جستجوی مقالات مرتبط با کلیدواژه « قطع آبیاری » در نشریات گروه « کشاورزی »

Water stress is one of the main factors in crop growth in arid and semi-arid regions of the world, which limits the grain yield of the safflower (Carthamus tinctorius L.). To increase the soil fertility and yield of crops, it is necessary to pay sufficient attention to the use of biomass of organic matter, especially crop residues, and its conversion to biochar. This research aims to evaluate the biochar application produced from cotton and wheat residues under late-season water stress in the south of Fars province (Darab) on photosynthetic pigments, enzyme activity, yield components, and yield of safflower.
In order to investigate the biochar application and water stress on the amount of photosynthetic pigments, enzyme activity, and yield of safflower, a field experiment was laid out as split plots in the form of randomized complete block design with 3 replications in the 2019-2020 growing season. The experimental factors include the irrigation regime as the main factor in two levels (optimal irrigation and cutting off irrigation after the flowering stage), and the secondary factors were fertilizer treatment as subplot including control (without fertilizer), consumption of 3 tons of biochar from wheat residues per hectare, consumption of 3 tons of biochar from cotton residues per hectare, consumption of 150 kg of urea per hectare + 50 kg of triple superphosphate per hectare, consumption of 112.5 kg of urea per hectare + 37.5 kg of triple superphosphate per hectare, consumption of 112.5 kg of urea + 37.5 kg of triple superphosphate + 3 tons wheat biomass per hectare, and 112.5 kg of urea + 37.5 kg of triple superphosphate + 3 tons of cotton biomass per hectare. In this research, chlorophyll a and b, total chlorophyll, catalase, and peroxidase activities, yield components, and yield of safflower were calculated.
The results of the experiment showed that the measured traits were significantly affected by the irrigation regime and fertilizer treatment. Under cutting-off irrigation after the flowering stage, the fertilizer treatment of 112.5 urea + 37.5 phosphate + 3 tons of wheat biochar per hectare increased 55 and 40% chlorophyll a and total chlorophyll compared to the control, respectively. Water stress increased the carotenoid content, catalase, and peroxidase enzymes. The highest amount of catalase and peroxidase enzyme activity was obtained in the control under cutting-off irrigation after the flowering stage, which increased by 48 and 38%, respectively, compared to the control under optimal irrigation. The number of seeds per capitule and the number of fertile capitules per plant in the treatment of 112.5 urea + 37.5 phosphate + 3 tons of cotton biochar under water stress conditions increased by 8.8 and 19.51%, respectively. Also, under water stress, the application of 112.5 urea + 37.5 phosphates + 3 tons of cotton biochar improved and increased the relative content of leaf water, biological capitules yield, and grain yield compared to the control by %53, %22, and %34, compared to control, respectively.
Results showed that in both of the irrigation regimes, application of 3 tons of cotton or wheat biochar alone can increase the biomass and grain yield compared to control. Overall, the application of 112.5 urea + 37.5 phosphate + 3 tons of cotton biochar under water stress conditions improved the relative water content of the leaves, the number of seeds per capitule, the number of fertile capitule per plant, and finally, biomass and yield of safflower. With respect to water shortage under late season in southern parts of Fars province, and in order to decrease the detrimental effects of water stress, farmers can use the biochar of cotton combined with reduced dosage of urea and triple superphosphate fertilizers.

This study was conducted to investigate the effect of foliar application of amino acids on yield and yield components of oil rapeseed under late-season drought stress conditions. The experiment was conducted as factorial based on a randomized complete blocks design in the research farm of the Faculty of Agriculture at Tarbiat Modares University during the 2021-22 growing season. The experimental treatments were irrigation regimes at three levels (normal irrigation, withholding irrigation from 50% flowering stage, and withholding irrigation from pod forming) and foliar spraying at five levels (no foliar, foliar spraying 0, 1, 2, and 3 g amino acids per liter of distilled water). The results showed that plant height, shoot dry weight, 1000-seed weight, harvest index, and biological and grain yield, number of seeds per pod, and the number of pods per plant were significantly affected by the interaction of irrigation regimes and foliar spraying. The highest plant height (166.5 cm), 1000-seed weight (3.58 g), number of pods per plant (131.4) and grain yield (4514 kg ha-1) were obtained by foliar spraying of two g amino acids per litre under normal irrigation conditions. According to the results, foliar spraying 2 g amino acids per liter had the most positive effect on the yield and yield components of oil rapeseed in all irrigation regimes (normal irrigation, withholding irrigation from 50% flowering stage, and withholding irrigation from pod forming). Therefore, upon approving in future research it could be recommended to use foliar spraying with 2 g amino acids per liter in oil rapeseed cultivation.

Barley (Hordeum vulgare L.) is among the most influential cereals, and a wide range of populations in several regions of the world (Sallam et al., 2019). However, there are some restrictions for accomplishment to the potential production, which the most consequential one among them, water shortage, a drastic obstacle in many regions of the world, in particular in arid and semi-arid areas. Water scarcity, results in plenty of disturbances in plant functions like cell division and elongation, water and nutrients relations, photosynthesis, enzymes activity, stomata movement, assimilate partitioning, respiration, oxidative damage, growth, and productivity, as several types of researches show that water shortage in the soil cause many disorders in plant tissues, which in turn leads to a punctual diminish in the photosynthesis rate (Todorova et al., 2022). Under circumstances of water shortage, the electron transport through PSII is prohibited, and the oxygen-evolving complex of PSII is damaged (Georgieva et al., 2005). In repercussion, depends on the times, duration of facing, and stress intensity, developmental stage, and kind of tissue, plant defenses against it differently.

