سیدفرهاد صابرعلی

Aridity is a climatic characteristic that has a significant impact on many aspects of life, mainly in agriculture but also in other economic sectors. In this study, a Google Earth Engine (GEE) platform was implemented to monitor and Evaluation of two aridity indexes, such as the De Martonne aridity index, and FAO aridity index at ten stations in Razavi Khorasan province from 2000 to 2021. The University of Idaho's monthly climate data set (TerraClimate) is used to calculate monthly potential evaporation and transpiration. MODIS dataset (MOD11A1 V6.1) used to calculate temperature. The product dataset (CHIRPS) is used for calculating the monthly rainfall. Satellite data, in comparison to the aridity index calculated with ground data, is evaluated using widely accepted statistical indices such as the correlation coefficient (CC), relative bias (RBIAS), root mean squared error (RMSE), Nash–Sutcliffe model efficiency coefficient (NSE), and probability of detection (POD). The results showed that the De Martonne aridity index in Mashhad, Torbat Jam, Neishabour, Gonabad, and Golmakan stations, with a correlation coefficient in the range of 0.704-0.851, root mean square error in the range of 1.228-2.419, relative bias (negative) in the range of 0.096-0.227, Nash-Sutcliffe index in the range of 0.142-0.633, and the probability of estimation in the range of 0.773-1, was chosen as the best method of calculating the yearly aridity index. In other studied stations, the FAO method is the best. Overall, the current study's use of satellite data is appropriate and yields dependable and satisfying results because of its suitable spatiotemporal separation.

Solar radiation is one of the main inputs to crop growth models to estimate growth and yield. This study was conducted with the aim of evaluating the impact of radiation estimation accuracy by different models on the accuracy of simulating wheat evapotranspiration and yield by CSM-CERES-Wheat model in Razavi Khorasan province. The efficiency of simple models including Angstrom-Prescott, Angstrom-Prescott suggested by FAO, Hargreaves-Samani, Hargreaves-Samani suggested by FAO, Kermani, Hunt and Power have been evaluated in this study. The results of the radiation estimation for different models in the calibration stage showed that Kermani, Angstrom-Prescott calibrated, Angstrom-Prescott models with FAO recommended coefficients, Power, Hunt and Hargreaves-Samani gave the closest estimates compared to the measured radiation in Mashhad, respectively. In the validation stage of the calibrated models, it is found that the Power, Kermani, Angstrom-Prescott models had the most accurate estimation of daily radiation compared to the measured radiation in the study areas, respectively. Furthermore, the lowest difference between simulated yield and evapotranspiration of wheat using the observed radiation data and the estimated radiation data is obtained from the models of Power, calibrated Angstrom-Prescott, Angstrom-Prescott with FAO suggested coefficients and finally the Kermani, respectively. Considering the accuracy and extensive spatial coverage of the radiation data in the Power model, it is recommended to use it as the best radiation estimation method for use in the crop models.

Water shortage stress is the most important obstacle to melon cultivation in arid and semi-arid regions of Iran. Regarding to the importance of melon production in Razavi Khorasan Province, this pot study was conducted with the aim of investigating the response of melon growth to drought stress and salicylic acid application in Torbat Jam Higher Education Complex in 1401. Melon seeds were planted in the growing bags filling with field soil, and the bags were placed in the outdoors to apply the treatments. Drought stress treatment included available soil water at different levels of 85, 75, 65, 55, 45 and 35% and salicylic acid treatment at two levels of zero and one millimolar. The results showed that drought stress had a significant effect on all measured growth traits, but the effect of salicylic acid was significant only on the content of chlorophyll a and b, carotenoids and relative leaf water. Decreasing soil water to less than 7% and 65%, respectively, caused a significant decrease in chlorophyll a and chlorophyll b. Soil moisture less than 65% also caused a significant decrease in leaf area, relative leaf water content, nitrogen uptake and root and shoot dry weight. In general, for each unit of moisture reduction to less than 67% of available soil water, the amount of aerial dry matter decreased by 2.4% compared to optimal moisture conditions. According to the results of this research, the best time to irrigate Khatouni melon is when only 40% of available soil moisture has been depleted.

Water scarcity is the main natural limitation for agricultural production in arid and semi-arid regions. The aim of this study was to investigate the effect of mycorrhizal fungi and salicylic acid on yield and quality of watermelon under water stress. For this purpose, a split factorial experiment was conducted with three replications based on a randomized complete block design in two years. Irrigation treatment at three levels of receiving 100%, 80% and 60% of water requirement were placed as the main factor in the main plots. Mycorrhizal fungus in two levels (including no inoculation and soil inoculation by 20 g m-2) along with spraying of salicylic acid in three levels (including 0, 50 and 100 mg L-1) were designated to the subplots. The highest amounts of proline concentration, peroxidase and catalase enzymes activities were recorded in 60% irrigation treatment. Electrolyte leakage decreased by salicylic acid application, though in each irrigation treatment the lowest electrolyte leakage was recorded in 100 mg L-1 treatment of salicylic acid. Electrolyte leakage was significantly reduced by mycorrhizal fungi application. The highest (9.12%) and the lowest (8.08%) level of total soluble solids were recorded respectively in 80% and 100% irrigation treatments. The highest amount of TSS (9.07%) was obtained with mycorrhizal fungi. TSS was significantly increased by 6.70% and 11.20% with 50 and 100 mg L-1 salicylic acid treatments, respectively, compared to the control. The lowest fruit yield (34.76 t ha-1) was obtained when the plants were exposed to 60% irrigation treatment and no mycorrhizal fungus inoculation conditions. Fruit yield increased significantly in the presence of mycorrhizal fungi inoculation across all irrigation treatment levels, with the highest fruit yield (68.82 t ha-1) being obtained when plants were grown under 100% irrigation treatment and mycorrhizal fungi inoculation conditions. It may be concluded that using mycorrhizal fungus as a biofertilizer and salicylic acid as a plant growth regulator can reduce the harmful effects of drought stress and, hence, it can be recommended to increase the fruit yield and quality of watermelon at least in arid-semiarid conditions.

