Effect of seedling density and nitrogen fertilizer rate on the growth indices and yield of the rice promising line no. 8405

In order to determine appropriate plant distribution and nitrogen fertilizer rates on rice promising line 8405، a field experiment was carried out at the Iranian Rice Research Institute – Deputy of Mazandaran (Amol) during 2006 and 2007. This experiment was laid out as factorial in basis of a Randomized Complete Block Design with 3 replications. The first factor was planting spaces in three levels، (16×30، 20×20 and 25×25 cm) and the second factor was nitrogen fertilizer in three levels، 92، 115 and 138 kg N ha-1 respectively). During growing season، some agronomical traits as well as LAI، NAR، CGR، RGR and yield were evaluated. Results showed that planting space and nitrogen fertilizer levels had a highly significant effect on grain yield. The highest grain yield was obtained in 20×20 cm planting space and use of 138 kg N ha-1.