ARS | Publication request: Assessment of SIMBLIGHT1, SIMPHYT1, and NOBLIGHT models for predicting Phytophthora infestans in the northeastern U.S.

Submitted to: American Phytopathological Society
Publication Type: Abstract Only
Publication Acceptance Date: May 10, 2010
Publication Date: August 7, 2010
Citation: Olanya, O.M., Honeycutt, C.W., Larkin, R.P., He, Z. 2010. Assessment of SIMBLIGHT1, SIMPHYT1, and NOBLIGHT models for predicting Phytophthora infestans in the northeastern U.S.. American Phytopathological Society. 100:592.

Technical Abstract: Accurate prediction of Phytophthora infestans outbreaks is crucial for effective late blight management. The SIMBLIGHT1, SIMPHYT1, and modified SIMPHYT1 models were assessed for predicting late blight outbreaks relative to the NOBLIGHT model using climatic data from field experiments at Presque Isle, ME. The dynamics of late blight infection pressure and Phytophthora efficiency (pew-values) were computed by the SIMPHYT3 model to assess conduciveness of climatic conditions for disease development. The SIMPHYT1 model recommended fungicide applications to commence on July 11, 21, 8, 10, 7 and 7 in 2004, 2005, 2006, 2007, 2008, and 2009, respectively. The modified SIMPHYT1 model (US version) recommended fungicide applications for July 11, 22, 8, 19, 7, and 7 in the same years. Model simulations of disease outbreak differed from actual recorded observations in untreated plots by 24-65 days. The NOBLIGHT model was accurate in forecasting the timing of first fungicide application for disease control. However, it appears significant improvements could result if such models are modified to account for external sources of inoculum.