High N supply and soil water deficits change the rate of fruit growth of bananas (cv. “Williams”) and promote tendency to ripen

Abstract

Cultural practices that change the relationship between fruit growth and the greenlife in bananas affect harvest strategies. In field experiments in a semi arid environment, fertilising with 450 kg N ha −1 year −1 increased the relative fruit growth rate, R f , of cv. “Williams” (Cavendish subgroup) bananas by 7% ( P ⩽ 0.05), hastened the relative loss of greenlife, R g , by 46% ( P ⩽ 0.05) and hastened the maturation rate, R m , by 25%. From 0 to 300 kg N ha −1 year −1 N had no significant effects on fruit growth or greenlife but the concentration of N in the dry matter of the fruit increased from 0.94 to 1.05% N, in direct proportion to supply. Soil water deficit reduced R f by 9% ( P ⩽ 0.05), hastened R g by 48% ( P ⩽ 0.05) and hastened R m by 76%. High N supply and preharvest soil water deficit promoted the tendency of the fruit to ripen, but high N promoted fruit growth while soil water deficit decreased it. Thus these two cultural practices changed the relationship between growth and capacity to ripen in bananas.