EFFECT OF IRRIGATION DEPTH ON THE YIELD AND FIBER QUALITY IN COTTON CULTIVARS (Gossypium hirsutum L. r. latifolium Hutch).

摘要

The main objective of the trial was to evaluate the effect of irrigation depths on the yield and fiber quality in cotton cultivars. CNPA 7H, CNPA Precoce 1, and CNPA 6H. The irrigation depths studied were: LIt = 671 mm, LI2 = 785 mm, LI3 = 872 mm and LI4 = 927 mm, which were applied in closed end levelled forrows. The experimental design adopted was a completely randomized block in a split - plot layout with 4 replications. The irrigation depths were the main plots, while the cultivars were the subplots. The adjusted regression equations for cotton yield had a quadratic model, with high significance for the irrigation depths. The maximun estimated cotton yields were 3051, 2763 and 2423 kg.ha-1, for the cultivars CnPa 7H, CNPA Precoce 1 and CNPA 6H for a total water application 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 affected by the irrigation depth.