The present study was conducted to examine the changes in monthly, seasonal, and annual trends in relative humidity of 13 meteorological stations in the Razavi-Khorasan Province from the beginning of the statistical period of each station until 2021. The study area includes Dargaz, Fariman, Golmakan, Gonabad, Kashmar, Khaf, Neyshabour, Mashhad, Quchan, Sarakhs, Sabzevar, Torbat-e Jam, and Torbat-e Heydarieh counties. Parametric linear regression and the nonparametric Mann-Kendall (MK) test were used to detect trends in relative humidity. The majority of stations have shown decreasing trends at 5% significance level in relative humidity in different time scales, and only in two stations, Quchan (June, December, and autumn season) and Sarakhs (autumn season), the relative humidity showed an increasing trend at 5% significance level. A decrease in monthly mean relative humidity for six stations has been found in the range of 0.7 to 3.5 percent/decade, while an increase for Quchan station 1.9 to 2.6  percent/decade was observed. In addition, most of the studied stations have experienced a decrease in relative humidity on a seasonal and annual scale. A decrease in Seasonal mean relative humidity for six stations has been found in the range of 0.6 to 2 percent/decade, while decreases in annual mean relative humidity stations ranged from 0.9 to 1.6 percent/decade. The results of this research indicate a decreasing trend in the average monthly, annual and seasonal relative humidity during recent years.

Water and moisture in the soil is one of the main factors in determining area under cultivation and as a result production of agricultural products, which is limited in arid and semi-arid areas such as Iran, this limitation and lack of water resources affects the performance of plants and especially Medicinal plants. Using deficit irrigation methods and promoting the concept of water productivity in the production of agricultural products is a practical and common method in different parts of the world to maintain and optimally use water resources. Water productivity actually expresses the amount of product or income. It is obtained from the water consumption unit. During their growth period, plants may face many environmental stresses that have different effects on their growth and performance based on the sensitivity and growth stage of the plant. Drought stress is one of the most important factors limiting the physiological and nutritional growth of plants. It is always necessary and important to know the combination or combinations that lead to reducing the effects of drought stress in plants. Although the toxicity of selenium in high concentrations is evident on plants and it is considered a type of stress, nevertheless, the beneficial effects of its low concentrations in protecting plants against non-living stresses through almost complex mechanisms have been identified. Nowadays medicinal and aromatic plants have received a lot of attention in various fields, including agriculture and pharmaceutical industries. Peppermint plant is a herbaceous and perennial plant that is considered as a medicinal and aromatic plant and is widely used in the pharmaceutical industry. The main purpose of this research is to compare and investigate the effect of selenium in different situations of its application (Mixing with irrigation water and foliar spraying before and after applying moisture stress) on water productivity and some properties of peppermint plant )Mentha piperita L) was under Drought Stress.
For this purpose and in order to investigate the effects of drought stress and different forms of selenium application on water productivity and some characteristics of Mentha piperita L, an experiment was performed in factorial form and in a completely randomized design and in three replications on Mentha piperita L in the research greenhouse university of Torbat-e Jam. The effects of drought stress include two levels 100 (I1) and 50 (I2) percent of water requirement and the application of selenium includes four levels (no application (zero), I (Mixing with irrigation water at the rate of 5 milligrams per liter of sodium selenate (, Leafbefore (Foliar application of selenium at the rate of 5 milligrams per liter of sodium selenate before applying moisture stress) and Leafafter (Foliar application of selenium at the rate of 5 milligrams per liter of sodium selenate after applying moisture stress) was investigated. In order to properly establish the seedlings, plants were irrigated once every other day for two weeks after the transfer of rhizomes. Then the process of applying the treatments began. In this way, in the treatment of selenium mixing with irrigation water, sodium selenate at the rate of 5 milligrams per liter was mixed with irrigation water and given to the desired pots in each irrigation cycle, and moisture stress treatments were also applied at the same time. Finally, after 5 weeks of selenium treatments and moisture stress, the plant was harvested. Also, in the Leafbefore treatment, the desired pots were treated with sodium selenate (Na2SeO4) with a concentration of 5 milligrams per liter as a foliar spray solution. Foliar spraying was done three times every other day and 24 hours after the last foliar spraying, the desired pots were subjected to moisture stress for 30 days and then the plant was harvested. Also, in the Leafafter treatment, after proper establishment of seedlings, the pots were first subjected to moisture stress, and after 30 days of applying moisture stress, foliar spraying of selenium at the rate of 5 milligrams per liter of sodium selenate three times as It was done every other day and one week after spraying the plant, the plant was harvested. The results of this research showed that with the increase of drought stress level from 100% of water requirement to 50% of water requirement, fresh weight, dry weight, percentage of essential oil, plant height, number of leaves and root fresh weight Mentha piperita L decreased by 34/95%, 33/64%, 34/53%, 29/35%, 34/17% and 33/61% respectively, and water productivity increased by 30/69%. Also, in the selenium treatments including Leafbefore, Leafafter and I, compared to the absence of selenium, water productivity 66/87%, 41/79% and 29/25% respectively increased. Among the selenium treatments, the Leafbefore treatment had the highest increase in fresh weight, dry weight, water productivity, essential oil percentage, plant height and number of leaves, and treatment I had the highest increase in the root fresh weight Mentha piperita L. The results showed that selenium in the concentration used in this research increased some properties of Mentha piperita L and was effective in reducing the effects of drought stress in this plant.

