Biometry and Water Consumption of Sunflower as Affected by NPK Fertilizer and Available Soil Water Content under Semiarid Brazilian Conditions

Abstract

The present study evaluated the effect of NPK fertilization and available soil water levels on the biometric response and water use of sunflower cv. Embrapa 122-V2000. The experiment was conducted at the Agricultural Engineering Department of the Federal University of Campina Grande, Paraiba State, Brazil, during 2009 and 2010, in a semi-controlled greenhouse using the Eutrofic Regosol. The treatments were defined according to a Baconian matrix, with eleven doses of the nitrogen, phosphorus and potassium and four available soil water levels. The experiment was arranged in a complete randomized design, with three replicates, in a total of 132 sample units. No effect of N and K was observed on plant height. However, it increased significantly with P levels. The stem diameter and the leaf area were affected by the N and K and not by the P. The number of leaves increased significantly with the amount of N, P and K fertilizer. Available soil water content increased significantly in all the variables studied. The best sunflower performance and water consumption were obtained with the 100:120:120 kg &middot ha -1 NPK and 100% of the available soil water content treatment.