Irrigação com água salina na cultura do girassol (Helianthus annuus l.) em solo com biofertilizante bovino

Abstract

This study aimed to evaluate initial growth and gas exchanges of sunflower plants (Helianthus annuus L.) irrigated with different salt concentrations in soil treated with and without bovine biofertilizer. The experiment was conducted at the experimental area in the Agrometeorological station, UFC, Fortaleza-CE, from September to November 2012. Treatments were arranged in a completely randomized 5 x 2 factorial design, with five replicates referring to five electrical conductivity values of irrigated water.: 0.8;1.5;3.0;4.5 and 6.0 dS m-1, in soil with and without bovine biofertilizer. The latter was applied only once, at 10% substrate volume, three days before sowing. The following parameters were evaluated: number of leaves, plant height, stem diameter, leaf area, photosynthesis, stomatal conductance, leaf temperature, internal CO2 concentration, plant transpiration, shoot, root and total dry matter. Salt stress affected stem diameter, leaf area and number of leaves of sunflower plants, and in a lesser degree, in the soil with bovine biofertilizer. Bovine biofertilizer also reduced the negative effects of increasing salt concentrations in the irrigation water observed in shoot, root and total dry matter of sunflower plants.