ANTIOXIDANT DEFENSES OF IRRIGATED FORAGE SORGHUM WITH SALINE AQUACULTURE EFFLUENT

ABSTRACT The objective of this work was to evaluate the biomass production and antioxidant enzymatic system activity of irrigated forage sorghum with saline aquaculture effluent under different leaching fractions. The experiment was conducted in the Caatinga Experimental Field of the Embrapa Semiarido, in Petrolina, State of Pernambuco, Brazil. The experimental design was a complete randomized block in a split-plot arrangement with four replications, consisting of three forage sorghum varieties (Volumax, F305 and Sudan) and four leaching fractions (0, 5, 10 and 15%). The vegetal materials were collected when the plants were at the soft-dough stage. The biomass production and activity of the enzymes superoxide dismutase, catalase and ascorbate peroxidase were evaluated. Irrigation with saline aquaculture effluent with leaching fraction of 15% results in low salinity level in the root zone and higher biomass production of forage sorghum Sudan and F305, in semiarid conditions. The antioxidant system was activated in the three sorghum varieties to prevent accumulation of reactive oxygen species, with the synchrony between the enzymes superoxide dismutase and catalase resulting in a better productive response of the varieties Sudan and F305.