The aim of this study was to investigate the interaction between planting date and the nitrogen application rate on the growth and yield of winter wheat in Torbat-e-Jam, Khorasan Razavi province. The field experiment was conducted in a randomized block design with split plot arrangements and three replications in Torbat-e-Jam, in the 2019-2020. Experimental treatments included three planting dates: 1 October, 17 October and 2 November as the main plot, and nitrogen fertilizer at levels 0 (as a control), 100, 125, 150, 175 and 200 kg nitrogen ha-1 as a subplot. Pishtaz cultivar was planted in experimental plots which included 7 planting lines with a row spacing of 15 cm and a length of 8 m. The results of the analysis of variance showed that planting date and nitrogen fertilizer application and their interaction had a significant effect on all measured traits. The results showed that the yield and yield components were the highest on 1 October, and the values of most of these traits showed a significant decrease in planting on 12 November compared to 10 October. The highest grain yield was obtained from a nitrogen application rate of 200 kg ha-1 on 1 October and 16 October, while the maximum yield was obtained with an application rate of 175 kg ha-1 on 2 November. The growth and yield response of wheat to the rate of nitrogen application decreased with a delay in planting date, and the option of planting date must be considered in order to recommend efficient fertilizer usage.

Fertilizer management is one of the most important managements to improve production and also to minimize its harmful effects on the environment. The aim of this study was to investigate the effect of optimal and conventional application of nitrogen (N), phosphorus (P) and potassium (K) on the yield of low-yielding (Deylamani and Hashemi) and high-yielding (Fajr and Shirodi) rice varieties. The experiment was conducted as a split plot in a randomized complete block design three replications at a research farms of Sari University of Agricultural Sciences and Natural Resources in 2019. In the absence of any of N, K and P fertilizers, yield of Shiroodi cultivar was 5458, 8399 and 9926 kg ha-1, respectively, and yield of Fajr cultivar was 4894, 7364 and 8903 kg ha-1, respectively. In low-yield cultivars, in the absence of any of N, K and P fertilizers, yield in Hashemi cultivar was 2969, 5134 and 4925 kg ha-1, respectively, and yield in Deylamani cultivar was 3028, 5408 and 5384 kg ha-1, respectively. Optimal application of N, P and K fertilizers caused a significant increase of 82, 65, 55 and 34% of yield in Shiroodi, Fajr, Hashemi Tarom and local Tarom cultivars, respectively, compared with the current application of these three nutrients. The results showed that a suboptimal application of nitrogen, phosphorus and potassium fertilizers is a main limiting factor for rice production, and improving the amount and split application of these fertilizers simultaneously can increase yield by 59% compared to their current application in the region.

Simulation models are suitable tools for predicting the effects of different management scenarios and selecting the most appropriate solutions in agricultural production systems. In this study, after evaluating the efficiency of the DSSAT model, the effect of water table management on rice growth and yield was investigated. The required field experiments were performed under a randomized complete block design with four irrigation treatments and three replications during a rice growing season in a research farm at the Sari Agricultural Sciences and Natural Resources University. Irrigation treatments included conventional or flooding irrigation (control) with water height of 5 cm above the soil surface (I1), water table control at soil level (I2), water table control at 5 cm below soil surface (I3) and water table control at 15 cm below soil surface (I4). During rice growing season and at harvest, leaf area index, shoot weight, plant height, number of tillers, biological yield and grain yield were measured. The data of I1 treatment were used for calibration and the data of other treatments were used for validation of the model. In both calibration and validation processes, the DSSAT model showed a good performance for predicting phenological dates, leaf area index, biological yield and grain yield. In the calibration and validation stages, root mean square error (NRMSE) values were in the range of 0.7-7.6% and 1-7.6%, respectively, and Wilmot agreement index (d) values were in the range of 0.73-0.99 and 0.82-0.99, respectively. Effects of irrigation treatments were significantly different on plant height, number of tillers per hill, leaf area index, grain yield and biological yield. Among different treatments, the highest grain yield was 5584 kg ha-1, related to the control treatment. Grain yield in I2, I3 and I4 treatments was 4.7, 4.6 and 39.2% lower than that in the control treatment, respectively. Water use efficiency in I1, I2, I3 and I4 treatments was 0.48, 0.65, 0.83 and 0.73 kg m-3, respectively. Based on the results, in order to maintain rice production while saving water, it is recommended to control the water table at a depth of 5 cm below the soil surface.

Suitable prediction of climatic parameters is considerably important for adapting to climate change and mitigating vulnerabilities in local scales. In current research, for climate change assessment, the CanESM2 model in the 5th IPCC report and Statistical down scaling model (SDSM) was used under three scenarios: RCP2.6, RCP4.5 and RCP8.5. The input data were minimum and maximum temperature and solar radiation of Gharakheil synoptic station in Ghaemshahr and NCEP data (National Environmental Prediction Center) for the base period (1984-2005). Sunshine hours were converted to solar radiation using adjusted Angstrom formula for climate condition of the north of Iran. Future climate scenarios were then developed for early-future (2011–2040), medium-future (2041-2070) and late-future (2071-2100). The results showed that during these periods, solar radiation, maximum temperature and minimum temperature will increase by 4-9 %, 5-24% and 8-34% compared to the base period. The largest increases (5.30c and 4.20c for maximum and minimum temperatures respectively, and 1.3 Mj/m2 for solar radiation) will occur during late future period under RCP8.5 scenario. Since temperature and radiation are the main affecting factors for crop growth and yield simulation, the planning is essential in order to choose the appropriate planting date to adapt to climate change in the study area

