Yield declines commonly observed under cereal monoculture are invariably attributed to disease buildup as well as nutrient and moisture depletions. While many long-term trials in the West Asia and North Africa region, especially in northern Syria rainfed cereal production belt, have assessed various cropping alternatives in comparison with fallow and continuous cereal cropping, few trials have involved measurement of fungal diseases. This paper reports observations made on the incidence of common root rot ( Cochliobolus sativus) from long-term trials at the International Center for Agriculture Research in the Dry Areas involving wheat and barley. With both cereals, crop rotation with legumes was shown to reduce the incidence of root rot. The results clearly indicated the need for a more comprehensive phytopathological assessment of the implications of continuous cereal cropping, especially considering the effects of residue management and nitrogen fertilization.
