EFFECT OF IRRIGATION FREQUENCY ON GROWTH AND YIELD OF SOYBEAN

Abstract

A field experiment was conducted at the research field of HSTU, Dinajpur during November 2019 to March 2020 to find out the effect of irrigation frequency on the growth and yield of Soybean (Glycine max L.) cv. BARI Soybean-6. The experiment was carried out with a RCBD with four replications of irrigation treatments viz, I0= no irrigation (control), I1= one time at 20 days after sowing (DAS), I2= two times (20 and 40 DAS), I3= three times (20, 40, and 60 DAS). At 105 DAS the highest plant height (52.53 cm) was found from I2 treatment and the shortest plant (45.82 cm) from I0 treatment. The highest (5.91) leaf area index was obtained from the treatment of three irrigation (I3) at 90 DAS and the lowest (5.1) leaf area index from the control (I0). At the 90 DAS highest nodule number (9.208) and the lowest nodule number was (6.459) recorded from I3 and I0, respectively. The highest (90.09 g) fresh weight was obtained from the treatment I2 at 90 DAS and the lowest (65.64 g) was recorded in I0. I3 produced the highest amount of dry matter of (29.50 g) and the lowest amount of dry matter production at harvest (20.67 g) in I0 treatment. The highest seed yield was observed from I2 (1.638 t ha-1 ) which was statistically similar with I3 whereas, the lowest obtained from I0 (1.075 t ha-1 ). The highest small stover yield was obtained from I3 (1.759 t ha-1 ) which is statistically similar to I2 (1.754 t ha-1 ) whereas the lowest was observed from I0 (1.540 t ha-1 ) which was statistically similar to I1 (1.566 t ha-1 ). The highest biological yield was found from I2 (3.425 t ha-1 ) which is statistically similar to I3 and the lowest was obtained from I0 (2.56 t ha-1 ). The maximum harvest index was found from I2 (47.71 %) and the minimum was obtained from I0 (40.81 %). I2 treatment showed more significant results than the other treatment I0, I1 and I3. So, two times irrigation showed significant effect showed the highest yield of 1.638 t ha-1.