Efficacy of Herbicides in Non-Puddled Transplanted Rice Under Conservation Agriculture Systems and Their Effect on Establishment of the Succeeding Crops

Abstract

Transplanting of rice seedlings in non-puddled soil under conservation agriculture systems is a new promising technology for which effective and economic weed control strategies have to develop. Therefore, a study was conducted in wet season rice during 2013 and 2014 with some commonly used pre-and post-emergence rice herbicides (pyrazosulfuron-ethyl, butachlor, orthosulfamuron, acetochlor + bensulfuron methyl, butachlor + propanil and 2,4-D amine) in strip tilled non-puddled field condition at Mymensingh, Bangladesh to evaluate their weed control efficacy singly or in sequences, their cost-effectiveness and residual effect on the succeeding crops like wheat and lentil. Sole application of herbicide was less effective to control all types of weed species than sequentially applied herbicides. Sequential application of pre-and late post-emergence, early post-and late post-emergence or pre-, early and late post-emergence herbicides controlled weeds by 46-98% and 43-95%, respectively in terms of weed density and biomass. Sequential application of pyrazosulfuron-ethyl followed by orthosulfamuron and butachlor + propanil provided the most effective and economic weed control under this new rice establishment practice. Moreover, the study suggested a range of effective herbicides for strip-tilled non-puddled wet season rice, but possible rotation of those herbicides in a sequential application is needed. Additionally, residue of those herbicides did not show any adverse effect on the succeeding crops of rice like wheat and lentil. However, further research is needed with various new molecules of herbicide and their residual effect on the subsequent crop as well as soil environment.

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.…”

Partially mechanized non-puddled rice establishment: on-farm performance and farmers’ perceptions

“…Other than hand weeding, there are many pre-and post-transplanting herbicides available Zahan et al, 2014). Selection of effective herbicides will play a key role in maintaining weed control for PT and NT rice (Zahan, Hashem, Rahman, Bell & Begum, 2018). It remains unclear whether residue retention and the lower suspended sediment load in standing water of non-puddled soils alters the efficacy of the pre-emergence and early post-emergence herbicides commonly used in wetland rice.…”

Assessment of Forest Ecosystem Health Based on Fuzzy Evaluation Method-a Case Study of Forest Ecosystem in Liangshui Natural Reserve

“…The index weight is used to quantify each index in the overall evaluation so as to show the different important levels and the reasonable factors that directly affect the scientificalness of final evaluation results (Li et al 2007, Xiao et al 1997, Zahan et al 2018. At present, many methods determine the weight of index, including the analytic hierarchy process, expert scoring method, factor analysis, discriminant analysis, sequence synthesis method and principal component analysis method (Wang et al 2008, Xiao andOuyang 2004).…”