Effect of suspension of the last irrigation on herbaceous cotton

Abstract

In an alluvial soil of the São Gongalo Irrigation Project, at Sousa, PB, Brazil, the last irrigation at 70, 85, 100 and 115 days of the herbaceous cotton (Gossypium hirsutum L.r. latifolium Hutch.) cycle did not affect cotton yield, with production average of 3,562; 4,196; 4,254 and 4,176 kg/ha of lint cotton, respectively. The herbaceous cotton cultivars IAC-20 with 4,510 kg/ha and CNPA 6H with 4,438 kg/ha yields were significantly more productive than the cultivars CNPA Precoce 1 (3,674 kg/ha) and the CNPA Acala 1 (3,567 kg/ha). When the last irrigation changed from 70 days to 85 days of plant cycle, CNPA Precoce 1, IAC-20, CNPA Acala 1 and CNPA 6H showed yield increases of 469, 520, 655 and 893 kg/ha, respectively.