Photoperiod and Temperature Manipulation Induces Early Anthesis in Pearl Millet1

The time requited for anthesis and head development by two inbred lines of pearl millet, Pennisetum typhoides (Burm, Staph, and C. E. Hubb), Tift‐23 and Tift‐31 was shortened by manipulating temperature and photoperiod regimes. Growth and development rates over a range of temperatures and photoperiods were determined using the controlled environment facilities in the Phytotron at Duke University. These studies showed that high day and night temperatures of 32 and 29 C, combined with long days (16 hours) of high light intensity, favored growth and that early flowering could be induced with 8‐hr days. Early anthesis and full head development were attained using 32‐C day with 29‐C night temperatures and the following photoperiod sequences: 21 days with a long photoperiod, 16 hrs; then 15 days with a short photoperiod, 8 hr; followed again by long days. This procedure resulted in anthesis in 45 to 48 days from date of planting, compared to previously reported times of 56 to 67 days.