Adaptation of cereal cultivars to extreme agroecologic environments of North Africa

Environmental stresses are very common in North Africa. In Tunisia, drought stress is the main constraint limiting grain production while in Morocco and Algeria, weather stresses from drought and cold are almost always combined together and heat stress is an important factor in the high plateaux areas. Libya is faced mostly with heat and drought stresses. The introduction of new agronomic practices and new cultivars are among the main ways of improving cereal production such environments. Alternating selection of genetic material in many contrasting locations and testing the advanced lines at several sites are the strategies adopted. The selection for these different environments is based on yield and its associated traits such as number of spikes per squared meter, number of kernels per head and kernel weight. Results in the different countries confirmed particularly that correlations between yield and associated characters exist in Tunisia and Morocco; in the Algerian studies, it appears that agronomic factors are very important and that various cultivars respond differently with the environment. Some cultivars are widely adapted and others perform well only in specific environments.