ISHS Acta Horticulturae 792: V International Symposium on Irrigation of Horticultural Crops
RESPONSE OF PINK LADY APPLE TO IRRIGATION ESTIMATED FROM EFFECTIVE AREA OF SHADE |
| Authors: | M.G. O¿Connell, I. Goodwin, A.D. Wheaton |
| Keywords: | crop coefficient, micro-irrigation, fruit growth, shoot growth, stem water potential, leaf conductance, irrigation efficiency |
| Abstract:
Seasonal irrigation inputs on a modern, high-density commercial apple orchard were scheduled based on a crop water requirement (ETc) derived from evaporative demand (ETo) and measures of tree canopy size (effective area of shade, EAS): ETc = 1.15.EAS.ETo + 0.1ETo. Five irrigation treatments were established applying water at 40, 70, 100 (Control), 140 and 170% of computed crop water requirement (viz: 0.4C, 0.7C, Control, 1.4C and 1.7C). Responses to irrigation were examined in terms of EAS, shoot and fruit growth rate, stem water potential, leaf conductance, yield, fruit soluble solids and trunk cross-sectional area. Results suggest that this simple seasonal ETc model matched full crop water requirement. A yield penalty occurred in 0.4C. A mid-season heavy rainfall event led to replenishment of plant-available water in the root-zone and the potential water deficit effects had been erased by harvest in 0.7C. | |
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