Potential yield and gap analysis (PYGA) of wheat in Ethiopia.

Abstract

Abstract Global demand for food is rising due to unparallel population growth compared to agricultural productivity. Yield is supposed to double to feed global population in 2050 but climate change is making sustainable food production difficult for the increasing population. Wheat is one of the strategic crops for food security and increasing its productivity is vital for self-sufficiency. Ethiopia is the second largest wheat producer in the sub-Saharan Africa where the national average yield is below 3 t/ha despite the increasing total production mainly due to areal expansion rather than productivity per hectare. It is imperative and timely to realise wheat potential yield and identify factors that underly the current yield gap. Farmers in southeast Ethiopia have reportedly seen potential yields rising above 10 t/ha which prompted the current study to conduct scientific assessment of the maximum potential yield in the area for better policy and intervention. The trial was designed in partially irrigated and rainfed conditions and here we report that the farmers' actual yield gap was as low as 74% as showcased specifically with the devastating epidemic of new stem rust race known as the ' Digalu race ' occurred in the region in 2014/15. This necessitated replacement of the old varieties with high yielding and disease resistant varieties Sanate and Mandoyu. As the growing condition in 2015/16 season was favourable coupled with best management practices, two high yielding varieties, Sanate and Dire, were identified with the maximum attainable yields of 8921 and 8219 kg/ha, only 3% and 10% away from the model-predicted theoretical yield, respectively. The two varieties also had minimum water limitation index indicating that they are perfect fits for the recent wheat initiative by the Government of Ethiopia to realise self-sufficiency through irrigation and maximising yield potential. Even though we recommend modern breeding programs to capitalise their efforts on realising wheat potential yield through generation of new varieties and the deployment of modern cultivars such as Sanate and Mandoyu with their full management package, we admit that this research is limited in scope to reflect the whole rainfed and irrigated production systems in Ethiopia and hence would highlight the importance of further replicated research across years and locations to capture the variability especially due to the unpredictable climate change.