Effects of certain cultural and chemical treatments on growth, productivity and seed composition of edible soybeans, Glycine max (L.) Merrill

Trails with edible soybeans, Glycine max (L.) Merrill, cultivar "Soylima" were carried out during 1969 and 1970 to investigate the effects of spacing of plants in the row, topping either mechanically or chemically and application of a growth retardant, succinic acid 2,2-Dimethylhydrazide (Alar) on plant growth, yield components and seed composition. Alar was applied at two stages of plant development and at three concentrations. Wider spacing or topping mechanically reduced plant height and increased number of branches. Plant weight (with pods), pod number, pod weight and green-mature seed weight were increased by wider spacing, and were generally affected by topping. Yield of green-mature beans were not significantly affected by spacing or topping treatments. Topping and Alar application reduced plant height and lodging. Differences in dry bean and dry matter yields were not significant due to interactions of topping. Alar application time or concentration. Topping mechanically and Alar at 3000 ppm significantly increased dry matter yield at green-mature stage. Ash content of green-mature beans was affected significantly due to topping and Alar concentration interactions. Percentage of oil was not affected in beans harvested green-mature, but differences occurred when harvested dry. Protein content of green-mature beans was higher than that of dry beans. Alar application at 3000 ppm increased percent age of protein of both green-mature and dry beans. The results suggest that, on an area basis, edible soybeans yield higher protein when harvested at green-mature stage of pod development.