Chapter 11 - Peanut

Peanut is presently grown in over 26 Mha worldwide with a total production of over 45 Mt. About 80% of the world peanut production comes from rainfed regions of the semiarid tropics, where the yields are generally low and variable due to erratic water deficits and elevated temperature. Peanut generally responds favourably to water deficit applied from emergence to start of flowering, resulting in increased pod yields. Sensitivity to water deficit increases progressively during the reproductive phase. Biomass accumulation in peanut is usually proportional to the amount of water transpired by the plant. Researchers have demonstrated variation in transpiration efficiency (TE) between peanut genotypes with similar transpiration (T). Tis chapter describes genotypic, environmental, and management factors affecting T and TE. This chapter describes major nutrient deficiencies that affect productivity and seed quality production in many regions of the world. With increasing drought frequency in semiarid tropics, there is interest in breeding shorter duration cultivars. However, much of the short-duration germplasm available in the global gene banks has low yield in favourable environments, and poor seed quality and foliar disease resistance. Major introgression effort to incorporate all these traits into adapted early-maturing genotypes has been largely successful over the past decade. In 1950’s peanut has been described as ‘the unpredictable legume’ because of its unpredictable responses to inputs. However, the physiological principles developed in the past decades have been successfully applied in peanut crop models making the crop performance predictable across diverse environments.