جستجوی مقالات مرتبط با کلیدواژه « deficit irrigation » در نشریات گروه « زراعت »

This experiment was conducted in order to evaluate the effect of water deficit irrigation on the agronomic characteristics of fodder sorghum cultivars in Kerman province. This experiment was carried out as a strip split-plot in a complete randomized block design with four replications in a research farm of agricultural research center of Jirof and Kahnooj, Kerman province, in 2019 and 2020. Drought stress as a vertical factor in four levels including without stress (irrigation after 80 mm evaporation from evaporation pan) as control, mild stress (irrigation after 110 mm evaporation from the evaporation pan), medium (irrigation after 140 mm evaporation) and sever (irrigation after 180 mm evaporation) and four sorghum cultivars including Spidfeed, Sugar graze, Jumbo and Pegah as a horizontal factor. The highest yield of fresh forage yield under non-stressed conditions (control) was observed in Spidfeed and Pegah (121.60 and 118.79 ton.ha-1, respectively). Also, Spidfeed and Pegah had the highest dry forage yield under non-stressed conditions (control) as 22.50 and 20.69 ton.ha-1, respectively. Also, the highest yield of dry forage in mild drought stress was observed in Pegah and Speedfeed varieties (15.30 and 14.88 ton.ha-1, respectively) and under medium drought stress in Pegah (11.12 ton.ha-1), whereas Spidfeed variety was superior to others for dry forage yield (7.42 ton.ha-1), in severe drought stress. Based on MP and STI indices, Spidfeed and Pegah cultivars with higher average of dry fodder yield were selected as the most suitable genotypes under drought stress conditions in Jiroft region of Kerman province.

The lack of irrigation water resources in the country in recent years has reduced the yield of crops and threatened food security; Therefore, it is necessary to think of ways to produce crops while saving water. One of the ways to increase production with limited irrigation water resources is the cultivation of drought-tolerant crops with high water use efficiency. Sorghum is known as one of the most important crops in arid and semi-arid regions of the world with its unique characteristics (including tolerance to environmental stresses, especially drought and heat, deep and extensive root system, C4 photosynthetic pathway, etc.). The use of appropriate irrigation methods is also known as another way to increase the production of crops with limited water resources. In this regard, the irrigation methods of alternate furrow irrigation and drip irrigation have been used as new irrigation management solutions in the country with favorable results. This study aimed to evaluate the effect of different irrigation regimes and methods on yield, morphological characteristics, water productivity, and drought tolerance of open-pollinated and hybrid forage sorghum cultivars.

This experiment was conducted as a factorial split-plot based on a randomized complete block design with three replications at the Seed and Plant Improvement Institute, Karaj, Iran, during the 2019 and 2020 cropping seasons. The factorial combination of four irrigation methods (CFI, conventional furrow irrigation; FFI, fixed alternate furrow irrigation; AFI, variable alternate furrow irrigation; and drip irrigation) and three levels of drought stress (full irrigation, moderate stress, and severe stress; including the supply 100, 75, and 50% of soil moisture deficit, respectively) as the main factor and two sorghum cultivars (Speedfeed and Pegah) as sub-factor were investigated. In this study, traits including silage yield, dry matter yield and percentage, irrigation water use efficiency, benefit per drop, net benefit per drop, leaf-to-stem ratio, plant height, and drought stress tolerance indices were evaluated. Due to the homogeneity of the variances of experimental errors over two years, the data were subjected to combined analysis of variance using SAS 9.1 statistical software, and Tukey's test (P≤0.05) was used to compare the means. In addition, IPASTIC online software was used to calculate stress tolerance indices and principal component analysis (PCA) based on these indices.
Research

The results showed that drought stress in all investigated irrigation methods decreased the silage yield, dry matter yield, and plant height and increased water use efficiency for silage and dry matter production, dry matter percentage, and leaf-to-stem ratio. The highest silage and dry matter yields (79.11 and 17.19 ton ha-1, respectively), and the maximum net benefit per drop (18854 Rials m-3) were obtained by cv. Pegah under full irrigation and drip method, whereas the maximum water use efficiency for silage and dry matter production (34.53 and 7.88 kg m-3, respectively) and the highest benefit per drop (60542 Rials m-3) were recorded in hybrid Speedfeed under severe stress and drip method. The highest leaf-to-stem ratio (0.715) was obtained in the FFI method under severe stress and the amount of this trait in cv. Pegah was about 8.6% higher than that of hybrid Speedfeed. Based on the stress tolerance indices, cv. Pegah under the CFI and drip methods and hybrid Speedfeed under the FFI method had more drought tolerance. In contrast, there was no significant difference between the cultivars under the FFI method.

In order to save water while achieving suitable forage yield and water productivity, the drip irrigation method and supplying 75% of soil moisture deficiency is recommended. If it is impossible to implement the drip irrigation system, the variable alternate furrow irrigation method can produce suitable forage yield while reducing the amount of water consumed.

The purpose of this field was to study the effect of biochar application and different planting patterns in different irrigation regimes on the growth and yield of thyme essential oil. The studied treatments include irrigation (irrigation of all furrows, irrigation of furrows as one in constant and one in variable (biochar (non-application of biochar and application of biochar at 8 tons per hectare) and planting pattern (single row cultivation) Thyme and cultivation of two rows of thyme) on the growth and yield of the thyme plant. This experiment was carried out in two cropping years of 1397 and 1398 in the form of split plots based on a randomized complete block design with three replications. The results showed that the highest yield of flowering branches was obtained in the treatment of irrigation of all furrows + application of biochar with mean of 1701 kg. ha-1. In this study, the highest yield of essential oil with 24.7 kg. ha-1 was obtained in the treatment of furrow irrigation as a constant interval + application of biochar + cultivation of two rows of thyme. Based on the results of this study, the application of biochar and two-row cultivation caused a significant increase in the yield of thyme essential oil. In general, despite the decrease in growth and yield of thyme dry matter, furrow irrigation treatments as one-to-one variables increased essential oil yield by significantly increasing the percentage of essential oil and reducing water consumption. Biochar treatment also had a positive effect on all vegetative and functional traits of thyme.

