Physiological Responses of Containerized Young Mango (Mangifera indica) cv. Harumanis to Water Stress

Water stress is one of the environmentally limiting factors for fruit tree establishment in the field, which may affects plant growth and crop productivity. Plant usually developed physiological responses as well as ecological strategies to cope with water stress. These responses allow them to survive and to sustain some growth under adverse conditions. Therefore, the present study was aimed at investigating the effect of different watering regimes on the gas exchange parameters. Three-year-old young mango (Mangifera indica) tree was grown in containers planted at Ladang Pertanian2; UPM was used as planting material. The plant was subjected to three different watering regimes treatment namely watering daily (control), witholding water for 21 days and witholding water for 30 days. Treatments were arranged in a Completely Randomized Design (CRD) replicated seven times. The physiological parameters determined were photosynthesis, stomatal conductance and transpiration rate, all determined by using Portable Photosynthesis System (Licor 6400 XTR). The results showed that increasing water stress reduced the physiological parameters particularly at the later days of plant growth, due to stomatal and non stomatal factors. In conclusion, it can be deduced that increase in water stress (increasing level of water deficit) reduces the gas exchange parameters of mango.