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To identify the fungi associated with foot and root rot of wheat in the Khuzestan province, diseased samples were collected at all growth stages in three growing seasons of 2004-2007. Pieces of infected parts of the root and foot were surface sterilized and cultured on acidic and non acidic PDA media. One hundred and fifteen isolates were obtained and on the basis of macroscopic and microscopic characters and valid keys were identified as Fusarium solani, F. equiseti, F. moniliforme, F. subglutinans, F. sambucinum, F. culmorum, F. proliferatum, F. pseudograminearum, F. longipes, F. avenacium, F. nygamai, F. semitectum, F. lateritium, Rhizoctonia solani, Bipolaris sorokiniana and Pythium sp. F. equiseti, F. solani and F. culmorum with occurrence frequencies of 16.07, 16.07 and 12.5 % respectively were more frequent than all other species. Results of Pathogenicity tests indicated that F. pseudograminearum and F.culmorum were the main fungi associated with wheat root and crown rot disease in khuzestan while other Fusarium spp. such as F. equiseti are probably aggravated by moisture stress at different growth stages of crop due to poor irrigation management. Rhizoctonia solani with occurrence frequency of 8.03 % in some regions such as Ahvaz, Shoush, Shoushtar and Baghmalek was important agent of crown and root rot of wheat second to Fusarium species. Bipolaris sorokiniana and Pythium sp also caused crown and root rot but with less frequency percent.  

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Current assimilation, as a source of carbon for grain filling in cereals, may be limited for normal grain filling under Mediterranean climate. In such conditions reserves accu-mulated before anthesis play an important role in grain growth, but the extent of their contribution depends on prevailing environmental conditions. The experiment described here was carried out to determine the effects of different levels of water stress on dry mat-ter and nitrogen accumulation and their remobilization from the shoot to the grain. The pot experiment was conducted in the glasshouse using two wheat cultivars (Sun 92A and Vasco) differing in yield and protein content. The plants were subjected to water stress at 10 days after anthesis (daa). The following treatments were established: not watered (se-vere stress), medium stress (-2 Mpa water potentional of the Flag leaf), mild stress (-1 Mpa water optional of the Flag leaf), divided root and control. Results indicated that the dry matter and N content of vegetative organs and its concentration were greater at 24 daa than at maturity under all conditions. Water stress during the post anthesis period was unfavorable to a high assimilation rate, so yield was determined to a great extent by the availability of water and the behavior of the cultivars related to shoot reserve remo-bilization during the grain filling period.

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Pepper plant Capsicum annuum L. has great nutritional value and many pharmaceutical properties but its sensitivity to pests such as Aphis gossypii Glover, especially in drought stress conditions, has limited its production. To evaluate the effect of drought stress on the population and damage rate of this pest in greenhouse condition, four moisture treatments including; full irrigation, 15, 30 and 45 percent of water deficit, and four treatments with different amounts of super absorbent polymer (SAP) containing 2, 4, 6 and 8 g per pot were separately performed in completely randomized design. Four weeks after applying drought stress, the pots were moved near the aphid sources. Density of aphids was examined after one month of infestation, and the plant growth characteristics after two months. It was found that the increase in severe drought stress (45% DI₄₅) significantly raised the population of this pest and remarkably decreased plant growth rate and yield. However, the low stress of drought (15% DI₁₅) not only caused relative reduction of insect’s population, but also saved water consumption and increased crop yield. However, the insect population was elevated as a result of increase in the amount of irrigation. Although the excessive use of SAP (8 g) increased the aphid population, the current experiment showed the use of 4 and 6 g of super absorbents could minimize the irrigation stress, decrease the pest population and improve yield of the plants by retaining the moisture in drought conditions.

