Breeding wheat for yield maximization under conservation agriculture

Abstract

Wheat based food security is being challenged due to declining profit, deteriorating production environment and changing climatic conditions. Conservation agriculture (CA) imbibing some components of the natural ecosystem can address some of these issues quite effectively. Wheat breeding so far, has managed to increase grain yield mainly by improving harvest index (HI) and adaptation through phenological manipulation. With limited scope for further increase in HI, an increase in biomass appears inevitable for wheat yield consolidation. The conflict between increased biomass and lodging that imposes a limitation to higher grain yield may have an answer in CA. The production environment under CA is much more congenial than conventional and hence offers an opportunity for identification of higher yielding genotypes. The article discusses the breeding issues and key traits for selection for yield maximization under CA. Integrating agronomic perspectives including cropping system, countering the tradeoff between stress adaptation and yield enhancement through management has been proposed. Selection indices build around increased coleoptile length, weed competitiveness, mild vernalization, increased duration and higher biomass could facilitate the development of CA adapted genotypes. These traits can be further fine-tuned according to different cropping and management practices.