Growth Dynamics of Soybean (Glycine max L.) As Affected by Varieties and Timing of Irrigation

An experiment was conducted at the Agronomy Field of Sher-e-Bangla Agricultural University, Dhaka-1207, Bangladesh during the period from December, 2005 to April, 2006 to study the responses of soybean varieties to the time of irrigation. The experiment was carried out with three soybean varieties viz. Shohag, Bangladesh soybean 4 and BARI soybean 5and 5 levels of irrigation viz. no irrigation, irrigation at elongation of main stem (EMS), irrigation at flowering (F), irrigation at pod development (PD) and EMS+F+PD stages of crop growth. The experiment was laid out in split plot design with three replications. Variety and irrigation level significantly influenced the growth and yield of the soybean. Among the three varieties, BARI soybean-5 influenced plant to have maximum dry matter, number of leaves plant , crop growth rate and relative 1 growth rate. But, the maximum plant height was found highest in Bangladesh soybean-4. Irrigation at EMS+F+PD stages increased yield with higher values of growth parameters. In most of the cases BARI soybean-5 coupled with irrigation at EMS+F+PD were found to be influenced for better growth.