Shiva Akbari; Iraj Allahdadi; Majid Ghorbani Javid; kourosh Kabiri; Elias Soltani
Abstract
In order to study the effect of slow release hydrogel-urea complex (SRHUC) on yield, yield components and physiological traits of barley under water deficit, an experiment was performed in 2017-2018 and conducted as factorial in Randomized Complete Block Design (RCBD) in three replications in greenhouse ...
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In order to study the effect of slow release hydrogel-urea complex (SRHUC) on yield, yield components and physiological traits of barley under water deficit, an experiment was performed in 2017-2018 and conducted as factorial in Randomized Complete Block Design (RCBD) in three replications in greenhouse of Aburaihan campus of University of Tehran. The combination of factorial levels were as fertilization factor containing nitrogen (N) from urea source in five levels of no use of N, equivalent 125 and 65 kg.ha-1 N (without SRHUC) as CU-N125 and CU-N65 and equivalent 125 and 65 kg.ha-1 N with SRHUC as SRHUC-N125 and SRHUC-N65 and water deficit in three levels of 70, 50 and 30% of FC. Water deficit decreased yield and yield components, RWC and SPAD. The highest grain yield in a pot belonged to SRHUC-N125 (41.9 g) and there was no significant difference between CU-N125 (41.5 g) and SRHUC-N65 (39.1 g). For most of the traits, there was no significant difference between SRHUC-N125 and SRHUC-N65 and CU-N125. Under stress, utilization of SRHUC for both N amount could generate a better biological yield and SPAD index. Using N in the form of SRHUC was preferred to using of N without SRHUC, especially under stressed conditions.
Shiva Akbari
Abstract
The goal of this study was to investigate climatic factors, crop management and plant growth traits, using a simple model to simulate growth and yield of soybean in Tehran climatic condition in order to be use as an efficient tool to study effective factors on yield. The model was evaluated under Tehran ...
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The goal of this study was to investigate climatic factors, crop management and plant growth traits, using a simple model to simulate growth and yield of soybean in Tehran climatic condition in order to be use as an efficient tool to study effective factors on yield. The model was evaluated under Tehran condition. Soybean is one of the important resources of herbal oil and protein. At the current study, production and partitioning of dry matter in vegetative parts and grains of soybean were investigated by changing the parameters of base temperature, the maximum leaf area index and the fraction of crop total dry matter at the beginning of grain growth. Decreasing and increasing of base temperature caused to decrease and increase the phenological stages, changing the production of dry matter and the allocation of dry matter to vegetative organs and grains. Decreasing and increasing of the fraction of remobilized dry matter to grains lead to enhance and reduce harvest index, respectively. To model evaluation, some statistics on differences between observed and simulated values were used. The simulated yield ranges were within 1890-2220 kg.ha-1 with mean values of 1982.5 kg.ha-1 and the observed yield ranges were 1632-2254 kg.ha-1 with mean values of 2014.5 kg.ha-1. The RMSE was 178.48 kg.ha-1 that was equal to 9% of average of observed and predicted values. All data points were included at the 80% of 1:1 line and it indicated that the model had suitable accuracy to predict soybean yield in Tehran climatic condition.