By 2050, seasonal temperatures are expected to increase over 2°C in all maize producing regions of eastern Africa. Africa is one of the most vulnerable continents in the world to rising temperatures and rainfall variability due to climate change, with 96% of Sub-Saharan African (SSA) farmers depending on rainfall to water their crops.
While climate change is expected to decrease maize yields in most parts of Africa by a margin of 6-12%, some countries like Ethiopia and Kenya may see overall maize yields increase under climate change, according to CIMMYT climate and crop models.
“Our results suggest that the likely maize yield increase in Ethiopia and Kenya is due to anticipated temperature increases in the highland regions,” says Jill Cairns, maize physiologist at CIMMYT. Current temperatures in this area are too low to produce good yields, so an increase in temperature could positively affect maize farmers’ harvests in the future.
“New maize varieties will be needed to capitalize on these potential yield gains in the highlands,” adds Cairns. Commercial maize varieties currently grown in the East African highlands will not tolerate future higher temperatures. Varieties that are adapted to the region’s future climate coupled with recommended agronomic practices and correct timing for planting will be necessary to increase farmers’ yields.
Maize production overall has been declining in Kenya since 1982, due largely to drought conditions experienced across Africa and lack of varieties that can withstand this stress. CIMMYT estimates that 40% of Africa’s maize growing areas face occasional drought stress, resulting in yield losses of 10-25%. As a result of these climate shocks, Africa yields just two tons per hectare of maize, compared to the world’s average of nearly five tons per hectare.
CIMMYT is currently developing climate and crop models to predict the impact of future climate on maize production, and has also established the world’s largest tropical maize stress screening network under public domain. This network is being used by partners, including national agricultural organizations in SSA, to develop improved varieties that will tolerate current and future climate challenges. Currently being addressed are drought, heat, low soil fertility, insect pests and diseases such as maize lethal necrosis (MLN).
Improved maize hybrids with drought tolerance and nitrogen use efficiency are already on the market across eastern Africa and in the larger SSA region. Significant efforts have been made in recent years to develop heat tolerant and MLN resistant maize varieties in Ethiopia, Kenya, Tanzania and Uganda. These improved varieties yield much more than current commercial varieties and most have stress tolerant traits that help farmers tackle multiple abiotic and biotic stresses.
CIMMYT, with the support of its partners, has developed 57 improved drought tolerant (DT) maize varieties for eastern Africa’s market, each with farmer-favored traits. Over 12 million people have benefited from DT maize varieties across Ethiopia, Kenya, Tanzania and Uganda. Through public and private seed companies, nearly 17,300 tons of certified DT maize seeds have been produced.
“With this work on climate resilient maize, we are playing an important part in making Africa a food-secure continent,” says Stephen Mugo, CIMMYT’s Regional Representative for Africa.