Phenotyping Maize for Drought and Low Nitrogen Tolerance in South Africa

South Africa is generally not suitable for crop production. Only about 13% of the country is arable due to low rainfall and poor soils. Maize yields obtained by smallholder farmers are very low because their crops are often subjected to moisture stress and they use very little fertilizer due to lack of financial resources. Only about 10% of the maize crop is grown under irrigation (mostly by large-scale commercial farmers) because of limited water resources. Climate change is predicted to worsen the situation with more variable rainfall and above average temperatures. Identifying ways to mitigate and adapt to climate change are fundamental to realising food security and improved livelihoods in South Africa and the rest of the continent.

To address these challenges the Agricultural Research Council (ARC) is participating in public-private partnerships called Water Efficient Maize for Africa (WEMA) and Improved Maize for African Soils (IMAS). The WEMA and IMAS projects are aimed at developing and deploying drought and low nitrogen tolerant maize hybrids to smallholder farmers in Sub-Saharan Africa. Phenotyping for drought tolerance is achieved by growing maize under managed drought during the dry season. Drought stress is imposed during the most critical stage that is from two weeks before flowering until two weeks after flowering. Phenotyping for low nitrogen tolerance is achieved by growing research trials in soils that are first depleted of nitrogen.