Effect of potassium fertilization during fruit development on tomato quality, potassium uptake, water and potassium use efficiency under deficit irrigation regime

Abstract

A pot experiment was conducted to investigate the effect of potassium (K) fertilization on tomato quality, plant K uptake, water and K use efficiency (WUE and KUE) under deficit irrigation regime. During fruit development stage of the first cluster of fruit, irrigation regimes were comprised of three levels, i.e. 80–90% field capacity (θf) (W1), 70–80% θf (W2) and 60–70% θf (W3); and K fertilization rates were also consisted of three different rates, i.e. 0 g K2O kg−1 soil (K1), 0.46 g K2O kg−1 soil (K2) and 0.92 g K2O kg−1 soil (K3). The result showed that deficit irrigation as well as increased K fertilization significantly improved quality of fruit where, soluble sugar, titratable acid and content of vitamin C were positively correlated to K concentration of leaf ([K]leaf), indicating that [K]leaf may have a role to improve fruit quality. The highest plant WUE was observed in W1 plants, which consumed the most water and produced the highest dry mass. K fertilization had no effect on WUE based on biomass, but had positive effect on K concentration and K accumulation in each tissue, hereby increased total K uptake, while decreased KUE.