RESPOSTA DE PLANTAS DE MELANCIEIRA IRRIGADAS COM ÁGUA SALINA AO TRATAMENTO PRÉ-GERMINATIVO DA SEMENTE COM H2O2 RESPONSE PLANS WATERMELON IRRIGATED WITH SALINE WATER PRE-TREATMENT WITH SEED GERMINATION H2O2

Water management is one of the most important factors for effective absorption of nutrients, since this can present with high concentrations of salts, which can affect the absorption process, as well as cause oxidative stress in plants, due to reactive oxygens species (ROS), mainly H2O2. The objective of this study was to evaluate the response of watermelon plants irrigated with saline water, treatment of pre-germination seed with H2O2. The experiment was conducted at the Centro de Ciencias e tecnologia Agroalimentar CCTA, UFCG Pombal PB. The experimental design was a randomized block split plot 2x5 with 4 replications, with the portion consisting of two levels of salinity of irrigation water (S1 = local water supply, 0.32 dS m , and S2 = saline water , 2.0 dS m) and the split watermelon seed treated with H2O2 solution at five concentrations (0, 5, 10, 15 and 20 mmol L ). Characteristics were evaluated: Fresh Pasta Part Air Dry Mass Part Air Number of Leaves per Plant and Main Stem Length, Rate of photosynthesis, transpiration, stomatal conductance and intracellular CO2 concentration . The irrigation water with salinity of 2.0 dS m 1 compromises the growth of watermelon , reducing the emission of leaves and, consequently, fresh and dry weight of shoots . H2O2 concentration between 9 and 11 mmol L -1 watermelon benefit growth, particularly the length of the main stem , under irrigation water salinda 2.0 2.0 dS m. H2O2 concentrations of 15 and 20 mmol L -1 can be toxic to plants of watermelon, compromising their vegetative growth.