Características fisicas e químicas do látex e crescimento da seringueira em função da calagem e da adubação NPK em dois sistemas de explotação

Abstract

The objective of this study was to evaluated physiological latex characteristics and the tapping systems of the clone RRIM 600 of rubber tree (Hevea sp.) an experiment was conducted with continuous supply NPK fertilizers with or without lime. The experiment was conducted in a randomized split-plot design with eight treatments: without fertilizer and without lime (T1), without fertilizer and with lime (T2), N1P1K0 + lime (T3), N2P2K0 + lime (T4), N1P1K1 + lime (T5), N2P2K1 + lime (T6), N1P1K2 + lime (T7) e N2P2K2 + lime (T8). In the two sub-treatments the following tapping systems were used: (S1) ½S d/4 6 d/7 ET 2.5% LaPa 1/1 10/y e (S2) ½S d/6 6 d/7 ET 5.0% LaPa 1/1 10/y with four replicates. The rates used were 0, 40 and 80 kg ha-1 y-1; 0, 17.5 e 35.0 kg ha-1 y-1 de P2O5 e 0, 33.2 e 66.4 kg ha-1 y-1 de K2O. The interaction of fertilizer with or without lime versus tapping system did not affect trunk girth increment. The bark thickness was significantly increased with liming, and N1P1K0 and tapping system ½S d/6 6 d/7 ET 5% 10/y increased latex saccharose concentration.