Acúmulo de matéria seca e produção de meloeiro sob estresse salino e adubação potássica.

Abstract

The region of Chapada Apodi in the State of Rio Grande do Norte, leads Brazilian production and exportion of melon. Due the low and bad rain distribution of this area, this crop is produced under irrigation. And for the application of fertilizers, the fertirrigation is used, this technique facilate the fraction of dosage of nutrients in several applications during the cycle of the crop, mainly the nitrogen and potassium. In Chapada Apodi exist two aquiffers, which possesses water of different electric conductivities, being one of lower cost, however of high salinity, another of low salinity, however with high cost and hmited use. Before the exposed, this work was carried out with objective to evaluate the effect of two waters of different salinities combined with five doses of K2C> in the dried matter accumulation and productivity of the melon plant (Cucumis melo L.) cultivar Goldex. The design adopted was split plot with complete blocks ramdomized, where the melon plant was irrigated with low (0,52 dS m"1) and high (2,41 dS m"1) water salinity combined with five doses of K (218, 273, 328, 383 and 438 kg ha"1 of K 2 O ) . Soil and plants were collected in 21, 28, 35, 49 and 63 days after the seedling, the plants were divided in branches (shot + leaves), flowers and fruits, and adding to obtain the total dried matter of the aerial part; the rate of absolute and relative growth were calculated. It was evaluated, still, the production of fruits. The rate of absolute growth of the plant was low in the first 21 days after the seedling, and maxims between 35 and 49, with subsequent reduction in the end of the period. The salinity didn't affect the commercial and total production, the commercial and total number of fruits, and also, the commercial and total medium weight of fruits. The electric conductivity of the soil increased in the course of time, and with the increment of the salinity of the water of 0,52 for 2,41 dS m"1.