Accurate estimation of reference crop evapotranspiration (ETo) is important in hydrological studies and water resource management that can influence the planning and policies for optimal allocation of agricultural water resources. For this purpose, in the present study, sensitivity analysis was employed to evaluate the effects of the changes in meteorological parameters (vapor pressure deficit (VPD), Mean Temperature (Tmean), net solar radiation (Rn), wind speed (u) and actual vapor pressure (ea)) on reference crop evapotranspiration (ETo) within the possible range of ±20% on a daily and growing season scale. ET0 was calculated by The Food and Agriculture Organization of the United Nations (FAO) 56 Penman-Monteith approach using long-term climate data from 13 meteorological stations of Khorasan Razavi province in northeast Iran. The sensitivity analysis indicated that ETo changes positively with vapor pressure deficit, mean temperature, net solar radiation and wind speed, while it changes negatively with actual vapor pressure. Also, over the whole period, ETo was most sensitive to vapor pressure deficit (VPD), followed by mean temperature (Tmean), net solar radiation (RN), actual vapor pressure (ea) and wind speed (WS). In the the warm growing season, ETo was most sensitive to vapor pressure deficit (VPD), followed by mean temperature (Tmean), net solar radiation (RN), wind speed (WS) and actual vapor pressure (ea) while, in the cool growing season, ETo was most sensitive to vapor pressure deficit (VPD), followed by actual vapor pressure (ea), Mean Temperature (Tmean), net solar radiation (RN) and wind speed (WS). The results showed that the sensitivity of ETo in different stations and different growth periods is different. The findings of this study showed that the importance of effective parameters on the reference crop evapotranspiration (ETo) was different between the hot and cool growing season of the region, which should be considered in sustainable planning of water resources and management of agriculture in Khorasan Razavi regions for development of adaptation strategies in arid climatic conditions.

Drought is the most important stress factor that affects agricultural production in the arid and semiarid areas and reduce crop production. Iran is a country with a warm and dry climate that more than 85% of it located in arid and semi-arid areas. Improving the water use efficiency through agronomic management is one of the most effective and low cost approches for water management in the agricultural fields. The main objective of this study was to investigate the growth and yield response of kidney bean to deficit irrigation with the aim of increasing water use efficiency. In addition, the other objective of this study was to determine the desired level of nitrogen fertilizer at each level of water stress that make improve water uses efficiency.

In order to study the effect of irrigation and nitrogen fertilizer on yield and water use efficiency of kidney bean, an experiment was conducted as a randomized complete block design with a split plot arrangement of tratment in 2016 in Saveh, Iran. The deficit irrigation treatments as a main plot were irrigation at 40% of soil moisture depletion (non-stress treatment), irrigation at 50% of soil moisture deplation and at 60% of soil moisture deplation. The irrgation at 40% soil moisture depletion was considered as an acceptable moisture discharge rate for achieving maximum yield and other irrigation treatments considered as deficit irrigation. Sub-plot was included nitrogen fertilizer application rate at 0 (control), 25, 50 and 100% of maximum nitrogen requirement of dry bean plant. The middle two rows of 60 cm length were harvested for seed yield and LAI determination. At harvest time, a sub-sample of 10 plants were sampled from each plot to determine the number of pods per plantand seeds per pod.Biomass was obtained by drying plants at 70◦C. After drying and threshing, grain yield was determined.

The results showed that drought stress under irrigation after 60% soil moisture depletion decreased leaf area index, dry matter, seed number per unit area and finally kidney bean seed yield. However, mild stress treatment (50% soil moisture deplation) had a significant decrease in seed number per unit area and seed yield compared to optimal irrigation treatment. Furthermore, water use efficiency in kidney bean was increased at both levels of deficit irrigation compared to the full irrigation treatment. The results also showed that growth and yield traits and water use efficiency of kidney bean improved with nitrogen fertilizer application compare to no nitrogen application. The results also showed that the response of seed yield to nitrogen fertilizer was dependent on the amount of applied irrigation water in different irrigation regimes. At irrigation regime by 40% soil moisture depletion, seed yield of kidney bean increased by 11, 16 and 13% with nitrogen application rates of 50, 100 and 200 kg ha-1, respectively. While, seed yield was increased by 9, 14 and 10% with nitrogen application rates of 50, 100 and 200 kg ha-1, respectively, when kidney bean plants irrigated at 60% soil moisture depletion. The water use efficiency of kidney bean had no significant differences between 100 and 200 kg N ha-1. However, the N application rate less than 100 N ha-1 caused a significant reduction in water use efficiency of kidney bean plant. The regression analysis also showed that the responses of seed yield and water use efficiency to nitrogen fertilizer application rate at all irrigation levels were quadratic, and this quadratic response explaind 99 % of varion in these traits.

The results showed that the irrigation of kidney bean at 50% soil moisture depletion compared to irrigation at 40% soil moisture depletion could increase water use efficiency without any significant reduction in seed yield. The irrigation at 50% soil moisture depletion saved irrigation water about 270 m-3 ha-1 compared to the irrigation at 40% soil moisture depletion. We also concluded that the application of 50 % of maximum nitrogen requirement for bean plant could produce maximum seed yield and water use efficiency in all irrigation regimes.

