**4.2 Heat tolerance**

Heat stress during reproductive, grain filling, storage root formation and root bulking leads to severe yield losses in field crops. Heat stress has damaging effects irrespective availability of other factors required for normal plant growth. Breeding for heat tolerance in field crops is one of the strategies of coping with high temperatures induced by climate change. Climate model predictions and simulations pointed to an increase between 1.8 and 4 degrees Celsius in temperature in the 21st century with high increases in southern Africa and Southeast Asia [2].
