Effect of Photoperiod and Temperature on the Development of Sorghum1
- J. L. Caddel and
- D. E. Weibel2
Three varieties of Sorghum bicolor (L.) Moench, (i.e., ‘Early Hegari,’ ‘80-Day Milo,’ and ‘Wheatland’) were grown in controlled environment chambers and subjected to all combinations of 10-, 12-, and 14-hour photoperiods, 27 and 32 C day temperatures, and 16 and 21 C night temperatures. Days to floral initiation were determined for each variety under each treatment combination. In addition, days to anthesis and days in the floral period (from initiation to anthesis) were determined for the treatment combinations involving 21 C night temperatures.
Ten-hour days hastened floral initiation and anthesis of each variety at all temperature combinations. Fourteen-hour days delayed development, but with some temperature regimes the delay was not significant, compared to the shorter days. The rate of development for the varieties under 12-hour days was highly dependent upon day and night temperatures, since floral initiation ranged from as early as that obtained with 10-hour days to later than that obtained with 14-hour days.
The response to day temperature during the floral period was small, but statistically significant. The time to anthesis followed a pattern similar to that for the time to floral initiation.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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