS, G - UNIV OF GA
item RUCKER, K - UNIV OF GA

Submitted to: International Congress of Nematology
Publication Type: Proceedings
Publication Acceptance Date: 4/1/2008
Publication Date: 7/24/2008
Citation: Davis, R.F.; Ortiz, B.V.; Perry, C.; Sullivan, D.G.; Kemerait, B.; Vellidis, G.; Rucker, K. 2008. Considering field physical characteristics in assessing risk and delineating nematode management zone. Proceedings from the Fifth International Congress of Nematology, Brisbane, Australia, July 13-18, 2008:136-137.

Interpretive Summary:

Technical Abstract: Site-specific management (SSM) of nematodes requires identifying factors affecting nematode distribution, nematode population density, and nematode-induced yield losses, and then using that information to predict where nematode management will cost-effectively reduce yield loss. Using cotton (Gossypium hirsutum) as a model system, we accomplished this by 1) using multiple regression analysis to evaluate the relationship between cotton yield, soil physical and chemical properties, and southern root-knot nematode (RKN, Meloidogyne incognita) population density to identify factors most strongly affecting yield; 2) using the most important factors affecting yield to create a logistic regression model which predicts the probability of yield loss due to RKN (assess risk); and 3) translating the model predicting the probability of yield loss into field maps which delineate areas with different levels of probability (risk) of yield loss which can then be used as management zones (MZ) for SSM. The factors most useful for delineating MZ were soil electrical conductivity (EC, a proxy for soil texture), elevation, slope, and normalized difference vegetation index (NDVI), though soil EC was the single most important factor. Models created from multiple fields in 2005 and 2006 were used to create a MZ map for a field in 2007. Nematicide treatments were randomized and replicated in each MZ, and nematicides were shown to have a much greater effect in MZ predicted to have the greatest risk for loss to RKN. Though the most expensive nematicide treatments generally led to the greatest yield increases in all MZ, they were the most cost-effective treatments only in MZ identified as higher risk for yield loss from RKN; in lower risk MZ, less expensive treatments were the most cost-effective. Therefore, MZ based on field physical characteristics will allow SSM of nematodes in some fields.