One of the most fundamental processes, which influence climate and weather, both global and local scales that a fact which gives it the status of agriculture, is Evapotranspiration (ET). In irrigation and water resources management, ecosystem modelers, environmental assessment and solar energy system, accurate assessment of evapotranspiration is essential. Potential evapotranspiration (ET) has commonly applied to calculate the actual evapotranspiration, which was difficult to estimate by lysimeter measurement and water balance approach under field conditions. Until now, many methods have reported to estimating ET, however, due to the availability of the observed data, it is difficult to choose the optimal method. In this study, to determination of the best potential evapotranspiration method for the Khorasan Razavi Province, three temperature-based methods, Hargreaves–Samani (HS), Hamon (HAM) and Linacre (LIN) and five radiation-based methods, Jensen-Haise (JH), Makkink (MAK), McGuinness and Bordne (MB), Abtew (ABT), and Priestley–Taylor (PT), were compared with PM at yearly scale, using long-term (11-67 years) data from 13 meteorology stations. Indicators, viz. The correlation coefficient (CC), Relative bias (BIAS), normalized root mean squared error (NRMSE) and Relative error(Re) were used to evaluate the performance of ET estimations by the above-mentioned eight methods. The results showed that the performance of the methods in ET estimation varied among regions; ETLIN overestimated ET, while others underestimated. In Dargaz and Golmakan, ETHS yielded similar estimations to that of ETPM, while, in Torbate-jam and Khaf, ETLIN showed better performances. Also in Mashhad and Gonabad, ETHAM, in Neyshabour, ETJH and in Torbat-e Heydarieh, ETABT showed better performances. But in Fariman, Kashmar, Sabzevar, Sarakhs and Quchan, all methods showed poor performance. It indicated that ETPM is acceptable for ET simulation for the yearly timescale in these areas.    ​

Melons are vegetable crops belonging to the family Cucurbitaceae, which consists of about 118 genera and 825 species. Persian melon is one of the most important melons with high economical and nutritional values and widely cultivated in Khorasan Razavi province. Nitrogen is the main plant nutrient resources with a structural and functional roles that affect growth and yield of melon production. Regarding to the importance of melon production in Khorasan Razavi province, this study aimed to determine the required amount of nitrogen fertilizer to reach maximum melon yield and to reduce excessive nitrogen application by farmers.

A field experiment was conducted at Torbat-e Jam in 2019. The effect of five levels of nitrogen fertilizer (0, 70, 140, 210 and 280 kg ha-1) was evaluated in a randomized complete block design with three replications. The size of each individual plot was 6 by 8 m and the melon row spacing was 2 m. Melon seedlings at three-leaf stage were planted about 75 cm apart in rows, on 23 June 2019. The studied traits in the experiment included leaf chlorophyll and leaf area at fruiting stage, number of fruits per plant, average fruit weight per plant, fruit yield, percentage of soluble solids and total dry matter.

Analysis of variance showed that nitrogen fertilizer application had a significant effect on all measured traits, except soluble solids of fruits. The results also showed that nitrogen fertilizer application increased leaf area index and leaf chlorophyll content by 37 and 22%, respectively. The highest leaf chlorophyll content and leaf area index was obtained from 210 and 140 kg nitrogen fertilizer application, respectively; and more nitrogen application was not a significant increase in leaf area and chlorophyll content. The melon dry matter production increased by 42% with nitrogen fertilizer application compared to non-nitrogen fertilizer application. The highest dry matter production was obtained from 210 kg N ha-1, and more nitrogen application was not a significant increase in dry matter production. The highest amount of the produced fruit per plant and fruit weight was obtained from 280 kg N ha-1. Fruit yield increased by 41% with nitrogen application compared with no N application. Fruit yield of melon at 70, 140, 210 and 280 kg N ha-1 increased by 39, 57, 41 and 28%, respectively. The highest fruit yield (33 ton ha-1) obtained at 140 kg N ha-1, and the more nitrogen application significantly reduced melon yield.

Nitrogen application improved growth and fruit yield of melon plants. The highest quality and quantity of melon yield was achieved with application rate of 140 kg N ha-1, and application of excess nitrogen would reduce fruit yield. Nitrogen agronomic efficiency showed that fruit yield increased by 87 kg ha-1 for each unite of N application rate under the optimum nitrogen fertilizer treatment. The study of the net economic income from the use of nitrogen fertilizer showed that the growers can experience up to 50% more economic profit with the optimal application of nitrogen fertilizer.

Melon (Cucumis melo L.) is one of the most important vegetables in Cucurbitaceae family and one of the most important economic crops in the Torbat-e Jam city (Longitude: 60 ̊48', latitude: 35 ̊31', altitude: 928 m). Growth and yield of agricultural crops are affected by biotic and abiotic environmental stresses. Cold stress can be one of the most important environmental factors reducing crops yield. Cold acclimation in plant is a complex process involving many morphological, physiological and biochemical changes, including a significant reduction in tissue hydration during cold hardening. Melatonin (MEL, N-acetyl-5-methoxytryptamine) is a conserved substance, which has been discovered in all living organisms, from bacteria to mammals. MEL regulates the growth of root, shoot, and explant, activates seed germination and rhizogenesis, and delays leaf senescence. In addition, the most frequently mentioned functions of MEL are related to various abiotic stresses such as drought, radiation, low/high temperature, heavy metals, and salinity stresses.
In order to investigate the effect of PEG priming and melatonin on cold stress resistance of melon seedlings, a factorial experiment was conducted in a completely randomized design with three replications in Torbat-e-Jam University. In this experiment polyethylene glycol 6000 was used to produce drought stress at three levels (0, 0.18 and 0.58 MPa) and melatonin was used at two levels (0 and 200 μmol). When melon seedlings were at 4 leaf stage, the amount of polyethylene glycol was added to the irrigation solution for a week and to prevent drought stress, drought stress was increased for 3 days and increased one third of the required concentration daily. Recovery was performed for three days after drought stress and during this period melatonin was added to the irrigation solution at the required concentration. Seedlings were then exposed to cold stress (T0: non-stress and T1: cold conditions). Control plants were kept in greenhouse conditions.
Comparison of the mean results showed that there was an increasing trend in proline production by increasing drought stress. The highest amount of proline (0.80 µmol g-1 FW) was recorded at the highest level of drought pretreatment with no melatonin and without cold stress (D2M0T0), and then a decreasing trend in proline production was observed. The results showed that melatonin significantly increased leaf relative water content compared to the control. Interaction effects of drought pretreatment and temperature showed that there was a trend of decrease in relative water content by increasing drought pretreatment.  Ghanbari and Sayyari (8) reported that drought pretreatment stress maintains relative water content of tomato seedlings under cold stress conditions. Drought pretreatment significantly reduced the amount of chlorophyll a and total chlorophyll. The results showed that the highest levels of drought pretreatment stress (D2) and melatonin (M1) maintained chlorophyll a under cold stress conditions. Results showed that the amount of chlorophyll b was decreased by drought pretreatment stress, but it increased by melatonin application in all compounds. Based on the results, it was found that only simple effects of treatments at 1% of probability level had significant effects on soluble sugars content. Comparison of the mean simple effects of drought pretreatment showed that under drought stress the amount of soluble sugars increased significantly and the highest sugar content was recorded at the highest drought stress level. The amount of soluble sugars in plants under cold stress also increased significantly. Melatonin application also significantly increased the amount of soluble sugars. Kabiri et al. (19) reported that the use of melatonin increased soluble sugars in Moldavian balm seedlings under osmotic stress which is similar to this study results. It was found that melatonin significantly increased phenolic compounds under stress conditions and significantly decreased electrolyte leakage.

