RUBBER TREE RESPONSE TO N, P and K DOSES IN FERTILIZATION AT PLANTING

Abstract

The objective of this study was to evaluate the growth, root and shoot dry mass accumulation and nutritional status of rubber tree in the initial stage of cultivation, under different combinations of nitrogen (N), phosphorus (P) and potassium (K). Combinations of the following doses were tested: 0, 20, 40 and 80 kg ha-1 of N; 0, 75, 150 and 300 kg ha-1 of P2O5; and 0, 25, 50 and 100 kg of K2O. Under the soil and climate conditions analyzed, the combinations of NPK fertilization applied at planting only caused significant growth responses of rubber tree plants as a function of the absence of N and its presence at the dose of 80 kg ha-1. Through leaf analysis it was possible to verify that N fertilization and P fertilization are adequately meeting the needs of rubber tree plants, while the K doses tested did not reach the adequate levels of sufficiency.