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Introduction
The land of Iran is located in a belt of dry and desert areas of the earth, which suffers the most unfavorable effects from climate change. Climate change is evident in the Zayandehrud basin, and its effects are evident in the decrease of rainfall and increase in temperature in recent years, as well as the continuation of droughts in the Zayandehrud watershed. With the reduction of river water flow, the allocation of water to the agricultural and environmental sectors in the middle and downstream parts has faced a problem. The need for water in this basin is high, so that during these years, the effort to obtain water in the Zayandehrud basin has entered a new arena in the form of tension, conflict, protests, and social unrest. One of the most important consequences of climate change is that it forces governments to plan inter-basin transfers. As a result of the water transfer policies without taking into account the religious rights and the environmental rights of the Zayandehrud bed and the Gavkhoni wetland, many social differences between the provinces have intensified.                                                                                                  
Methodology
In terms of its purpose, the current research is an applied research that considering the historical, geographical, economic and political importance of the area, identifies the dimensions and effects of climate change in the Zayandehrud watershed and explains how climate change can increase crisis and tension in the watershed. This can be a useful guide for planners and decision makers in the field. In terms of method and nature, this research is descriptive-analytic, and the method of data gathering procedure is based on library sources, including books, magazines, and databases.                              
Research findings
The turning of snow into rain at the source of the Zayandehrud and the increase in evaporation has led to the reduction of lands in the downstream part of the river, so that the area of "agricultural" and "pasture" lands has decreased in the middle and downstream parts. The number of wells has increased dramatically in recent years. The number of wells in the middle and downstream parts has increased significantly in this period, the average depth of the wells in the basin has increased by 4.8 meters, which is 6.65 meters in the upstream part, 5.55 meters in the middle part, and 28.28 meters in the downstream part. An average of 6 meters has been added to the depth of the wells. The increase in inter-provincial tensions, of which prominent examples were observed between Khuzestan, Isfahan and Chaharmahal Bakhtiari provinces in recent years, is one of the most important political consequences of climate change, which forces governments to plan inter-basin transfers. Isfahan farmers are the most important group protesting the critical water situation in this basin. One of the most important concerns of the people of the region and the most important cause of strikes and conflicts in recent years is the reduction of water resources and the reduction of agricultural activity. In recent years, the farmers of the region have expressed their protests in various ways, such as breaking and breaking water pipes, strikes, demonstrations and blocking the road with tractors, referring to the province and other ways. Public tension and protests regarding water supply and optimal water management for the residents of Zayandehrud Basin are not limited to the residents and beneficiaries of Zayandehrud Watershed. Hydro-political issues of the Behesht Abad water transfer project in the upper part of the Karun Basin, which has been the cause of local, regional and even national disputes between people and officials at the source and destination. This has caused social and political differences between the residents and beneficiaries of the upstream watersheds and the mentioned watersheds, and due to the ethnic differences of the watersheds, this issue has turned into an internal hydro-political crisis that has created gaps between ethnic groups. Climate change has hit the agriculture sector the most. Also, the first procedural consequence is the increase in the amount of unemployment and the immigration crisis. Immigration has led to the dispersal of kinship relations and the loss of solidarity, ethnic cohesion, and the increase of individualism and isolation, and as a result marginalization and drug addiction. The drying of Zayandehroud riverbed due to climate change has caused numerous cracks and subsidence in different areas of the watershed in Isfahan province. The depth of these cracks is very deep and in some cases they have a depth of more than 10 meters. Cracks have caused serious damages to roads and agricultural land.                                 
Conclusions
Climate change in the Zayandehrud basin is one of the factors that threaten the water resources in the basin. The climate change and decrease in rainfall and the expansion of agriculture and water-bearing industries has led to the destruction of nature and the geographical space and the lowering of the underground water level and even the transformation of permanent rivers into seasonal and seasonal into casual and dry rivers, and to compensate for this situation, the water transfer policy. This approach has caused political and security tensions in this region. Among the hydro-political issues of the water transfer projects in the mentioned catchment basin and its negative social-political consequences can be the intensification of local and regional conflicts and divergences, jeopardizing local and regional security, political activism of people and officials, ethnic diversity and political and regional sensitivities. One of the factors that play a basic role in creating negative political activism caused by water transfer is the strengthening of political regionalism, which itself is caused by weak management policies. This leads to the formulation of "negative hydro-politics" on a national and regional scale, and in turn has negative effects on local, regional and even national security issues.

