Advances, challenges and opportunities in cool-season food legumes in dry area

Abstract

Cool-season food legumes (chickpea, lentil, faba bean, field pea, and grass pea) are an integral part of subsistence farming in dry areas because these crops are a great source of nutritious food, feed, and income to small holder farmers. These crops also contribute to soil fertility in the cereal based cropping systems because of atmospheric nitrogen fixation. Together, these crops occupy 26.1 m ha area with 31.3 million tonnes production and 1197 kg/ha average productivity at global level. These figures account for 33 and 45% of the global pulse area and production, suggesting a better yield as compared to what we harvest from the warm-season food legume crops. Past research and development efforts have resulted in development of improved varieties with medium to high levels of resistance to key diseases such as Fusarium wilt/root rot complex in chickpea and lentil, Ascochyta blights in chickpea, lentil and faba bean, rust in lentil and faba bean, and chocolate spot and orobanche in faba bean. The most significant improvement in yield stability has resulted from the genetic modification to develop appropriate phenology so that the durations of the vegetative and reproductive phases are well matched with the expected water supply. Expansion of chickpea in Central and South India, Myanmar and Ethiopia is an example of such development. With increasing pace of climate change and reduced genetic diversity at farm levels, intensity and frequency of abiotic stresses especially heat and drought and emergence of new diseases and insect pests have increased manifold with serious yield losses. This drives the demand to produce more crops per drop of water and per unit area to enhance crop and water productivity. The yield potential of legume crops is still low and requires substantial improvement in source-sink equilibrium to fit in various cropping systems. To achieve this goal, appropriate changes in phenology and plant type that can be grown in conjunction with cereals, or fit within the shortseason windows available between major cereal crops and are amenable to machine harvest, disease and pest resistance, and post emergence herbicide application to control obnoxious weeds are required. Thus, enhancing economic competitiveness and stability in performance of coolseason food legume crops under climate and farming system changes require a three-pronged research strategy involving stress characterization, trait/gene discovery using high throughput phenotyping and genotyping platforms, and trait deployment through precision breeding in the desired agronomic and quality background along with a variety specific production technologies. This strategy looks promising, particularly for developing more nutritious, input efficient varieties for enhancing food and nutritional security in developing countries