Cashew improvement in India: retrospect and prospects

Abstract

Cashew, being an economically important crop, has been witnessing steady internal demand in addition to its export potential in the recent years. It is imperative to invest in crop improvement efforts for improving productivity and production. ICAR-Directorate of Cashew Research in Puttur, Karnataka is the nodal agency for cashew research in the country and it has the largest germplasm collection of cashew in its field gene bank. Sizable portion of the germplasm collection had been utilized in hybridization programme and molecular studies in various AICRP centers spread across the country. As many as 54 improved varieties have been released countrywide. The breeding efforts in cashew so far have concentrated on cashew nut but none of the evolve varieties are in jumbo nut category (>10 g nut weight). Also efforts are initiated towards development of varieties for cashew apple (fruit) and Cashew Nut Shell Liquid (CNSL) which have high industrial application. Recently, attempts are being made to change the genetic architecture of the plant from tall to dwarf, to cater to the needs of high density planting systems. However, source of resistance for major pests of cashew i.e. Tea Mosquito Bug (TMB) and Cashew Stem and Root Borer (CARB) are not available and this has hindered the development of resistant varieties. With these in background, a stock of information has been generated on genetic resource management, diversity analysis of cashew germplasm, finger printing, various breeding methods deployed and future thrust areas in crop improvement of cashew are discussed to address the ever increasing demand for cashew kernel, cashew apple and CNSL.