Status of yam (Dioscorea spp.) in the Democratic Republic of Congo

Abstract

Yam is an important tuber crop with enormous potential to enhance rural sustenance and livelihood in DRC. However, studies to enhance its genetic improvement are very far from sufficient with only a handful of information available on the crop. Yam has been treated as an orphan crop compared to contemporary crops such as cassava and sweet potato which have adapted to different cropping systems and become widespread in production. The lack of research attention to address the major production challenges has further decreased the value and potential of the crop compared to its contemporaries. These production constraints include lack of adequate quality planting materials, low yield potential, poor resistance/tolerance to yam mosaic and anthracnose diseases and ultimately poor tuber quality attributes focusing on tuber taste, flesh oxidation and dry matter contents of the majority of the farmers preferred varieties. In this review, we evaluated the status of yam in DRC and presented the needful activities to be incorporated for its improvement. Diversity has however been maintained mainly through ennoblement efforts in house gardens and small farmlands using traditional farming methods. Studies from other nations where yam has been successful with prominence in characterization and genetic improvement brought to light the need for DRC to consider yam as a staple carbohydrate food source, even to the extent of modifications in food public policy. Reversal of the yam's current stigma is a challenge to the scientific community and the population in general.

Farming practices, varietal preferences, and land suitability analyses for yam production in Eastern D.R. Congo: implications for breeding initiatives and food sovereignty

“…In this way, yam farming is key for food security as it diversifies food and income of rural households in eastern DRC. These results agree with those of Adejumobi et al (2022bAdejumobi et al ( , 2023 in northwestern DRC that showed that yam is, in surface and volume, a secondary crop and is mainly on house gardens and small farmlands (<0.25 ha), using traditional farming methods and local landraces. Previous reports listed yam among neglected and underutilized (orphan) crop species in DRC (Mondo et al, 2021;Adejumobi et al, 2023).…”

“…Seed access depended largely on seed exchanges among farmers or purchased from informal markets. Since yam diversity is high in DRC (Magwé-Tindo et al, 2018), farmers were also acquiring seeds from forest environments, a practice referred to as ennoblement elsewhere (Scarcelli et al, 2006;Chikwendu and Okezie, 2014;Agre et al, 2021;Adejumobi et al, 2023). In addition to poor farming practices and informal seed system, farmers lacked sufficient knowledge of tuber storage techniques and value addition, leading to high post-harvest losses.…”

“…Fortunately, more than 50% of yam cultivars grown in eastern DRC flowered, and thus, it opens an avenue for cross-breeding to generate variable offspring for selection (Mondo et al, 2023). Some of the traits lacking in yam in DRC are mainly yield-related traits, earliness, disease and pest resistance, and tuber quality attributes (long post-harvest shelf life, low tuber flesh oxidation, sweet taste, tuber softness, short cooking time, high tuber dry matter, ease of peeling, reduced bitterness, tuber size and shape) of local landraces (Adejumobi et al, 2022b(Adejumobi et al, , 2023. Consequently, yam has been gradually replaced by other staples like cassava, maize, sweet potato, etc.…”

“…Alongside other root and tuber crops, yam has been a major food security pillar in sub-Saharan Africa (SSA) owing to its resilience to climate hazards and pests when compared to cereals and legumes (Thiele et al, 2017). Despite its potential for food security and wealth creation, yam is still regarded as a subsistence crop, practiced mainly by women on small plots, in Democratic Republic of Congo (DRC) where it was listed among neglected and underutilized (orphan) crop species (Mondo et al, 2021;Adejumobi et al, 2022aAdejumobi et al, , 2023.…”

“…There is extensive yam production in the western forest regions of DRC and the highlands of Kivu in the eastern part (Adejumobi et al, 2023). In eastern DRC, mainly in the North-and South-Kivu provinces, yam is highly valued for its cultural and therapeutic virtues.…”