CLIMATE CHANGE AND CHICKPEA: IMPACTS OF WARMING AND INCREASED VARIABILITY ON GROWTH AND YIELD ACROSS THE INDIAN SUB-CONTINENT

Abstract

In Indian sub-continent, chickpea (Cicer arietinum L.) is the most important winter (rabi) grain legume crop. It is a dietary protein source for more than one billion people, and also plays an important role in the cereal-legume farming system. The phenology and crop production is highly sensitive to the slow climatic changes, and also to the fast short-term variations induced on these changes, since the crop is cultivated almost exclusively from the residual soil moisture from a narrow period of post-monsoon. It is a review that puts together all the knowledge gained from the physiology, agronomy, genetics and models on the possible interactions of the increase in mean temperature, rainfall variability, terminal heat and drought stress, occasional chilling events and the higher concentration of CO2 in the atmosphere and how all these are likely to influence the growth and productivity of the chickpea in the sub-continent. The information is based on reproductive stage physiology (pollen viability, sucrose metabolism, anther and stigma function), root-trait and drought-avoidance studies, genomics-assisted breeding, crop-simulation studies (DSSAT, InfoCrop) and climate-pest interaction studies. Major abiotic constraints identified from the review are due to delayed sowing, often coupled with abiotic stress such as terminal heat stress and drought that could cause a 20-60% loss in the yields in susceptible cultivars, and cold events during flowering period, which are locally important in the northern plains and hills. There is a localised, irregular, positive compensatory effect from increased CO2 that is probably not enough at many sites to offset the warming effects. Biotic pressure from the gram pod borer (Helicoverpa armigera) and Ascochyta blight is also expected to get more intense due to climate variability. The review concludes with the discussion on the genetic, agronomic and policy level adaptation options, and gaps in research, including a lack of free air CO2 enrichment (FACE) experiments in chickpea. The Indian sub-continent is at significant risk, based on the climate change and climate variability observed due to the observed trends and is very much sensitive to the impacts of climate change and climate variability.