Efficacy ofExserohilum monocerasfor the control ofEchinochloaspecies in rice (Oryza sativa)
Efficacy of an indigenous fungus,Exserohilum monoceras, for the control of 3Echinochloaspecies was evaluated and compared under both regulated greenhouse and screenhouse (field plots netted with 2 layers of metal mesh screening to exclude vertebrate pests) conditions. Under greenhouse conditions, an inoculum dose of 2.5 × 107conidia m−2killed all seedlings of both barnyardgrass andE. glabrescens, whereas an inoculum dose of 5.0 × 107conidia m−2was required to obtain 100% mortality of junglerice seedlings. The 1.5-leaf stage of all 3Echinochloaspecies was the most susceptible. Increasing inoculum density increased weed control efficacy on younger or olderEchinochloaseedlings. The highest level of control was observed forE. glabrescens, less for barnyardgrass, and least for junglerice. Under screenhouse conditions,Exserohilum monocerascaused more than 90% mortality ofEchinochloaspecies when the inoculum was formulated as an oil emulsion or when applied as a dry powder.