Produtividade e características de fibras do algodoeiro herbáceo sob déficit hídrico.

Abstract

The herbaceous cotton (Gossypium hirsutum L.), dicotyledonous of great economic and social importance, cultivated in more than 100 countries of the world and its fiber, its main product. The semi-arid region is characterized by persistent periods of drought, with this, one of the alternatives for cotton cultivation in this region with the use of irrigation technique. The objective of this work was to study the effect of the water deficit on the various phenological phases in two herbaceous cotton cultivars. The experiment was conducted under field conditions in the experimental area located in the Center of Science and Technology Agroalimentaria (CCTA), belonging to the Federal University of Campina Grande, campus of Pombal, PB. The treatments were constituted in a factorial scheme of 6 x 2, related to six conditions of water regime, being five times of deficit (T2 = water deficit in the initial growth phase, T3 = water deficit in the appearance phase of the first floral bud, T4 = water deficit in the first flower appearance phase, T5 = water deficit in the appearance phase of the first morning and T6 = water deficit in the appearance phase of the first open bud) and T1 = a control (100 of available water without soil), applied in two herbaceous cotton cultivars (BRS 286 and BRS 336), distributed a randomized complete block design and subdivided plot four replications. The water deficit applied in each phase, according to treatments at a suspension of the irrigation for a period of 14 days, with irrigations with the equivalent of a control in the other phases of the crop. Irrigations are done according to the availability rules of 2 days, always in the morning, based on the availability of water, without soil for plants, using a localized irrigation system with drip tapes. The results were submitted to analysis of variance (Test F) and as averages compared by the Tukey test at 5% of significance by the statistical program Sisvar. The water deficit affects as cotton productivity variables, especially when applied in the apple phase. In general, as fiber characteristics were not statistically influenced, except fiber length. A cultivar BRS 286 had higher productivity when compared to BRS 336. As cultivars are within their varietal standard in relation to the fibers.