ISHS Acta Horticulturae 732: VIII International Symposium on Canopy, Rootstocks and Environmental Physiology in Orchard Systems
WATER CONSUMPTION AND XYLEM FLUX OF APPLE TREES |
| Authors: | M. Backes, M.M. Blanke |
| Keywords: | Malus domestica Borkh., apple, climate change, crop factor Kc, evapotranspiration, heat-balance, Penman, precision agriculture, stomata, water vapour deficit (VPD), xylem |
| Abstract:
Xylem flux or transpiration was measured in situ using the heat balance method on eight 4-year-old 'Braeburn' apple trees (4.9 m2 leaf area) during summer 1999 at Klein-Altendorf experimental station near Bonn, Germany. The apple trees consumed from 70 ml of water per night per tree on cool summer nights to 180 ml water on warm summer nights. During the day, the apple trees transpired 1.7 litres per tree on cool, cloudy days and 4.8 litres on warm, sunny summer days. The midday depression in transpiration was more pronounced on sunny than on cloudy, cool days. The daily water consumption of the apple trees ranged from 1.8 to 5 litres water per tree, which was equivalent to 0.4-1 litres per day per m2 leaf area. The best correlation was found between water consumption of the apple trees and water vapour deficit and, to a lesser extent, global radiation. These evaporation data now contribute to the weather fax and online service by the German National Meteorological Service (dwd), which supports growers in their decision making for irrigation based on meteorological data from dwd and evaporation values for fruit trees. | |
Download Adobe Acrobat Reader (free software to read PDF files) | |
