Joint action of Cochliobolus lunatus and atrazine on Echinochloa crus-galli (L.) Beauv.
The potential of the endemic fungus C. lunatus as a biological control agent against E. crus-galli was investigated. Under appropriate conditions the fungus produced leaf necrosis on E. crus-galli resulting in death of young seedlings. However, plants with >2 leaves mostly recovered after some time. Phaseolus vulgaris, barley, maize, oats, rye, tomatoes and wheat were highly resistant to the fungus. In growth chamber or greenhouse experiments, E. crus-galli with >2 leaves was effectively controlled by C. lunatus in combination with a sublethal dose of atrazine as low as 2.5 mg/m2, due to a positive interaction between fungus and herbicide.