An experiment as a factorial in a completely randomized block design in five replications at the experimental greenhouse of the University of Zanjan was carried out in two years 2021 and 2022. In this study two regimes of irrigation (D0, regular irrigation as the control, D1, Water Deficit for two weeks immediately after flowering), four levels of biochar (zero% as the control treatment, 0.25, 0.5 and 1 percent of soil weight) and three levels of spraying Methyl Jasmonate (zero μmol as the control treatment, 50 and 100 μmol) at the same time with flowering stage and starting withholding water, were executed.

Results demonstrated that utilized treatments had significant effects on studied parameters. Results illustrated that, despite the fact that proline content, carbohydrate and quantity of electrolyte leakage were elevated as a result of drought stress, and accumulation of photosynthetic pigments were dwindled, however, application of biochar in the soil and foliar spraying of methyl Jasmonate caused modulating the effects of drought stress. Lack of water can reduce the concentration of photosynthetic pigments, mainly chlorophylls and carotenoids, as it causes oxidation which leads to diminishing the biosynthesis of pigments (Pandey et al., 2012). It is claimed that using biochar ameliorates the reduction of pigments in stressed plants as a result of better surface area, higher water holding capacity, more cation exchange capacity, and useful absorptive features of biochar (Ibrahim et al., 2020). Moreover, the drought stress resulted in a substantial elevation in the concentration of proline (PC) which might be as a result of devastating impacts of drought on the performance of plasma membrane as well as the process which leads to dehydration of cytoplasm, which in turn results in boosting proline concentration in Barley plants under drought situation (Hafez et al., 2020). It is said that biochar reduces proline content, because of its impact on maintenance of plasma membrane in a stable situation, modulating the pressure of water in cell, and enhancing the ability of plants in conserving relative water content (Ahmed et al., 2016). Furthermore, methyl Jasmonate (MJ) may facilitate the strengthening of cell walls and effectively neutralize excessive increase in the level of ROS during further exposure to the stress factor, thereby preventing the damage of cellular membrane structures and changes in their permeability under stress conditions (Hayat and Ahmad., 2007).

The current study represents that Barley can tolerate drought stress through several mechanisms such as modulating some biochemical compounds. In this study drought was shown to have negative impacts on some of the studied physiological and biochemical parameters. Results demonstrated that the use of biochar and Methyl Jasmonate can improve the adaptation ability of Barley plants to water shortage, associated with enhancement in morpho-physiological and biochemical traits. Soil content of biochar at 0.25% w/w and Methyl Jasmonate leaf applies at 50 micro moles protected plants against drought stress. Importantly higher doses of biochar and Methyl Jasmonate had negative impacts, highlighting the need to better understand optimal doses, and mechanisms of action of these amendments.

Rapeseed is the second most important plant for oil production in the country due to having more than 40% of oil in the seed, resistance to some environmental stresses, and suitable combination of fatty acids. Water deficit in the stage of reproductive growth severely affects the rapeseed yield because the number of seeds and the weight of seeds decrease. Water shortage in the flowering stage also reduces the seed oil percentage and oil yield of rapeseed. In some areas of Khuzestan province, rapeseed is mainly cultivated as a beak crop. This issue causes the growth period of rapeseed to coincide with the growth of some other crops. In this situation, some irrigation turns are necessarily allocated to other plants (including wheat, which is in the pollination stage, and okra, which is in the germination stage), which causes rapeseed to face water shortage, even in the flowering stage. Therefore, it is necessary to apply appropriate management methods to reduce the effects of drought stress on rapeseed during the flowering stage. Among these methods is the use of vermicompost fertilizer and changing the planting date. The present study aimed to address the following inquiries: What impact does vermicompost fertilizer, planting date, and drought stress during the flowering stage have on rapeseed seed and oil production? Can the utilization of vermicompost fertilizer and adjustments to planting dates mitigate the adverse effects of water deficit stress on rapeseed yield?

A field experiment was conducted at the research farm of Shadegan Payam Noor University, Khuzestan, Iran in 2022-23 growing season. The experiment was carried out as a three-factor factorial 2x3x2 with three repetitions. The experimental factors included planting date (November 25 and December 25), vermicompost fertilizer (0.0, 10, and 20 ton ha-1), and irrigation (full irrigation and interruption of irrigation during the flowering stage). In each irrigation stage, the volume of irrigation water was measured and to calculate the efficiency of water consumption, the yield (seed and oil) was divided by the amount of evapotranspiration. At the maturity stage, the seed yield and its related traits included the number of pods per plant, the number of seeds per pod, the weight of 1000 seeds, biological yield, harvest index, oil and protein percentage of seed were calculated.

Rapeseed had the highest seed yield (2667 kg ha-1) on the planting date of November 25 with full irrigation, while delay in planting (planting date of November 25) and interruption of irrigation during the flowering stage resulted in the lowest seed yield (1247 kg ha-1) which means a decrease of more than 50% in seed yield. However, if rapeseed is planted on December 25 and fully irrigated, it has a higher seed yield (about 15%) than planting on November 25, along with stopping irrigation during the flowering stage. A similar trend was observed in seed oil percentage and oil yield, so the highest and lowest percentage and yield of rapeseed oil were obtained on the planting date of November 25 with full irrigation and the planting date of December 25 and stopping irrigation at the flowering stage, respectively. The delay in planting and drought stress in the flowering stage reduced the percentage of rapeseed oil by 6% and the yield of oil by about 60%. On the planting date of November 25, rapeseed was superior to the planting date of December 25 in terms of the number of seeds, 1000-seed weight, biological yield, and water efficiency by 35, 25, 23, 18, and 38%, respectively.

