A field investigation under tropical climate was undertaken in the research plot of the Universiti Putra Malaysia, Selangor, Malaysia to study the effects of exogenous application of plant growth regulators on growth performance, physiology changes and biochemical analysis of banana plants (Musa acuminata cv. Berangan) under irrigated and rain-fed condition. The experiment was laid out as split-plot in randomized complete block design. According to the results showed that, banana plants grown under rain-fed condition significantly reduced morphological characters such as plant height, pseudo-stem, canopy diameter, but enhanced accumulation of proline and malondialdehyde content in leaves tissue by stress-treated plants when compared to control. Physiological characters which include total chlorophyll content, relative water content and electrolyte leakage was measured and indicate significant effect under two different water regime conditions. Application of plant growth regulators on Berangan banana under different water regime conditions might be able to tolerate water stress conditions by changes in vapour pressure deficit as affected by decreasing stomata opening besides enhanced net photosynthesis to produce higher yield of banana fruits.
Keywords: Water regime;water stress;banana;productivity;proline