Effect of Climate Change on the Production and Productivity of Wheat Crop in the Highlands of Ethiopia: A Review

Climate change is a recent challenge on crop production and productivity in the world. The objective of this paper is to review the major effects of climate change on the production and productivity of wheat in the high lands of Ethiopia. Effects of climate change on wheat would be mainly through changes in [CO2], temperature, rainfall, length of growing period, actual growth rate and increased evapo-transpiration, which may lead to reduce yield or complete crop failure. Moreover, flower fertilization and grain set are highly sensitive to heat stress during mid-anthesis. In C3 crops like wheat, the elevated CO2 level is expected to increase productivity as a result of higher CO2 diffusion through stomata leading to a higher photosynthesis rate. But, elevated [CO2] may have negative effects on the grain-quality of wheat in terms of protein, lipids, number of mitochondria and nitrogen contents. Unlike CO2, elevated temperature affects crop production negatively by increasing rate of respiration; hastening plant growth and development; increasing photorespiration of wheat, reducing photosynthetic efficiency due to O2 interrupts the photosynthetic path way instead of CO2, increasing rate of water loss by increasing evapo-transpiration and decreasing nutrient use-efficiency through increased rate of decomposition and mineralization. As a result, wheat area is forecast to be displaced by other crop types. In order to tackle this issue, major mitigation and adaptation measures for example promoting area closures and conservation agriculture-based (CA), agroforestry practices, efficient use of energy sources, etc. should be practiced and given special attention by the communities as well as the government to solve the effects of climate change on wheat production and productivity in the country.