Melon (Cucumis melo L.) is one of the most important vegetables in Cucurbitaceae family and one of the most important economic crops in the Torbat-e Jam. Growth and yield of agricultural crops are affected by biotic and abiotic environmental stresses. Salinity stress can be one of the most important environmental factors limiting the yield of plants, especially in arid and semi-arid regions. It has been reported that by application of bio-fertilizers, root and shoot dry weight and nitrogen concentration in alfalfa increased under salt stress. Sarabi et al (44) in a study of different genotypes of melons under salinity stress reported that salinity stress increases soluble sugars and proline content and decreases photosynthetic pigments. Growth-promoting bacteria can help plants under stress conditions by stabilizing atmospheric nitrogen, increasing the accessibility of nutrients, and interfering by the production of plant hormones such as auxin, cytokinin, and gibberellins. Soliman et al. (49) also reported that growth-promoting bacteria increase the absorption of elements, especially nitrogen, in Acacia saligana. Basilio et al. (7) showed that growth-promoting bacteria increase plant height and yield of wheat. The use of salicylic acid to create plant reactions to environmental stresses has been suggested. Raghami et al (39) reported that salicylic acid improves vegetative indexes and photosynthetic pigments in eggplant under salt stress. It has been reported that salicylic acid treatment increased K in wheat under salt stress. Due to the expansion of saline soils as well as the reduction of fresh water resources, the purpose of this experiment is to better establish melon seedlings under adverse environmental conditions and to maintain and develop this valuable crop.

In order to study the effect of biological fertilizers and salicylic acid on physiological parameters and growth of Khatooni melon under salinity stress conditions, a factorial experiment was conducted based on completely randomized design with three replications in Torbat-e-Jam University. Salicylic acid treatment was selected at two levels, without (SA0) and one mM (SA1) salicylic acid. Bacteria treatments were including Azotobacter (B1), Azospirilium (B2), Azotobacter and Azospirilum (B3) and without inoculation (B0) and salinity treatments were prepared in five concentrations: control (S0), 50 (S1), 100 (S2), 150 (S3) and 200 (S4) mM of sodium chloride.

Interaction effects of salinity, salicylic acid and bacteria showed, proline content was increased by salinity stress. The highest of proline content was obtained by combination of 200 mM salinity, one mM of salicylic acid and Azetobacter + Azospirilum (S4 SA1 B3) and the minimum of it was recorded in contorol (S0 SA0 B0). Under salinity conditions, the accumulation of compatible solutions such as proline, glycine, betaine and other organic solutions in the plant occurs, which play an important role in protecting the plant against the harmful effects of stress. On the other hand, the increase in proline content by growth-promoting bacteria may be due to an increase in the absorption of nutrients, especially nitrogen, because proline has a nitrogenous structure.
Without salinity stress no significant difference observed between salicylic acid treatments on soluble sugars, but soluble sugars content were significantly increased by increasing salinity stress. The maximum and minimum of soluble sugars content were recorded in combination 200 mM salinity and one mM of salicylic acid (S4 SA1) and control (S0 SA0) respectively. Plants try to overcome salinity stress by producing organic compounds that are osmotically active such as soluble sugars.
It has been reported that the use of salicylic acid in eggplant and barley under salinity stress has increased the production of soluble sugars, which is consistent with the results of this study. In general, accumulation of proline and soluble sugars content might be due to increased synthesis and decreased degradation under stress conditions. According to the results, photosynthetic pigments and relative water content percentage (RWC %) were decreased under salinity stress. Simple effects of salicylic acid (SA1) and bacteria treatments especially combination of bacteria (B3) significantly improved Chlorophyll a, b, carotenoids and RWC. Sarabi et al. (43) reported that chlorophyll content, carotenoids and RWC were decreased in melon under salinity stress. Kheirizadeh Arough et al (29) reported that application of bio-fertilizers and nano zinc oxid increased content of chlorophyll a, chlorophyll b and carotenoids in Triticale under salinity conditions.   

Based on the obtained results in this study, we can use Azotobacter and Azospirillum together for seed inoculation and spraying with salicylic acid for obtaining better growth and yield under salt stress.

A rapid, complete, and uniform seed germination is important to establish a healthy seedling that is a critical key to successful crop production. Therefore, identification of effective factors on germination and plant response to various conditions are important to use an appropriate agronomic managements. Temperature and water are the most important environmental factors controlling seed germination in plants. The crop growth models are among the most effective tools for using in crop management decisions. The response of seed germination to temperature and water potential can be simulated by thermal time, hydrotime and hydrothermal time models. Regarding the importance of watermelon production in Iran, this study was conducted to determine the cardinal temperatures of germination in watermelon plant, and also to quantify its germination in response to the temperature and water potential interaction. .

