350-1 Effects of Supra-Optimum Temperatures On Soybean Growth and Development.

Poster Number 221

See more from this Division: ASA Section: Climatology & Modeling
See more from this Session: Agroclimatology and Agronomic Modeling: III
Wednesday, October 24, 2012
Duke Energy Convention Center, Exhibit Hall AB, Level 1
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Lingxiao Zhang1, Kenneth J. Boote2, Ya-Ying Wang3, Hauser A. Bernard3 and Leon Allen4, (1)Chemistry Research Unit, USDA-ARS, Gainesville, FL
(2)Agronomy, Univerisity of Florida, Gainesville, FL
(3)Department of Biology, Univerisity of Florida, Gainesville, FL
(4)USDA-ARS, Gainesville, FL
Poster Presentation
  • Zhang et al _soyeban-temperature 2012-ASA poster-final.pdf (623.4 kB)
  • Elevated temperature often negatively affects crop growth and development, resulting in impaired reproductive growth and lower seed yields. A study was conducted to investigate the vegetative and reproductive growth responses of soybean (Glycine max L.) cv. Maverick (MG III, indeterminate) by increasing temperatures at two oxygen levels (21% and 32%) in a controlled greenhouse environment. Carbon dioxide concentration was held constant at 700 ppm to minimize photorespiration. Seed were sown in pots on 16 May 2011 and grown at day/night temperatures of 30/22 degrees C in eight rooms of the controlled environment greenhouse for 21 days. Four day/night temperature regimes were established at 21 days for the duration to harvest maturity: 30/22 (control, “optimal” regime), 34/26, 38/30 and 42/34 degrees C. Flowering (R1) occurred at 24 days after sowing. Results indicated that elevated oxygen had no significant effect on development rate and had a non-significant tendency for a reduction in biomass productivity. Therefore, results were averaged over oxygen treatments. Supra-optimal temperatures accelerated soybean vegetative growth. Plants grown at higher temperatures had more nodes, greater plant height (except at 42/34 degrees C), increased plant leaf area (except at 42/34 degrees C), increased leaf dry weight, and increased stem dry weight (except at 42/34 degrees C). In addition, supra-optimal temperature slowed reproductive development (reproductive stage progression), as well as decreased pod number, pod weight per plant, and pod harvest index. The highest temperature regime (42/34 degrees C) inhibited both vegetative growth and reproductive development, leading to the formation of the smallest plants with the lowest leaf area and a failure to develop pollen, with zero seed yield. We conclude that supra-optimal temperature shifted the balance from reproductive to vegetative development. Understanding the processes of impaired reproductive development and growth is important for ameliorating the effects of global climate change.
    See more from this Division: ASA Section: Climatology & Modeling
    See more from this Session: Agroclimatology and Agronomic Modeling: III
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