Effect of Alternaria cassiae, Psudocercospora nigricans, and Soybean (Glycine max) Planting Density on the Biological Control of Sicklepod (Senna obtusifolia)

摘要

The interactions of two fungal biocontrol agents, Alternaria cassiae and Pseudocercospora nigricans, and soybean planting density on sicklepod mortality and dry weight were studied in the field over 2 yr. The experimental field was divided into three equal areas: one without soybean and two where the soybean was sown in densities of 20 and 36 seeds per meter row with a 0.95-m row spacing. The fungi were sprayed alone or in a mixture at three growth stages of sicklepod plants grown at three levels of crop interference resulting form the three sobyean planting densities.