majid moslemi; hamidreza mobasser; nematollah sedaghat; eiman eshghi
Abstract
Objective: Optimizing the consumption rate of nitrogen fertilizers is one of the important management strategies to improve performance. This experiment was carried out to investigate the effects of nitrogen stress and levels on the morphological characteristics and agronomic ...
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Objective: Optimizing the consumption rate of nitrogen fertilizers is one of the important management strategies to improve performance. This experiment was carried out to investigate the effects of nitrogen stress and levels on the morphological characteristics and agronomic traits of rice.Methods: An experiment was conducted in the form of split plots in a randomized complete block design with four replications in 2009 & 2010 at the research farm located in Amol. Nitrogen levels were considered the main factor at three levels (46, 69, 92 kg N/ha-1 from urea source) and the sub-factor included four levels of stress or lack of nitrogen consumption (T1= stress at the full clustering stage, T2= stress at the emergence of the initial cluster stage, T3= stress at the tillering stage, and T4= stress at the transplanting stage).Results: The results demonstrated that the number of full panicles per panicle, 1000-seed weight, grain yield, and harvest index were higher in 2009 than in 2010. Grain yield in the first year (450.25 g/m2) was higher than that of the second year (395.1 g/m2). The maximum harvest index was also obtained in 2009 with nitrogen stress at the full clustering stage.Conclusion: Therefore, the application of 69 kg of nitrogen per hectare in installments can be recommended to produce the highest grain yield.