Vermicompost fertilizer helped to improve rapeseed seed yield by providing important nutrients. Stopping irrigation during the flowering stage and delaying planting caused a decrease in seed yield and rapeseed oil production. Therefore, to obtain the maximum yield of seed and oil, it is recommended to plant on the 25th of November and full irrigation. It is better to modify the planting pattern in the region to prevent the flowering stages of rapeseed from encountering water shortage.

Drought is one of the most important environmental stresses in the ecosystem of crops. In order to select potato tolerant genotypes to drought stress.

This experiment was conducted in the form of a randomized complete block design with the method of strip chopped blocks in three replications during the two cropping years was performed in Ardabil region. Two levels of non-stress and stress irrigation were compared as vertical factor and 20 potato genotypes were compared as horizontal factor.

The results showed that all measured traits were affected by stress treatments. Under stress treatment, genotype 905675 had the highest tuber yield and tuber weight per plant. The lowest tuber yield and tuber weight per plant were obtained from Marfona cultivar. In addition, with the application of stress, the activity of enzymatic and non-enzymatic antioxidants increased. The highest amount of reducing sugar with 122%, vitamin C with 63%, proline with 106% The percentage of catalase enzyme with 249% increase compared to non-stress conditions was observed in genotype 905675. The highest activity of superoxide dismutase and polyphenol oxidase with 214 and 42% increase belonged to genotype 901375, respectively.

In general, considering the amount of changes in tuber yield, tuber weight per plant, increasing the activity of enzymatic and non-enzymatic antioxidants, genotypes 905675, 901575 and 901375 were selected as tolerant and high yield potential genotypes in both stress and non-stress conditions, respectively, and Milva, Jelly and Marfona cultivars can be introduced as susceptible cultivars.

Safflower has been cultivated in different parts of Sistan and Baluchestan since ancient times and is relatively tolerant of drought. It has many medicinal and food uses for the people of this region. Saravan is also one of the arid regions of the country, so the cultivation of plants compatible with these regions can be effective to improve agriculture in this region. Several studies have been shown that a small amount of nutrients, particularly Zn and Mn applied by foliar spraying can significantly increase the yield of crops Also, foliar nutrition is an option when nutrient deficiencies cannot be corrected by applications of nutrients to the soil. It is likely therefore, in open-field conditions, where the factors that influence the uptake of the nutrients are very variable, foliar fertilization is a privilege. Among the micronutrients, Zn and Mn nutrition can affect the susceptibility of plants to drought stress. Zinc plays an important role in the production of biomass. Furthermore, zinc may be required for chlorophyll production, pollen function, fertilization and germination. Mn plays essential roles in the metabolism of isoprenoids, chlorophylls, carotenoids and phenolics. External application of Mn2+ increases photosynthesis, net assimilation, and relative growth and yield.

this experiment was conducted to investigate different levels of irrigation and foliar application of zinc and manganese sulfate in November 2020 in the research farm of Saravan Higher Educational Complex as a split plot in a randomized complete block design with three replications. Experimental treatments include three levels of irrigation, including: full irrigation, cessation of irrigation at the beginning of stem emergence and cessation of irrigation at the stage of flowering, and three levels of foliar application with zinc sulfate (three per thousand), manganese sulfate (three per thousand) and no foliar application. Study traits include speed, plant height, number of branches, number of heads per plant, seed weight per plant, head weight per plant, 100-seed weight, biological yield, grain yield and harvest index (division of grain yield by biological yield by percent). Data analyzed was performed using SAS software (version 9/1) and mean comparisons at the level of 5% probability were performed using LSD test.

The results showed that the interaction effects of irrigation and foliar application in plant height, number of branches, number of heads, 1000-seed weight, seed-per-plant weight, head-per-plant weight, biological yield, grain yield, harvest index and chlorophyll meter (SPAD) were significant (P≤ 1%). foliar application with zinc sulfate increased grain yield more than three times in all irrigation treatments, also grain yield in foliar application with zinc sulfate in non-interruption irrigation treatment (693 kg) Per hectare was seven times higher than the conditions for stopping irrigation at the stage of stemming and lack of foliar application (100 kg ha-1). In all irrigation treatments, foliar application of zinc sulfate Element was relatively superior to manganese sulfate and no foliar application. The highest grain yield was observed in the treatments of non-interruption of irrigation, cessation of irrigation in flowering stage and cessation of irrigation in stem stage, respectively. Was seven times the grain yield. In general, foliar application of zinc sulfate can be used as an agricultural solution to increase yield and reduce the effects of cessation of irrigation at the end of the growing season in safflower in Saravan climate. In general, the results of this study showed that under different conditions of irrigation interruption, foliar application of zinc sulfate and manganese can play an important role in mitigating the effects of drought stress on safflower compared to no foliar application. Discontinuation of irrigation at the end of the growing season in the stem and flowering stages reduced the seed yield of safflower compared to full irrigation conditions. Zinc sulfate foliar application improved yield-related traits in this plant, zinc sulfate foliar application increased grain yield about twice and in manganese sulfate foliar application this increase was about 30% compared to non-foliar conditions. The highest correlation was observed with number of heads per plant, head weight, seed weight per plant and number of branches. Due to the alkalinity of the soil in dry areas and the non-absorption of these elements by the plant and the positive effects of this element in relation to the defense system and photosynthesis of the plant, foliar application of zinc sulfate Element is recommended for safflower in Saravan climate.

