CRESCIMENTO E MARCHA DE ACÚMULO DE NUTRIENTES EM MELANCIA cv. TOP GUN EM VARZÉA IRRIGADA NO TOCANTINS

Abstract

One of the obstacles to the growth of the area cultivated with watermelon has been the lack of technical information, especially regarding crop nutrition, which can directly affect fruit productivity and quality. The nutrient absorption gait is a fundamental tool for the knowledge of the nutritional requirement of the plant in different phenological stages, showing the right time for nutrient application. Given the above, this work aimed to determine the growth and gait of macronutrient accumulation by watermelon cv. Top Gun in floodplain area in the municipality of Lagoa da Confusion - TO. The experiment was conducted in a rural property located in Lagoa da Confusion - TO, from June to August 2016. The experimental design was a randomized block design with five plant collection periods (15, 30, 45, 60 and 75 days after sowing), in four replications, and in each repetition two plants were collected. After each collection, the plants were fractionated in shoots (branches and leaves) and fruits to determine the constant dry matter. Subsequently, the nutrient levels N, P, K, Ca, Mg and S were determined, using the extraction method by nitro-perchloric digestion. The most accumulated nutrients of watermelon plants during the cycle were K, N, Ca, Mg, P and S, with 101,27, 75,54, 59,45, 14,91, 13,09 and 5,84 kg ha^-1, respectively. The nutrients most transported by the fruits were K, N, P, Mg, Ca and S, corresponding to 80,56, 50,96, 11,16, 6,45, 5,93 and 4,88 kg ha^-1, respectively. The period of greatest dry matter accumulation in watermelon plants cv. Top Gun was 30-45 DAS for shoots (branches and leaves) and 60-75 DAS for fruits.

Keywords: Citrullus lanatus L.; plant development; macronutrients; absorption gear.