CRESCIMENTO E ACÚMULO DE MACRONUTRIENTES EM MELANCIA 'QUETZALE' CULTIVADA SOB DIFERENTES NÍVEIS DE SALINIDADE DA ÁGUA DE IRRIGAÇÃO

Abstract

In order to evaluate the growth and accumulation of nutrients in watermelon 'Quetzal' grown under different levels of salinity of irrigation water, was developed in the period november/2007 to January 2008, an experiment at the Experimental Farm "Rafael Fernandes", University Federal Rural do Semi-arid (UFERSA) Mossoró-RN. The experiment was a randomized blocks design with four replications. The treatments were arranged in split plots with the plots represented by the salinity levels of irrigation water: 0.60, 1.69, 2.36, 3.46 and 3.98 dS m-1, and the subplots consist of samplings of plants: 12, 22, 32, 42 and 52 days after transplanting, DAT. In achieving the levels of salinity were mixed natural waters and / or saline in order to obtain approximate composition of natural waters in the region. Plant growth, expressed by the accumulation of dry matter and accumulation of macronutrients by watermelon over the age of the plants decreased with increasing water salinity. The largest increases of dry matter and macronutrients occurred after fruit set, which took place from 42 DAT. The period of greatest demand for phosphorus, potassium and calcium was 42-52 DAT, and nitrogen, and magnesium was 32-42 DAT. The order of extracted nutrients was K> N> Ca> Mg> P.