Response of ‘Atlas’ Cotton to Variations in Plants Per Hill and Within‐Row Spacings¹

Abstract

To determine the effects of variations in plants per hill, spacing arrangements, and plant populations on agronomic and fiber properties of cotton (Gossypium hirsutum L.) we conducted a 2‐year study at Experiment, Ga., using ‘Atlas’ cotton on Cecil scl. Each trial was a randomized block split‐plot with number of plants (2, 3, 4, or 5 per hill) as the main plots and within‐row spacings (20, 40, and 60 cm) as subplots. The variations in plants/ hill and spacings represent a range in population of 32,110 to 240,825 plants/hectare. Significant differences in yield due to years and to within‐row spacings were found, but number of plants per hill did not affect yield. The plants in hills spaced 20 and 40 cm apart produced higher yields than the plants spaced 60 cm. A population range of 96,330 to 144,495 plants/ha produced best yields. We found differences in lint percentage and boll size due to years, plants/hill, and within‐row spacings. Lint percentage was highest and bolls were largest from plants at the 60‐cm spacing and when there were 2 plants/hill. The only significant difference in seed size was that associated with years. Fiber length differences were due to years, plants/hill, and within‐row spacings; the longest fibers were produced by 3 plants/hill and by plants at 40‐cm spacing. Differences in fiber strength were due to years and within‐row spacings; the strongest fibers were produced by plants spaced 60 cm apart. Fiber fineness was influenced by years only. The following interactions were found: Years × plants/hill: boll size, fiber length, fiber fineness, yield, lint percentage, and seed size. Years × spacings: lint percentage, boll size, and fiber fineness. Plants/hill × spacings: lint percentage. There were no significant second order interactions. Although mean differences were statistically significant, they are so small that they may be of no practical value. However, results demonstrate the relative stability of the characters stodied over a wide range of planting patterns and population densities.

Comparative Growth and Yield of Cotton Planted at Various Densities and Configurations

“…Limited information is available on the effect of intrarow seeding configuration at a given population on growth and development parameters. Hawkins and Peacock (1970) reported that plant population, as long as the stand is of uniform density, may be a more important factor than either spacing or number of plants per hill; and that boll and fiber characteristics were relatively stable across a wide range of planting patterns (Hawkins and Peacock, 1971).…”

“…Several researchers have concluded that seed cotton yield and plant density are unrelated (Ray et al, 1959; Hawkins and Peacock, 1973; Baker, 1976; Buxton et al, 1977; Jones and Wells, 1998; Bednarz et al, 2000; Franklin et al, 2000). Other researchers, however, have observed reduced yields with extremely high or low plant densities (Hawkins and Peacock, 1971; Bridge et al, 1973; Smith et al, 1979).…”

Effects of Irrigation, Cultivar, and Plant Density on Cotton Within‐Boll Fiber Quality

“…Baker (1976) and Hawkins and Peacock (1971) also reported that fi ber length and elongation were not infl uenced by plant density. Bednarz and Nichols (2005) also showed that, at the fi eld level (i.e., when plots were machine harvested, blending seed cotton across fruiting positions, and ginned together), mean fi ber length and UQL did not diff er among plant densities.…”

Optimizing Irrigation and Plant Density for Improved Cotton Yield and Fiber Quality

“…An acceptable plant density may vary with location, environmental conditions, cultivar, and grower preference (Silvertooth et al, 1999). Fiber length, strength, and elongation were not influenced by plant density (Baker,1976; Bridge et al, 1973; Hawkins and Peacock, 1971). Boquet (2005) reported that plant density affected fiber properties although the effects were very small.…”