جستجوی مقالات مرتبط با کلیدواژه "کلر" در نشریات گروه "زراعت"

 Cotton (Gossypim hirsutum L.) has a special position as one of the most important crops in the country. Considering that salinity stress is one of the most important stresses, it threatens cotton production in arid and semi-arid regions of the country and the world, it is possible to reduce the adverse effects of salinity stress through application of organic fertilizers (manure and humic acid). In addition, Organic inputs can guarantee both agricultural production and nature conservation. The current approach is to employ the organic compounds like manure and humic acid (that are cost-effective and eco-friendly) as an appropriate substitute for chemical fertilizers.

This study was carried out to assess the effect of manure and humic acid application on some elements accumulation and ions concentrations in cotton (Gossypim hirsutum L.) (cotton leaves) under salinity stress. The experiment was conducted as a factorial split plot in the form of a randomized complete block design (RCBD) with four replications in the 2019-2020 cropping year in Beshravieh city in South Khorasan. The main plot included different levels of irrigation water salinity at three levels (2.5, 5.5 and 8.5 ds.m-1) and sub-plots consisted of a factorial combination of manure at two levels (0 and 20 t/h) and humic acid at two levels (0 and 200 gr/ 100 kg of seeds as priming). In order to measure the concentration of sodium (Na) and potassium (K) elements, it was done using a flame photometer and chlorine concentration based on the method provided by Johnson and Ulrich (1995).  In order to assess the cotton yield, the yield of two consecutive harvests were added together and was considered as the seed cotton yield of each experimental unit.

The results of the present study illustrated that the salinity stress increased Na+ and Cl- concentration in cotton leaves and consequently decreased K+ concentration. The increase of salinity stress from 2.5 to 5.5 and 8.5 dSm-1 caused a significant decrease in seed cotton yield. Manure application treatment increased Na+ (13.45%), K+ (2.67%), Cl- (18.30%) concentration in the leaves and seed cotton yield (13/90 %) compared to the no use of manure. Humic acid application treatment decreased Na+ (3.08%), Cl- (9.78%) concentration and increased K+ concentration (4.17%) and cotton yield (9/15 %) and improved the growth conditions compared to the treatment of no use of humic acid. The application of manure (before planting) and humic acid (as priming treatment) increased the seed cotton yield by improving the accumulation of beneficial elements in the leaves under salinity stress conditions.

Based on the results of this experiment, it can be concluded that the application of manure and humic acid (priming) moderated the negative effects of salinity stress on seed cotton yield. In addition, manure and humic acid can be used as an effective and alternative fertilizer in order to reduce the consumption of chemical fertilizers and salinity stress in hot and dry climates. Therefore, manure and humic acid (organic fertilizers) are recommended to be applied under (environmental stresses) salinity stress conditions to mitigate the effects of salt stress and obtain a higher seed cotton yield.

To study the effect of irrigation water salinity on physiological characteristics and the concentration of leaf elements of different accession of melons a split-plot experiment was designed based on RCBD with 3 replicates on two accessions, tolerant (Sooski and Diamond) and two accessions sensitive (Daregazi and Zard Ivanaki) and two salinity levels (tap water  2.3 ds/m (control) and 8 ds/m) according to the salinity of wells) in the field of Isfahan research station in 2016-2017. The results showed that with increasing salinity, the chlorophyll index decreased in all sensitive and tolerant accessions 21 and 16% respectivly. Photosynthesis and stomatal conductance showed the highest and lowest reduction in the Zard Ivanaki and Diamond accessions,62 and 19% respectively in comparison to the control. Stomata conductance was lowest in Zard Ivanaki (0.05) and highest in Diamond (0.39). CO2 substomatal was reduced by 44%, 26%, and 11%, respectively, in the Zard Ivanaki, Sooski and Diamond accessions. Photosynthetic water use efficiency did not have a significant effect with increasing salinity in all accessions. The amount of Na and Cl increased in the Daregazi and Zard Ivanaki accessions compared to the control, and K showed the lowest decrease by 26% in the Diamond accession. The highest reduction K/Na ratio was observed in Daregazi by 71%. The amount of P decreased in all of the accessions, except for the Daregazi, Overall, the results showed that by applying salt stress, photosynthetic parameters, K and P elements decreased, and Na and Cl increased, and this decrease was lowest in Diamonds and highest in Zard Ivanaki. Diamond resistant mass has a higher tolerance to salinity compared to sensitive cultivar through defense mechanism by restricting the uptake or transfer of sodium to aerial parts and also maintaining a good level of potassium and can be used as a tolerant cultivar under salinity conditions.

