Evaluation of herbaceous cotton cultivars under irrigation

Abstract

A field experiment with four upland cotton cultivars (Gossypium hirsutum L. r. latifolium Hutch) was conducted during four years, 1988/91, in an alluvial soil of the São Gonçalo project, in the State of Paraíba, Brazil, to study the effect of competition among cultivars in furrow irrigated soil, concerning yield. The experimental design utilized was a randomized block with four treatments and six repetitions. In terms of average lint cotton yield, the cultivars IAC-20 with 4,224 kg/ha and CNPA-6H with 4,132 kg/ha of yields were significantly more productive than the cultivars CNPA Precoce 1 (3,461 kg/ha) and CNPA Acala 1 (3,224 kg/ha). The data on first buds, first flowering and first boll opening show a maximum variation of two days among cultivars, and all cultivars attained their cycle in a maximum of 125 days. As to harvest at 105 days, the precocity index were 81%, 79%, 74% and 61%, for cultivars CNPA Precoce 1, IAC-20, CNPA-6H and CNPA Acala 1, respectively, and only the CNPA Acala 1 was significantly different from the other cultivars.