Abstract

This study examined the relationship between the yield reduction by chlorophyll stability index (CSI), membrane stability index (MSI) and relative water content (RWC). The field experiment was conducted at National Research Centre for banana to screen the banana cultivars and hybrids for water deficit tolerance and to elucidate information on growth attributes mechanism of banana cultivars and hybrids. Water stress was imposed at different critical growth stages viz., 3^rd, 5^th, 7^th and 9^th month after planting. The stress was given by scheduling irrigation at the 50% available soil moisture (ASM) 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 the soil water potential of about -6 bars. In stressed plots, the irrigation was given at 50% ASM with the soil water potential of -14 bars. In stressed plots, 50% ASM was reached around 30 days. The present study was conducted with twelve cultivars and hybrids with three replications. The data were analyzed by using split plot design. The results revealed that the cultivars of Karpuravalli, Karpuravalli x Pisang Jajee, Saba and Sannachenkathali recorded significantly higher yield (67.3, 52.4, 55.8 and 41.3 t ha^-1) and the magnitude of yield was decreased by 12% than the cultivars and hybrids of Matti, Pisang Jajee x Matti, Matti x Anaikomban and Anaikomban x Pisang Jajee (14.9, 11.1, 10.3 and 10.6 t/ha). Similarly, Karpuravalli, Karpuravalli x Pisang Jajee, Saba and Sannachenkathali recorded significantly high relative water content, chlorophyll stability index and membrane stability index with lesser reduction percent were shown than the cultivars and hybrids of Matti, Pisang Jajee x Matti, Matti x Anaikomban and Anaikomban x Pisang Jajee.

Key words: Water deficit, relative water content (RWC), chlorophyll stability index (CSI), membrane stability index (MSI), yield, banana.