The effect of date of planting on the fibre properties of four cotton cultivars grown under irrigation

Abstract

The effects of date of planting on the fibre properties of four cotton cultivars, Acala 1517–70, Albar 70C, Deltapine 5826 and Albacala CS-2, were investigated under irrigated conditions over a 3-year period near Groblersdal. Six dates of planting at fortnightly intervals were compared, starting 6 October and ending 15 December. Results indicate that both the 2,5% and 50% span lengths and the uniformity ratio were significantly affected by planting date. Actual fibre lengths increased with later dates of planting, but the increases were very small. Fibre strength significantly increased as planting was delayed; differences among cultivars were greater than differences among dates of planting. Micronaire index, fibre maturity ratio and fibre fineness were all significantly affected by planting dates, with fibres becoming finer and less mature with later plantings. Fibre properties were least influenced when plantings were made between 6 October and 3 November, indicating that this period is the optimal planting time for the fibre development of the four commercial cultivars evaluated in this study.