Residual Effect of Herbicides Applied in Unpuddled Transplanted Aman Rice on The Succeeding Crops Assessed by Bioassay Technique

Abstract

The residual effect of eight herbicides (pendimethalin, pyrazosulfuron-ethyl, butachlor, pretilachlor, orthosulfamuron, acetochlor + bensulfuron methyl, butachlor + propanil and 2,4-D amine) was applied in unpuddled transplanted aman rice in aa weedy and a hand weeded controls, was evaluated for succeeding crops viz. wheat, lentil and sunflower by following bioassay technique. A study was conducted at Bangladesh Agricultural University, Mymensingh from November 2013 to January 2014 after harvest of unpuddled transplanted aman rice. All herbicides were imposed as weed management practice of unpuddled transplanted aman rice during July to August 2013. The experiment was laid out in a randomized complete block design (RCBD) with three replications. As a consequence, the residual effect of those herbicides on the succeeding wheat, lentil and sunflower crops was evaluated in term of germination, leaf chlorophyll content, seedling shoot length and dry matter. The results showed that seedling germination of all these succeeding crops in the herbicide treated plots did not differ significantly from those of weedy and hand weeded control plots. Moreover, leaf chlorophyll content, seedling shoot length and dry matter of wheat, lentil and sunflower were not adversely affected by any of the herbicide treatments imposed in aman rice. It was concluded that herbicides used in unpuddled transplanted aman rice had no residual effect on the germination and leaf chlorophyll content, seedling shoot length and dry matter of the succeeding wheat, lentil and sunflower crops.

Conservation Agriculture for Rice-Based Intensive Cropping by Smallholders in the Eastern Gangetic Plain

“…Research and development in Bangladesh have developed effective CA practices for smallholder farms in the EGP using minimum soil disturbing implements mounted on 2WTs. The key outcomes are new knowledge developed on: (i) effective strip planting using the VMP [4][5][6]; (ii) planting machinery development and performance testing in the small fields using 2WTs [4,9]; (iii) agronomy for mechanised seeding with minimum soil disturbance and residue retention [5,6]; (iv) weed dynamics and weed management under CA [11][12][13][14][15][16]33]; (v) crop rotation effects on soils and weeds [33,34]; (vi) mechanised transplanting of NPT rice [24,25]; (vii) soil improvement under CA [17][18][19][20][21][22]; (viii) decreased greenhouse gas emissions under CA [23]; (ix) increased profit from CA-based SP + NPT rice in farmers' fields [8]; (x) water balance [27], which showed that wheat under CA (SP and increased residue retained) required 11-33% less irrigation water than the convention practices; and (xi) commercialisation models for sales of planters to LSP [31]. Based on the evidence presented, there should now be sufficient confidence for more widespread demonstrations across different agro-ecosystems in the EIP and for programmes to engage the private sector and farmers in adoption and out-scaling of CA for smallholder rice-based crop production in the EGP.…”

“…Selection of herbicides with different modes of action is an essential tool to minimize the risk of herbicide resistance developing in weeds. From several papers [11][12][13][14][15][16], it can be concluded that rotational use at the recommended dose of the effective herbicides in a rice-wheat-mung bean pattern could be effective to control weeds in the CA system as the herbicides applied to rice and wheat had no residual effect on the succeeding crops. Moreover, almost all rice and wheat varieties were tolerant to herbicides at the recommended rate on the product label.…”

Effect of preceding rice herbicide residue towards control of weeds and urdbean productivity in rice -Bhendi-urdbean sequence under high rainfall area

“…The similar line of findings was reported by Chandolia (2009). Herbicide applied to unpuddled transplanted rice showed no effect on subsequent wheat, lentil, and sunflower germination, leaf chlorophyll content, shoot length, or dry matter (Zahan et al, 2016).…”