MINERAL AND ORGANIC FERTILIZER OF THE HYBRID SQUASH: NUTRITIONAL STATE AND PRODUCTION

Abstract

In order to evaluate the response of hybrid squash cv. Tetsukabuto to organic compost and mineral fertilizer (NPK), seven experiments were carried out on a cambic yellow-red Podzol soil under field conditions at Ponte Nova, Minas Gerais State. Each experiment constituted one sampling date, that begun at the 21st day and ended at the 105th day after planting, with 14 days intervals. In these experiments five fertilizing treatments were tested plus a control (no treatment). In the fertilizing treatments, defined by a diagonal section of a complete factorial, rates of 0, 3, 6, 9 and 12 t/ha (dry basis) of organic compound, associated were applied with rates of 0.772, 0.579, 0.386, 0.193 and 0 t/ha of NPK (4-14-8), respectively, with four replications in a randomized blocks design. The NPK and organic compost association increased the plant leaf number, the main branch length and the fruit yield. The maximum yield and maximum economical efficiency, 13.596 and 13.368 t/ha, were obtained with the rates 6.402 t/ha of organic compost and 0.360 t/ha of NPK and with 5.247 t/ha of compost and 0.434 t/ha of NPK, respectively. At the 49th day after sowing, the concentrations of N, P, K, S, Ca and Mg, in the leaf blade dry matter, associated with the maximum economic return, were: 38.8; 5.2; 27.5; 2.5; 21.3 and 3.8 g/kg, respectively. These data, at the 63rd day after sowing, were: 43.8; 4.7; 24.4; 2.5; 18.3 and 5.3 g/kg, respectively. At 105th after sowing, the estimated contents of N, P, K, S, Ca and Mg in the aerial part and expressed in g/plant were 27.8; 4.7; 26.7; 1.8; 10.1 and 4.8, respectively.

KEY-WORDS: Hybrid squash; organic compost; nutrient content; mineral fertilizer.