The use of low irrigation regimes by saving water consumption can help as a water management solution to increase the cultivated area and also determine the optimal cultivation pattern. The importance of oil products such as safflower has increased in recent years in the world. In general, safflower is produced in relatively dry marginal lands with low input. Efforts are being made to improve the yield and seed quality of this plant through the development of new genotypes and agricultural practices around the world. But the fact is that drought also affects the growth and performance of this plant. Zinc plays an important role in seed and biomass production, chlorophyll production, pollination process and even plant germination.

The purpose of this experiment was to investigate different levels of irrigation regime and foliar application of zinc and manganese sulfate in the research farm of Saravan Education Complex as a split plot in a randomized complete block design with three replications. The main plot included full irrigation, cut-off of irrigation at the stem stage and cut-off of irrigation at the flowering stage, and the sub-plot included three levels of foliar application with zinc sulfate (three per thousand), manganese sulfate (three per thousand) and without foliar application (control). The harvest was done manually, depending on the time of full processing, from the end of May to the beginning of June 2019. In order to evaluate the yield, the plants were harvested after removing the margins and after beating and separating the seeds, the yield was measured. The dry matter of plant leaves was also measured by collecting the leaves of three plants in each plot; Thus, by placing the collected leaves in an oven at 75°C for 48 hours and calculating the average leaf weight of three plants, the leaf dry matter was obtained. Analysis of data variance was done using SAS software (9/1 version) and mean comparisons were done at the five percent probability level using the LSD test.

The results showed that the cut-off of irrigation in the stem and flowering stages reduced number of days up to heading, number of days up to 50% flowering and the number of days up to maturity irrigation than full irrigation. Also, interruption of irrigation in stem and flowering stages compared to full irrigation conditions significantly reduced RWC and significantly increased electrolyte leakage. Foliar application with zinc sulfate compared to manganese sulfate and no foliar application caused a significant increase of 0.53 and 2.31 percent in number of days to heading, 1.71 and 2.54 percent in number of days up to 50% flowering and 0.52 and 1.64 percent number of days up to maturity, respectively. Foliar application of zinc sulfate and manganese sulfate significantly increased RWC and decreased significantly electrolyte leakage compared to no foliar application. At each level of irrigation regime, foliar application significantly increased seed yield, which was more effective in zinc sulfate treatment than manganese sulfate.

In general, full irrigation and foliar application of zinc sulfate is recommended for safflower cultivation in Saravan climate. In general, the cut-off of irrigation in the stages of stem growth and flowering caused a sharp decrease in grain yield in safflower plants compared to full irrigation conditions. Considering the high ambient temperature in the study area, it seems that the risk of under-irrigation in safflower cultivation in this area is very high and therefore it is recommended to carry out full irrigation in safflower cultivation in this area. Also, due to the alkalinity of the soil in dry areas and the non-absorbability of zinc and manganese elements by the plant and the positive effects of these elements in relation to the defense and photosynthesis system of the plant (especially zinc sulfate), foliar spraying with zinc sulfate for safflower in conditions Saravan weather is recommended.

This experiment works on the physiological, growth, and yield responses of sesame to the application of potassium nano-fertilizers, chitosan, and fulvic acid under drought stress in Semnan Agricultural and Natural Resources Research Center as a factorial split-plot based on randomized complete block design with three replications in 2019. The experimental treatments include drought as the main plot (normal irrigation, irrigation cut offin 70 and 60 BBCH as moderate, and severe stress, respectively) and potassium nano-fertilizer (0, 1.5, and 2.5 per thousand) and foliar application (control, chitosan, fulvic acid, and 50% of chitosan+ fulvic acid) as sub-plots.Application of potassium nano-fertilizer under normal and stress conditions significantly cuts chlorophyll b and total, leaf area index, number of capsules, 1000-seed weight, and oil percentage.The highest grain yield belongs to the application of 1.5 and 2.5 per thousand nano fertilizers, using fulvic acid alone or in combination with 50% chitosan (2516, 2277.5, 2506.6, and 2313.2 kg/ha, respectively). The highest oil content has been in 1.5 and 2.5 per thousand nano fertilizer application under normal irrigation, which has increased 13.2% and 15.4%, respectively. Foliar application of fulvic acid with nano potassium fertilizer (1.5 per thousand) under severe drought stress show the highest activity of antioxidant enzymes catalase, peroxidase, ascorbate peroxidase, and superoxide dismutase. In general, the results show that the application of 1.5 per thousand nano potassium fertilizer and combined foliar application of chitosan and fulvic acid under severe drought by improving physiological traits, manage to modify the adverse effects of drought, increasing growth, yield, and quality indices of sesame.

Drought stress, reduces physiologic and qualitative traits of triticale. Also, using compost fertilizer has beneficial effects on physical, chemical and biological conditions of the soil and reducing the negative effect of environmental stresses like drought stress on physiologic and qualitative traits of crop plants. This study designed and carried out with aim to study the effect of sugarcane residue compost fertilizer on physiologic and qualitative traits of triticale under drought stress conditions in Ahwaz weather conditions in Agricultural Sciences and Natural Resources University of Khuzestan.

