EFFECT OF IRRIGATION ON THE GROWTH AND YIELD OF SOYBEAN (Glycine maxL.) VARIETIES

Abstract

An experiment was conducted at the Agronomy Field of Sher-e-Bangla Agricultural University, Dhaka-1 207 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-5 and five levels of irrigation viz, no irrigation, irrigation at elongation of main stem (EMS), irrigation at flowering (F), irrigation at pod development (PD) and one irrigation each at EMS±F-fPD stages of crop growth. The experiment was laid out in split plot design with three replications. The results showed that variety and irrigation level significantly influenced the growth, development, yield characters and yield of the soybean. Among the three varieties, BARI soybean-5 influenced plants to have maximum dsy matter, number of branches plant' 1 , pod length, number of seeds pod', seed yield, stover yield, biological yield and harvest index. But the plant height and number of pods plant' 1 were found highest in Bangladesh soybean4. The grain yield status among the three varieties in this experiment was that the BARI soybean-5 out yielded Shohag and Bangladesh soybean-4, by 6.93% and 0.28%, respectively. Irrigation at EMS+F+PD stages increased yield with higher values of harvest index as the yield attributes like branches plani', pods plant 4 , seeds pod', pod length and 100- seed weight were higher. Application of irrigation at different times significantly Ill increased seed yield ranging from 23.94% to 96.92% compared to the control (no irrigation). In most of the cases BARI soybean-5 coupled with irrigation at EMS+F+PD was found to be influenced for better growth and yield. The highest seed yield was found with the interaction of BAR! soybean-5 with irrigation given at EMS+F+PD stages. This was achieved due to rna'cjmum number of branches plani', number of seeds pod' and greater pod length. The higher yield attributes were achieved with abundant production of dry matter due to irrigation at EMS+F+PD stages.