Fator de sensibilidade ao déficit hídrico e resposta à irrigação deficitária em duas cultivares de tomate cereja

Abstract

With the estimated increase in the number of areas subjected to water stress in various regions of the world, it is necessary to adopt strategies to minimize the adverse effects of this abiotic factor. The research had the hypothesis that in som e phases of the cultivation of cherry tomatoes grown in the semiarid region, controlled water deficit can be applied in the management of irrigation without, however, harming the productivity of the crop. In view of this, the objective was to determine the coefficients of sensitivity to the water deficit and to understand the responses of this deficit in different phenological stages in two cultivars of cherry tomatoes grown in a semiarid region. The experimental design was in randomized blocks, in a split plot scheme, with six primary treatments in the plots (time of water deficit induction) and two secondary treatments in the subplots (cherry tomato cultivars) with four replications. For the purposes of seasons, the tomato phenological phases were consider ed, classified as vegetative, flowering, fruiting and maturation. For the cultivar factor, orange and red cultivars were used. The water deficit was established as 50% of the ETcloc. The plants were grown in an organic production system, with phytosanitary control carried out by monitoring the insect population and applying natural pesticides. The irrigation system was of the type located by drip with emitters with flow of 1.6 L h 1, spaced without 0.30 m. The agronomic variables of the fruits, the sensitiv ity factor to water deficit, pr oductivity of irrigation water and physiological variables The results of the research allowed the following conclusions: The coefficient of sensitivity to water deficit in both cultivars var ies in the phenological stages in the following decreasing order: flowering, maturation, fruiting and vegetative. In conditions of scarcity of water for irrigation, the vegetative phase is recommended for deficit irrigation strategy providing less agronomi c losses. The flowering phenological period is considered the most critical for the application of water deficit in both cultivars, but more pronounced for the orange cultivar.