Managing Pod Rot of Lima Bean Caused by Phytophthora capsici with Fungicides in the Mid-Atlantic Region

Abstract

The baby lima bean (Phaseolus lunatus) is one of the most economically important crops for Delaware. Pod rot of lima bean caused by Phytophthora capsici is a relatively new disease that threatens production and profitability of lima beans grown in Delaware and the mid-Atlantic region. Insensitivity to the fungicide mefenoxam has made managing the disease challenging in recent years. In 2014, 12 fungicides in two trials were tested for their efficacy against P. capsici in lima bean. Results indicated that all fungicide treatments significantly reduced disease incidence compared to the control, with oxathiapiprolin achieving the best control in Trial 1 and fluazinam and mefenoxam achieving the best control in Trial 2. Fungicide treated plots also yielded significantly greater than controls in Trial 2. These results indicate that there are additional fungicides on the market with efficacy towards managing pod rot of lima bean and warrant further investigation for possible new labels. Accepted for publication 16 May 2016. Published 9 June 2016.