جستجوی مقالات مرتبط با کلیدواژه « گندم » در نشریات گروه « باغبانی »

One of the main problems of crop production in our country is the difference between the actual grain yield of farmers and the achievable grain yield or the yield gap. In order to investigate the management factors affecting the reduction of wheat yield in Mahdasht of Karaj, a field experiment was conducted in the crop year 2017-18 in the farms of Mahdasht which was previously selected by the researcher. In this study, using stepwise regression, the contribution of all management factors that may play a role in reducing yield has been investigated. The results of correlation between different factors showed a positive and significant correlation between grain yield with the number of irrigations, nitrogen application in the second stage, total nitrogen consumption during the growing period and micronutrient consumption at a probability level of 1%, and there was a positive and significant correlation with the area under cultivation at the 5% probability level. According to the recorded wheat grain yield values, the average actual wheat grain yield was 4775 kg.ha-1 and factors affecting yield reduction in this area including the number of irrigations (42%), area under cultivation (9%), previously cultivated crop (6%) and total nitrogen consumption (5%) were determined. Other management factors had little effect on grain yield reduction. Potential grain yield in Mahdasht of Karaj according to the regression model can be raised to 7630 kg.ha-1, and the grain yield gap in this area is 2860 kg.ha-1.

Arbuscular Mycorrhizal Fungi (AMF) are a group of soil-borne obligate symbionts which develop a close mutualistic association with plant roots specially with important plant crops. The genus Acaulospora is one of the largest worldwide taxa in the phylum Glomeromycota. Fifty-nine species of this genus have been identified in the world so far of which 14 of them have been reported from Iran. In this research, five other species of this genus are reported for the first time from Iran viz. Acaulospora alpina, from the feverfew (Tanacetum parthenium) in Isfahan; A. gedanensis, A. herrerae, and A. scrobiculata from sugarcane (Saccharum officinarum) in Khuzestan, and A. punctata from wheat (Triticum aestivum) in Sistan and Baluchestan provinces, respectively. These species had spores that randomly observed among other species that were recovered from soils of different regions. The most important morphological features of the spores of this genus are lack of subtending hyphae, formation of inner walls, and possible ornamentation on their walls.

This experiment was conducted in order to investigate the effect of zinc foliar application and different levels of sulfur fertilizer on yield and wheat yield components of Baharan cultivar in 2016-2017 in Tehran Agricultural and Natural Resource Research Center. The statistical format of the design was factorial based on random complete blocks in 3 replications. The factors include sulfur fertilizer at three levels (zero, 250 and 500 kg.ha-1 from biosulfur or thiobacillus sulfur) and zinc element foliar application of zinc sulfate source (ZnSo4, 2H2o) at three levels (pure water spraying, solution Zinc spraying with a concentration of 0.5% and 1%). Zinc sulfate contained 34% pure zinc. The results showed that sulfur consumption had a significant effect on yield and quantitative components of wheat growth. The effect of consumption of this element on gluten, protein and grain content was also significant. Foliar application of zinc also had a significant effect on the weight characteristics of one thousand seeds, number of fertile tillers, grain yield, biological yield and leaf surface index. Also, all the qualitative traits of the grain were significantly affected by this element. The highest grain yield was obtained from the treatment of 500 kg of sulfur with 1% solution of zinc spraying at 6789 kg.ha-1. The combined use of biofuels and zinc increased the yield of wheat grains by 36%. The highest weight of 1000 grains was obtained from the consumption of 500 kg.ha-1 of sulfur and zinc foliar application with a concentration of 1% and a rate of 49.6 g. The maximum gluten in the grain was obtained from the consumption of 500 kg.ha-1 of sulfur and zinc foliar application with a concentration of 1%, respectively. Under the conditions of sulfur consumption, the positive effect of zinc foliar application on this trait increased. Zinc consumption increased the protein content by 10.3% and 17.7% for two concentrations of 0.5% and 1% of foliar application, respectively. The highest percentage of protein was obtained in the treatment of 500 kg.ha-1 of biofuels. The highest amount of zinc was recorded in the treatment of sulfur consumption of 500 kg.ha-1 along with 1% solution of zinc spraying at a rate of 63.30 mg.kg-1. The increase in leaf area index for both sulfur and zinc was significant compared to control.