Pomegranate (Punica granatum L.) is an economically important commercial fruit plant species belonging to the family of Punicaceae. Saline irrigation water is currently one of the most severe limiting factors in the cultivation area. In recent years, nearly 7% of the global cultivated lands are affected by salinity, and soil salinization aggravating has been a more significant threat to the healthy and sustainable development of agriculture worldwide. Therefore, the study aimed to determine the effects of salt stress on physiological and biochemical characteristics in pomegranate cuttings to better understand the salt resistance of pomegranate and offer a reference for pomegranate cultivation on saline lands.

A pot experiment was conducted for nine months to evaluate and compare three Iranian cultivar salinity tolerance of commercial pomegranate in 2017-2018. The experiment was arranged in factorial based on a completely randomized design with two factors included water salinity in 5 levels of 1, 3, 5, 7, and 9 dSm-1 and three commercial pomegranate genotypes (‘Shishehcap Ferdos,’ ‘Malas Saveh’ and ‘Malas Yazdi’) in 4 replications and generally with 60 pots. At the end of the experiment, the vegetative yield and fresh and dry weight of leaves, ion leakage, relative water content, chlorophyll a, b and total were also measured. In addition, leaves were analyzed for Na+, K+, Cl–, and Na/K ratio elements.

Results showed that cultivar and salinity levels were affected by morphological and physiological characteristics, and concentration of nutritional elements. In all the three studied cultivars, an increase in the salinity levels led to a significant decrease in the growth characteristics, the relative water content of leaves, and chlorophyll. Moreover, the percentage of leaf necrosis, fall, and ion leakage increased considerably. Also, with increasing salinity levels, Na+, Cl- and Na+/Cl- significantly increased. In the highest level of salinity (9 dS.m-1), the maximum growth characteristics, fresh and dry weight of leaves, green leaves, the relative water content of leaves, chlorophyll, and potassium, and the lowest percentage of leaf necrosis, ion leakage, Na+, Cl- and Na+/Cl- were obtained in a cultivar of ‘Malas Yazdi.’

Generally, among the investigated cultivars, ‘Malas Yazdi’ and ‘Malas Saveh’ were the highest and the lowest tolerants, respectively. Our study showed that the adverse effects on physiological and morphological indexes aggravated over stress time. We inferred that it was one of the mechanisms for pomegranate alleviating the detrimental effects of salt stress. This study would provide a theoretical basis for the cultivation and utilization of pomegranate plants on saline soil.

Pomegranate (Punica granatum L.), from the family Punicaceae, is a popular fruit of tropical and subtropical regions that is native to the area stretching from Iran to the Himalayas in northern India. Pomegranate has been widely cultivated in arid and semi-arid regions of Iran, which these areas are frequently affected by high salinity. The present study was therefore, carried out with the objective to identify and introduce the most-tolerant Iranian genotypes of ornamental pomegranate to different salinity levels of irrigation water.

A pot experiment was conducted during a six-month period in order to evaluate and compare the salinity tolerance of three Iranian ornamental genotypes of pomegranate during 2017-2018. The experiment was arranged in factorial based on the completely randomized design with two factors included water salinity in 5 levels of 1, 3, 5, 7 and 9 dSm-1 and three ornamental pomegranate genotypes (‘Golnar Saravan’, ‘Golnar Shahdad’ and ‘Golnar saveh’) in 4 replications. The properties concerned during the experiment were vegetative growth, the fallen, chlorosis and green of leaves. At the end of the experiment, the vegetative yield and fresh and dry weight of leaves and shoots, ion leakage, relative water content and chlorophyll index were also measured. In addition, leaves were analyzed for elements such as Na+, K+, Cl– and Na/K ratio.