In order to investigate the effect of sugarcane residue compost fertilizer on physiologic and qualitative traits of triticale under drought stress conditions, a field experiment using a split-plot arrangement accomplished in a randomized complete block design with four replicates in the research farm of Agricultural Sciences and Natural Resources University of Khuzestan during 2018-2019 growing season. Experimental factors include four levels of drought stress (complete irrigation, drought stress from spike emergence stage, drought stress from pollination stage and drought stress from milky-dough stage) in main plots and five amounts of sugarcane residues compost fertilizer (0, 10, 20, 30 and 40 t ha-1) in sub-plots.

Analysis of variance showed that the effect of drought stress, sugarcane residue compost fertilizer and their interaction on the most of measured traits (SPAD, chlorophyll a, chlorophyll b, carotenoids, relative water content, cell membrane stability, canopy temperature, redistribution, grain protein, grain Fe and grain Zn) were significant. Mean comparison of above measured traits in interaction effects of drought stress and sugarcane residue compost fertilizer showed that drought stress decreased these traits and the maximum amount of these traits was obtained in full irrigation and the lowest amount was observed in drought stress from spike emergence to complete maturity. Also, in different drought stress levels, with increasing the amount of sugarcane residue compost fertilizer, the amount of traits increased and reached a maximum at the level of 40 t ha-1. Therefore, the maximum amount of these traits was under full irrigation and 40 t.ha-1 of sugarcane residue compost and the lowest amount of them was obtained in drought stress from spike emergence and non-use of sugarcane residue compost.

Generally, drought stress from irrigation cut off decreased physiologic and qualitative traits of triticale. Also, in different drought stress levels with increasing the amount of sugarcane residue compost fertilizer, the amount of above traits increased. Therfore using sugarcane residues compost fertilizer decreased the negative impact of drought stress from spike emergence conditions on physiologic and qualitative traits of triticale between 6 to 46 percent.

To investigate the effect of different levels of irrigation and nitrogen fertilizer on yield and yield components of some safflower cultivars, an experiment was conducted as a split-split plot in a randomized complete blocks design with three replications in the research farms of the University of Tehran, Karaj during 2018-2019. Main plots were irrigation (normal irrigation, irrigation until at middle of flowering stage and irrigation until the beginning of seed filling), sub plots were nitrogen (supply of 100 % and 50 % of nitrogen needs) and sub-sub plots were safflower cultivars (Goldasht, Golmehr, Padideh and Parnian). The effect of irrigation, nitrogen, and cultivar factors on number of heads per plant, number of seeds per head, 1000-seed weight, grain yield, and biomass were significant. According to the results, cut-off of irrigation at the beginning of seed filling and middle of flowering stages leads to a reduction of 16.2 % and 68.1 % of seed yield compared to normal irrigation, respectively. Reducing the amount of nitrogen by 50 % compared to 100 % supply decreases seed yield 8.5 % and biomass by 12 %. The triple interaction of irrigation, fertilizer and cultivar was significant in stem diameter and head diameter. The interaction of irrigation and nitrogen levels showed that with decreasing irrigation levels, nitrogen uptake also decreased and reduced the number of seed per head. However, providing 100 % of the nitrogen requirement under drought stress conditions prevents a more severe decline in the number of grains per head.

In order to investigate the effects of drought stress on grain yield, biological yield, yield components and harvest barley index of Gohar cultivar, an experiment was conducted as a randomized complete block design in the experimental farm of Shushtar Azad University. For this purpose, in field conditions, drought stress treatment at five levels was applied as irrigation interruption in the stages of tillering, stem emergence, flowering, seed filling and no irrigation interruption (control treatment). The amount of water consumed was measured by a volume meter. The results showed that there was a significant difference between drought stress treatments in all studied traits except harvest index. Stress-free treatment produced the highest grain yield by producing the highest biological yield, number of spikes per unit area and number of grains per high spike and suitable 1000-grain weight. In terminal stress conditions or cessation of irrigation in the grain filling stage after non-stress conditions had a higher yield than other stages. The study of correlation coefficients showed that among the yield components, the number of spikes per unit area had the highest correlation (0.63) with grain yield. In this experiment, the lowest grain yield was obtained in the cut-off treatment at the flowering stage, which indicates the sensitivity of this stage of plant growth to dehydration stress

Triticale is a commercial cereal with a vast potential to feed human and animal. This plant can be cultivated in poor soils that are not suitable for wheat production. In irrigation cutoff stress conditions, reduces growth and yield and yield components of triticale. One of the most important ways to reduce the negative effect of drought stress on plant is using compost fertilizer in the soil. Using compost fertilizer in agricultural soils lead to increase nutrient elements and conserving the soil water. Generally, compost fertilizer of sugarcane residues, improves moisture storage and physical and chemical conditions of the soil. So that sugarcane residue compost fertilizer contributes to preserving the moisture storage of the soil and to supply the nutrients required by the plant. In this study, the most important aim is to study the effect of sugarcane residue compost fertilizer on triticale yield and yield components under irrigation cutoff stress condition in Mollasani region, Ahwaz, Kuzestan province.

