Interactive Effects of Strip Planting, Herbicides and Wheat Straw Mulch on Weed Control and Yield of Mungbean in Northern Bangladesh

Crisis of agricultural labors in the rural areas is pushing the smallholder farms in South Asia to seek for a mechanized planting system together with crop residue mulching and the application of herbicides. The present on-farm study was undertaken to determine the effectiveness of residue mulching relative to herbicides and manual weeding by hands for controlling weeds and yield of mungbean in strip planted soil in northern Bangladesh. In this experiment, mungbean cv. BARI Mungbean 6 was grown after wheat during the April-June in 2015 and 2016, under two tillage types combined with the two weed control practices [P1: conventional tillage (CT) + three hand weeding, P2: Pre-plant (PRE) herbicide + strip planting (SP) + pre-emergence (PE) herbicide + post-emergence (PO) herbicide]; and two levels of wheat straw mulch [M0: no-mulch and M50: 50% standing mulch]. The CT was done by two primary and two secondary tillage operations by a two-wheel tractor, while the SP was done by a Versatile Multi-crop Planter in a single-pass process. The PRE herbicide (glyphosate), PE herbicide (pendimethalin) and PO herbicide (fenoxaprop-p-ethyl) was applied at recommended doses. The combination of applied PRE, SP, followed by sequential application of PE and PO herbicides plus retention of 50% wheat straw mulch achieved the highest weed control efficacy. Furthermore, this practice produced the 21% higher yield and 62% higher profit relative to conventional tillage with three hand weedings without mulch.