Influência da acidez do solo e da adição de fósforo sobre a produção de fitomassa na cultivar BRS Rubi de cor marrom na sua fase inicial de crescimento.

Abstract

The BRS-RUBY colored cotton cultivar reduces the production costs for the textile industry and the release of chemical and toxicant effluents to the environment. Adapted to the conditions of the semi-arid, it has turned an alternative for income generation. The acidity and lack of phosphorus of the soils of the area have reduced the root system diminishing therefore the water and nutrients absorption. Due to the scarce information on this respect, mainly on the initial stage of the plant, a study was conducted on a greenhouse of the Agricultural Engineering Academic Coordination – UFCG, during the period of February to March of 2006. The experiment was conducted on randomized blocks on a 2 x 2 factorial statistical design having as treatments the acidity of the soil and the phosphorus application, with four replicates, totalizing 16 plots. After the experimental period, it was measured the aerial phytomass, the leaf area and the relation between the aerial phytomass ad leaf area. The data was analyzed using a variance analysis and the means compared through the Tuckey test to the 5% of probability. It was found that the initial growth of the cotton was not influenced by the acidity of the soil. The phosphorus application was extremely efficient to promote the initial growth of the plant. The efficiency in the assimilation of phosphorus was greater on the corrected soil.