Identifying suitable germplasm for the future
By Gloria Otieno, Bioversity International and Charles Nkhoma, Community Technology Development Trust
Photo by: Annie Chikanji, Biodiversity Conservation Network
Farmers in most parts of Zambia report changes in climate and weather patterns including unpredictable rains; shifting and shortening of the growing season; increases in temperatures; and longer dry spells. According to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC) What’s in it for Africa? southern Africa has experienced an increase in annual average, maximum and minimum temperatures since the early 1990s with the most significant warming occurring during the last two decades. Minimum temperatures have risen more rapidly compared to maximum temperatures over inland southern Africa (IPCC AR5). In Zambia where maize is the staple food crop, production of maize is predicted to decrease by up to 20% in some places by 2050 under such temperature and precipitation scenarios (Schlenker & Lobell, 2010, Robust negative impacts of climate change on African agriculture. Environmental Research Letters, Vol 5, No 1). One adaptation strategy is to identify varieties of maize that can withstand these temperature and precipitation changes as well as the shortening of the growing season. Another strategy is to switch to more resilient crops such as millets and sorghum.
To build capacity, Bioversity International, in collaboration with Community Technology Development Trust (CTDT), Zambia, organized a five day training workshop on resilience of seed systems and adaptation to climate change, bringing together scientists, breeders, Geographic information system (GIS) specialists, climate change specialists and extension workers. Two communities, Chikankata and Rufunsa, were identified by CTDT, based on their vulnerability to climate change and reduction in productivity over the last couple of years. An analysis of their weather and climate was done using meteorological data and predictions of 2050s climate. According to the analysis, the two communities are already experiencing shorter growing seasons, unpredictable rainfall and longer dry spells. Predictions for the 2050s indicate a general increase in mean temperatures by 1 degree Celsius, a relatively shorter growing season and a slight increase in precipitation. GIS and climate modelling techniques were used to identify climate challenges in the two communities and identify suitable maize and sorghum varieties from the national genebank as well as the international collections already in the multilateral system of the Plant Treaty.
Through participatory exercises and a visit to a community seed fair in Chikankata (see photo), local diversity within the community was assessed to determine whether these meet the community’s needs. Traits that are required and preferred for present and future climate change adaptation were also identified. An assessment of local diversity of maize reveals that there are three local maize varieties that have promising traits in terms of early maturity, taste, high yielding and resistance to pests and diseases. Sources for accessions of sorghum and maize were found by searching through national genebank accessions and international sources such as GENESYS (global portal to information about Plant Genetic Resources for Food and Agriculture). These can now be tested with farmers to compare their performance with local promising varieties. See map below showing areas with similar temperatures (minimum and maximum) in 2050s and the selected accessions from those areas.
For further information about capacity building for resilient seed systems visit http://bit.ly/seeds-resource-box.