Yield potential, potential yield and realized yield at farmer level of cereals with special reference to rice ( Oryza sativa L.)

Abstract

Rice (Oryza sativa L.), wheat (Triticum aestivum L.) and maize (Zea mays L.) are the three main cereals that account for the majority of calories in human diets and they will continue to remain the main sources of human nutrition. In order to meet the food demand of increasing population the only option left to increase production of these crops is to increase crop productivity per unit land area in the existing cultivable lands. Grain production of cereals is largely influenced by their yield potential. However, the terms ‘yield potential’, ‘potential yield’ and ‘maximum potential yield’ are synonymously used in the literature to describe different yield ceilings of crop plants without making a clear distinction among them. These terms have been defined in relation to the realized yield at farmer level. This review discusses the methods of estimating yield potential and potential yields of cereals, their physiological basis, and genetic improvement, with special reference to rice. The role of light interception, radiation use efficiency and harvest index as components of a varietal yield potential in relation to their genetic improvement and importance of improving varietal resistance to biotic and abiotic stresses in relation to improving potential yield have been discussed.