ALLELOPATHIC EFFECTS OF RAPESEED/MUSTARD VARIETIES ON LENTIL AND ITS ASSOCIATED WEEDS

Abstract

The experiment was conducted at the Agronomy research field, Sher-e-Bangla Agricultural University, Dhaka from November, 2011 to March, 2012 to find out the allelopathic effect of Brassica biomass on weed control and yield of lentil. There were eleven treatments in the experiment. The treatment of the experiment consisted green Brassica biomass and water extract of dry Brassica biomass. Green Brassica biomass (30 days old) was incorporated in the soil at the sowing time of lentil @ 2.6 tha-1. Extracted water of dry Brassica biomass of each variety were sprayed two times (30 & 60 DAS of lentil) in the specific plot @1.3 t 6666 L-1 water ha-1. The treatments were-T1 = Control, T2 = Tori 7-Biomass incorporated @2.6 t ha-1 at sowing, T3 = Tori 7-Dry matter water extract spray @ 1.3 t 6666 L-1 water ha-1 at 30 and 60 DAS of lentil, T4 = BARI Sarisha8-Biomass incorporated @2.6 t ha-1 at sowing, T5 = BARI Sarisha8-Dry matter water extract spray @ 1.3 t 6666 L-1 water ha-1 at 30 and 60 DAS of lentil, T6 = BARI Sarisha11-Biomass incorporated @2.6 t ha-1 at sowing, T7 = BARI Sarisha11-Dry matter water extract spray @ 1.3 t 6666 L-1 water ha-1 at 30 and 60 DAS of lentil, T8 = BARI Sarisha13-Biomass incorporated @2.6 t ha-1 at sowing, T9 = BARI Sarisha13-Dry matter water extract spray @ 1.3 t 6666 L-1 water ha-1 at 30 and 60 DAS of lentil, T10 = BARI Sarisha15-Biomass incorporated @2.6 t ha-1 at sowing, T11 = BARI Sarisha15-Dry matter water extract spray @ 1.3 t 6666 L-1 water ha-1 at 30 and 60 DAS of lentil. The highest no. of weeds m-2 both at 30 and 60 DAS were observed in treatment T1 (164.00 and 169.00 respectively) and lowest in T2 (62.00) and T7 (70.00) while highest dry weight of weeds m-2 both at 30 and 60 DAS were found in treatment T1 (4.80g and 16.10g respectively) and minimum in T9 (1.17g) and T2 (6.63g) respectively. At harvest the maximum plant height (34.81cm) and dry weight plant-1 (3.83g) were found in treatment T11 and T7 and minimum in T5 (23.99cm) and T6 (2.47g) respectively. The highest branches plant-1(5.17), pods plant-1(71.70), grains pod-1 (1.93), 1000 grains wt. (20.37g) were found in treatment T8, T10, T8 and T8 respectively. But lowest branches plant-1 (3.83), pods plant-1 (33.53), grains pod-1 (1.70), 1000 grains wt.(18.07gm) were found in treatment T11, T3, T7 and T2 respectively. There is a significant result on biological yield, grain yield, straw yield, harvest index and shelling percentage. The highest biological yield (2.83tha-1), grain yield (0.95tha-1), straw yield (2.17tha-1), harvest index (39.23%) and shelling percentage (29.60%) were observed in treatment T10, T11, T10, T11 and T2 respectively. The lowest biological yield (2.10 tha-1), grain yield (0.52 tha-1), straw yield (1.13 tha-1), harvest index (25.17%) and shelling percentage (19.70 %) were found in treatment T4, T4, T4, T6 and T10 respectively.