Early and Late Blight Potential on Russet Burbank Potato as Affected by Microclimate, Cropping Systems and Irrigation Management in Northeastern United States

Soil and irrigation management have been used to optimize crop production; however, their effects on microclimate, development, and control of potato diseases have not been adequately quantified. The effects of soil, crop, and water management on development of potato early blight and late blight were quantified in a potato cropping systems experiment from 2006 to 2008. Microclimate, (soil temp, air temp, relative humidity, soil water content and leaf wetness) was not significantly impacted by cropping systems, and varied within seasons and across years. Irrigation management had little impact on microclimate, suggesting that treatment induced effects were not significant. Early blight incidence, severity, and lesion numbers were, however, impacted by management systems and years. Disease incidence was significantly (P 90%, predicted area under disease progress curves (AUDPC), severity values, and blight units had similar values among cropping systems and water management. Microclimatic variables were not significantly correlated to early blight or late blight potential, perhaps due to the small-scale size of experimental plots and influence of the surrounding environment, or lack of significant treatment effects. In addition to the positive attributes often associated with potato cropping systems (increased crop growth, yield, soil health, economic returns, production sustainability), this research demonstrated improved management of potato early blight with cropping systems, but no effect on late blight, a potentially explosive foliar disease. Nevertheless, cropping systems and irrigation management provide useful tools for the enhanced sustainability of potato production systems.