The aims of this study is evaluate AquaCrop in simulating rapeseed yield, biomass and water use efficiency under different irrigation amounts (E1, E2, E3 and E4, indicating water supply of 50, 75, 100 and 125 mm from the evaporation pan, respectivly) was performed in three cropping years (Y1, Y2 and Y3 representing the first, second and third years, respectively). In order to calibrate this model, the data collected from the first year used for calibration and data for the second and third year were used for validation. The results showed that AquaCrop had an overestimated error (MBE< 0) to simulate all three parameters studied. The accuracy of AquaCrop was excellent for simulating yield and biomass (NRMSE <0.1) and good for water use efficiency (NRMSE <0.2). The mean differences between simulated and observed yield, biomass and water use efficiency water were 0.19 t.ha-1, 0.78 t.ha-1 and 0.05 kg.m-3, respectively. Based on the results, use of AquaCrop to simulate rapeseed yield, biomass and water use efficiency is recommended.

Rice is one of the most important crops in Asian countries, which is cultivated in more than half of the continent's agricultural lands. Environmental conditions are different and uncontrollable even in different parts of an area, so the response of rice cultivars to these conditions will be different. Therefore, it is necessary to perform performance comparison experiments to achieve high quality, quantity, consistency and stability in different regions. More than 50 percent of human food is supplied from cereals, and rice is a cereal that has a high crop after wheat, but more than wheat and others in terms of energy production per hectare Cereals are important. By using the GGE biplot method, by using multivariate methods, in addition to proper data analysis, the work facilitates the interpretation of the results. The aim of this study was to evaluate the stability of the lakes by using GGE biplot analysis and selecting and introducing superior lanes for stability and response in underwater stress conditions and flooding.

In this experiment, the eight lines with the control cultivar of the region and IR29 cultivar during 2014 and 2015 with the desirable qualitative and qualitative characteristics and suitable growth period in a completely randomized block design with three replications in two regions of Gonbad Kavous and Ali-Abad were cultivated. Ten plants of 15 cultivated plants were randomly selected and separated from the soil at a depth of 50 cm. After removing the bushes from the soil using the shovelomics method, the plants were first immersed in water for seven days. Then the root and part of the air organs were separated. To record the root characteristics, each root of the plant is separated and the number of roots is less than 5 cm, the number of roots is 7-6 cm, the number of roots between 20-8 cm, the number of roots 21-30 cm and the number of roots greater than 30 cm, root volume and root dry weight were measured. Using the aerial parts, related traits such as panicle number, plant height, stem weight, straw weight, panicle length, number of filled grains, weight of grains and cluster number were recorded.

The results of analysis of variance showed that the difference between locations for days to days of traits, number of roots, total length of roots, root number between 7 to 20 cm, stem weight, panicle weight, root dry weight, straw weight and seed number Poke was significant, and the difference between years was significant for number of pancakes, root number was significant. Comparison of mean of studied sites and years showed that grain yield per hectare had no significant difference, but the mean comparison of this trait in terms of waterlogging and stress conditions indicated that flooding conditions had a higher yield than tension. Separation of the interaction of location × planting time × irrigation conditions with different cultivars by biplot method showed that the cultivar 87.5.103 in all states related to Aliabad city had the highest yield. In irrigation stress conditions, IR55411, IR70360, 87.5.21, IR66424 and 87.110 lines had lower yields, but in terms of flooding, IR55411, IR70360, 87.5.21, IR66424 and 87.110 lines had the highest yield, respectively. In both cases, all of the cultivars had a higher yield than IR-29

Separation of the interaction of location × planting time × irrigation conditions with different cultivars by biplot showed that cultivar 87.5.103 in all states related to Aliabad city has the highest performance. In general, the cultivar 87.5.103 among all cultivars and the floodplain dome in the first year was the best environment for all the environments in terms of day.

Lack of irrigation water resources has been identified as the most important problem in forage production. Therefore, to increase the productivity of crop production using limited water resources, it is necessary to pay attention to the cultivation of drought-tolerant crops. Sorghum has a high resistance to abiotic stresses and can perform well in comparison with other summer crops. Irrigation and fertilization are not only costly but also are of the most important factors affecting the quantity and quality of forage crops. Therefore, the present study was conducted to evaluate the effects of different levels of drought stress and nitrogen fertilizer on the sorghum forage yield and quality, and water use efficiency.

This study was conducted as split-plots based on a randomized complete block design with three replications in Karaj, Iran, during the 2018 growing season. Drought stress at three levels (no-stress, moderate and severe stress; including the supply of 100, 75, and 50% soil moisture deficit, respectively) as the main factor and nitrogen fertilizer application from urea source at four levels (0, 150, 300, and 450 kg ha-1) as the sub-factor were evaluated. In all experimental treatments, nitrogen fertilizer was applied in two equal parts, at planting and 5-6 leaf stage. In the present study, drip tape irrigation approach was applied (with a diameter of 16 mm and drip distance of 10 cm). Irrigation cycle was considered constant for all plots and different levels of irrigation water were applied. In order to properly establish the sorghum crops, deficit irrigation regimes were started after 2-4 leaf stage. Sorghum forage was harvested at the milky-dough stage. Data were subjected to two-way analysis of variance (ANOVA) and the difference between treatment means was separated using LSD test. A significance level of 95% was applied by GLM procedure of SAS 9.1.

