Water Use Efficiency on Cabbage and Cauliflower Treated with a New Biostimulant Composition

We developed a new plant biostimulant composition, containing low doses of sodium selenate, glycine betaine and a spray adjuvant. We performed an experiment to test the influence of treatments with this new biostimulant composition, on cabbage and cauliflower crops, cultivated under normal watered and water stress conditions. We aimed to prove that an efficient technology of protective biofortification with selenium of crops would solve two technical problems of cruciferous cultivation into a semi-arid area, with selenium soil deficit: (i) safety supplementation of food chain and, concomitant, (ii) enhanced water use efficiency. Normal watered plants were irrigated at a rate of 100% crop evapotranspiration (ETc). Water stressed cabbage and cauliflower plants were irrigated under deficit conditions, at a 75% ETc. Six different treatments, including the new biostimulant composition and its ingredients, separate and/or in combination, were applied on cabbage and cauliflower, in a field experiment, organised in split plot design, with three replications. The treatments were applied by foliar spraying, 3 weeks and 6 weeks after seedlings transplantation in the field. During vegetation, physiological parameters (chlorophyll a fluorescence and stomatal conductance) were assayed. After harvesting, yield parameters were determined, for each treatment applied to both normal watered and water stressed plants. We calculated the water use efficiency as ratio between the marketable yield and the water used. We tested in field conditions this new biostimulant composition, which allows to obtain, under conditions of moderate water stress, a marketable production similar to that of the normal watered crop. Physiological parameters demonstrated also enhanced water-use efficiency on cabbage and cauliflower treated with the new biostimulant composition, containing sodium selenate, betaine and spraying adjuvant based on ethyl rapeseedate.