Current and potential development of perennial grasses in rainfed mediterranean farming systems
Past and recent development of perennial grasses in the rainfed Euro-Mediterranean region is reviewed concerning climatic constraints and main types of farming systems. The few Mediterranean cultivars that are registered and available are used for livestock production and cover crops only in subtemperate areas. These cultivars are adapted where annual rainfall exceeds 500 mm and accumulated water deficit from May to September is <800 mm. For the future, grass–legume mixtures need to be developed to meet the contrasting situations of livestock production and environmental use, with both functions contributing to farm income through the market and from public subsidies. Concern for environmental uses of perennial grasses raises interest in new germplasm that could accelerate cultivar breeding and seed production. Research programs should ensure a diversification of available germplasm in the principal forage species for phenology, drought tolerance, summer dormancy levels, and dehydration tolerance.