The results of ANOVA showed that the main effect of drought stress and nitrogen fertilizer on the forage yield, irrigation water use efficiency (IWUE), plant height, and quality characteristics of sorghum forage (except hemicellulose) was significant (p≤0.01). Also, the interaction effect of drought stress × nitrogen fertilizer on the forage yield, IWUE, plant height, and crude protein content at the probability level of 1%, and on other quality characteristics of sorghum forage (except hemicellulose) at the probability level of 5% was significant. The highest dry-matter and protein yield (40.03 and 3.48 t ha-1, respectively) and the maximum plant height (224 cm) were obtained with full irrigation and application of 450 kg nitrogen ha-1, whereas the maximum IWUE for dry matter and protein production (6.793 and 0.672 kg m-3, respectively) was obtained under moderate stress and with the application of 450 kg nitrogen ha-1. By increasing the nitrogen fertilizer application from 0 to 450 kg ha-1 under full irrigation, moderate stress, and severe stress conditions, the dry matter yield increased by 167, 181 and 101%, respectively, protein yield increased by 238, 284 and 174%, respectively, forage protein content increased by 27, 36 and 39%, respectively, and relative feed value increased by 8, 6 and -2%, respectively. Overall, in order to achieve the maximum quantity and quality of forage and the highest water use efficiency in full irrigation and moderate drought stress conditions, application of 450 kg nitrogen ha-1, and in severe stress conditions, application of 300 kg nitrogen ha-1 can be recommended.

Generally, the results illustrated that the treatment of moderate drought stress (supply of 75% soil moisture deficit) with the application of 450 kg nitrogen ha-1, along with saving water and producing high forage yield, among the studied treatments resulted in the highest water use efficiency, DMD, NEL, and RFV, and the minimum ADF and NDF, can be recommended as the superior treatment for sorghum forage. In case of severe limitation of irrigation water resources, supply of 50% soil moisture deficit (severe drought stress) along with application of 300 kg nitrogen ha-1 can be recommended.

In confectionary sunflower cultivation, drought stress at the stage of vegetative growth and plant density are two important variables that determine grain yield. In order to increase the 1000-seed weight and marketability of sunflower seeds, farmers usually consider plant density less than oily sunflower, and on the other hand, for more root growth and dormancy resistance due to large heads, in the vegetative growth stage of sunflower they bring drought stress to the sunflower farm. In some regions of Kermanshah province, confectionary sunflower (local cultivar Songhori) is cultivated with very low density (1-3 plants per square meter). On the other hand, farmers, based on their experiences, in the vegetative growth stage (2-6 leaves), cut off the field irrigation, and this watering interruption may take 30-45 days. The purpose of stopping irrigation in such conditions is to grow more roots and prevent lodgings of plants due to the weight of the head. In the present study, the effect of cutting irrigation at vegetative stage and plant density on yield and other agronomic characteristics of local confectionary sunflower was investigated to identify the most appropriate treatments.

The present study was conducted using split plot experiment based on randomized complete block design with three replications in the farmers' farm of Kermanshah province in 2016. Drought stress was as the main factor at three levels including severe stress, moderate stress and non-stress. The sub-factor was three levels of plant density with changes in plant space on 60 cm planting rows in the form of 20, 40 and 60 cm. Important agronomic traits including number of days to star, number of days to full flowering, stem diameter, plant height, number of leaves, leaf area, head diameter, percentage of hollow, number of seeds per head, 1000 seed weight and yield were measured according to Schneider and Miller (1981). In order to measure the grain yield of each plot, the middle row plants were harvested after removing the marginal plants (one row and one plant from the beginning and end of each plot) and the grain yield was measured after threshing. Based on the harvested area, it was converted to kilograms per hectare. In order to statistical analysis, SAS Ver 9.1 statistical software was used to analyze the variance and the means of treatments was compared by Duncan’s multiple range test.

The results of variance analysis showed that drought stress significantly reduced plant height, days to maturity, seeds per head and stem diameter and increased days to flowering. Effect of Density was significant on all studied traits except plant height and number of leaves. While increasing density, stem diameter, head diameter, number and weight of seeds per head and 1000-seed weight was decreased and the hollow percentage of head, the number of days to flowering was increased. Mean comparison of data showed that grain yield under severe and non-stress condition was 2749 and 4543 kg ha-1, respectively. The highest and the lowest grain yield was belonged to plant spacing of 40 cm and 20 cm with 4599 and 3538 kg ha-1, respectively.Given the water crisis in Iran, the real value of water consumption should be considered and water loss should be prevented by using different methods in crop production. According to the mean grain yield, it can be seen that the average yield of mild drought stress (two less irrigations) is slightly different from the average yield in non-stress irrigation. The two removed irrigations in the mild stress treatment coincide with the time of grain filling of crops such as wheat, barley and canola or the cultivation of some spring crops such as corn. Irrigation in these stages is important in the grain yield of these plants. So by eliminating two irrigations after the establishment of the sunflower, the saved water can be used to irrigate other crops. On the other hand, low and high density treatments both had lower grain yield than intermediate density treatment. Plant spacing of 40 cm with high 1000-seed weight had higher grain yield than plant spacing of 20 and 60 cm, so that a plant distance of 40 cm can be recommended in confectionary sunflower. It can also be recommended that, after the establishment of the sunflower plant, by eliminating two irrigations before reproductive growth, without effective reduction of grain yield, water resources can be used for other crops such as wheat, barley and canola.

