Abstract

The determination of cotton (Gossypium hirsutum L.) bud age in days relative to anthesis (DRA) is of value for studies of fiber differentiation. Bud age is easily judged at l-d preanthesis (− IDRA) but is less discernible in younger buds. The objective of this study was to relate bud length to bud age relative to antbesis and to determine the effect of bud position on bud length. ‘Stoneville 506’ cotton was grown in a greenhouse in 4-L pots of potting mixture. Data were taken from 48 plants planted 14 Mar. 1991. Bud length was measured from the midpoint of the base of a bract to the tip of the corolla whorl. Mean bud length at − 1DRA peaked at 3.2 cm at main-stem node (MSN) 10 for the first sympodial node (Position 1 buds) and 3.0 cm at MSN 8 for Position 2 buds. Also, mean bud lengths at Positions 2 and 3 on sympodial branches below MSN 9 were as long or longer (P ≤ 0.05) than mean lengths at Position 1, but a reverse trend of Position I buds being longer than Position 2 buds was observed from MSN 9 through 13. The peaks in length for Position I and 2 buds were indicative of a period of maximum bud growth around 94 days after planting that impacted buds at both positions simultaneously. Bud length was correlated with bud age only at −2DRA and − IDRA and was affected by sympodial position and MSN as well as by the interaction of sympodial position and MSN.

Copyright © 1994. Crop Science Society of America, Inc.. Copyright © 1994 by the Crop Science Society of America, Inc.