The effects of limestone and phosphogypsum applications on bolls characteristics and technological properties of the cotton fiber were studied in a permanent trial on a Dystrophic Dusky Latosol, acid and of low fertility during growing seasons of 1986/87 to 1989/90. A randomized complete block design was used, arranged in split split-plots with four replications where the dolomitic limestone doses were the main plots (0.6, 1.8 and 3.0 t.ha-1), and the phosphogypsum doses (0, 2, 4, and 6 t.ha-1) were the subplots. Lime and phosphogypsum were applied in the first year and reaplicated during 1988/89. Liming caused an increase in mass of bolls and reduced the Micronaire index and fiber maturity, and did not affect the mass of seed, the percentage of fiber, the length, the length uniformity and fiber tenacity. The use of phosphogypsum increase the mass of bolls and mass of seed, mainly when associated with extremes doses of lime. Otherwise, its effects upon Micronaire index and fiber maturity values, were significant at low level of liming.
cotton; Gossypium hirsutum L.; fiber quality; limestone; phosphogypsum; boll yield
