Climate threats to red kidney bean cultivation: A CCAFS report

The main climate risks to beans cultivation Rwanda are: (i) extreme precipitation levels, primarily in the northern and western regions (Ruhengeri, Gisenyi, Gikongoro and Byumba) where abundant rainfall can cause erosion, flooding and landslides;(ii) Biotic stresses, primarily plant diseases and pests; (iii) post-harvest losses resulting from increasingly favourable environments for damaging micro-organisms and insects.

The main adaptation measures for managing the expected impacts of climate change on bean cultivation include: (i) continued development and adoption of both climate resilient and higher-nutrition bean varieties; (ii) integration of flood and land management practises at the catchment and farm-scale; (iii) improved provision of drying, threshing and storage facilities.

CCAFS validates the climate threats and solutions highlighted in the IFAD statements below (which refer to maize as well as beans). CCAFS also identifies drought stress as a possible climatic hazard to bean cultivation.

One caveat is that CCAFS research, using modelling approaches and shown in Figure 2, indicates that average growing conditions, including average precipitation levels, are conducive to the continued and, in some areas, improved viability of bean cultivation.

This does not preclude, however, the possibility of continued or increased variability in precipitation and elevated evapotranspiration combining to enhance the prevalence or severity of droughts during some seasons in future years. But it remains unclear if such an effect would prevail in the situation of generally increasing annual average levels of rainfall. Comparably, if the impact of temperature extremes remains moderate and the risks of biotic stresses can be mitigated, the analysis from climatic niche modelling suggests the continued viability of bean growth in a changing climate. 

Less can be said from the scientific point of view about post-harvest risks and solutions in the harvesting, storage and transport of beans, since little research has been done.   However any reductions of post-harvest losses will have both adaptation and mitigation benefits.

IFAD statement on climate risks:

  • In Sub-Saharan Africa maize is predominantly grown in smallholder farming systems under rainfed conditions with limited inputs. Low yields in this region are largely associated with drought stress, low soil fertility, weeds, pests, diseases, low input availability, low input use and inappropriate seeds. Reliance on rainfall increases the vulnerability of growing beans and other staples to climate variability and change. While farmers have a long record of adapting to the impacts of climate variability, current and future climate change represents a greater challenge because the probable impacts are out of the range of farmers' previous experiences. Climate change will, therefore, severely test farmers' resourcefulness and adaptation capacity.
  • Precipitation projections in the eastern region suggest changes in rainfall patterns could cause disruptions to the two cropping seasons that characterize Rwanda's rainfed system.
  • In the Eastern region, the decline and uneven distribution of rains in September negatively impacted on the germination stage of crops which led to a re-planting of those crops in some areas, mostly in the South-eastern region (Bugesera and Kayonza districts). Climate model scenarios suggest that the eastern region will experience greater risk of drought stress in the future.

 

ASAP Solutions:

  • Promote crop varieties with crop maturities periods better suited to the changing growing season lengths.
  • Facilitate greater collaboration between MINAGRI and National Meteorological Services to support the development of climate information services that provide relevant and timely information to project beneficiaries to mitigate the impacts of climate variability on planting, harvesting and drying.
  • Support a detailed survey of existing post-harvest storage structures and MCCs to develop appropriate guidance/ building codes that will ensure that current and future infrastructure investments are climate smart and include appropriate measures to manage excess rainwater.
  • HUB business investments in improved climate resilient and low carbon post-harvesting procedures, drying, processing and value addition, storage, logistics and distribution to achieve reductions in product losses and increase smallholder and rural labourer incomes.
  • Invest in small scale shelling, threshing, drying etc. of maize to improve efficiency and value added industries.

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