Efeito de lâminas de irrigação sobre o rendimento e qualidade da fibra de cultivares de algodoeiro herbáceo. (Gossypium hirsutum L. r. latifolium Hutch).

Abstract

The main objective of the trial was to evaluate the effect of irrigation depths on the yield and fiber quality in annual cotton cultivars (CNPA 7H, CNPA Precoce l, and CNPA 6H). The irrigation depth were: LI1 = 671 mm, LI2 = 785 mm, LI3 = 872 mm and LI4 = 927mm, which were applied in closed-level-forrow. The randomized complete block was the experimental design used in a split-plot layout, with 4 replications. The irrigation depths were the main plots, while the cultivars were the subplots. The ajusted regression equations for cotton yield had a quadratic model, with high significance for the different irrigation depths. The maximun estimated cotton yields were 3031, 2760, and 2434 kg/ha for the cultivars CNPA 7H, CNPA Precoce 1 and CNPA 6H for a total water applied of 836, 882 and 821 mm, respectively. The fiber uniformity varied significantly with the management and the intensity of irrigation. On the other hand, the length, the resistence, and the fineness were not offected by the irrigation depth.