Above and below-ground interference of soybean (Glycine max (L.) Merrille) by shattercane (Sorghum bicolor (L.) Moench) and soybean

摘要

A greenhouse experiment was designed to investigate the above- and below-ground interactions of soybean with shattercane and soybean. This experiment included a randomised complete block design with seven treatments and four replications. The treatments included above-ground only, below-ground only, full interaction of soybean-shattercane and soybean-soybean, and no interaction (control) of soybean. The maximum competitive effects on biomass and grain yield of soybean related to full interspecific interference of shattercane. In soybean-shattercane and soybean-soybean associations, no significant difference was observed between full and above-ground interference. Also, soybean biological and economical yield loss due to shoot competition was about two-fold that of root competition. In all interactions, the grain yield of soybean was more sensitive to interference than the biological yield of soybean. The greatest reduction (of about 50%) of number of leaves and pods per soybean plant occurred withfull competition with sorghum. At each interaction, inter-specific competition was greater than soybean intra-specific competition.