Effect of Seedling Age and Seeding Rate in Nursery on Some Agronomic Traits and Seed Yield of Rice (Oryza sativa L.) cv. Tarom Hashemi

To study the effects of seedling age and seeding rate in nursery on some quantitative traits of rice, a field experiment was conducted as split plot in a randomized complete block design with three replications in Amol during the 2012 growing season. Seedling ages with three levels (20, 30 and 40 days old) were considered as main plots and seeding rates with four levels (10, 30, 50 and 70 kg.ha-1) as sub-plots. Results showed that the effect of seedling age on panicle length, total tiller number and fertile tillers per hill, percent of furtile and unfurtile florets and harvest index and seeding rates on seed yield were significant. The interaction effects of experimental treatments on plant height, stem and panicle lengths, number of furtile and unfurtile florets and harvest index were also significant. Increasing seedling age from 20 to 40 days, decreased the total tiller number per hill, number of fertile tillers, percent of furtile florets and harvest index, while, they increased panicle length and number of unfilled florets. The highest seed yield (3033 kg.ha-1) was obtained by seeding rate of 30 kg.ha-1. Increasing seeding rates beyond 30 kg.ha-1, decreased the seed yield by 15% (2567 kg.ha-1). Therefore, using 20 days old seedlings and seeding rate of 30 kg.ha-1 in the nursery plots can be recommended to the Tarom Hashemi cultivar to the experimental site.