In order to investigate the effect of sugarcane residue compost fertilizer on growth, yield and yield components of triticale under drought stress conditions, a field experiment using a split-plot arrangement accomplished in a randomized complete block design with four replicates in the research farm of Agricultural Sciences and Natural Resources University of Khuzestan (in 31º N, 48º E, 35 Km north-east of Ahwaz, and 20 m above the sea level) during 2018-2019 growing season. Experimental factors include four levels of drought stress (complete irrigation, irrigation cutoff from spike emergence to physiological maturity, irrigation cutoff from pollination stage to physiological maturity and irrigation cutoff from milky-dough stage to physiological maturity) as a main factor in main plots and five amounts of sugarcane residues compost (0, 10, 20, 30 and 40 t ha-1) as a sub factor in sub-plots.

Analysis of variance showed that the effect of drought stress, sugarcane residue compost and their interaction on the measured traits were significant. Mean comparison showed that the maximum amount of triticale traits was obtained in full irrigation and the lowest amount was observed in drought stress from spike emergence to physiological maturity. Also, with increasing the amount of sugarcane residue compost, the amount of traits increased and reached a maximum at the level of 40 t ha-1. Mean comparison of grain yield under the interaction of drought stress and sugarcane residue compost showed that the highest grain yield (4288 kg ha-1) was under full irrigation and 40 t.ha-1 of sugarcane residue compost and the lowest grain yield (1134 kg ha-1) was obtained in drought stress from spike emergence to physiological maturity and non-use of sugarcane residue compost. In the conditions of drought stress caused by the interruption of irrigation, the vegetative and reproductive growth of the plant is reduced, which causes a decrease in yield components and ultimately leads to a decrease in seed yield. On the other hand, the use of compost fertilizer reduces the effect of stress by preserving water and providing nutrients needed for plant growth and leads to an increase in seed yield.

Generally, the results showed that drought stress conditions decreased growth, grain yield and yield components of triticale but using sugarcane residues compost fertilizer decreased the negative impact of drought stress conditions on measured traits. Also, in areas with irrigation shortage or lack of rainfall at the beginning of flowering stage, 40 tons per hectare of sugarcane residues compost fertilizer is recommended for maintaining grain yield.

The current study tries to evaluate the effect of auxin foliar application in two safflower cultivars under drought stress condition, using a factorial split plot experiment with randomized complete block design in two years (2017-2018 and 2018-2019). It has been conducted at research field of Seed and Plant Improvement Research Institute in Karaj and evaluates irrigation at two levels including normal irrigation (control) and interruption of irrigation from the beginning of grain filling stage (drought) in the main plots and cultivars of Padideh and Goldasht and auxin foliar application in two levels of non-foliar application of distilled water (control) and foliar application of auxin (indole acetic acid) in one step (mid-flowering) at a concentration of 3000 mg.l-1 (30 ppm) in sub-plots as a factorial. In the auxin foliar application and non-foliar application (control) in both normal irrigation and drought stress treatments, the highest total number of heads per plant in Goldasht cultivar have been 26.3 and 24.3 respectively, and the highest grain number per plant observed in Goldasht cultivar have been at 708 and 592, respectively. Auxin foliar application and irrigation has had no significant effect on the grain oil percentage. Goldasht cultivar demonstrates a higher grain yield compared to Padideh cultivar due to lower head temperature, higher soluble carbohydrate concentration, number of heads, and 1000-grain weight. Generally, results show that the effect of the studied treatments is affected by the year and despite the positive effect of auxin foliar application on some yield components at both irrigation levels, foliar application of auxin at middle of flowering stage has no significant effect on grain yield.

In order to study the effect of different irrigation regimes, and application of biological and chemical fertilizers on morphological characteristics, antioxidant enzyme activity, and sugar content of melon fruit cv. Ahlam, an experimental split-factorial plots has been done in a randomized complete block design with three replications in Khuonj County in 2018-19. The main factor has been irrigation at 3 levels including 50%, 75%, and 100% of water requirement, with the sub-factor including NPK chemical fertilizer at 0, 60, 120, and 180 kg/ha as well as non-application of Nitroxin biofertilizer along with application of 100% of the recommended amount. Results show that different irrigation regimes, different fertilizer treatments, and their interaction have had a significant effect on some of the studied traits. The combined application of chemical fertilizers with biofertilizers show a significant effect on the number of sub-branches, total plant weight, length and diameter of the most branch, total soluble solids (TSS), the quantity of xylose and fructose sugars and activity of catalase, superoxide dismutase, and peroxidase enzymes. The highest number of sub-branches and plant fresh weight, branch length and diameter are obtained in the chemical fertilizer treatment of 120, and 180 kg/ha with the utilization of Nitroxin fertilizer under 100% water stress. However, it has been observed that biofertilizers has had no significant effect on sugars and enzyme activity in fruit, so that the very best levels of catalase, superoxide dismutase, and peroxidase are obtained within the treatment of 50% of field capacity with 120 and 180 kg/ha of chemical fertilizer without using Nitroxin. In general, it can be concluded that the application of biofertilizers reduce the adverse effects of water stress and the application of chemical fertilizers with biofertilizers hasa significant impact on increasing the studied traits.