Results showed that with increasing of salinity levels in all three investigated genotypes, growth characteristics, significantly decreased, ion leakage, the relative water content of leaves and chlorophyll index significantly increased. Also with increasing of salinity levels Na+, Cl- and Na+/Cl- significantly increased. In all studied genotypes, plant height and leaf area decreased from salinity level of 5 and 7 dS.m-1 respectively. Increasing in leaf necrosis, and decreasing in percentage of green leaves and also relative water content in ‘Golnar Sarvestan’ were observed from salinity level of 5 dS.m-1and from salinity level of 7 dS.m-1 in ‘Golnar Shahdad’ and ‘Gonar Saveh’. Leaves falldown in ‘Gonar Saveh’ and ‘Golnar Sarvestan’ were increased in salinity level of 7 dS.m-1 and in ‘Golnar Shahdad’ in 5 dS.m-1 salinity level. In two genotypes (‘Golnar Sarvestan’and ‘Golnar Shahdad’) the ion leakage increased in 7 dS.m-1 salinity level and in ‘Gonar Saveh’ in salinity level of 5 dS.m-1. In higher salinity levels (7 and 9 dS.m-1) Na+, Cl- and Na+/Cl- uptake were significantly decreased in ‘Golnar Sarvestan’and ‘Golnar Shahdad’ in compared to ‘Golnar Sarvestan’.

Generally among all studied genotypes, ‘Golnar Shahdad’ has been showed the maximum growth characteristics, and the lowest appearance injury, accumulation of Na+, Cl- in higher levels of salinity. So it seems that this genotype is the most tolerant of the salinity.

Recently barley cultivated area has been increased in Iran due to its adaptation to drought and salinity. To investigate some barley promising lines under saline conditions and introducing the superior lines, a field experiment was carried out in Zarrindasht region, Darab, Iran, during two consecutive years (2010-2011 and 2011-2012(. In this experiment, Nimrooz as the control variety along with 13 promising barley lines were compared in a randomized complete block design with three replications. The average soil and water salinity of the experimental site were about 6 and 9 dS.m-1, respectively. The results showed that the highest grain yield belonged to EBYT-79-10 line in both years (with two years mean of 5095 kg.ha-1) which was 21.3% more than the control variety Nimrooz (with average grain yield of 4173 kg ha-1). Also, L.527/Chn-01…, MBD-85-8, Karoon/Kavir//…, On-Farm No. 4 (Yazd), MBD-85-6,¡ Rihanee"s"//… and Productive/Rojo with grain yield of 4740, 4705, 4575, 4470, 4390, 4275 and 4205 kg.ha-1, respectively, were superior than control and the other lines produced lower yield than control. Grain yield of the studied lines and showed a significant negative correlation with sodium concentration of plant leaf and a significant positive correlation with potassium concentration and potassium to sodium ratio. In the present study, EBYT-79-10 with highest grain yield, proper early maturity, less water consumption and suitable salinity tolerance was identified as the best line for cultivating under saline conditions of Zarindasht regions, Darab, Iran.

Nitrogen (N) affects adversely the tobacco yield quantity and quality as it increases yield, Chlorine and nicotine contents, but decrease potassium content. This experiment was aimed at optimization of (the balance between) N concentration in leaf, stem and root to increase both yield quantity and quality (high potassium, low Chlorine and medium nicotine contents) using artificial neural network. Two field experiments based on complete block design with three replications were conducted in Tirtash and Urmia tobacco research centers. Treatments were factorial arrangement of two N sources (urea and nitrate ammonium) and four application patterns (basal, 2/3 basal and 1/3 after initiation of rapid growth (AIRG), 1/2 basal and 1/2 at AIRG, 1/3 basal and 2/3 at AIRG). The N concentration of leaf, stem and root (model inputs) was measured in 30, 50, 70, 85 and 100 days after transplanting. After harvesting, the quantity of cured leaf and its Cl, K and nicotine content (model outputs) were also determined. The results indicated that a model with one hidden layer and configuration of 15-15-4 is appropriate and there were no significant different between two N sources. The best pattern was use of nitrate ammonium in 2/3 basal and urea 1/3 basal. The average value of optimized N concentration was 3.06, 2.42 and 1.5 percent for leaf, stem and root, respectively. These optimized concentrations can lead to potential increase in quality and quantity of tobacco which should be taken into consideration by breeders and agronomists.