Table grape water requirements in the submedium Sao Francisco Region

This study used data of a field experiment conducted at the Bebedouro exper imental base of the Embrapa-Centro de Pesquisa Agropecuaria do Tropico Semi -Arido in Petrolina, PE, Brazil, from May to August, 1996, during the growi ng period of a five-year-old table grape (Vitis vinifera L.), Italy cultiva r. The plants were conducted in a two-meter above soil surface trellis syst em, four meters between rows by two meters between plants, and daily irriga ted by trickling system. The crop evapotranspiration was determined by the soil water balance method, and the reference evapotranspiration was estimat ed by the method of Penman, used to analyse the behaviour of the crop coeff icient (K-c) throughout the crop growing period. The maximum crop daily wat er use was 4.33 mm d(-1) and the total water consumption was 333.6 mm for t he whole growing period. The crop coefficient values varied from 0.50 to 0. 74. A characteristic curve of K-c for the table grape vegetative cycle was obtained which allows to obtain daily values of K-c as a function of days a fter pruning.