Author
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Wanjura, Donald |
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Upchurch, Dan |
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Submitted to: National Cotton Council Beltwide Cotton Conference
Publication Type: Proceedings Publication Acceptance Date: 1/8/1998 Publication Date: N/A Citation: N/A Interpretive Summary: Wind and hail from thunder storms frequently damage the leaves of young cotton seedlings. Leaf damage reduces vigor and a decision is required to either keep the existing stand of seedlings or to replant. Quantitative information that relates damage to young seedlings to yield is needed to make informed production management decisions. We evaluated the effect of simulated weather damage to young cotton seedlings at the two-true leaf growth stage on their recovery rate and lint yield in a 2-year study. The leaf area in the second year was greater than the first year; however, the recovery in leaf area four weeks after treatment resulted in similar leaf areas in both years. Plant survival and yield were significantly reduced by removing all leaves in both years. In both years lint yield increased with increased amount of leaf area that remained on seedlings immediately after treatments were applied. Technical Abstract: Wind and hail events commonly damage young cotton seedlings. This reduces vigor and calls into question a replanting decision. Quantitative infor- mation that relates damage to young seedlings to yield is needed to make informed production management decisions. Simulated weather damage studies using young cotton seedlings were conducted under full irrigation in 1996 and under limited irrigation in 1997. The treatments included removing (a) no leaves -Control, (b) one cotyledon -C, (c) two cotyledons -2C, (d) all true leaves -TL, (e) one cotyledon and all true leaves -C-TL, and (f) two cotyledons and all true leaves -2C-TL. Cotton seedlings had leaf areas of 362 cm2/m2 and 592 cm2/m2 when treatments were imposed in 1996 and 1997, respectively. The difference in leaf area between years was due to greater true leaf area in 1997 than in 1996. Seedlings had between 2 and 3 mainstem nodes each year when weather damage treatments were applied. Plant tsurvival was significantly reduced by the most severe treatment, -2C-TL, in both years. Water supply differences between years did not affect vegetative development prior to four weeks after treatments were applied. Lint yield was reduced by the most severe simulated weather damage treat- ment, -2C-TL, in both years. In 1996 when water was not limited there was a strong relationship between leaf area immediately after treatments were applied and lint yield; however, the limited water supply in 1997 diminished the relationship between post treatment leaf area and yield. |