Quinoa is a pseudo cereal from Amaranthaceae family, which is currently considered as a suitable alternative for plants with high water consumption due to its high nutritional value and stresses tolerance, especially drought and salinity. Meanwhile, reduction in crop yield caused by weeds competing for water, light and nutrients is well known. Hence, a study was conducted in Karaj to investigate the competitive capacity of quinoa with weeds under normal irrigation and drought stress and also to determine the required time for weed control. The experiment was arranged in split plot randomized complete block design with four replications consisted of irrigation levels (60, 80 and 100 mm evaporation from the evaporation pan) as main plots and weed control levels (0, 7, 14, 28 days of control and control in all seasons) as subplots. The highest quinoa grain (331 g/m2) and biological yields (1262 g/m2) were obtained under normal irrigation in weeds free treatment. Also, the lowest grain and biological yields were 139 and 723 g/m2, respectively that obtained under high drought stress in weeds infestation during growing season. In one month weeds free treatment under medium drought stress, grain and biological yields were 290 and 1010.25 g/m2, which show that despite the competitive potency of summer weeds, quinoa has good competitiveness in drought stress, and with one month of weed control, can achieve performance close to full control. In logistic model fitting to the grain yield, the maximum and minimum values of y0 and a, i.e. upper and lower limits, were observed in normal irrigation and high drought stress, respectively; although, the maximum and minimum values of GDD50 were obtained in high drought stress and normal irrigation, respectively.

In order to investigate the quantitative and qualitative response of three sesame cultivars (Sesamum indicum L.) to different irrigation and fertilizer treatments, an experiment was conducted in the research farm of Karaj Seed and Plant Breeding Institute during 2016 and 2017. The experiment was performed as split-factorial plots in a randomized complete block design with three replications. Irrigation treatments at two levels including low irrigation regime (irrigation after 80% of usable soil moisture) and full irrigation (irrigation after 40% of usable soil moisture) in main and factorial plots with different amounts of nitrogen (0, 60 and 120 kg N ha-1) and sesame cultivars (Oltan, Dashtestan 2 and Naz single-branched) were placed in subplots. The results showed that in full irrigation conditions, application of 120 kg N ha-1 increased sesame seed yield by 83% compared to non-application. In contrast, this increase in yield in response to the application of nitrogen in low irrigation treatment was 40%. In general, the results showed that in full irrigation treatment, the use of nitrogen fertilizer for all three cultivars can be justified. Maximum grain yield was obtained in Oltan (1106 kg ha-1), Dashtestan 2 (1012 kg ha-1) and Naz single-branched (634 kg ha-1) cultivars with 115, 117 and 100 kg N ha-1, respectively. In contrast, in conditions of low irrigation, in none of the cultivars, grain yield higher than 500 kg N ha-1 was not achieved even with high amounts of nitrogen (60 and 120 kg N ha-1).

Mung bean (Vigna radiata L.) is native to India and its seeds are rich in phosphorus and protein. Drought is one of the most important limiting agents of plant production. Carbohydrate metabolism and the process of dry matter distribution is disrupted by limitation of carbon stabilization due to stomata closure and reduction of photosynthesis under drought stress. Potassium is an essential nutrient and the most abundant cation that it has a major role in plant growth and almost all related activities. The presence of potassium enhanced the synthesis of hydrocarbons and proteins, which results in amplification of plant tolerance to drought stress.

Experiment was performed at Agricultural Research Institute, in 2017-2018 to study the yield and nutritive value of mung bean. This research was conducted as split plot based on a randomized complete block design with three replications. Main plot was drought stress consist of 60, 90 and 120 mm evaporation from the A class pan and sub plot was including 0, 85, 170 and 255 kg.ha-1 potassium sulfate fertilizer. The characteristics plant height, biological yield, seed yield, insoluble fiber in neutral detergent, insoluble fiber in acid detergent, water soluble carbohydrate, crude protein and dry matter digestibility were measured. The samples nitrogen content was estimated by Kjeldahl set and it was multiplied by the protein coefficient 6.25 and the crude protein percentage was calculated. Van Soest method was used for measuring of insoluble fiber in neutral detergent and insoluble fiber in acid detergent. Ethanol was utilized to measure soluble sugars by sulfuric acid method. The percentage of digestible dry matter was estimated according to Equation (1).DMD= 88.9 - (0.779×ADF%) (1) Variance analysis of data was carried out by MSTAT-C software and the comparison of the means was done with Duncan's multiple range test at the 5% probability level.

The results showed that drought stress treatment on all mung bean plant characteristics was significance at 1% level. The effect of sulfate potassium fertilizer on plant height, biological yield, seed yield, insoluble fiber in acid detergent, water soluble carbohydrate, crude protein and dry matter digestibility at 1% significance level and on insoluble fiber in neutral detergent were significant at 5% level. The interaction effect of drought stress and potassium sulfate fertilizer on Plant height, biological yield, insoluble fiber in neutral detergent, insoluble fiber in acid detergent, water soluble carbohydrate, crude protein and dry matter digestibility at 1% significance level and on seed yield were significant at 5% level. The results showed that in the control irrigation + application of potassium sulfate fertilizer (170 kg.ha-1) compared to the control potassium treatment, plant height and biological yield increased by 37.9% and 89.6%, respectively. In the control irrigation + application of potassium sulfate fertilizer (170 kg.ha-1) compared to the control potassium treatment, dry matter digestibility increased by 30.12% and insoluble fiber in neutral detergent and insoluble fiber in acid detergent decreased by 44.3% and 43.8%, respectively. The most amount of water soluble carbohydrate (18.3%) in 120 mm evaporation from A class pan and the highest value of crude protein (22.8%) in 90 mm evaporation from A class pan and in both characteristic application were effective 170 kg.ha-1 of potassium sulfate.

