GROWTH AND YIELD OF SOYBEANAS AFFECTED BY IRRIGATION AND WEED CONTROL METHOD

Abstract

Soybean (Glycine max L.) is one of the most nutritious crops in the world which is now a new prospective crop in Bangladesh. A field experiment was conducted at Sher-e-Bangla Agricultural University, Dhaka during December, 2013 to March,2014 with a view to find out the influence of irrigation and weed control methods on the growth and yield of Soybean cv. BARI Soybean 6.The experiment was carried out with four(4) irrigation treatments viz, no irrigation (control), one time(at 20 DAS) ,two times (at 20 and 40 DAS), three times (at 20, 40, and 60 D AS), and four weed management treatments i.e., no weeding (control), one time hand weeding(at 20 DAS), two times hand weeding (at 20 and 40 DAS) and chemical control by Whip Super® (75g/L Fenoxaprop-p-ethyl)@75g ha-1 at 20 DAS. Results showed different types of weed werefound to infest experimental fields, among them Echinochloacolonum (72.19%), Linderniaprocumbens (28.28%)and Cynodondactylon (14.25%) had the highest relative density. It is also noticed that Linderniaprocumbens created dominancy throughout the field the later stage of crop. Three times irrigation gave the highest (1.63 t ha-1) seed yield on the other hand two times hand weeding gave the highest (1.56 t ha-1) seed yield. Interaction effects showed the highest (1.92 t ha-1) seed yield from the combination of three times irrigation andtwo times hand weeding. This was also observed that herbicide Whip Super® showed better performance to control grass weeds but failed to control Linderniaprocumbens. However, crop plants treated with herbicide became mature one week earlier than other treated crop plants. Considering weed control cost application of herbicide Whip Super®found to be most economic for cultivation of soybean.