Effect of seedling age on yield and yield components in rice varieties

One of the most important factors in rice cultivation is determination of the timly transplanting for better agronomic management. In most cases, this subject is used as a best way against deficiency of water, while there must surely be irrigation water as much as is needed or wanted. The best of a particular type of the agronomic management in rice cultivation is seedling age for different rice cultivars. Seedling age was found to be the most influential factor affecting morphological characteristies after transplanting. Younger seedling performed better than older seedling transplanted into either flooded or non-flooded soil with greater uptake for nutrients from the soil. This experiment was conducted on rice seedlimg age in different rice cultivars. Seedling of different age as a main plot were including 15, 21, 28 and 35 days and different rice cultivars as a sub plot were Hashemi, Khazar, Deylam and Shiroodi. The experiment design was Split plot based on randomized complitly block with three replications, which it was carried out in two locations (Rasht and Chaparsar) in two consecutive years (2010 and 2011). Combin analysis results clearly showed significant differences between treatments, year effect, location and its interaction effectwere on many characters. Comparision means with Touky method for yield showed that Deylam and Shiroodi varieties have a 6011 and 6137 Kg per hectars respectively. Comparision means for seedling age showed that seedling age 15 and 21 days have a yield beter than other treatment with means 5176 and 5220 Kg per hectars respectively. Howevre, no significantly interaction between varieties and seedling age but Deylam and Shiroodi varieties in first seedling age (15 days) have a 6134 and 6322 Kg and second seedling age (21 days) have a 6215 and 6199 Kg per hectars respectivly. In this case younger seedling age in different varieties can be used environmental factors such as water, light and nutrient have a high yield against older seedling age. Therefore we can transplant the younger seedling age (15-21 days) to main land hence there haven,t same limits such as land praperation, land leveling, labour, tools and etc. finally we could saved water for land praperation with using rain and other water that it would be aggregated on the dam. Key words: Rice Seedling Age Water Use Efficiency -Yield Yield Component