HARGREAVES & SAMANI SUBESTIMA A EVAPOTRANSPIRAÇÃO DA CEBOLA NO ALTO VALE DO ITAJAÍ

Abstract

The onion crop is widespread in the Alto Vale of Itajaí region, SC, which plays a prominent role in national production. This research aimed to evaluate the efficiency of the reference evapotranspiration equation of reference Hargreaves & Samani (HS) in onion for the Alto Vale of Itajaí region, SC. The experiment was conducted in a greenhouse using the cultivar Bola Precoce. To estimate the water depth to be applied, the reference evapotranspiration equation for HS was used. The treatments consisted of: slide calculated by HS, 70% of slide calculated by HS, 130% of slide calculated by HS and local precipitation. The experimental design was randomized blocks. The number of leaves, diameter of pseudostem, diameter, classification and estimate of bulb productivity, fresh / dry biomass of the bulbs, in addition to the dry biomass of the shoot were evaluated. The water depth based on 130% of the equation showed bulbs with a larger diameter, fresh / dry biomass, a higher percentage of class 3 bulbs and a higher estimate of productivity. Therefore, the HS equation underestimates the reference onion evapotranspiration for the Alto Vale do Itajaí region, SC, requiring adjustments for use.