Effect of soil water deficit on the attack of Macrophomina phaseolina on beans

Abstract

The effect of water stress on the incidence of charcoal stalk rot of beans caused by Macrophomina phaseolina (Tassi) Goid. was evaluated under field conditions. A randomized complete block design with four replications was used. Water stress treatments 1 to 7 corresponded to 0, 6, 9, 11, 13, 16, and 18 days withholding irrigation from the beginning of the flowering period, respectively. The soil of the experimental plots was maintained at optimum moisture conditions before and after the water stress treatments. The evaluations of diseased plants were performed at 49, 63, and 84 days after planting, respectively. Plant mortality caused by the fungus in the treatments was significantly different at the 1% level. The incidence of dead plants increased as the water stress was prolonged, resulting in 8.6% dead plants under ideal soil moisture conditions against 63.9% dead plants in plots with 18 days of water deficit.