Sesame (Sesamum indicum L.) is one of the important oil crops that get attentions due to its relatively high oil content and tolerance to drought. Drought is one of the most important causes of crop products reduction and can affect plant phenology, growth and yield depending on the severity, time and stage of plant development. Superabsorbent polymers are suitable materials for increasing soil water retention capacity that can provide better conditions for crop growth, especially under water deficit conditions. The importance of useing chemical fertilizers in addition to their nutritional role, is to support the crop in tolerating environmental stresses such as drought and preventing yield loss which potassium has such role in plant life and survival under stress conditions. Potassium fertilizers, especially potassium sulfate, can play an important role in reducing the negative effects of water stress. Potassium is the third main nutrient for plant growth and plays a special role in the survival of plants under environmental stress and increasing their resistance to drought, high temperatures, cold, disease, salinity, weeds and maintaining osmotic potential.

In order to investigate the effect of superabsorbent polymer, potassium sulfate and water deficit on growth, yield and yield components of sesame (Sesamum indicum L.), an experiment was conducted out on factorial arrangment based on randomized complete block design with three replications in Research Field of Agricultural College, at Birjand University in 2018. Experimental factors included three levels of irrigation (full irrigation in the whole growing season, irrigation up to 50% flowering stage and cutoff irrigation until maturity, and irrigation up to 50% capsules appearance and cutoff irrigation until maturity), potassium fertilization at three levels (No potassium application, fertilizing at optimum recommendation using 100 kg.ha-1 potassium fertilizer and fertilizing 50% higher than optimum recommendation using 150 kg.ha-1 potassium fertilizer) and superabsorbent at two levels, including no application and 100 kg.ha-1 application. The studied traits were plant height, number of lateral branches, seeds per capsule, capsule per plant, 1000-grain weight, grain yield and days to maturity.

Results showed that irrigation levels had a significant effect on measured traits except for number of lateral branches. The highest grain yield (2316.61 kg.ha-1) was obtained under full irrigation conditions and the lowest seed yield (667.89 kg.ha-1) was observed at 50% flowering cutoff irrigation. The effect of superabsorbent on all traits was significant. The results showed that superabsorbent moderated the effects of drought and improved sesame growth indices. Interaction effect of potassium and irrigation on grain yield was also significant. Although, under water deficit conditions, grain yield was significantly reduced, but potassium sulfate application under these conditions partially prevented the yield loss. Due to the role of potassium in the plant, the presence of this element in water deficit conditions can be effective in tolerance and crop yield increment. The highest number of days to maturity (124.77 day) in interaction effect of water deficit and superabsorbent was obtained from full irrigation and 100 kg/ha superabsorbent treatment and the least amount (109.55 day) was obtained from50% flowering cutoff irrigation and non-superabsorbent treatment.The increase in soil moisture caused by the use of soil moisture absorbers can increase the duration of the day to maturity.

The results showed that irrigation levels decreased sesame growth and yield. Water deficit at flowering and encapsulation stages reduced grain yield compared to full irrigation treatment. Therefore, it is necessary to irrigate the crop according to water requirement during these stages. Due to the necessity of conserving available water resources as well as optimum consumption of water, the use of superabsorbent and potassium can be effective in increasing crop yield and drought resistance. Obviously, it is necessary to provide sufficient water requirement in order to achieve higher grain yield. Therefore, it seems that hydrogels reduce the negative effects of drought by absorbing water and making it available for the crop. Potassium application in environments with different levels of drought can be considered as a practical method to reduce drought damage and prevent yield loss.

A two-year experiment (2017-2019) was conducted at Karaj, Iran, to investigate the effect of ammonium and potassium sulfates on the physiological traits and seed and oil yields of camelina under late-season deficit irrigation conditions. The experiment was carried out as a split plot-factorial in a randomized complete block design with three replicates and irrigation regimes (full irrigation, restricted irrigation from flowering and siliqueformation stages) as the main plots and a combination of ammonium sulfate (0, 25, 50, and 75 kg ha-1) and potassium sulfate (0, 25, 50, and 75 kg ha-1) fertilizers as the subplots. Leaf relative water content, canopy temperature, stomata resistance, proline, carbohydrate, chlorophyll and seed and oil yields were affected by the three-way interaction between irrigation regime, ammonium and potassium sulfates. Camelina seed and oil yields were 2470 and 833 kg ha-1 in full irrigation, 613 and 118 kg ha-1 in restricted irrigation from the flowering stage, and 1320 and 407 kg ha-1 in restricted irrigation from the silique formation stages, respectively. Application of ammonium and potassium sulfates increased seed and oil yields in all irrigation treatments. The maximum seed and oil yields were obtained from 75 kg ha-1 ammonium + 75 kg ha-1 potassium sulfates with the averages of 1950 and 643 kg ha-1, respectively. The results of this study suggest that the application of 75 kg ha-1 ammonium + 75 kg ha-1 potassium sulfates can improve the camelina seed and oil yields under full irrigation and late-season drought stress treatments.

In order to evaluate the effect of two isolates of arbuscular mycorrhizal fungus in saffron rhizosphere on some of saffron agronomic traits under different irrigation regimes, an experiment was conducted as split plots factorial in a randomized completely design with three replications at the Institute of Soil and Water Research, Karaj, Iran. The treatments consisted of three irrigation regimes (normal irrigation (control), irrigation cut off at the beginning of the growing season and at the beginning and middle of the growing season) as the main factors, three organic planting media (no organic fertilizer, vermicompost (20 t.ha-1) and biochar (10 t.ha-1) and arbuscular mycorrhizal fungal in three levels (no application, isolate a and isolate b) as a sub factors. Molecular findings indicated that, both strains isolated from saffron rhizosphere belonged to Rhizophagus irregularis. The results showed that the interaction effect of water stress and planting media on economic yield and also, the interaction effect of water stress, planting media and R. irregularis fungus on leaf number, fresh and dry weights and corm weight and diameter per pot were significant. The highest yield (0.062 g/pot) belonged to the full irrigation with biochar. Meanwhile, the highest leaves number (180), fresh and dry weights (90.2 and 23.96 g, respectively) and corm weight (7.67 g) and diameter (2.38 cm) per pot were obtained at full irrigation with biochar and Rhizophagus irregularis isolate b. In general, the use of biochar fertilizer with Rhizophagus irregularis isolate b had the greatest effect on the measured traits of saffron in different irrigation regimes.

