Growth, Boll Opening Rate, and Fiber Properties of Narrow‐Row Cotton

Abstract

AbstractRow spacing has the potential to affect agronomic traits of upland cotton (Gossypium hirsutum L.). Although narrow‐rows can pose numerous management challenges (e.g., cultivation and harvesting), the benefits of narrow‐rows may justify their use. Unfortunately, the extent and consistency of cotton's response to narrow‐rows is variable, which makes management decisions more difficult. The objective of this study was to determine whether row spacing affected the earliness (date at which 65% of the lint was on open bolls), fiber properties, and vegetative dry matter of normal‐leaf and okra‐leaf cotton. In 1989 and 1990, an okra‐leaf genotype and its normal‐leaf isoline were grown in field experiments on a Bosket fine sandy loam, using 0.5‐ and 1.0‐ m row spacings in early and late plantings each year. During midand late‐bloom, the vegetative dry matter was determined. At maturity, seed cotton in open bolls was picked at approximately 10‐d intervals, ginned, and earliness (date when 65% of total lint was on open bolls) calculated. Okra‐leaf grown in 0.5‐m rows reached 65% open 3 d earlier than okra‐leaf grown in 1.0‐m rows in the early planting of 1990. Otherwise, earliness was not affected by row spacing. Except for a small increase in the 2.5% span length of normalleaf grown in 1.0‐m rows above that in 0.5‐m rows, the other fiber properties, vegetative dry matter, vertical boll distribution, and average seed mass were unaffected by row spacing. Since many agronomic traits were unaffected by row spacing, management practices (e.g. date of defoliation) of narrow‐rows might be expected to similar be to that of conventional rows.