Rice is grown on 1.5 million ha in Maharashtra State, India. Of the total area under rice, about 56% is planted to fine and superfine varieties; the rest is under coarse-grained varieties. Early, medium-late, and late varieties, respectively, occupy about 40%, 40%, and 20% of the area in the state. Because fine-grained varieties are preferred, the Karjat rice research station developed Karjat 4, an early-maturing variety (115-120d), and Karjat 6, a medium-duration (130-135 d) line suitable to the varied agroecological conditions in the state. Karjat 6 (KJT-12-6-25-9-13-50-13) was developed through the pedigree method. It involved a cross of Heera and Karjat 4. Recommended for commercial cultivation in Maharashtra in 2005, Karjat 6 is a semidwarf (95-100cm) variety having short, slender grains, 1,000-kernel weight of 13.30 g, and average grain yield of 3.5-4.0 t ha-1. The variety has 68.1% milling and 65% head rice recovery.

The experiment was formulated to assess the effect of seedling age at transplanting on 50% flowering of A, B, and R lines of Sahyadri rice hybrid. Three parental lines of Sahyadri rice hybrid were sown at same time in nursery and transplanted at the seedling age 20, 25, 30, 35 and 40 days at eight locations in the State. It was observed from mean data that IR - -58025 A line was earlier by 12.0 -12.25 days as compared to B R-827-35-3-1-1-1 R line and IR - 58025B line earlier by 2.62 - 2.99 days than IR-58025A line for 50% flowering. The mean deviations of delayed 50% flowering from the recommended age of transplanting (25 days old) was maximum in 40 days old seedling transplanting by 7.50, 7.12 and 7.63 days for A, B, and R lines, respectively followed by 35 days old seedlings (4.88, 4.75 and 5.00 days), 30 days old seedlings (2.25, 2.00 and 2.25 days) and 20 days old seeldings (2.25, 2.00 and 2.50 days). The 50% flowering was delayed in both younger and older aged seedlings than the recommended age of seedling (25 days old) at transplanting by approximately half the number of days by which the seedings were younger and older than the recommended age. The complete synchronization of flowering in IR - 58025A and B lines could be obtained by three staggered sowings of IR-58025B line with three days interval without altering the age of nursery at transplanting. The synchronization in A and R lines could be achieved by three staggered sowings of R line by 5 days intervals on 1st, 6th an 11th day of the month and A line on 23rd day of the month due to the effect of over aged seedling of R line at transplanting.