Crescimento, produtividade e consumo de solução nutritiva em diferentes concentrações pelo tomateiro cultivado em casca de arroz in natura

Abstract

The goal of this work was to determine the effect of different nutritive solution concentration about the growth, yield and consuption of nutritive solution of this crop using rusk rice substrate in natura. Two experiments were carried in two periods, in spring/summer and summer/autumn in a plastic greenhouse in the Department of Fitotecny of University Federal of Pelotas. Treatments consisted of five concentrations of nutritive solution, in bifactorial scheme and casualized design randomized. The testemmun (T3) was the nutritive solution with concentration standarized and the other treatments were concentrations of 0,9 (T1); 1,6 (T2); 3,0 (T4) and 3,7 (T5) dS m-1. The determination of transpirated volumes in treatments with concentrations 1,6, 2,3, 3,0 e 3,7 dS m-1 was made through estimative of nutritive solution volume decreased in recipient of similar form of methodology used by Valandro (1999). The leaf area was determined through a measured image equipment (LI-COR 3100). The temperature and solar radiation were measured daily. The absorved volumes were converted for unity of solar radiation and leaf area. The substrate was placed in bags of 10 L drilled in the base and put in density 2,81 pl m-2. Fresh and dry vegetative mass, fresh and dry fruit mass and also leaf area in three plants in each repetition were determined. The dry vegetative mass, the dry fruit mass and the total dry mass showed polinomial effect of nutritive solution concentration. The leaf area evolution of crop in two periods, adjusted similar polinomial tendency observed in fresh and dry mass. The results show values for EC of 2,3 and 3,0 dS m-1, like the ones that maximize fruit production in spring/summer and summer/autumn, respectively. There was a decrease of leaf area after the EC 2,3 and 3,0 dS m-1 in spring/summer and summer/autumn, respectively. A polinomial regression was adjusted between EC and consumo of nutritive solution in spring/summer. Solanum esculentum, eletrical condutivity, substrate