Economic Evaluation of Weed Control and Herbicide Residues on Cassava (Manihot esculenta Crantz) in Ghana

Abstract

<p>A study on economic evaluation of some weed management strategies and herbicide residues analysis on roots of cassava (<em>Manihot esculenta</em> Crantz) was conducted during 2014 and 2015 cropping season in Kumasi, Ghana. Cost and benefits were computed from the use of two manual weedings (hoeing and cutlassing), two pre-emergence herbicides (Butachlor 60% EC and Terbulor 500 EC) with two-supplemenatary hoe weeding, weed-free and weedy check. These were evaluated using two varieties of cassava, Ampong (Early branching) and Dokuduade (Late branching). The treatment was a factorial laid out in a randomized complete block design (RCBD) with four replicates. Partial farm budgeting were used for economic analysis of data and herbicide residues analysis in roots of cassava were determined using Gas Chromatography-Electron Capture Detector (GC-ECD). Results showed that Terbulor 500 EC with two supplementary hoe weeding was more economical, profitable and beneficial than those other treatments applied in the production of cassava. In addition, the average concentration of Terbulor 500 EC (0.003 mg/kg) and Butachlor 60% EC (0.001 mg/kg) residues in roots of cassava varieties were below the maximum residue limit (MRL) of 0.01 mg/kg set by Ghana Standards Authority for cassava. In conclusion, Terbulor 500 EC with two supplementary hoe weeding was more effective and financially rewarding and both herbicides had lower residual effects on cassava.</p>

Canopy Structure Influence the Critical Period for Weed Removal of Three Cassava (Manihot esculenta Crantz) Varieties in Zambia

“…These manual methods are inefficient because of drudgery, time consuming, expensive, and high labour demands during peak production periods (Islami et al, 2017;Maniyam et al, 2013). Alternative weed management practices such as chemical control (herbicides), cultural methods and integrated weed management practice have been tried elsewhere with variable results in cassava production systems (Ola et al, 2021a;Quee et al, 2016). Similarly, mechanical weed control tools that are gender neutral and labour saving have not attained the desired impact due to high initial cash outlay and hence low uptake by smallholder farmers (Johnson et al, 2019;Rodenburg et al, 2015).…”