Irrigação sob déficit hídrico controlado para a cultura do tomateiro, na região de Seropédica-RJ

Abstract

The irrigation regime for “in natura” tomato cultivation was studied at the experimental area of the Horticulture sector of the Crop Science Department of the Universidade Federal Rural do Rio de Janeiro, located at Seropédica-RJ. The first experiment was realized to evaluate the effect of the water lamina (40, 60, 80, 100 e 120% of ETc) on biomass and foliar area accumulation, to obtain growth parameters for a growth analysis and production of the culture, for Debora plus hybrid, a long life type. In the second essay, the influence of the irrigation schedules (TR0 every day; TR1 every two days; TR2 every three days; and TR3 every four days) was investigated, by the growth analysis and production of the same hybrid. In the third experiment, the growth and production was studied for three genotypes (Debora plus hybrid, a long life type; Carmem hybrid; and the variety Santa Clara), all for in natura use, all under the same irrigation regime. The results obtained in the first experiment demonstrated that the maximal biomass accumulation occurs between 70 and 80 days after transplanting, for all treatments. The quantity of water applied above 80% of ETc resulted in higher vegetative growth and general production, but with the same commercial production as for the others treatments. Above 80% of th Etc, there was an augmentation of defective fruits, with a higher input for the culture, using more water and energy, without an augmentation of commercial fruits of tomato. In the second essay, there was no difference among the irrigation schedules and, therefore, the longer schedule of every four days had the same fruit quality as the others schedules. The third experiment showed differences for the growth pattern and water and nutrient requirements of the genotypes. The quantity of water used by the Carmem hybrid was lower than for Debora hybrid, which indicated the necessity of detailed studies with different irrigation strategies for each genotype of tomato. Therefore, for an optimization of inputs use for the “regulated deficit irrigation”, the irrigation management needs to be adequate to the different requirement, during the cycle, of each genotype