Genetic Improvement of Maize in India: Retrospect and Prospects

Maize (Zea mays L.) is the third most important crop of country after rice and wheat and is cultivated round the year. Its grain is used as feed, food and industrial raw material. Enormous progress has been made during last six decades to enhance yield potential through genetic improvement and alleviate effects due to various biotic- and abiotic-stresses. This review presents an overview of strategies followed in genetic improvement of maize and assesses their impact on productivity and production of the crop. A diverse range of indigenous and exotic germplasm and breeding material have been utilized. Breeding programme has been very vibrant and various strategies viz., composite breeding, double cross, three way cross and single-cross hybrid breeding have been adopted in cultivar development to enhance productivity across a range of production ecologies. Since 2000, more than 165 high-yielding cultivars of different maturity periods and types [field corn, sweet corn, baby corn and quality protein maize] having adaptation to different agro-ecological zones have been released. Development of cultivars having tolerance to abiotic-stresses (water and temperature extremes) and resistance to diseases has been a priority area in maize improvement. Both conventional and molecular approaches have been and continue to be used in development of disease resistant, stress adapted and nutritionally superior cultivars. In order to realize full potential of improved cultivars, agronomic research has targeted several management interventions like plant density, mineral fertilization, water management, resource conservation and various maize-based cropping systems across different ecologies. Improved products have been delivered to farmers by both public and private sectors involved in maize seed production and distribution. As a result, area under improved cultivars has been increasing consistently, and currently approximately 65 % of maize area is under improved cultivars (mostly hybrids). Adoption of high-yielding cultivars, improved production technology and increased demand of maize resulted in increased production (from 1.7 to 24.4 million ton) and productivity (from 547 to 2583 kg/ha) from 1950–1951 to 2013–2014. Future prospects of maize cultivation and improvement strategies in context of climate change and in providing nutritional security are also discussed in this review.