Phenology of herbaceous cotton cultivars, in Maracanaú county, Ceará state, Brazil

Abstract

This work was conducted at the Coastal Research Department of the Ceará State Research Service at Maracanaú County, CE, Brazil. The objective was to study the phenology of herbaceus cotton cultivars Gossypium hirsutum L., r. latifolium Hutch. The following cultivars: IAC 17, IAC 19, IAC 20, CNPA Precoce 1, CNPA Acala 1, EPAMIG 3, EPAMIG 4 (MG 79 - 1506) and PR 380/82 were used. Four experiments were conducted: two under dryland conditions, one under dryland conditions and complementation with water, and one under irrigated conditions. The plot had four rows, 1 m apart, with 5 m long. The following parameters were observed: first flower-bud, first flower-bud with 6 mm in diameter, first flower, first hard boll, first open boll, first and last picking. The data showed that in a same cropping season the phenological events practically showed no difference. The phenological stages changed among cropping seasons probably due to water supply. The values of the four cropping seasons showed the first flower-bud with 26,63 days after plant emergence; first flower-bud with 6 mm with 32,45 days; first flower with 46,73 days; first hard boll with 68,95 days; first open boll with 95,00 days; first picking with 114-124 days; and last picking with 138-146 days.