The result showed that interaction of drought stress and potassium sulfate fertilizer on quantitative and qualitative of mung bean traits was significant. Plant height and biological yield increased 37.9% and 89.6% by addition of sulfate potassium consumption from 0 to 170 kg.ha-1, respectively. Seed yield enhanced compared to control treatment (33.8%) by using of 255 kg.ha-1 potassium sulfate. Drought stress decreased dry matter digestibility and it increased crude protein, water soluble carbohydrate, insoluble fiber in neutral detergent and insoluble fiber in acid detergent. Potassium sulfate fertilizer amount 170 and 255 kg.ha-1 recommend for maintaining of yield and qualitative of mung bean in Sistan region in non-stress and drought stress conditions.

Maize is the third most important agricultural crop in the world in terms of production, That production and demand has increased by 45% in 2020 compared to 1997. Abiotic stresses in many cultivated areas of this plant have a negative impact on its production and these effects are expected to intensify in the near future.Inefficient use of water in agricultural production in arid and semi-arid regions is one of the most important factors in exacerbating the water crisis and water shortage is a serious limiting factor in agricultural production. The use of technologies to improve water use efficiency in crops is very important for sustainable crop production and food security. Deficit irrigation is a water-saving strategy that is commonly used in arid and semi-arid regions and leads to increased water efficiency. According to studies, Deficit irrigation can save irrigation water, maintain or increase crop production and improve its quality. One of the methods for optimizing water consumption in agriculture is the addition of moisture absorbent such as Zeolite, which by gradually providing absorbed water and nutrients to the soil, play an important role in fertility and preventing water loss. The use of zeolite, especially in sandy soils that exposed to drought stress, can improve growth and final yield by absorbing and controlling moisture release and increasing soil moisture capacity. Because of low rainfall and also limitation of water resources in Birjand region, efficient use of water in agriculture, especially in the production of important cereals such as Miaze, is very important. The aim of this study was to investigate the application of zeolite and deficit irrigation methods for optimal use of water and achieving optimum yield in Maize in this region.

In order to investigate the effect of irrigation and Zeolite on maize, a field experiment was conducted on two planting dates in 2017, factorial based on a randomized complete block design with three replications. The factors including Zeolite in two levels and deficit irrigation in eight levels include: 100% water requirement, 75% water requirement in vegetative stage with: conventional irrigation, Fixed alternate partial root-zone irrigation, nonfixed alternate partial root-zone irrigation, and 75% water requirement in total growth with Fixed alternate partial root-zone irrigation, 50% water requirement in vegetative stage with: conventional irrigation, Fixed alternate partial root-zone irrigation, nonfixed alternate partial root-zone irrigation.

Traits measured on the second date of planting had the highest value compared to the first date. Deficit Irrigation reduced the total dry weight and grain yield, but the use of zeolite improved these indicators. Total dry weight, number of grains per ear, grain yield, harvest index and water use efficiency had the highest value in irrigation control treatment and decreased with deficit irrigation, so that the lowest value in conventional irrigation treatment The basis of 50% of water requirement in the growing season was observed with 23, 26, 38, 27 and 19% reduction, respectively. Zeolite application had a favorable effect on all traits, but the effectiveness of some traits was different during planting dates, so that the rate of yield increase on the second planting date (37%) was higher than the first date (27%). The highest water use efficiency was obtained on the second planting date and Fixed alternate partial root-zone irrigation based on 75% of water requirements during the growing season and total growth with 0.7 and 7.6 due to the increase in observation, had the highest Were the amount. Although the yield decreased in deficit irrigation treatments, but due to the increase in harvest index and water use efficiency, excess water due to under-irrigation can be spent on irrigating more lands and increasing production.

One of the important goals of production in areas with water constraints is to increase the yield per unit of water. According to the results, after the control treatment, the highest harvest index was related to 75% water requirement in vegetative stage with Fixed alternate partial root-zone irrigation treatment. Also, based on water use efficiency, to 75% water requirement in vegetative stage with Fixed alternate partial root-zone irrigation and 75% water requirement in total growth with Fixed alternate partial root-zone irrigation treatments were better than other treatments with a superiority of 0.69 and 7.59% compared to the control treatment. Despite saving 19.84% of water consumption in low irrigation treatments, 50% of water requirement in the growing period, but did not get an acceptable result from this treatment (33.74% reduction in yield and 13.79% efficiency). Water consumption). It seems that the relatively severe lack of water during vegetative growth has caused serious damage to the roots of the plant, which in the later stages of growth, despite the optimal irrigation of the plant could not use the water in the root environment well. Regardless of the reduction in yield and considering the water use efficiency that was obtained in 75 water requirements treatments in the form of atmospheres and constant intermediate stacks in the vegetative period and the whole growth period, it seems that these two treatments for Execution in Birjand region should be more appropriate.