In order to investigate the effects of temperature and drought stress on seed germination and quantifying the germination responses; a factorial experiment was conducted with seven  levels  of temperature including  10, 15, 20, 25, 30, 35 and 40 °C and  the  six levels of water potential including 0, –0.25, –0.5, −0.75, –1.0, and –1.25 MPa, respectively. A Ψ of 0 MPa was obtained using distilled water. The negative Ψ levels were prepared by polyethylene glycol (PEG 6000; Merck, Germany) according to Michel and Kaufman (1973). For each treatment, four 25-seed replicates were placed in 9-cm petri dishes containing one disk of Whatman No. 1 filter paper, with 7 mL of test solutions. Cumulative germination percentage was transformed to probit regression against time log (Finney, 1971; Steinmaus et al., 2000), and the time taken for cumulative germination (tg) to reach subpopulation percentiles (10–90%) was estimated from this function according to Steinmaus et al. (2000). Then the germination rates (GR) were calculated as the inverses of the germination times for each percentile at each T or Ψ. The preliminary estimation of the parameters in the TT, and HT models were obtained by plotting GR versus T and Ψ for each percentile. Then using repeated probit analysis developed by Ellis et al. (1986), the exact parameters for the TT, HT and HTT models were determined for the whole seed population. All statistical procedure were done by SAS and Excel software, and the figures were drawn by SigmaPlot10 software.

The analysis of variance showed that the temperature, water potential and their interaction had significant effect on the germination percentage of the watermelon plant. Seed germination of watermelon was about 96 % under the optimal conditions. However, the germination ability was affected by the temperature and water potential of the seedbed. The results showed that the germination was decreased by decreasing water potential, at all temperature levels. The seeds of watermelon germinated over a range of water potentials from 0 to -1 MPa. Furthermore, the lowest germination loss associated with decreasing water potential observed at temperature range of 20-30 °C (compared to temperatures below and above this range). The maximum percentage of germination was recorded at 20-30 °C, while no seeds germinated at 10 and 40 ° C. The results also showed that the highest germination rate was obtained at 25 °C and the germination rate decreased at lower and higher temperature than this range. While watermelon seeds were grown under no water stress condition, the estimated base and ceiling temperatures of germination by a linear regression method were 10.7 and 40.0 °C, respectively. However thermal time model was used, but the base and the maximum temperatures were estimated as 11.5 and 40.1 °C, respectively. Furthermore, an optimum temperature of 25.2 °C was predicted by hydrothermal time model for watermelon germination. The results showed that the base temperature and median thermal time to germination were varied with changing water potential. The hydrotime analysis showed that the base water potentials was in a range from -0.45 to -1.23 Mpa, that differed with changing water potential. Watermelon seeds had higher base water potential and also required a longer hydrotime for germination under non-optimal temperature. Hydrothermal time analysis showed that seed germination responses to temperature and water potential might as well quantified by parameters derived from hydrothermal time models (R2= 0.90-0.92). The amount of hydrothermal time required to germinate was 40.5 MPa °C days on the suboptimal and supra optimal temperature ranges. The HTT model showed that the Ψb(50) increased by 0.09 MPa with every degree increase in temperature above optimum temperature.

The thermal time, hydrotime and hydrothermal time models well described germination time course of watermelon seeds in response to temperature and water potential.Thus, the estimated parameters of these germination models allowed us to characterize the germination behavior of watermelon seeds under varying environmental conditions and global warming.

In Mazandaran Province the performance of different drainage systems is essential for Canola cultivation as a second crop in paddies. For this purpose an experiment was conducted in Sari agricultural Sciences and Natural Resources University as base, in 2017-2018 cropping season. In different canola growth stage intervals, eight sampling were established under randomized complete block design with three replications in subsurface drainage systems and surface (Control) in order to determinate leaf area (LA), leaf area index (LAI), numbers of leaves (SLN) and leaf dry weight (LDW). Then Statistical analysis was carried for study of drainage depth and space on the mentioned growth index and mathematical relationship between leaf area and its dry weight with the evaluation of linear and nonlinear regression models was determined in different drainage systems. Maximum of LA in all treatments occurred about 90 day after planting. Mathematical relations between LA and LDW were described by linear and power model is suitable as a correlation coefficient was 0.98. Among the mathematical functions, reverse polynomial functions with degrees 4 and 5, logarithmic equations and inverse logarithmic equations with degrees 3, 4, and 5 showed better results than other mathematical functions The relations obtained in this experiment can be used in simulation models of winter canola growth under water table control conditions.

Pistachio is one of the most important horticultural products that plays an important role in exports and foreign exchange earnings of the country. In recent years, some nutritional and management problems have reduced the yield of this product. The current research was conducted to evaluate the foliar application effect of an amino acid Compound and seaweed extract on quantitative and qualitative yield of pistachio. The experiment was factorial experiment in a randomized complete block design with three replications. The treatments included an amino acid components (Aminosuren) and seaweed extract (Ascophyllum nodosum) both them at three levels (0, 1 and 2 mg.L-1). The results showed that all the studied traits, were significantly affected by Aminosuren treatment at a probability level of 1% except of open-shell percentage and width of pistachio cluster. The effect of seaweed extract on cluster weight, number of pistachios in cluster, cluster length, leaf chlorophyll and carotenoids were significant at a probability level of 1%. the interaction between amino acids and seaweed extracts showed that the highest cluster weight (68.33 g), number of pistachios in the cluster (28.33), cluster length (22.8 cm), Chlorophyll content (3.95 mg.kg-1) and carotenoids (0.759 mg.kg-1) were obtained from the treatment with 2mg/L of aminosuren and 2mg.l-1 of seaweed. According to the results, the combined application of amino acids and seaweed extract could play an important role in improving quantitative and qualitative traits of pistachio.

