ارزیابی اثر سن گیاهچه بر عملکرد و اجزای عملکرد چهار رقم برنج (Oryza sativa L.)

This study was carried out in order to determine the more suitable seedling age on rice cultivars in Chaparsar Rice Research station of Mazandaran province in 2009. This experiment was laid out as split plot in a randomized complete block design with 3 replications. The main plots were seedling age with four levels (20, 33, 37 and 40 days) and sub plots were rice cultivars (Hashemei, Khazar, hybrid and Shirodi). During growth stage different traits including plant height, total tiller, fertile tiller, panicle length, number of grains (filled, unfilled and total) per panicle, 1000-grain weight, flag leaf area, day to emersion of panicle, day to 50% of flowering, day to maturity and grain yield were measured. Results of statistical analysis showed significant difference in fertile tiller, number of grains (filled, unfilled and total) per panicle, day to emersion, day to 50% of flowering and day at 5 and 1 probability levels. Effect of cultivars for all characters was significant. Correlation coefficients were also showed positively significant relationship in total tiller, fertile tiller, number of grains (filled, unfilled and total) per panicle, day to emersion of panicle, day to 50% of flowering and day to maturity in with grain yield in different cultivars. The highest grain yield (5166.9 kg/ha-1) was obtained in 20 days seedling age. The greatest grain yield (5899.9 kg/ha-1) was also belonged to in Shiroodi cultivar. Therefore, according to the results and to reach to highest yield, 20 days seeding age and Shiroodi cultivar is recommended.