RESPONSE OF HLACKCRAM TO DIFFERENT LEVELS OF WEED CONTROL AND PLANT DENSITY.

Abstract

An experiment was conducted at the Agronomy field of Sher-e-Bangta Agricultural University, Dhaka during August to October 2013 to study the effect of row spacing and weed management on the performance of Blackgram (BARI Mash-3). The experiment comprised of two factors vic (i) plant spacing and (ii) weed management with three plant spacing (S1 = 20 cm x 10 cm, S2= 30 cm x 10 cm, S 40 cm x cm ) and live levels of weeding treatments (W l = No weeding, W 2= Hand weeding at 20 DAS. W 3 = Hand weeding at 20 and 40 DAS, W4 = Pre emergence herbicide. Sunup 480 SL spraying alter land preparation. W 5 = Post emergence herbicide. Release 9 EC spraying at 15-20 DAG . Results revealed that plant spacing with 30 cm x 10 cm stand superior than other in respect of above ground dry matter weight plant' (15.80 g), pod length (4.64 cm), seeds pod' (6.63), 1000 seed weight (39.46g), seed yield (1.38 t hi') and harvest index (40.71%) respectively while maximum number of pods plant ' (17.26), branches plant' (2.73), were found in 40 cm x 10 cm spacing. Among weed management practices, the highest plant height (97.34 cm), dry matter content plant" (16.49 g), pod length (4.84 cm), seeds pod" (6.63) and seed yield (1.60 t ha" ), pods plant" (18.43), grain yield (1.60 t ha'), biological yield (4.15 t ha") and harvest index (38.32 %) was obtained from two hand weeding treatment. In interaction, the maximum dry matter weight plant" (17.99 g), pod length (5.02cm), seeds pod' (6.96). 1000 seed weight (42.20g). grain yield (2.2 t ha') and biological yield (4.7 t ha') were gained by 30 x 10 cm row spacing with two times of hand weeding (at 20 DAS and 40 DAS). However, the highest number of pods plant" (21.66) were recorded in 40 x 10 cm row spacing with two times of hand weeding. Economic analysis revealed that 30 cmx 10 cm plant spacing Ibliowed by two hand weeding (at 20 DAS and 40 DAS) for weed control recorded maximum gross margin (1K- 176843 ha") and benefit cost ratio (4.47) which indicated that blackgram should be cultivate giving spacing of 30 em x 10 cm along with two hand weeding.