In order to study the effects of late-season drought stress and foliar application of potassium silicate on yield and yield components of spring genotypes of canola, a factorial split-plot experiment is conducted in Karaj, Iran in a randomized complete block configuration with three replications for two years of cultivation (2016-2018). The irrigation is performed at two levels in this study, including routine irrigation (control) and interruption of irrigation from the pod formation stage. Potassium silicate foliar application at two levels is comprised of 0 and 4 g liter-1 in factorial status in main plots and five Brassica napus L. genotypes including OG×AL, RGS×SLM, DALGAN, RGS003 and RGS×Okapi in subplots.  The results show that the measured properties are affected by the applied treatments. Full irrigation with foliar application in OG×AL genotype results in highest seed yield (5620 Kg/ha) and total chlorophyll content (1.71 mg/g.FW) increase stomatal resistance, leaf proline, leaf soluble and carbohydrates, decreasing total chlorophyll content and relative leaf water content. Under drought stress conditions, DALGAN and RGS× SLM genotypes have higher yield, which indicates its better performance under stress conditions. Finally, our research demonstrates Potassium Silicate's beneficial effects in improving the drought tolerance of canola plants, particularly at the end of the season. Our study will act as a foundation for any attempt in new approaches to mitigate drought damage, establishing a functional connection between the position of potassium silicate, physiological response, and drought stress tolerance in canola plants.

One of the most important and valuable plants in the pharmaceutical industry is the hull-less pumpkin (Cucurbita pepo L. var. Hamedani) plant, which belongs to the cucurbitaceous family. The aim of this research was to evaluate the effect of deficit irrigation and kaolin clay on yield and yield components of (Cucurbita pepo L.). Experiment was laid out as a split plot design with randomized complete block design with three replications at the field located in Siahbaz village, Khoy district, Iran. The main factors included irrigation at four levels (complete irrigation, deficit irrigation from the shoot stage, deficit irrigation from flowering stage, Deficit irrigation from seed filling stage) and sub-factor including three levels of kaolin (control, 3% kaolin, 6% kaolin) was considered. Analysis of variance showed that the effect of deficit irrigation and kaolin on number of seeds per fruit, fruit yield, 1000 grain weight, grain and biological yield, harvest index, oil and protein percentage, oil yield and protein yield were significant. Analysis of variance showed that irrigation treatment at different growth stages had significant effect on leaf number at 1% probability level, but application of kaolin and interaction of irrigation and kaolin on number of leaves per plant was not significant. The results showed that the highest grain weight (294.55 gr), grain yield (807.2 kg/ha), oil percentage (46.2) and oil yield (373.3 kg/ha) were related to complete irrigation treatment. Irrigation at grain filling stage had no significant effect. Deficit irrigation treatment at the stem stage showed the lowest of studied traits. The highest grain weight (257.07 gr), grain yield (733.7 kg/ha) and fruit yield (23.84 kg/ha) were observed in the 3% kaolin spraying treatment. Kaolin 3% increased oil yield, oil percentage, protein percentage and protein yield compared to control treatment. Interaction between deficit irrigation and kaolin consumption was not significant on any of the traits of pumpkin. According to the results of means of oil and protein yield, complete irrigation and cessation of irrigation at filling of grain, were in a statistical group and there was no significant difference with kaolin 3% and cessation of irrigation in filling of grain, the desired quantitative and qualitative yield can be achieved in Pumpkin.

In order to evaluate the physiological and biochemical characteristics of rapeseed (Brassica napus L) cultivars in terms of irrigation interruption and delay planting date، an experiment was implemented in two crop years as a factorial split-plot in the form of a randomized complete block design with three replications in Karaj region. In the present study، irrigation in two levels including normal irrigation (80 mm evaporation from Class A evaporation pan) and irrigation cut-off from the stage of sowing and pod formation stages in two levels including Sep، 26 and Oct، 26 was placed in main plot and four winter rapeseed cultivars including Tassilo، Elvise، Neptune and Okapi were placed in subplots. According to the results، the highest content of chlorophyll in both planting dates (Sep. 26 and Oct. 26، respectively، with values of 1.59 and 1.88 mg. g-1 FW) and under normal irrigation conditions belonged to Elvise cultivar. The results showed that irrigation cut-off reduced the relative water content of leaves and increased leaf proline، soluble protein content and soluble carbohydrate content. Elvise and Neptune cultivars had the highest grain yield under normal irrigation conditions with 3346 and 3220 kg / ha، respectively، and under irrigation cut-off conditions، with a mean of 3211 and 3081 kg / ha، respectively. According to the Stress Tolerance Index (STI)، Elvise cultivar was identified as the most tolerant cultivar under dehydration stress in the pod formation stage onwards.