Effect of seedling age on the growth, yield and yield components of rice

This research was conducted at the Bangladesh Rice Research Institute (BRRI) Gazipur Farm during T. Aman seasons of 2014 and 2015 to determine the tillering pattern, growth, yield and yield components rice as affected by seedling age. The treatments were six different ages of seedling, such as 15, 20, 25, 30, 35, and 40 days. The treatments were arranged in a RCB Design with three replications. The variety BRRI dhan46 was used in this experiment. The unit plot size was 4m X 4m. One seedling per hill at 20cm X 20cm spacing was transplanted. Irrespective of seedling ages, the stem dry weight of all sampling dates increased slightly at PI stage (about 60 DAT) then sharply increased at FS (about 90 DAT) after that decreased and reached minimum at maturity stage. The leaf dry weight also followed the same trend as stem dry weight. The panicle dry weight in all the treatments sharply increased from flowering to maturity stage. Irrespective of seedling ages, the tiller number gradually increased with the DAT and reached maximum at 45 DAT then gradually decreased and reached minimum at ripening and maturity stage. Fifteen -day -old seedling produced the highest number of tiller per hill from 15 to 120 DAT. The lowest number of tillers was recorded in 40- day- old seedling in all the sampling dates. The panicle number m-2 also increased with decreasing seedling age. It was the highest in 15- day- old seedling and lowest in 40- day- old seedling. Fifteen to 30 -day- old seedling produced statistically identical and higher number of grain panicle-1 and 40 -day- old seedling gave the lowest number of grain panicle-1. The highest grain yield obtained from 15- day-old seedling transplanted plot followed by 20, 25, 30, 35 and lowest in 40- day-old but no significant difference was observed from 15 to 30- day- old seedling.