In order to investigate the effect of deficit irrigation on vegetative growth characteristics and potato tuber and the effect of foliar application of chitosan and salicylic acid on yield and physiological characteristics of experimental potatoes as a split plot in a randomized complete block design with three replications in 2019 at an agricultural reaearch station in the city of Fariman. Experimental treatments included irrigation levels (60, 80 and 100% water requirement) and foliar application of chitosan and salicylic acid (control treatment, 2 g/l chitosan, 0.5 g/l salicylic acid and combined treatment with chitosan and salicylic acids). Irrigation levels in main plots and foliar spraying treatments were included in sub-treatments. Deficit irrigation treatments were applied 20 days after after plant emergence and at each irrigation period, and foliar application of chitosan and salicylic acid was performed in two stages during the growing season: at the flowering stage (beginning of tuber development), and at the mid-growth stage of tubers. The results showed that by reducing the irrigation volume by 20%, the same performance can be achieved with the performance in full irrigation conditions. Foliar application chitosan and salicylic acid also yielded different results. Foliar application of chitosan prevented a decrease in chlorophyll a concentration as the most important leaf photosynthetic pigment in 80% irrigation treatment. Other pigments showed similar behavior to chlorophyll a in solutions sprayed with chitosan or a combination of chitosan with salicylic acid. Proline, free phenols and soluble carbohydrates as secondary metabolites that undergo stress-induced osmotic regulation of leaf cells also had higher concentrations in chitosan foliar application at 80% irrigation treatment than their control treatment. Foliar application of chitosan and salicylic acid separately or in combination in treatments that were irrigated at 20 and 40% also maintained the concentration of glutathione peroxidase. Despite the above effects, foliar treatments could not clearly have a significant effect on glandular function.It does this by playing an important role in counteracting oxidative stress and balancing oxygen free radicals, as well as its role in protecting cell membranes, especially under stress conditions. According to the results of this experiment, it can be concluded that although these compounds have a significant role in the interaction of potato plant with deficit irrigation conditions, but the time and dose of its use requires more detailed research. Time and dose used that can compensate for the effects of stress and improve yield in deficit irrigation treatments. 

In recent years shortage of water and necessity of forage production have led to a tendency towards low-input plants such as Kochia. Kochia, that plant that, in addition to drought and salinity tolerance, have the potential to produce forage in less favorable environmental conditions. To evaluate forage yield and quality of Kochia as affected by drought stress, plant density and harvesting stage a field experiment was conducted in 2020 and 2021 at the Jupar agricultural research rtation of Kerman. The experiment was carried out as split plot factorial arrangements in randomized complete block design with three replications. Drought stress at three levels; irrigation at 50%, 70% and 90% depletion of soil available moisture were assigned to main plots and two planting density; 33.3 and 16.6 plant m-2 and two harvesting stages; vegetative growth stage (55 days after emergence) and flowering stage as factorial were randomized in sub plots. In irrigation at 50% and 90% soil available moisture depletion dry forage yield was 7.15 and 6.45 ton ha-1, respectively, however, this difference was not significant. Harvesting at the flowering stage with production of 31.30 ton ha-1 of fresh forage and 8.96 ton ha-1 of dry forage was significantly superior in comparison with other treatments. The highest amount of forage protein (10.94%), and the lowest amount of NDF (%50.6) and ADF (%33.8) were obtained in the severe drought stress (90% depletion of soil available moisture). Harvesting at the flowering stage had lower protein and higher NDF than vegetative growth stage. The results of this study indicated that it is possible to produce 4.5 ton ha-1 of dry forage by harvesting at vegetative growth stage and 8.5 t ha-1 of dry forage at the flowering stage by application of irrigation at 70% to 90% soil available moisture depletion.

Quinoa is a plant that has received worldwide attention due to its ability to grow in different stresses. The seed protein content of this plant is higher than seeds and its protein quality is better than seeds and legumes. It is rich in the amino acids lysine, globulin, which makes it suitable for patients with celiac disease. These issues have led the food and agriculture organization of the United Nations (FAO) to prioritize its development, especially in countries facing environmental tensions.

An experiment was conducted during the two cropping years of 2019-20 as split plot in a randomized complete block design with three replications in the academic center for education, culture, and research (ACECR), Birjand, IR Iran in 2019 and 2020. The main factor was irrigation regimes at three levels (100% of reference evapotranspiration (ET0) (control), 65% of reference evapotranspiration, and 30% of reference evapotranspiration; the secondary factor was fertilizer levels at six levels (control, manure, vermicompost, NPK, 50% manure+ 50% NPK and 50% vermicompost+ 50% NPK). Water requirement was calculated using the FAO method using class A evaporation pan using equations 1 and 2. Then, considering the efficiency of 90% for water distribution in the field, irrigation was performed. In this method, to calculate the amount of water required by the plant, first evaporation was obtained from the daily pan evaporation (Ep) of the meteorological department and then multiplied by the pan coefficient (Kpan). The obtained value was the ET0. In this study inflorescence number per square meter, number of seed per plant, 1000 seeds weight, Chlorophyll index, leaf relative water content, seed yield and harvest index were measured.

The results showed that irrigation treatment of 30% of the reference evapotranspiration (severe stress) had a significant effect on the measured traits in both cropping years. In this treatment, seed yield decreased 38.4% and 32.6% compared to the 100% reference evapotranspiration treatment (control) in the first and second years, respectively. Also, yield and yield components were higher in integrated feeding systems than chemical and organic systems. The highest seed yield with an average of 3040.1 kg.ha-1 was obtained from 50% vermicompost+ 50% NPK application. Based on the correlation results, 1000 seed weight was one of the most important components affecting on seed yield of quinoa. In both years, with increasing the intensity of stress from 100 to 35% of reference evapotranspiration, SPAD reading showed an increasing trend. The results of trait correlation showed that there is a positive and significant correlation between harvest index and 1000 seed weight with seed yield (r = 0.74) and (r = 0.83), respectively.

