جستجوی مقالات مرتبط با کلیدواژه « leaf chlorophyll » در نشریات گروه « زراعت »

The aim of this research is to introduce the superior characteristics of P.betulifolia pear rootstock in comparison to the commercial Pyrodwarf (control) in terms of leaf parameters {leaf-N, -K, -Mg, Ca, -Fe, -Zn and leaf-B content; leaf area; chlorophyll (SPAD-Value); Chlorophyll fluorescence parameters (F0:minimum fluorescence; FM: maximum; fluorescence and value of photochemical capacity of photosystem 2 (FV/FM)}, growth traits (shoot length, diameter of shoot) under active lime tolerance in heavy-textured to clayey soils.

 The experiment was conducted in a factorial design within the construction of a completely randomized blocks design, using pots. The factors included: 1- Soils with lime in the range of 15% (texture: clay-loam), 20% (texture: clay), 25% (texture: loam), and 45% (texture: sandy loam). 2- Rootstocks P.betulifolia, Pirrodwarf (as a control). In total, the experiment was carried out on 120 units (5 different levels of soil lime * 2 non-grafted rootstocks * 3 replications * 4 trunk of each studied rootstock/). Data analysis was performed using SPSS and SAS software, involving mean comparisons using Duncan’s method and determining regression relationships.The preparation of pots was carried out as follows: initially, drainage holes were created at the bottom of plastic pots and covered with gravel. Then, a layer of sand and gravel was added to the depth of the pots, followed by the application of animal manure. At this stage, the soils under study, representing different combinations of texture and lime treatments, were added to the 3-kilogram pots. Each pot’s soil composition consisted of 1/3 sand and gravel, 1/3 animal manure, and the remaining being the specified soil samples. Prior to commencing the experiment, the soil samples underwent chemical analysis to determine their general characteristics, including total neutralizing value (TNV), saturation pH, electrical conductivity, soil texture, and organic matter content. In this research, the “Chlorosis Power Index” (CPI) was employed using the formula: CPI = 10000 * (active lime) / (Fe, ppm) ² to estimate the intensity of chlorosis resulting from soil liming for the studied rootstocks. The iron content, extracted as active iron (Fe, ppm) ² using ammonium oxalate, was reported in milligrams per liter, while CPI was reported in milligrams per kilogram.

P.betulifolia rootstock, compared to the control rootstock Pyrodwarf, showed lower sensitivity to the soil’s “Chlorosis Power Index.” Negative and significant regression relationships between the increase in the soil’s “Chlorosis Power Index” and the investigated traits were not observed in the P.betulifolia rootstock.

Notably, P.betulifolia demonstrated superior features, including active lime soil tolerance up to 45% lime (sandy loam texture and alkaline pH), in terms of leaf uptake of nutrients such as potassium, boron, total iron, and active iron, chlorophyll content, and growth traits like leaf length, leaf width, height, and trunk diameter.

To study the effect of chemical and manure fertilizers on the yield of tobacco, cultivar K326, an experiment was conducted in Taqar Tappeh village (Golestan province) in 2016 in a randomized complete block design with four replications. Treatments including chemical fertilizer (100%), livestock manure (at two levels of 10 and 20 t/ha), the combination of chemical and manure fertilizers (10 t/ha of manure + 50% chemical fertilizer), and no fertilization (control) During the growing period and before harvest, necessary evaluations were performed on leaf length, leaf width, leaf chlorophyll index (spad), leaf fresh weight, leaf dry weight, leaf nicotine percentage, average price and gross income per hectare. The results showed that except for chlorophyll index, mean price and leaf nicotine percentage, other traits such as leaf length and width, fresh and dry leaf weight and gross yield per hectare were statistically significant. Comparison of means also showed that the highest leaf length (63.2 cm), leaf width (32.5 cm), leaf fresh weight (35851 kg/ha.), dry leaf yield (6343 kg/ha.) and gross income (508550072 Rials) was obtained from the combined treatment of 10 t/ha of manure + 50% chemical fertilizer. Therefore, the findings of this study showed that there is a possibility of combined application of chemical and livestock fertilizers without a significant reduction in tobacco leaf yield and no environmental degradation consequential in a sustainable agricultural system.

