Effects of Simulated Rain on the Persistence of Beauveria bassiana Conidia on Leaves of Alfalfa and Wheat

The effect of simulated rain at two intensities (26.7 or 112.7 mm h-1) and durations (30 or 60 min) on the persistence of Beauveria bassiana conidia applied in water on leaves of alfalfa leaves of alfalfa (Medicago sativa) or wheat (Triticum aestivum) was investigated. Initial populations of conidia on the leaves of both crops were similar, and ranged from 1.7 105 to 3.5 105 colony-forming units cm-2. The simulated rain reduced the concentration of conidia on leaves by 28-61%. Although there was a slight effect due to rain intensity for alfalfa, there was no influence of either rain duration or crop type on the retention of B. bassiana conidia.