Storage of intercepted water on vegetable plants measured by gamma scanning technique.
An estimate of water losses caused by canopy interception is required to calculate soil water balances or to parameterise models of crop water demand. A gamma-scanning technique allows to measure ion-desuuctively and accürately as well as continuously over a short-time period the amount of intercepted water in a veqetable crop canopy. To evaluate intercepted amounti, spinach (Spn aA ä’ol er acea L. var. „fcoolinotvrmol leHde gi ‚Boeing) canopies were treated with änoonts öf ittig“riott water supplied by a sprinkler (to simulate rain and irrigation conditions) ör a nozzlä (to reproduce dewfall äd wetting agents used in plant-protection). For plant masses from 1.5 to 5.0 kg m-2, the storage of water was from 0.25 to about l00mm when“water amounts from 3 to 2L mmwere applied by sprinkler. Using amounts of 0.38 and 0.75 mm water supplied by nozzle, the interceotion iacreased from 0.05 to almost 0.40 mm for ipinach fresh masses benveen 0.25 and 2.25 kgm-2. Here, we assume that the accutacy of mass determination of spinach is equivalent to broccoli that was examined in a previous study by weighing broccoli plants at different growth stages. The error of measurement was estimated within <5 7o for fresh plant masses of about 0.100 kg m4, and within <1. o/o for masses >7.25 ks m-2.
Gutezeit, B. 2006. Storage of intercepted water on vegetable plants measured by gamma scanning technique. European Journal of Horticultural Science 71 (1), 30-35.