On a global scale, the demand for agricultural products is increasing at the same time as the human population is growing. Low and middle income countries are struggling to deal with their food security challenges. from one side, Modern agriculture is being done with the aim of producing maximum crops to meet the needs of the world's growing population and without ensuring its effects on the environment. Conventional agricultural practices around the world depend on the extensive use of chemical fertilizers and pesticides. nowadays, in all cropping systems, reducing dependence on subsidized energy (fertilizers and chemical pesticides) is one of the main goals. Therefore, it is very important to use the best management practices of nutrients in diverse ecosystems and different production systems to increase food production and improve farm profitability along with improving the efficiency of natural resources. Sustainable cropping systems ensure the long-term performance of the products produced for the developing population now and in the future without compromising the biological and physical components of the environment in which the production is taking place. One of the most important tools to achieve this goal is the use of organic fertilizers of natural origin and effective microorganisms during the production of crops. As a result, it will be possible to maintain crop productivity and increase soil health in the long term only by increasing the share of organic resources and biological fertilizers in agricultural ecosystems. In several field researches, the beneficial role and efficiency of using mycorrhizal and rhizobium biofertilizers and biochar and vermicompost organic fertilizers in the production of legumes, especially Red beans, have been reported.

 This experiment was conducted as factorial layout based on a randomized complete block design with three replications during growing season of 2021 at the experimental field of beiranshahr city of Khorramabad in Lorestan Province, Iran (48° 29' E, 33° 40' N and 1657m above the sea level). Before conducting the experiment to determine the physical and chemical properties of soil samples were collected from 0-30 and 30-60 cm depth of soil. During this experiment effects of tow factors were studied: different cropping systems included (ecological, integrated, low input, medium input and high input) and different variety of red beans (Ofogh, Dadfar, Goli and Yaghot). Arbuscular mycorrhizal inoculum was used at the rate of 250 kg. ha-1. Inoculation with rhizobium inoculum in the shade. Rhizobium inoculum was added at the rate of 50 ml for each kilogram of seeds. Biochar was used at the rate of 10 tons per hectare and vermicompost at the rate of 15 tons per hectare. Seed yield (with 10-14% moisture) was measured. The number of stem diameter, number of branches per plant, plant height, number of leaves per plant, and number of pods per plant were determined by randomly selecting 10 plants (60 cm long) from each experimental unit and Chlorophyll content of the leaf was estimated by using chlorophyll meter SPAD-502 Plus, Konica Minolta.

The results showed that the main effect of cropping systems on the stem diameter, number of branches, plant height, number of leaves, chlorophyll content, number of pods, seed weight, biomass yield, seed yield and harvest index were significantly increased. The main effect of variety the number of branches, plant height, number of leaves, chlorophyll content, pod number, seed weight, biomass yield, seed yield and harvest index were significantly increased too. and the interaction effects of cropping systems and variety, the stem diameter, number of branches, plant height, number of leaves, chlorophyll content, number of pods, seed weight, biomass yield, seed yield and harvest index of red bean variety were significantly increased. The highest seed yield was obtained in Yaghot variety in high inpout cropping system (3054.30 kg/ha-1) and Yaghot variety in integrated cropping system (3007.33 kg/ha-1), both in the same statistical class. The grain yield in Yaqut cultivar increased by 27.56, 18.14 and 40.09 percent, respectively, compared to Ofogh, Dadfar and Goli cultivars in the high-input cropping system. And in the integrated cropping system, it showed an increase of 26.02, 13.25 and 16.50 percent, respectively.

Obtained results of this experiment showed that the integrated cropping system was able to bring the agricultural characteristics of red bean variety to the highest level in comparison with the ecological, low-input and medium-input cropping systems, in order to increase economic production, on par with the high-input cropping system. As a result, it is predicted that the results of this study can be useful for shaping new management methods to improve red bean crop production.

This study has been conducted to recognize some of the physiological mechanisms related to the storage in different wheat cultivars as a split-plot experiment in a randomized complete blocks design with three replications at the experimental farm of Agriculture and Natural Resources ofUniversity of Tehran in Karaj, during two crop years of 2014-2016. Experimental treatments consisted of 22 wheat cultivars as the main plots and gibberellic acid (GA3) at two levels (0 mg/L (control) and 100 mg/L) as the sub plots. Results showed that gibberellic acid spraying significantly increased stem dry and specific weights, leaf area, chlorophyll and grain yield in different wheat cultivars in both experimental years. Among these traits, the shoot dry weight had the highest response to gibberellic acid spraying. There was also a significant positive correlation between stem dry and stem specific weights and remobilization in different cultivars under gibberellic acid spraying condition. Shabrang and Dez cultivars had the highest storage related traits (stem dry and specific weights) under gibberellic acid spraying condition which resulted in higher grain yield. These cultivars had the highest grain yield due to higher stem reserves remobilization capacity. In this study, exogenous application of gibberellic acid has generally strengthened the stem storage capacity, source strength and yield in different wheat cultivars.