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The performance of different yield loss models from an exponential family was evaluated in safflower-redroot pigweed systems in two field experiments conducted during 2007 and 2008 growing seasons at the research field of Agricultural College of Shiraz University, Iran. The yield loss of safflower was recorded as relative yield loss in experimental plots laid out in split plot design with three replicates. Three different irrigation treatments were allocated to the main plots and consisted of full irrigation or 100% field capacity (FC), 75% FC, and 50% FC, while five weed densities (0, 3, 6, 9, and 12 weeds m-2) were assigned to the sub-plots The Logistic and Gompertz models and a user defined Power-Exponential model were fitted to the data to relate crop yield loss to the weed densities under different water stress conditions. The Power-Exponential model was chosen as the best fit to the data with statistically acceptable model diagnostics. Logistic and Gompertz models showed good fit to the observed data, but underestimated the yield loss under three levels of irrigation. Model performance in all cases was influenced by water stress as models generally showed greater constant and systematic biases under severe water stress (50% FC). Model parameters were used to explain the impact of water stress in crop/weed system. The exponential family models globally performed better over common empirical models such as Spitters, Kropff and Lotz and Cousens models.

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Zagros (drought tolerant) and Pishtaz (drought susceptible) cultivars were classified on the basis of shoot dry weight and were used as plant material in this study. Total chlorophyll, carotenoids, antocyanins, proline, soluble sugar contents, lipid peroxidation, antioxidant enzyme activities and protein patterns were determined. Seedlings of wheat genotypes were grown in nutrient solution cultures under 16 h d^-1 period at room temperature. With the decrease in osmotic potential, total chlorophyll initially increased but then decreased in the tolerant cultivar. The amount of total carotenoids and antocyanins in both cultivars increased in response to drought stress. However, the increase was only significant (P< 0.05) at some osmotic potentials. The increase was more pronounced in the tolerant cultivar. Soluble sugars and proline increased significantly in both cultivars, but were higher in the tolerant one. The sensitive cultivar showed higher rates of lipid peroxidation as compared to the tolerant cultivar. Antioxidant enzymes activities increased with the decrease in osmotic potential in both cultivars. The tolerant cultivar exhibited a higher antioxidant activity compared to the sensitive one. SDS-PAGE showed new protein bands under water stress. These results indicated that proline, soluble sugars contents and antioxidant enzyme activities are part of the defense mechanisms which confer water deficit tolerance to wheat cultivars. APX= Ascorbate peroxidase; CAT= Catalase; GR= Glutathione reductase; MDA= Malondialdehyde; ROS= Reactive oxygen species, SOD= Superoxide dismutase.

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Field experiments were conducted to investigate the effects of sowing dates and irrigation on seed quality of a spring-type safflower cultivar, in Karaj-Iran, during 2008 and 2009 growing seasons. A split plot design based on a randomized complete block layout with three replications was used in which sowing dates and irrigation treatments comprised the main plot and sub-plot, respectively. The results showed the highest oil yield, oil content, protein yield, and linoleic acid content of safflower seed for sowing date of 19^th of April and under non-water stress conditions. The highest seed protein, oleic acid, and palmitic acid contents were obtained for sowing dates of May 5^th and 20^th along with ceasing irrigation at heading, flowering, and seed filling stages, respectively. Under arid and semiarid Mediterranean conditions prevailing in Karaj, late sowing date led to a greater simultaneity of reproductive stages and higher temperature, which made the negative effect of water stress more prominent than in the early sowing dates.

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Within the context of climate change, water scarcity is the major constraint to the viability of many crops. Thus, it is necessary to develop strategies for sustainable water management, and introduce alternative crops to sustain the viability of agro-ecosystems. The main objective of this work was to assess the performance of hemp (Cannabis sativa L.) subjected to different plant densities and irrigation. Two cultivars (Carma and Ermes) were tested at three plant densities i.e. 40,000, 20,000, and 10,000 plants ha^-1, under two irrigation regimes: i) fully irrigated with total water supply equal to 100% of ETc; and ii) deficit irrigation with 80% of ETc. The experimental design was a split-split plot with four replications per combination. At harvest, yield and its components (weight, plant height, stem diameter, and the weight of leaves and flowers relative to the stem weight) were evaluated. Also, the production of chemical compounds for medical use (terpenoids, and fatty acids Omega 3 and 6) were analyzed. The results showed that cv. Carma was the most appropriate in agricultural terms, with a yield significantly higher than cv. Ermes. In terms of plant density, 40,000 and 20,000 plants ha^-1 gave the best results for yield, without significant impact by irrigation rates. Regarding the capability of these varieties to produce relevant chemicals, cv. Ermes yielded higher amounts than did cv. Carma. This work offers a preliminary assessment for hemp cultivation in Andalusia (SW Spain), with important potential under local agro-climatic conditions.

