Chlorophyll Content and Biological Yield of Modern and Old Rice Cultivars in Different Urea Fertilizer Rates and Applications

摘要

In order to investigating the effects of different urea fertilizer applications and split application on leaves chlorophyll content (flag leaf and other leaves) and biological yield of modern and old rice cultivars, an experiment was conducted at Rice Research Institute of Iran (Deputy of Mazandaran, Amol) during, 2005. Experiment was arranged in split-split plots based on completely randomized block design with 3 replications in which nitrogen fertilizer as urea (including 100, 150 and 200 kg ha^-1), split application of urea (including pre-transplanting, tillering and heading stage with different rates) and cultivars (Tarom (old cultivar), Shafagh and GRH1 Hybrid (modern cultivar) were the treatments. Results showed that all mentioned factors had significant effects on chlorophyll content of flag leaf in which the greatest amount of chlorophyll content was belonged to GRH1 hybrid, also increasing of fertilizer rates caused a significant increase in flag leaf chlorophyll content and the among split application levels, the third type of split application had the highest chlorophyll amount of flag leaf. Chlorophyll content of the other leaves also was affected by cultivar and split application in which the highest amount of this trait was observed in GRH1 hybrid and the third type of split application. Biological yield of different cultivars in response to fertilizer amount and split application were significant in which among cultivars Tarom had the highest biological yield. Summary, 200 kg nitrogen fertilizer per hectare and the third type of split application caused a significant increasing of flag leaf chlorophyll content probably related to photosynthesis rate.