To evaluate the effects of application of herbicides and different plant densities on seed yield, weed density and chlorophyll content in wheat (cv. Bahar), a split plot experiment based on randomized complete blocks design with three replications was conducted at the Agricultural Research Staion of Sarableh, Ilam, in 2014-2015 cropping season. Plant densities in (200, 250 and 300 kg of seed/ha) were considered as main factor and application of herbicides (2, 4-D, Granstar, Shovalyeh, and control, without herbicide application) as sub factor. Results indicated that plant densities affected traits under study significantly. As a result number of seed per spike, 1000-seed weight, relative water content, chlorophyll a and b contents decreased, while weed density and weed dry weight number of spike per m2 and percent lodging increased by increasing plant density. Application of herbicide increased number of spike per m2, number of seed per spike, 1000 seed weight, harvest index, relative water content, chlorophyll a and b contents, while it decreased weed dry weight and its density. Interaction effect of plant density and application of herbicide were significant on seed yield and biological yield. The highest seed yield (5500 kg.ha-1) was produced by using 250 kg seed/ha and application of Granstar herbicide and the lowest (2400 kg.ha-1) from 200 kg seed/ha and without application of herbicide. Thus, using 250 kg seed/ha and Granstar herbicide would increase wheat seed yield in this region as compared with the other treatments.

In order to investigate the time of potassium application and irrigation regimes effects on agronomic traits، yield and seed quality of foxtail millet، a field experiment was conducted as split plot based on randomized complete block design with three replications at Agricultural Research Center of Yasuj، Iran، during 2009. The experiment was conducted in split plot design based on randomized complete block design with three replications. The irrigation regimes included: 7، 14 and 21 day intervals as main plots and sub-plots including potassium fertilizer application in four stages of planting، tillering، stem development and flowering. The results showed that the effect of irrigation regimes was statically significant on plant height، leaf number، ear size، grain yield، leaf chlorophyll content، water soluble carbohydrate and protein percentage. By increasing the irrigation period، all of the above mentioned traits were decreased، except protein percentage. Also time of potassium application significantly affected plant height، grain yield، leaf chlorophyll content، water soluble carbohydrate and protein percentage، so that potassium application until flowering stage increased the studied traits. The interaction effects of irrigation and potassium application on plant height، seed yield، leaf chlorophyll and soluble carbohydrates was significant. The maximum seed yield was obtained by using potassium at the stem development stage and 7 days irrigation regime، and the maximum seed protein percentage was obtained in 21 days irrigation regime and potassium application at flowering stage.

The research on reducing the water consumption in conventional cropping system is one of the important strategies to improve the water use efficiency in agriculture. In order to investigate the effect of time of potassium application under different irrigation regimes on millet grain yield and protein percent, a field experiment was carried out in Agricultural Research Center of Yasuj, Iran, in 2009. The experiment was conducted as split plot design in a randomized complete blocks design with 3 replications. Irrigation regime included 7, 14 and 21-day intervals as main factor and sub-plots included time of potassium fertilizer application in four stages: planting, tillering, stem development and flowering. The results showed that the effect of irrigation interval was significant on 1000-seed weight, grain and biological yield, number of grains per spike, harvest index, protein content, and chlorophyll a, b and total of leaves. By increasing the irrigation interval, all the above-mentioned traits decreased, except the protein percent that increased. The 1000-seed weight, grain and biological yield, harvest index and protein content were affected significantly by the time of potassium application. Maximum grain yield was obtained by interaction of 7- day irrigation interval and potassium application at the stem development stage. Maximum grain protein content was measured in potassium application at flowering stage. In general, increasing the irrigation interval, and subsequent water stress, reduced plant growth and yield components. Application of potassium fertilizer at early growth stages increased yield and yield components, while in reproductive stages increased seed quality.