Accumulation of dry matter and nutrients in irrigated melon under strategies of salimity management/Acumulo de materia seca e nutrientes no meloeiro irrigado sob estrategias de manejo da salinidade

A study was carried out aiming to investigate management strategies for use of brackish water in the accumulation of dry matter and nutrients in two cultivars of melon ([C.sub.1] - Sancho and [C.sub.2] - Medellin) irrigated with low ([S.sub.1] = 0.61 dS [m.sup. -1]) and high ([S.sub.2] = 4.78 dS [m.sup. -1]) salinity water in different phases of crop: [S.sub.1] [S.sub.1] [S.sub.2] [S.sub.2] - [T.sub.1], [S.sub.2] [S.sub.1] [S.sub.2] [S.sub.2] - [T.sub.2], [S.sub.2] [S.sub.2] [S.sub.1] [S.sub.2] - [T.sub.3]. The 1st, 2nd, 3rd and 4th term correspond, respectively, to different phases--initial growth, flowering, fruit maturation and harvest. Alternate irrigation during the crop cycle, two days of consecutive application with [S.sub.1] water followed by one day with [S.sub.2] water ([S.sub.1] 2 days + [S.sub.2] 1 day - [T.sub.4]) and irrigation with [S.sub.2] water throughout the cycle - [T.sub.5] was also tested. Furthermore, as control, management practice at the farm where the experiment was conducted consisting of irrigation with a mixture of 37% [S.sub.1] water and 63% of [S.sub.2] water - [T.sub.0] was used. The experiment was conducted in a completely randomized design in a 6 x 2 split-plots with four replications. The total dry matter accumulation in shoots of cv. Sancho was greater than Medellin in all management strategies. The nutrients required most by the two cultivars were calcium, potassium and nitrogen. Key words: Cucumis melo L., salt stress, plant nutrient O presente estudo foi realizado com o objetivo de investigar estrategias de uso de agua salobra sobre o acumulo de materia seca e nutrientes, duas cultivares de melao (Sancho - [C.sub.1] e Medellin - [C.sub.2]) irrigadas com agua de baixa ([S.sub.1] = 0,61 dS [m.sup. -1]) e alta ([S.sub.2] = 4,78 dS [m.sup. -1]) salinidade por fase da cultura: [S.sub.1] [S.sub.1] [S.sub.2] [S.sub.2] [T.sub.1], [S.sub.2] [S.sub.1] [S.sub.2] [S.sub.2] - [T.sub.2], [S.sub.2] [S.sub.2] [S.sub.1] [S.sub.2] - [T.sub.3] (os 1, 2, 3 e 4[degrees] termos correspondem, respectivamente, as fases de crescimento, floracao, crescimento dos frutos e maturacao e colheita) e, ainda a irrigacao alternada, durante todo o ciclo, com agua [S.sub.1] por 2 dias consecutivos seguido com agua [S.sub.2] por um dia ([S.sub.1] 2 dias + [S.sub.2] 1 dia - [T.sub.4]) e a irrigacao com agua [S.sub.2] durante todo o ciclo - [T.sub.5]. Alem disto foi utilizada, como testemunha, a irrigacao com a mistura de 37% da agua [S.sub.1] e 63% da agu