ISHS Acta Horticulturae 171: I International Symposium on Water Relations in Fruit Crops
THE EFFECTS OF WATER STRESS ON PHYSIOLOGICAL PROCESSES IN FRUIT CROPS |
| Author: | A.N. Lakso |
| Abstract:
Although perennial fruit crops show qualitative responses to water deficits similar to other crops, the levels of water potential at which these responses occur are generally lower than in annual crops. Osmotic potentials can differ greatly among species or time periods and high plant resistances definitions of "stress" for different organs especially difficult. In general water deficits reduce transpiration greatest, then photosynthesis while dark respiration is relatively insensitive. A strong reduction in leaf area coupled with reduced photosynthesis gives major reductions in dry weight growth. Cropping accentuates the leaf area reduction, but increases transpiration rates/leaf area. The relationship between stomatal and non-stomatal components of photosynthesis reduction appears to be variable, but the non-stomatal component is more responsive to stress than previously thought. Water stress reduces mineral availabilty and uptake, but specific elements can be affected diferentially. Areas of major lack of information for fruit crop responses to water stress include biochemical constituents, interactions with mineral nutrients and hormones, whole plant respiration, and long-term interactions with cropping. | |
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