Late blight (LB) devastates potato crops under a range of agroecosystems.  Because environmental conditions, socio-economic conditions and market requirements differ among potato production systems, different disease management strategies must be adopted in different areas.  For several reasons, the strategies that have been developed in temperate countries for IPM-LB are ill suited to potato production systems in developing countries.  IPM-LB for temperate agroecosystems is based on the use of seasonal cropping patterns, susceptible varieties, and the heavy use of fungicides.  Research has focused on the precise and timely application of fungicides.

Because of differences among agroecosystems where LB is an important problem, there is a need to develop agroecosystem-specific management strategies suitable for poor farmers in developing countries.  In regions with continuous cropping, inoculum pressure may be high and much earlier in the growing season than in regions where cropping is seasonal.  Therefore, LB epidemics begin earlier in the growing season.  While sanitation is an important strategy for LB management under temperate conditions, it may be ineffective when diseased potato crops are chronically present.  Because temperatures can be cool in the highland tropics, epidemics may proceed more slowly than they do under warm, moist conditions that may occur during the growing season in temperate countries.  Simulation models can help researchers synthesize the diverse factors affecting disease, and develop a theoretical understanding of how management options might function.  These options are tested through field experiments conducted by researchers and/or farmers.

Forecast models can help farmers take decisions about when (not) to spray. However, developing country farmers often do not have access to the weather data and models needed. We would like to develop forecast models that are not computer based. But use computers to develop these models.

We are developing a new simulation model to develop better late blight management systems