Effect of seedling age on 50 per cent flowering of parental lines of Sahyadri rice hybrid.

摘要

The effects of staggered transplanting of seedlings varying in age on 50% flowering were studied in Maharashtra, India, during the kharif of 2002. Three parental lines (IR-58025-A, IR-58025B and BR-827-35-3-1-1-1R, or A, B and R lines, respectively) of Sahyadri hybrid rice were grown. IR-58025A line was earlier by 12.0-12.25 days than R line and IR-58025B line was earlier by 2.62-2.99 days than IR-58025A line (50% cent flowering). The mean deviations of delayed 50% flowering from the recommended age of transplanting (25 days old) was highest for transplanting 40-day-old seedlings (by 7.50, 7.12 and 7.63 days for A, B, and R lines, respectively), followed by 35-day-old seedlings (4.88, 4.75 and 5.00 days), 30-day-old seedlings (2.25, 2.00 and 2.25 days) and 20-day-old seedlings (2.25, 2.00 and 2.50 days). The 50% flowering was delayed in seedlings that were younger or older than the seedlings with optimum age (25 days old). The complete synchronization of flowering in IR-58025A and B was obtained by 3 staggered sowing of IR-58025B line at 3-day intervals without altering the age of nursery plants during transplanting. The synchronization in A and R line was achieved by 3 staggered sowing of R line at 5-day intervals on the 1st, 6th and 11th day of the month, and of A line on the 23rd day of the month due to the effect of overaged seedlings of R line at transplanting.