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Water is the most limiting factor in irrigated agriculture, mainly in Mediterranean environments, as in the case of southwest Spain. In this area, almond is one of the most valuable crops due to its high drought tolerance. This work examines the crop coefficients (K_C) based on four drainage lysimeters installed in an experimental young almond orchard. Complementary, two deficit-irrigation treatments were tested: (1) moderate deficit-irrigation (M_DI), which received 100% of the crop evapotranspiration (ET_C) during the irrigation period, except during the kernel-filling stage and pre-harvest, when irrigation was 50% of ET_C; and (2) severe deficit irrigation (S_DI), in which water was applied according to the values of leaf-water potential at midday (Ψ_leaf), this being maintained at between -1.6 and -2.0 MPa. The crop’s physiological response to water stress was monitored throughout the study period by assessing the leaf-water potential (Ψ_leaf) and canopy temperature (T_C) dynamics. The K_C values changed from 0.4 at the beginning of irrigation period to a maximum of 1.1 during the maximum evaporative demand period. From this stage on, the Kc gradually decreased to 0.4 at the end of the season. In physiological terms, both Ψ_leaf and T_C showed a temporal evolution according to defined irrigation strategies. Moreover, significant relationship (r2 = 0.63, P<0.05) was obtained between Yleaf and the difference between leaf and air temperature values (AT). the difference between leaf and air temperature values; evidencing the feasibility of using T_C for water-stress management. Thus, the findings highlight the importance of local K_C to optimize water use and irrigation scheduling in almond orchards.

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The anatomical and epidermal characteristics, as well as the physiological response, of 'Colombia' ecotype cape gooseberry plants treated or untreated with foliar applications of kaolin at 2 irrigation levels (well-irrigated plants vs. water-stressed plants) were evaluated. Relative Water Content (RWC), stomatal density, and chlorophyll index were reduced under water stress. Water stress increased leaf temperature and trichome density. In water-stressed plants, the foliar application of kaolin decreased transpiration rates, leaf temperature, trichome density, and leaf thickness. Kaolin also improved the plant height, total plant dry mass, water-use efficiency, and increased stomatal density in water-stressed plants. The results suggest that kaolin may be a useful tool to mitigate the negative effects of water stress and may improve the efficient use of water in cape gooseberry plants with especial water conditions.

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One of the most important problems in the field of cultivation and production of garden products, especially oranges, is the irrigation of the plant and its amount. Iran has many challenges in growing and producing orange fruit due to its diverse climate and being located in a dry region.  Based on, in the present study, the effect of water stress and storage time of the product in cold storage (fruits of Thomson Novell cultivar after harvest in cold storage at 5 ° C and 85% humidity for 90 days and Valencia oranges at 20 ° C for Stored for 30 days) on chemical properties (antioxidant activity, ascorbic acid content), physical (weight, width, length, volume, volume, weight and weight of the extract), color characteristics and sensory properties were evaluated. The physical changes of Thomson and Valencia oranges in the samples without water stress on the first day were not significantly different, although minor reduction in storage time. According to the results, the highest weight loss, extract weight, antioxidant, ascorbic acid and volume of orange varieties during storage were in samples under dehydration stress. The color components include brightness, a * and b * decreased in Thomson orange samples under water stress and during storage, but the Valencia orange but did not significant difference was observed. Sensory properties of bad taste and bitterness were higher in oranges under water stress and scored lower in terms of sensory evaluators.