Wheat is one of the most important crops in the world. So, use of crop models helps to have an acceptable estimation of its grain yield in different conditions. Regarding that, in order to evaluate AquaCrop, as one of the most useful crop model, under different irrigation water condition in farm, this research was conducted in Kosar irrigation network located at Khuzistan province. Regarding that, long term data in three farms were collected. Then, 70 percent of data were used for calibration. AquaCrop validation results showed that this model had low error and good efficiency. AquaCrop were evaluated using the remaining 30 percent of data. Results showed that the difference between observed and simulated results for wheat grain yield and water use efficiency were 0.45 ton.ha-1 and 0.05 kg.m-3, respectively. In addition, MBE, RMSE and NRMSE results for wheat grain yield were 0.14 ton.ha-1, 0.52 ton.ha-1 and 0.13, respectively. Those results for water use efficiency were 0.01 kg.m-3, 0.06 kg.m-3 and 0.10, respectively. EF and d values for wheat grain yield 0.3 and 0.99, respectively, and those values for water use efficiency were 0.1 and 0.99, respectively. So, AquaCrop accuracy was acceptable for simulation of both parameters and it is recommended to use this model for simulation of mentioned parameters.

An experiment was conducted in order to evaluate the effects of Zn spraying and nitrogen fertilizer application on wheat under water stress condition, in varamin agricultural research center in 2005-16. a split-factorial layout within randomized complete block design with three replications were used. main plots were three irrigation treatments and sub plots were two, Zn spraying and Nitrogen fertilizer treatments with factorial arrangment. The result showed that, Cutting irrigation at both flowering and grain filling stages significantly reduced biological yield and grain yield, but the severity of this reduction was greater for stopping irrigation at flowering time. The highest grain yield was observed in the optimal irrigation treatment at 6667 kg ha-1. Non-Irrigation at the beginning of flowering and seed filling stages resulted in a yield reduction of 30 and 18.6%, respectively. The average weight loss of TKW due to stress at flowering and grain filling stages were 35.5 and 29.7%, respectively. On the other hand, stress caused an increase in protein content as well as moisture content of gluten, while the amount of zinc in grain decreased significantly. Weight loss of 1000 grains of wheat, followed by loss of starch storage increased the protein to starch ratio. There was no significant difference between nitrogen fertilizer supply from urea and ammonium sulfate except for plant height and peduncle length. Foliar application of zinc reduced stress damage on grain yield and increased zinc content from 36 to 38.2 ppm.

In order to study effect of super absorbent polymer application to mitigate adverse effects of nickel (Ni), a greenhouse experiment was conductedin Varamin, Iran during the growing season of 2016 in wheat. The experiment was installed in a completely randomized design, with treatments arranged in a factorial scheme with three levels of nickel (0, 60 and 120 mg per kg of soil) by three levels super absorbent polymer application (with out super absorbent polymer application (Control), 2 and 4 g per kg of soil), with three replicates. The results showed that nickel treatment significantly for all experimental traits. The nickel contamination caused a significant decreased plant height, total dry weight per plant and root dry weight per plant at by 8.51%, 31.52 and 56.06% respectively to control, Whereas, increased proline content, superoxide dismutase enzyme activity and the accumulation of nickel in leaves. Also the results showed that super absorbent polymer application increased plant height, total dry weight per plant and root dry weight per plant whereas, decreased proline content, superoxide dismutase enzyme activityand the accumulation of nickel in leaves. Generally the results of the present study indicate that super absorbent polymer application reduces the harmful effects of nickel stress and super absorbent polymer application treatment decreased oxidative stress in wheat plant.