Water use efficiency in sugarbeet cultivars under different soil water tensions

Abstract

The efficiency of water use correlates biomass production to the amount of water applied and its knowledge is very important in irrigated agriculture. An experiment was conducted in a greenhouse at the Faculty of Agricultural Sciences, UNESP, Botucatu - SP, Brazil, during the period from April to June 2012. Treatments were arranged in a 2 x 6 factorial, with two cultivars of sugarbeet (Early Wonder and Itapuã) and six levels of soil water tensions (15, 25, 35, 45, 55, 65 kPa) in random blocks with 4 replications comprising a total of 48 plots. The number of leaves, the efficiency of water use, the relative water content, masses of fresh and dry matter of the whole plant were evaluated. The efficiency of water use by plants was reduced by 5.44 (Itapuã) and 5.34 (Early Wonder) kg ha^-1 mm^-1 for each unit increase in soil water tension. Total fresh weight of plants decreased by 0.44 and 0.47 g with per unit increase in soil water tension for the studied cultivars. A higher crop yield was observed in treatments irrigated with tension of 15 kPa.