Comparative studies on different methods for perfect synchronization of parental lines of Sahyadri 3 rice hybrid for commercial hybrid rice seed production

Perfect synchronization between the parental lines of Sahyadri rice hybrid viz., IR 58025A (A-line), IR 58025B (B-line) and KJTR-3 (R-line) were determined by using three methods viz., Growth duration difference, (GDD) Leaf number difference (LND) and Effective accumulated temperature (EAT). The seeding interval between A x B line was 2.66 days and between A x R was 11.89 days. The B line flowered 2.66 days before A line and R line flowered 11.89 days after A line. The Effective Accumulated temperatures (EAT) for attaining 50% flowering of A, B, & R line were 2265.91oC, 2189.61 oC and 2596.29 oC respectively. The difference of EAT between A and B lines was 76.30 oC and between A and R lines was 330.38oC. Parental lines viz., A, B, and R lines flowered after 13.60, 12.60 and 16.70 leaves respectively. The leaf number difference between A and B lines was 1.0 leaf and between A & R line 3.2 leaves. The perfect synchronization of flowering between A and B lines can be achieved by sowing A line 3 days before second date of seeding of B line, sowing of B line after emergence of 1.0 leaf of A line and when A line reaches its EAT to 76.30 oC. Similarly, the synchronization of flowering between A and R line can be achieved by sowing A line 12 days after second date of seeding of R line, after emergence of 3.2 leaves of R line and when R line reaches its EAT to 330.38oC. This phenology model can be exploited for perfect synchronization of flowering in commercial seed production of A x B line and A x R line of Sahyadri rice hybrid.