DEVELOPMENT OF WATER STRESS AND STOMATAL CLOSURE IN JUVENILE MANGO (MANGIFERA INDICA L.) STRESS

W. Pongsomboon, A.W. Whiley, R.A. Stephenson, S. Subhadrabandhu
Water deficit is one of several factors limiting mango production. Information on mango water relations and other physiological activities influenced by water stress is limited. The development of stress symptoms of two-year-old potted mango trees cv. Kensington, were investigated in a glasshouse after withholding water. Leaf water potential (L), latex osmotic potential (s latex) and osmotic potential (pi) were measured using dew point hygrometry. Wilting initially occurred when L reached between -1.20 to -1.51 MPa, and developed basipetally, the younger leaves and shoots being most sensitive to water loss. At a L of -2.45 MPa, all mature leaves became dull and flaccid, and the pulvinus was wrinkled. Necrosis developed on the oldest leaves when L reached -3.2 MPa. The critical L of -3.45 MPa at which damage was non-reversible, corresponded to 77 percent relative water content (RWC). The pattern of decline of L, s latex, and RWC was similar during the 44 day period after withholding water. The decline in was linear as water deficit developed. Correlations between L and s latex, and between L and RWC during gradual stress development were high. Since latex exudation in mango leaves obscures the end point of water potential measurement using the pressure chamber, it is suggested that the measurement of s latex be used to estimate L as it is easier and faster to measure.
Pongsomboon, W., Whiley, A.W., Stephenson, R.A. and Subhadrabandhu, S. (1992). DEVELOPMENT OF WATER STRESS AND STOMATAL CLOSURE IN JUVENILE MANGO (MANGIFERA INDICA L.) STRESS. Acta Hortic. 321, 496-503
DOI: 10.17660/ActaHortic.1992.321.54
https://doi.org/10.17660/ActaHortic.1992.321.54

Acta Horticulturae