Farmer perceptions of the biophysical constraints to rice production in sub-Saharan Africa, and potential impact of research.

Diagne, Aliou; Alia, Didier; Amovin-Assagba, Eyram; Wopereis, M.C.S.; Saito, Kazuki; Nakelse, Tebila

doi:10.1079/9781845938123.0046

Cited by 39 publications

(44 citation statements)

References 6 publications

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“…Weeds are perceived by farmers as the most important overarching production constraint in rice in SSA (Diagne et al 2013). Rice systems in SSA are characterized by diverse weed communities.…”

Section: Weed Management In Rice: Importance Of Herbicidesmentioning

confidence: 99%

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

et al. 2019

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If future rice production is to contribute to food security for the increasing population of sub-Saharan Africa (SSA), effective strategies are needed to control weeds, the crop's fiercest competitors for resources. To gain better insights into farmers' access to, and use of, herbicides as part of weed control strategies, surveys were conducted in key rice production locations across SSA. Farm surveys were held among 1965 farmers across 20 countries to collect data on rice yields, farmer's weed management practices, herbicide use, frequencies of interventions and information sources regarding herbicides. Markets were surveyed across 17 countries to collect data on herbicide availability, brand names and local prices (converted to US$ ha −1 ). Herbicides are used by 34% of the rice farmers in SSA, but adoption ranges from 0 to 72% across countries. Herbicides are more often used by men (40%) than by women (27%) and more often in irrigated (44% of farmers) than in rainfed lowland (36%) or upland rice growing environments (24%). Herbicides are always used supplementary to hand weeding. Following this combination, yield loss reductions in irrigated lowlands and rainfed uplands are estimated to be 0.4 t ha −1 higher than hand weeding alone. In rainfed lowlands no benefits were observed from herbicide use. Sixty-two percent of the herbicides sold at rural agro-chemical supply markets are unauthorized. These markets are dominated by glyphosate and 2,4-D, sold under 55 and 41 different brand names, respectively, and at relatively competitive prices (below average herbicide price of US $17 ha −1 ). They are also the most popular herbicides among farmers. For advice on herbicide application methods, farmers primarily rely on their peers, and only a few receive advice from extension services (<23%) or inform themselves by reading the product label (<16%). Herbicide application timings are therefore often (38%) sub-optimal. Herbicide technologies can contribute to reduced production losses in rice in SSA. However, through negative effects on crop, environment and human health, incorrect herbicide use may unintentionally counteract efforts to increase food security. Moving away from this status quo will require strict implementation and monitoring of national pesticide regulations and investment in research and development to innovate and diversify the currently followed weed management strategies, agricultural service provision and communications with farmers.

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Section: Weed Management In Rice: Importance Of Herbicidesmentioning

confidence: 99%

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

et al. 2019

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“…I n West Africa, upland rice is typically grown in low-input production systems and accounts for about 40% of the total rice area, yielding 1 to 2 t ha −1 (Diagne et al, 2013a). Low soil fertility, which generally results from low organic N and P availability, is a major constraint to upland rice productivity (Becker and Johnson, 2001;Somado et al, 2011;Diagne et al, 2013b). Thus, farmers need to supply nutrients either in the form of inorganic fertilizer or from leguminous crops by adopting crop rotation systems (Becker and Johnson, 1998).…”

Section: Notementioning

confidence: 99%

Plant Characteristics of High‐Yielding Upland Rice Cultivars in West Africa

Saito

2016

Crop Science

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In West Africa, upland rice (Oryza spp.) is typically grown in low‐input production systems under low soil fertility conditions. Genetic improvement may offer a cost‐effective approach to improving the productivity rather than approaches that rely solely on external nutrient inputs. In the 1990s, the upland rice breeding program of the West Africa Rice Development Association (now Africa Rice Center [AfricaRice]) developed New Rice for Africa (NERICA) cultivars. However, recent studies suggest that there is scope for improving on the currently available NERICA cultivars. The objectives of this study are to (i) quantify yield advantage of two cultivars (Aus 257 and IR 74371‐3‐1‐1) which were identified as high‐yielding ones from a wide range of materials, over NERICA 1, and (ii) identify plant characteristics of these two high‐yielding cultivars. Data were compiled from nine on‐station and 23 on‐farm trials in Benin. On average over all the trials, the two cultivars out yielded local check upland NERICA 1. Particularly, their relative yield advantage was higher when NERICA 1 showed low yield. Aus 257 had greater biomass accumulation, harvest index (HI), and uptake of N, P, and K. Greater biomass accumulation was the result of high leaf area index (LAI). Cultivar variation in nutrient‐use efficiency also contributed to high yield, and IR 74371‐3‐1‐1 showed higher nutrient‐use efficiency than NERICA 1 and Aus 257. These results suggest that the use of the two cultivars with greater biomass accumulation, harvest index, nutrient uptake, and use efficiency is critical for improving rice yield.

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“…Low yields of upland rice are often attributed to sub-optimal crop management practices, limited availability of high-yielding varieties, and abiotic and biotic stresses (some of which might be associated with land use pressure) (Becker & Johnson, 2001;Diagne et al, 2013;Niang et al, 2017;Saito, Linquist, Keobualapha, et al, 2006;Saito et al, 2013;Tanaka et al, 2017). Typical major abiotic and biotic stresses include cold stress in highlands (Ahmadi et al, 2004;Raboin et al, 2014), drought (Kijima et al, 2011;Niang et al, 2017Niang et al, , 2018Saito et al, 2013Saito et al, , 2017, soil-related problems including acidity and N and P deficiency (Asai et al, 2009;Haefele et al, 2014;Okada & Fischer, 2001;Saito, Linquist, Keobualapha, et al, 2006;Saito et al, 2007Saito et al, , 2013, weeds (Becker & Johnson, 2001;, and soil-borne pests such as nematodes (Balasubramanian et al, 2007).…”

Section: Introductionmentioning

confidence: 99%

Progress in varietal improvement for increasing upland rice productivity in the tropics

Saito

Asai

Zhao

et al. 2018

Plant Production Science

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Enhancing rice yield in upland rice systems through genetic improvement remains a major challenge in the tropics. This review aims to provide the trends on upland rice cultivation over the last 30 years and recent distribution of upland rice in the tropics, and to report progress in studies on genetic improvement for enhancing productivity in Africa, Asia, and Latin America. While upland rice cultivation area has reduced in Asia and Latin America over the last 30 years, the area in Africa has increased. The current share of upland rice area in total rice area is related to rainfall and gross national income per capita, especially in Africa, and higher share is associated with lower rice selfsufficiency at national level. Breeding programs in Asia and Latin America have developed highyielding varieties using indica materials as parents. In Africa, New Rice for Africa (NERICA) varieties were developed from crosses between improved tropical japonica and Oryza glaberrima. However, recent studies report that there is scope for improving existing NERICA using upland indica materials from Asia. In highlands of Africa, there are ongoing breeding programs using japonica varieties, such as the Nepalese Chhomrong Dhan. Key important plant traits used in the breeding programs are not largely different across regions, especially intermediate plant height and tillering capacity (which may be related to weed-suppressive ability), and high harvest index. In conclusion, we propose an international network for breeding upland rice with accelerating seed exchange across regions that could enhance upland rice productivity through genetic improvement.

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Farmer perceptions of the biophysical constraints to rice production in sub-Saharan Africa, and potential impact of research.

Cited by 39 publications

References 6 publications

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

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

Plant Characteristics of High‐Yielding Upland Rice Cultivars in West Africa

Progress in varietal improvement for increasing upland rice productivity in the tropics

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