WEED MANAGEMENT FOR MUNGBEAN UNDER DIFFERENT LEVEL OF PLANT SPACING

Abstract

An experiment was conducted at the Agronomy field of Sher-e-Bangla Agricultural University, Dhaka during August to October 2013 to study the effect of row spacing and weed management on the performance of mungbean (cv. BARI Mung-6). The experiment comprised of two factors viz. (i) plant spacing and (ii) weed management with three plant spacing (S 1 = 20 cm × 10 cm, S 2 = 30 cm × 10 cm,

S = 40 cm × 10 cm ) and five levels of weeding treatments (W 1 = No weeding, W 2 3 = Hand weeding at 20 DAS, W = Hand weeding at 20 and 40 DAS, W 4 3 = Pre emergence herbicide, Sunup 480 SL spraying after land preparation, W = 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 branches plant 5 -1 (1.04), above ground dry matter weight plant -1 (12.26 g), pod length (9.02 cm), seeds pod -1 (10.71), seed yield (1.08 t ha -1 ), respectively while maximum number of pods plant -1 (10.39), 1000-seeds weight (47.16 g) and harvest index (37.90 %) were found in 40 cm x 10 cm spacing. Among weed management practices, the highest plant height (65.60 cm), dry matter content plant -1 (13.37 g), pod length (9.16 cm), seeds pod -1 (10.98) and straw yield ( 2.18 t ha -1 ) were obtained by the application of post emergence herbicide at 15-20 DAG (W 5 ) while maximum number of pods plant -1 (9.89), grain yield (1.34 t ha ), biological yield (3.51 t ha -1 ) and harvest index (38.71 %) was obtained from two hand weeding treatment. In interaction, the maximum dry matter weight plant -1 (15.48 g), pod length (10.75 cm), seeds pod -1 (12.71), grain yield (1.51 t ha -1 -1 ) and biological yield (3.973 t ha ) were gained by 30 × 10 cm row spacing with application of post emergence herbicide for weed management. However, the highest number of pods plant -1 (12.67) and harvest index (45.19%) were achieved by 40 × 10 cm row spacing with two times of hand weeding. But maximum 1000-grains weight (50.89) was found in 40 × 10 cm row spacing with single weeding. Economic analysis revealed that 30 cm x 10 cm plant spacing followed by application of post emergence herbicide (Release 9 EC @ 650 ml ha -1 ) for weed control recorded maximum gross margin (111735 TK ha-1) and benefit cost ratio (3.50) which indicated that mungbean was used to cultivate giving spacing as 30 cm x 10 cm along with Release spraying at 15 days after germination.

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