According to the results of this experiment, different irrigation regimes have different effects on quinoa growth. It is concluded that in quinoa, the dry matter decreases with increasing drought stress. In compared to optimal irrigation treatment (100% of evapotranspiration), moderate and severe stress were significant decreased the number of fertile lateral branches per plant, inflorescence number per m2, number of seeds per plant, 1000 seed weight, Chlorophyll index and seed yield treatments. Also, there was not a significant difference in seed yield between mild stress (65% of reference evapotranspiration) and control. The quinoa response to fertilizer application under enough irrigation was almost constant.

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.

Drought is undoubtedly one of the most important environmental stresses limiting the productivity of crop plants around the world. An optimal partitioning of dry matter between root and shoot, therefore is of crucial importance for crop yield under drought stress. Deficit irrigation strategy and planting crops with low water requirements and low expectations, for example, Kochia is very important under drought stress. Kochia is a salt- and drought-tolerant species that can be grown on drought soils, yielding fodder in quantities approaching that produced by alfalfa. The aim of this greenhouse study was investigating root and shoot growth of Kochia under drought stress conditions.

To study the effects of drought stress on root and shoot growth of kochia, a pot experiment was carried out as completely randomized design with three replications in University of Ferdowsi in 2013. There were 9 treatments included control (no stress) (NS-NS=100% field capacity (FC)), moderate drought stress (70% FC) during the vegetative phase (MS-NS), severe drought stress (30% FC) during the vegetative phase (SS-NS), moderate drought stress during the reproductive phase (NS-MS), severe drought stress during the reproductive phase (NS-SS), moderate drought stress during the vegetative phase and severe drought stress during the reproductive phase (MS-SS), severe drought stress during the vegetative phase and moderate drought stress during the reproductive phase (SS-MS), moderate drought stress during total growth period (MS-MS) and severe drought stress during total growth period (SS-SS). At the beginning of anthesis, plant height and branch number were recorded. Then plants were harvested and leaves, stems, and roots were separated. The fresh weight of the organs was recorded. Root volume was measured. Leaf area measured using a leaf area meter (LI-COR model) and root area was measured by Atkinson method. Then, leaves, stems, and roots dried in an oven at 75°C for 48 hours until mass reached and dry weight was recorded. For statistical analysis, analysis of variance (ANOVA) and LSD test were performed using SAS ver. 9.1 software.

Results showed that the highest and lowest plant height, leaf area, leaf, stem and total fresh and dry weight observed in control and severe drought stress during growth period, respectively. Significance of traits related to plant aerial parts due to morphological changes of root plants, which is actually a plant response to drought stress. Also, effect of drought stress was significant on root length, area and volume, fresh and dry weight, root length ratio to plant height. The highest and lowest of these traits were observed in control and severe drought stress during growth period, respectively. Drought stress thereby mostly reduced plant height and increased at least root length, leading to higher root/shoot ratio. Most importantly, the length of root was greater in the moderate drought-treated plants than the control plants at the end of the drought and recovery periods. Number of lateral branches and root dry weight/shoot dry weight ratio did not differ significantly with control. Generally, root and shoot growth under drought stress conditions is reduced that the amount of reduction depends on the growth stage of the plant, intensity and duration of the stress.

Finally, this study showed that the maximum amount of Kochia forage was obtained when the water is 100% FC to increase the number and size of the cells and, consequently, increase the yield. However, Kochia forage decreased 19% by decreasing 30% of irrigation water in treatments of moderate stress during total growth period in compared to the control plants. In addition to saving water, more land can be cultivated.

A prerequisite to model crop growth is an appropriate quantification of crop canopy structure in response to management and environmental conditions. Under water stress, the light distributions over canopy depth are more complicated because water stress affects not only appearance and elongation of leaves, but also morphological aspects of leaf positioning, leaf angle and azimuth angle (Archontoulis et al., 2011). Water stress reduces RUE by preventing effective photosynthesis for growth due to lower intercepted PAR as a result of reduced leaf area and leaf rolling or wilting (Wilson and Jamieson, 1985; Xianshi et al., 1998; Ngugi et al., 2013).We devised a two-year field experiment under different irrigation regimes at the two stage growths tomato with the aims of quantifying and describing the response of canopy light extinction coefficient, radiation use efficiencies, leaf area index and yield to reduced water at vegetative and reproductive stages of tomato in order to obtaining the best yield.

A field experiment was conducted over two consecutive seasons (2016-2017) in the experimental field of Ferdowsi University of Mashhad located in Khorasan Razavi province, North East of Iran. The experiment was laid out in a split plot design with different irrigation regimes at the reproductive and at the vegetative stage as the main and subplot factors, replicated thrice. The following experimental factors were studied: three irrigation regimes (100= 100% of water requirement, 75= 75% of water requirement, 50= 50% of water requirement) and two crop growth stages (V= vegetative stage and R= Reproductive stage). The drip irrigation method was used for irrigation. The tomato water requirement was calculated using CROPWAT 8.0 software. The irrigation water was supplied based on total gross irrigation and obtained irrigation schedule of CROPWAT. In the both growing seasons, plant growth and physiological parameters were assessed in two weekly intervals on two plants per plot starting 45 days after transplanting (DAT) up to 145 DAT.

