Impact of Climate Change on Cashew and Adaptation Strategies

Abstract

Cashew (Anacardium occidentale L.) is an important export-oriented horticultural crop of our country. Cashew is presently grown in an area of 0.945 million ha with annual production of 0.653 million t of raw cashew nuts in the country (DCCD Cashew Cocoa J 1:23, 2011). Climate change may pose problem for cashew cultivation since cashew is grown in ecologically sensitive areas such as coastal belts, hilly areas and areas with high rainfall and humidity. The flowering, fruiting, insect pest incidence, yield and quality of cashew nut and kernels are more vulnerable for climate change. Unseasonal rains and heavy dew during flowering and fruiting periods are the major factors which adversely affect the yield and quality of cashew nut. Cloudy conditions, high RH and heavy dew are favourable for outbreak of insect pests and diseases. Drought conditions drastically reduce cashew nut production. The climate change-induced drought can be partially mitigated by adopting mulching, conservation agriculture and soil and water conservation measures, by providing protective/drip irrigation/fertigation during the fruit development stages. The sea level rise due to the melting of glaciers as a result of increase in temperature may also pose problem for cashew cultivation since large proportion of cashew plantations exist in Eastern and Western Coastal regions of India. Cashew is ideal crop for carbon sequestration. Based on research undertaken at Directorate of Cashew Research (DCR), it was found that cashew genotype (VTH-174) trees of 7 years old sequestered about 2.2-fold higher carbon (C) under high-density planting system (625 trees/ha) as compared to normal-density planting system (156 trees/ha). Carbon storage by cashew has been estimated as 32.25 and 59.22 t CO2/ha at 5th and 7th year of growth, respectively, under high-density planting.