Absorção de n p k por alface crespa cultivada em sistema hidrôponico

Abstract

Hydroponics has characteristic of water economy that favor his appointment to semi-arid regions, but the lack of information and, especially, the use of non-adapted cultivars, are some of the factors that hinder the use of this technique. The objective of this study was to evaluate the dry matter production of the aerial part, content and accumulation of nitrogen (N), phosphorus (P) and potassium (K) for the cultivation of four lettuce cultivars of crisped type grown hydroponically. The survey was conducted in JCT farm agricultural, Caucaia, CE, from April to June 2016. The factors studied were distributed in a randomized block design in a split plot, with four replications, the plots were composed by the cultivars' Elba ',' Vanda ',' Isabella 'and' Crespa for summer ', and the subplots the sampling time (days after transplanting - DAT). At each sampling time, collected to the shoot and, after drying, evaluated the dry matter production, content and accumulation of N, P and K. The evaluated data were submitted to analysis of variance, mean test and analysis regression. In general, the cultivar 'Crespa for summer' showed higher dry matter yield compared to other cultivars. The concentrations of N, P, K decreased with increasing number of DAT, and that the accumulation of these nutrients did not differ among cultivars. The greater accumulation of N, P and K, occurred in the period between 15 to 20 DAT, suggesting that at this stage no need to increase the availability of the nutrient solution. The nutrient accumulation sequence followed the order K> N> P, for the cultivars 'Vanda' and 'Isabella', and N> K> P to 'Elba' cultivars 'Crespa for summer'.