Leaf area index (LAI) of tomato varied between irrigation regimes. According to ANOVA, the treatments had a significant effect on maximum LAI in both years (Table 5).The fraction of PAR intercepted by tomato canopy, measured in two years of study, increased from a few days after transplanting (May) onwards, reaching its maximum value in mid-August (around 100 DAT) in all treatments and later on decreased with progress of season till final measurement except 75V-100R and 50V-100R where the fraction of intercepted PAR raised up to the end of growing season (Fig. 5).As shown in Fig. 4, with increasing LAI, the transmitted fraction of radiation through the canopy decreased exponentially in all treatments. The highest and lowest k value was recorded by full irrigation treatment with 0.69 and 50V-50R treatment with 0.41, respectively. k values were strongly variable among different irrigation regimes.RUE altered according to amount of water applied at different growth stages. In this research, RUE values ranged from 0.38 to 0.9 g MJ-1. However, applying irrigation during vegetative stages could accelerate increase in leaf area, light interception and photosynthesis (Comas et al., 2019) and, thus, improve RUE.Timing of water stress had a significant effect (p < 0.01) on total fresh and dry fruit yield in both years of the experiment (Table 6). In general, tomato yield increased as the amount of irrigation water increased, however it was severely affected by timing applied irrigation. In 2016 and 2017 total fresh fruit approached 99.81 and 101.01 t ha-1 under full irrigation (100V-100R), significantly greater than that produced under full deficit irrigation (50V-50R) with 22.2 and 15.66 t ha-1, respectively (Fig. 7).

The experiment results clearly indicate adverse effect of water shortage on tomato yield, so that the highest fresh yield was obtained with full irrigation. However, the results suggest that this adverse effect can be reduced by a proper irrigation management at different growth stages. We showed that the effect of water provided at sensitive growth stage on the productivity of tomato was largely due to the positive effect of water apply on RUE.

In order to investigate the effect of different methods, levels and salinity of irrigation water ‎on cotton, a two-year experiment was carried out‏ ‏at the Hashemabad Cotton Research Station ‎in Gorgan city.‎‏ ‏The experiment was performed in a randomized complete block design with ‎three replications. So, four salinity levels of irrigation water (1, 4, 8, 12 dS/m) as main factors, ‎four different levels of irrigation water‏ ‏‎(33, 66, 100 and 133% of water requirements) was ‎considered as the first factor and two irrigation methods (complete irrigation and Partial Root ‎Dry irrigation/PRD) were considered as the second factor. The results showed that compared ‎to control, cotton yield decreased by 41%, 22% and 19%, in 12, 8 and 4 dS/m salinity, ‎respectively. The water use efficiency was reduced at rate of 30, 18 and 16 percent. As the ‎salinity of irrigation water increased, the average weight of the boll, fiber index, earliness and ‎the fibers decreased significantly. As the moisture level increased, the yield of cotton, average ‎boll weight, the number of seed in a boll and the number of bolls increased significantly. In ‎additional the water use efficiency of the 133, 100 and 66% treatments compared to 33 ‎percent decreased by 32, 16 and 10 percent,‎‏ ‏respectively. The cotton yield under133, 100 and ‎‎66% treatments decreased by 32%, 16% and 10%, respectively, compared to the 33% of the ‎water requirement. Although PRD reduced crop yields by 15 percent compared to full ‎irrigation treatment, but the water use efficiency increased by 36%.‎‎‎‎‎‎

Quinoa plant (Chenopodium quinoa Willd) is a grain- like crop with high nutritional values and resistant to abiotic stresses such as drought and salinity stress. Drought stress is one of major stresses, which had the undesirable effects on qualitative and quantitative yield of crops in arid and semi-arid regions of the world. On the other hand, Jasmonate (Jasmonic acid), are a new plant growth regulator that plays an important role in increase the resistance of plants to environmental stresses such as drought stress. That's why this experiment aims to investigate the impact of drought stress and foliar application Jasmonic acid on yield and some agronomic and physiologic characteristics of Quinoa cultivars.

This experiment was carried out in split factorial design based on randomized complete block design with three replications in Kerman agricultural research and education center (Joupar station) during 2018. The main factor was included non-stress (normal irrigation) and drought stress (based on 60% and 90% of usable soil moisture discharge) and foliar application of JA in three levels (0, 1 and 2 mg/l) and varieties (Giza1, Titicaca, Q29) as factorial arranged in sub factor. The measured traits were seed yield, inflorescence number in plant, seed 1000 weight, biological yield, plant height, harvest index, relative water content and chlorophyll index.

The results showed that drought stress reduced the seed yield and some agronomic and physiologic traits of Quinoa.  The application of JA, especially concentration of 2 mg/L improved these traits compared to the control treatments. The highest seed yield and biological yield were obtained from interaction of normal irrigation and 2 mg/l JA  and Titicaca cultivar by 3316 and 13265 kg/ha, respectively. The lowest seed yield and biological yield related to interaction of drought stress and non-application of JA and Giza1 cultivar by 1682 and 7733 kg/ha, respectively. The highest plant height was achieved from the interaction of Titicaca cultivar under non-stress conditions and application of 2 mg/l JA by 142.4 cm. The highest chlorophyll leaf index (SPAD index) was observed under non stress conditions and spraying of 1 mg/l JA in Giza1 by 58.8.

According to the result of this research, it can be suggested that JA as a growth regulator, can increase seed yield and productivity of quinoa cultivars, especially Titicaca cultivar through the reducing the negative effect of drought stress and improving plant growth.