Plant density; plant growth retardants: Its direct and residual effects on cotton yield and fiber properties

Foliar sprays of (PGR's) Cycocel and Alar were applied at concentrations of 250, 500, and 750 ppm after 105 days after plantation (square and boll setting stage) to Egyptian cotton cultivar planted at three plant densities (166.000, 222.000, and 333.000 plant ha(-1)). Number of opened bolls plant(-1), seed-cotton yield plant(-1), and earliness increased as plant density decreased in both years, as did seed-cotton and lint yield ha(-1) in the second season. In the first year, the intermediate plant density gave highest yields. Plant density had no significant effect on lint percentage or fiber properties. Both Cycocel and Alar increased the number of opened bolls plant(-1), boll weight, seed and lint indices, seed-cotton yield plant(-1) and both seed-cotton and lint yield ha(-1), but effects were not always significant and response varied for different traits. Neither Cycocel nor Alar affected lint percentage, yield earliness or fiber properties at any plant density.