摘要：The experiment was conducted at the Agronomy farm of Sher-e-Bangla Agricultural University to identify the allelopathic effect of Brassica species along with their incorporation methods to control weeds in wheat field. The experiment was assigned in a split-plot design where three cultivated Brassica spp. were in the main plot and five different ways of green Brassica biomass inclusion were in the sub-plot. Brassica crops were uprooted at 30 days after sowing (DAS) and incorporated to the soil @ 0.5 kg m -2 as per treatment. Wheat seeds were sown on December 04, 2007 using 20 cm line to line distance. Weeds e.g., Amaranthus spinosus , A. viridis , Lindernia procumbens , Heliotropium indicum, Polygonum hydropiper, Celosis argentina, Ageratum conyzoides, Brassica kaber and Digitaria ischaemum were not found in the wheat field. Significantly the highest weed dry matter (1.72 g m -2 ) was found in Brassica juncea plots at 30 DAS but in Brassica napus field (1.44 g m -2 ) at 50 DAS. The lowest weed dry matter at 30 DAS (0.89 g m -2 ) was recorded with total incorporation of Brassica biomass to the soil but 50% incorporation and 50% spreading at 50 DAS. The Brassica biomass spreading above ground, mixed with soil and 50% spreading + 50% mixed with soil resulted positively compared to other ways of biomass incorporation. The highest grain yield (3.83 t ha -1 ) of wheat was given by Brassica juncea when spreaded on the above ground soil. Bangladesh Agron. J. 2014, 17(1): 73-80
