NPK effect, in foliar spraying, on the nutrients composition of cotton leaves

Abstract

This research was carried out in greenhouse situated in the Escola Superior de Agricultura Luiz de Queiroz, São Paulo State, Brazil, in 1975/76, to study the influence of NPK spraying on leaves, on the NPK com position in leaves to cotton plant (Gossypium hirsutum L.) cv. IAC-13-1. The experimental design was a Randomized Complete Blocks with the treatments combined in a 2 x 3³ factorial with 3 replications. The treatments were: spraying-two (4 and 8), fertilizers three (N,P,K) in three levels (0,1,2). This three levels had the following averages according to the number of spraying, such as: four spraying - N0 = 0, N1 = 0,44, N2 = 0,84; P0 = 0, P1= 0,05, P2 = 0,09; K0 = 0, K1 = 0,33, K2 = 0,66; eight spraying - N0 = 0; N1 = 0,91, N2 = 1,87; P0 = 0, P1 = 0,10, P2 = 0,20; K0 = 0, K1 = 0,70, K2 = 1,40. The levels are expressed in Kg/ha and the source of fertilizers used were; NH4NO3; NaH2PO5H2O and KC1 for N, P(2)0(5) and K(2)0 respectively. The evaluation of the treatments were done based upon: percentage of N, P, K dry matter of young leaves and old leaves. The following conclusions could be drawn from this research: the N caused increase in P level in old leaves. The cotton plants no treated with N increased the percentage of K in old leaves. The P caused reduction in N levels in old and young leaves; increased the P levels in old leaves in N presence. The K increased the P leavel in old and young leaves, descreased the K levels in old leaves.