Effect of Water Deficit on Bunch Yield and Antioxidants Content in Ratoon Banana Cultivars and Hybrids

Abstract

The field experiment was conducted at the National Research center for Banana to screen the ratoon banana cultivars and hybrids for water deficit tolerance and to elucidate information on the growth attribute mechanism of banana cultivars and hybrids. Stress was imposed at different critical stages viz., 3rd, 5th, 7th, and 9th months after planting. The stress was given by scheduling irrigation at the 50 percent available soil moisture (ASM) characteristic during critical stages. The soil moisture content was analyzed by using pressure plate membrane apparatus. In control plots, the irrigation was given at the ASM of 80% with a soil water potential of around -6 bars, and in the case of stressed plots; the irrigation was given when an ASM reached 50% with a soil water potential of -14 bars. In stressed plots, 50% ASM was reached around 30 days. This present study was conducted with twelve cultivars and hybrids with three replications. The data were analyzed by using a split-plot design. The antioxidative enzymes of catalase, superoxide dismutase, and ascorbate peroxidase were significantly enhanced during water deficit conditions. Among the twelve ratoon cultivars and hybrids, Karpuravalli, Karpuravalli×Pisang Jajee, Saba, and Sannachenkathali were identified as tolerant to water stress with highly accelerated by water stress treatment in the range of 20% to 28% over control in catalase (CAT), superoxide dismutase (SOD) and ascorbate peroxidase (APX) leads to reduce the cellular membrane damaged by reactive oxygen species and get higher yield; whereas, Matti, Pisang Jajee×Matti, Matti×Anaikomban, and Anaikomban×Pisang Jajee were notified as sensitive ratoon cultivars and hybrids with a lesser increase in antioxidative enzyme activity of 13 percent than control which leads to getting very low yield.