Biocontrol of Sicklepod (Cassia obtusifolia) in Soybeans (Glycine max) withAlternaria cassiae

Abstract

In four tests conducted in 2 years,Alternaria cassiaeJurair and Khan effectively controlled sicklepod (Cassia obtusifoliaL. ♯ CASOB) as indicated by stand counts of the weed and by soybean [Glycine max(L.) Merr.] yields. The number of sicklepod seedlings was reduced more than 90% within 14 days after foliar applications ofA. cassiaeconidia were banded (46 cm) at rates of 4.2 and 2.1 kg/ha (9.4 and 4.7 kg/ha broadcast, respectively). One banded application of 0.04 or 0.4 kg/ha (0.09 or 0.9 kg/ha broadcast, respectively) did not satisfactorily control sicklepod. These results indicate that sicklepod control may be enhanced by multiple applications ofA. cassiae.