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This study was conducted in field conditions to determine the response of cabbage to four different irrigation levels, from 2015 to 2016. The experiment was laid out in randomized block design. Plots were irrigated using a drip irrigation system and the irrigation interval was fixed as 4 days for all treatments. Evaporation was determined by Class-A pan. Six organic acids (ascorbic, tartaric, lactic, citric, malic and oxalic) were identified and quantified by HPLC-UV. White cabbage yields were significantly increased by water applications, but deficit irrigation produced negative results. Maximum amounts of ascorbic, lactic, tartaric and malic acids were found in the low water content treatment, while reducing sugar and total sugar increased in the full irrigation treatment. In the study, supplying different amounts of irrigation water caused changes in the growth and quality of white cabbage (Brassica oleracea L.cv. Capitata). When water stress in cabbage production exceeded more than 30%, the yield and, especially, the quality of cabbage decreased significantly. The results revealed evidence that different soil moisture content in the root depth affected the yield, organic acids, and sugar content.
 

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During the last few years, due to inadequate rainfall, Iran has faced water scarcity. This made the fertile zones including the Fars Province and especially the Marvdasht District to face many problems. Salt concentrations increase and the groundwater resources reduction in the central part of this district are currently occurring. Recently, the farmers have attempted to change the cultivation pattern by cultivation of salt-resistant plants including olive and pistachio. Therefore, in this study, interaction between salinity of the irrigation water and the water deficit on physiological growth of the olive plant (Olea europaea L.) was investigated. The experiment was conducted as a completely randomized block design for three years (2013-2015) in a 7-years-old olive grove (Roghani-Fishomi cultivar) grown in a sandy soil with planting density of 5.5×5.5 meters. Treatments included five Irrigation levels (I₁= 25%, I₂= 50%, I₃= 75%, I₄= 100%, and I₅= 125 percent of olive water requirements) and three Salinity levels of 2.2 to 7.7 dS m^-1 (S₁), incorporation of 50% well water with 50% drinking water from the local region (S₂), and pure drinking water from the region (S₃= Salinity of 0.4 to 0.85 dS m^-1) of irrigation water. Treatments were applied in a factorial arrangement, with three replications. Daily irrigation of trees was performed by drip irrigation. The results showed that in all of the three consecutive years, the highest Intrinsic Water Use Efficiency (IWUE) values were obtained in I₃S₁ (131.94, 114.14 and 96.95 by years, respectively). Also, the highest transpiration efficiency was achieved in I₃S₃ (1.24, 1.06 and 0.88 respectively). In high salinity, due to the stress applied to the olive trees, leaf water potential decreased and, consequently, the water in the leaves could not meet the existing VPD_l.a (saturation Vapor Pressure Deficit near leaf area), thus causing stomatal closure and reduction in stomatal conductance (gs). Generally, for I₁ to I₄ irrigation levels, the highest salinity effect on Transpiration Efficiency (TE) happened in S₃ salinity level.
 

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Water deficit is a major factor limiting plant productivity of fruit quantity and quality, particularly in arid and semi-arid regions of the world. The total yield, fruit physical characteristics and nutritional value of four drought tolerant tomato genotypes (KSU-TOM-102, KSU-TOM-106, KSU-TOM-107 and TL–01860) were evaluated in response to deficit irrigation (DI) under field conditions. Three levels of crop evapo-transpiration (ETc; 50%, 75% and 100%) were applied at three different growth stages (vegetative, flowering and fruiting stage) to the four tomato genotypes. Tomato genotypes differed in their responses to water deficit. Among different genotypes, KSU-TOM-102 recorded the highest average total yield (89.54 t.ha^-1) under irrigation treatment with 100% of ETc during all stages as well as 75% of ETc during the fruiting stage. But, in general, total yield decreased under water deficit. Significant (P≤0.05) differences in fruits quality characteristics exerted by irrigation water treatments, tomato genotypes and their interactions. Irrigation with water at 50% ETc at all growth stages significantly (P≤0.05)  increased vitamin C, titratable acidity, total soluble solids and total sugar contents for tomato ‘KSU-TOM-107’ followed by ‘KSU-TOM-102’. But, this increase in nutritional value was accompanied with decrease in total yields by nearly 40-50%.   KSU-TOM-102 irrigated with water at 75% ETc at fruiting stage or vegetative stage recorded 0% and 12% reduction of the total yield, respectively, while maintaining good nutritional value as compared with 100% of ETc during all stages. Therefore, these treatments can be recommended as irrigation management strategy for tomato ‘KSU-TOM-102’ production under field conditions.