Crescimento e desenvolvimento do algodoeiro colorido BRS 200 marrom em função de lâminas de irrigação e regulador de crescimento.

Abstract

The colored cotton (Gossypium hirsutum L.) has great potentiality to be cultivated in the semi-arid area, for the conditions favorable climatic. However, some technological steps should be improved as the handling of water and of the plants. The use of products said growth regulators, mainly in the case of the irrigated cotton, they have been providing improvement in the productivity of the cotton, for obtaining more efficient plants for they have better balance among the reproductive and vegetative parts. The experiment was in the Embrapa Algodao experimental farm in Barbalha -Ceara, Brazil in the period of August to November of 2003, in the desing randomized blocks to the maybe, I arrange factorial 5 x 4 , with 4 repetitions. The studied factors were four doses of growth regulator (0.0 1.0 1.5 2.0, L ha"1) and five irrigation sheets (125.30; 298.35; 353.89; 521.86 and 741.64 mm). The planting was led in double arrays (1.80 x 0.45 x 0.20m). The accomplished evaluations consisted of the characteristics of the growth of the plant, of the cotton revenue in pit and fiber, opening of the first capsule, medium weight of capsule and the fiber characteristics and thread. The growths of the cotton was influenced by the irrigation sheets and for the regulator, incline the dose of 1.0 L ha"1 proportionate the increase of the medium weight of capsule. The cotton revenue in pit and fiber showed a quadratic relationship with the irrigation sheets, was obtained a revenue of 1655.96 kg ha"1 with the largest sheet of 741.64mm and with the smallest sheet (125.30 mm) it was obtained a revenue of 380.36 kg ha"1, denoting a decrement of 340%. The fiber characteristics and thread were influenced by the irrigation sheets, while the growth regulator just influenced fiabilidade index and the index of short fibers, but being, inside of the patterns demanded by the modern it elaborates textile.