Water Balance, Bioclimatic Method as a Base of Rational Irrigation Regime of Onion

Abstract

An investigation of the effect of irrigation on yield and potential evapotranspiration (ETP) of onions (Allium cepa L.) was conducted at Rimski Sancevi experiment station of Institute of Field and Vegetable Crops in Novi Sad. The aim was to determine hydrophitothermic coefficients (HFTC) for the onion growing season in the climatic conditions of Vojvodina. Experiments were conducted in three years (2005-2007), in a random blocks design, adapted to sprinkling irrigation. The treatments consisted of three allowable depletion levels of available soil moisture, 60, 70 and 80% of field water capacity (FWC) and a treatment with no irrigation. The basis for calculation were the obtained yields (34.274-36.651 t ha(-1)) and potential evapotranspiration rates (ETP) (482.7-493.8 mm). The average hydrophtothermic coefficients for the onion vegetative season was 0.19. The obtained values of hydrophtothermic coefficients can be used as a base in performing a rational irrigation regime of onion.