Farmers’ Perceptions on Mechanical Weeders for Rice Production in Sub-Saharan Africa

Abstract

SUMMARYCompetition from weeds is one of the major biophysical constraints to rice (Oryza spp.) production in sub-Saharan Africa. Smallholder rice farmers require efficient, affordable and labour-saving weed management technologies. Mechanical weeders have shown to fit this profile. Several mechanical weeder types exist but little is known about locally specific differences in performance and farmer preference between these types. Three to six different weeder types were evaluated at 10 different sites across seven countries – i.e., Benin, Burkina Faso, Côte d'Ivoire, Ghana, Nigeria, Rwanda and Togo. A total of 310 farmers (173 male, 137 female) tested the weeders, scored them for their preference, and compared them with their own weed management practices. In a follow-up study, 186 farmers from Benin and Nigeria received the ring hoe, which was the most preferred in these two countries, to use it during the entire crop growing season. Farmers were surveyed on their experiences. The probability of the ring hoe having the highest score among the tested weeders was 71%. The probability of farmers’ preference of the ring hoe over their usual practices – i.e., herbicide, traditional hoe and hand weeding – was 52, 95 and 91%, respectively. The preference of this weeder was not related to gender, years of experience with rice cultivation, rice field size, weed infestation level, water status or soil texture. In the follow-up study, 80% of farmers who used the ring hoe indicated that weeding time was reduced by at least 31%. Of the farmers testing the ring hoe in the follow-up study, 35% used it also for other crops such as vegetables, maize, sorghum, cassava and millet. These results suggest that the ring hoe offers a gender-neutral solution for reducing labour for weeding in rice as well as other crops and that it is compatible with a wide range of environments. The implications of our findings and challenges for out-scaling of mechanical weeders are discussed.

Quantifying rice yield gaps and their causes in Eastern and Southern Africa

“…In only four sites, weeding frequencies above three were observed, and the share of farmers weeding three‐time, or more was only substantial (70% in Ambohibary) or fairly substantial (16% in Ankazomiriotra) in Madagascar. Mechanical weed control using a rotary weeder (Johnson et al., 2018; Rodenburg et al., 2015) was used in 97% and 49% of the farmers in Madagascar (Ambohibary and Ankazomiriotra respectively), 28% of the farmers in Kahama (Tanzania) and 50% of the farmers in Doho (Uganda). Predominant use of rotary weeders in Madagascar and absence of mechanical weeding in Ethiopia and Rwanda has been reported recently (Rodenburg et al., 2019).…”

Status quo of chemical weed control in rice in sub-Saharan Africa

“…The first option, hand weeding, is labor intensive; in upland rice systems hand weeding was estimated to take 173 to 376 person-hours per hectare, depending on the number of weeding interventions (Ogwuike et al 2014). Mechanical tools for weeding, either person-driven, animaldriven or engine-driven, are scarce in rice systems in Africa (Rodenburg and Johnson 2009;Gongotchame et al 2014), despite a latent interest from farmers (Johnson et al 2018). Herbicide application, when applied well, is usually the most effective and least labor-intensive weed control method with the highest yield return .…”

Integrated Research for Development Approach to Upgrade the Whole Rice Value-chain in Sub-Saharan Africa: Contribution of Africa Rice Center after NERICA (New Rice for Africa)

“…Although no differences in weed control efficacy were observed between mechanical and hand weeding, weeding time was significantly reduced (32-97%) by mechanical weeding compared with hand weeding (Rodenburg et al 2015). To understand farmers' perceptions on mechanical weeders, three to six different weeder types were evaluated at 10 different sites across seven countries in SSA (Johnson et al 2018). Among the mechanical weeders tested, ring hoe was most preferred; the probability of farmers' preference of the ring hoe over their usual practices-herbicide, traditional hoe and hand weeding-was 52%, 95% and 91%, respectively and this particular preference of ring hoe was not related to gender, years of experience with rice cultivation, rice field size, weed infestation level, water status or soil texture (Johnson et al 2018).…”