WEED SUPPRESSION STUDY OF MULCH MATERIALS IN T. AMAN CULTIVATION

Abstract

The study was conducted at the Agronomy Farm, Sher-e-Bangla Agricultural University, Dhaka-1207, Bangladesh, during the period from August to December 2013 to evaluate the weed suppression efficacies of six mulch materials applied with three rice varieties experimented in a randomized complete bock designed plots. The varieties under the trial were BRRI dhan33; BRRI dhan56 and BRRI dhan57 designated V1, V2 and V3 respectively. The mulch materials used were maize stover; mustard straw; rice straw; sesame straw; water smart weed (Bishkathali) and no mulch as also designated T1, T2, T3, T4, T5 and T6 respectively. The plant height was influenced significantly by rice varieties but mulch materials showed no effect on it. The highest plant height was observed in combination effect of BRRI dhan56 x mustard straw mulch (124.3cm) and that of the lowest was found in BRRI dhan57 with No mulch (97.2cm). At 80 DAT, the highest number of tillers hill-1(23.88) was observed in BRRI dhan57. Moreover, the highest number of tillers hill-1 (25.33) was observed in BRRI dhan57 treated with maize stover. The plant dry matter was influenced significantly by rice varieties but effect of mulch materials was not significant. The highest grain yield (5.415 t ha-1) was found in BRRI dhan33 which might have supported by higher panicle length(27.03cm) , number of filled grain panicle-1 (148.55) and thousand grain weight (28.41gm). Grain yield of rice did not differ significantly due to mulch materials. However, the highest grain yield (5.508 t ha-1) was observed due to combined effect of BRRI dhan33 and rice straw while the lowest (3.717 t ha-1) was estimated in BRRI dhan57 x no mulch combination. Mustard straw mulch reflected higher harvest index (50.02%) which is statistically similar with sesame stover (49.7%). BRRI dhan33 x mustard straw and BRRI dhan56 x water smart weed showed higher harvest index 53.81% and 53.11%, respectively while BRRI dhan57 x no mulch showed the lowest (43.2%).The highest and the lowest number of weeds at first weed collection was found in BRRI dhan56 (29.11) and BRRI dhan57 (11.72). respectively. Significant variation was recorded in number of weed production at second weed collection with the highest density at no mulch (15.88) and the lowest number (2.44) at water smart weed straw. The result indicated that mulch materials had influence on weed suppression. In interaction effect, BRRI dhan 56 x no mulch showed highest weeds while BRRI dhan 56 x water smart weed and BRRI dhan57 x water smart weed produce lowest (2) weed at 2nd weed collection.