Efeito do espaçamento e manejo da irrigação no desenvolvimento e produção do algodão herbáceo (Gossypium hirsutum L.) no município de Boqueirão, PB.

Abstract

The purpose of t h i s work was to study the effect of the irrigation mana gement on the behavior of the cotton (Go&òyp-Lum hÁASutum L.) cultivar CNPA Precoce 1. The experiment was conducted i n Boqueirão State of Parai ba on a Non-Calcic Bron s o i l , medium textured during the period of Octo ber 1988 to January 1989. The experimental design used was a factorial, randomized blocks with 3 (three) replicates. The treatments were row spacings of 0,5m; 0,8m; 1,0m and 2,0 meters (double row) and two kind of irrigation managements: continuous irrigation and alternated irrigation. The analysis of the results showed that the cotton production depended mainly on the water management, being observed an increase of production of 33,371 with the continuous irrigation management, when compared with the alternated irrigation. The row space of 0,8m was the most productive (8,75 kg/lot) and it was significantly different of the other spacings. The spacings a 0,5 and 1,0m showed st atistic differences among them showing a produtivity of 8,12 and 6,39 kg/lot, respectively. The spacing of 2,0m, with double cotton row, showed the least productivity (5.00kg /lot ). There was not difference among height of plants for all the treatments analized. The stem diameter differed significantly among water treatments for the narrowest spacing (0,5m between lines). With respect to the techonologic characteristics of the cotton fiber, there was signi ficant difference of fiber uniformity among the water management treat ments. The was not significant difference for fiber, resistance, and length of fiber for any studied treatment. The economical analysis showed that for the conditions under which the study was conducted, the row spacing of 1,0m and continuous irrigation was the most suitable alter native.