Pistachio is one of the most important nut crops that has a special place among agricultural products. In recent years, the rate of yield production in Iran was less than that of global amounts, which the plant nutritional problems are of the most important reason for that. Present study was conducted to evaluate the effect of foliar spray with amino acids and seaweed extract on yield and quality of pistachios (cv Ahmad Aghaei). The experiment was carried out as a factorial randomized complete block design with three replications. Treatments was spraying with amino acids (aminosauren) and seaweed (Ascophyllum nodosum), both at three levels (0, 1 and 2 mg/L).  Among the treatments, aminosuren had more positive effects on the yield of pistachio, than the algae extract of Ascophyllum. Different concentrations of amino acids and seaweed extracts showed significant effects on leaf area and pistachio yield compared with the control samples. Based on the results, combination treatment of aminosauren and seaweed at a concentration of 2 mg/L had the best effect on yield (4.58 kg/tree), leaf area (109/8 cm2) and nut weigh (18.8 ounces). Finally, according to the results of this study, the combined fertilizer containing amino acids and seaweed can play a significant role in improving the yield and quality attributes of pistachio.

The main objective of this research is to assess the daily rainfall data from the Tropical Rainfall Measurement Mission (TRMM-3B42 V7) and Global Precipitation Measurement (GPM) products with rain gauge data and Comparison the performance of two widely-used models for spatial assessment over the semiarid climate of Khorasan Razavi Province, Iran. Measured rainfall data from 13 rain gauge stations for the period of 2 years, starting from Feb 2015 to Dec 2016 were collected and compared with the available annual GPM and TRMM-3B42 V7 data. In order to assess the efficiency of Kriging and Inverse Distance Weighting (IDW) models for annual precipitation zoning, the statistical Root Mean Square Error (RMSE) and Mean Error (ME) methods were used in the Arc GIS software version 10.1.The results of statistical analysis comparing the two methods with the satellite production data showed that at the annual scale the results of the TRMM satellite data are close to the GPM satellite data. However, TRMM satellite simulates precipitation data with slightly higher correlation coefficient and lower relative bias than GPM satellite. The results also showed that in all three precipitation data, Kriging method performs more accurately than the inverse Distance Weighting (IDW) method. In both interpolation methods, zoning was performed with much less error in the GPM data. This study showed that the average annual precipitation of both TRMM and GPM satellite precipitation products can be used to estimate precipitation and could potentially be one of the reliable sources for hydrological modeling.This study showed that the average annual precipitation of both TRMM and GPM satellite precipitation products can be used to estimate precipitation and could potentially be one of the reliable sources for hydrological modeling.This study showed that the average annual precipitation of both TRMM and GPM satellite precipitation products can be used to estimate precipitation and could potentially be one of the reliable sources for hydrological modeling.

Temperature and water are the most important environmental factors controlling seed germination in ‎plants. In order to investigate the effect of temperature and drought stress on seed germination and ‎quantifying of germination; a factorial experiment was conducted with eight temperature levels including ‎‎5, 10, 15, 20, 25, 30, 35 and 40 degrees Celsius and the seven levels of drought stress including 0, 0.5-‎‎0.0, -0.2, -0.3, -0.4, -0.5 and -0.6 MPa, respectively. The results showed that the germination was ‎decreased by decreasing osmotic potential at all temperature levels. However, the intensity of this ‎decrease was less in the range of 20 to 30°C. Using two different methods, the base and maximum ‎temperature of dill germination was estimated in the range of 2.3 and 2.9 °C and 43.0 and 47.3 °C, ‎respectively. The optimum temperature for dill germination was 26 °C. The estimated value of base ‎water potential for germination was -0.53 Mpa with the hydrothermal time model. The results also ‎showed that water base potential for dill germination was increased by -0.5 Mpa as temperature ‎increased. Finally, it was found that if the base water potential taking into account variable in response to ‎changing temperature, then the hydrothermal time model can be good enough to quntify dill germination ‎response to temperature and water.‎

Wheat production is an important component for national food security. Studying the impact of future climate change on crop production is crucial to manage crop productivity. Improving our understanding of potential responses of the wheat plant to these changes while taking into consideration agricultural management is required for identifying best adaptation strategies. In Khorasan Razavi province, over 12% of the total cultivated wheat area is belong to Torbat-e Jam region. The current study aimed to quantify the potential impacts of climate change on irrigated wheat yield in the next 30 years for this region. In this study, information on regional cropping systems and meteorological data to study the effects of climate change were collected and finally, the impact of climate change on irrigated wheat yield was studied using simulation approaches under different climatic scenarios. Long-term daily weather data for future was generated using MarkSim weather generator software and the past meteorological data was gathered from regional weather station. Daily weather data generated by four scenarios RCP2.6, RCP4.5, RCP6, and RCP8.5 for a 30-year period. The generated and measured daily weather data was used for running CERES-Wheat model. Finally, crop model outputs were used to interpret climate change impacts on wheat growth and production. The average air temperature during the wheat growth period showed that temperature increased about 1.6% in the last five years compared to the first five years of the baseline 30-years period. Furthermore, the average annual precipitation for the last 5 years was 51 mm less than the first 5 years of the baseline period. The air temperature will increase about 1.1, 1.6, 1.2 and 1.8 °C during the wheat growth period for the near future (30 years) under the RCP2.6, RCP4.5, RCP6, and RCP8.5 scenarios, respectively. The precipitation over the wheat growth period will reduce by 9 and 8% under RCP4.5 and RCP8.5 scenarios, respectively. Furthermore, the precipitation over the growth period would increase by 11 and 17% under RCP2.6 and RCP6 scenarios, respectively. The simulated wheat yield by the CEREC-Wheat model showed that the grain yield increased by 5% in the first 5 years compared to the last 5 years of the baseline period (1998-2017). The biomass production and harvest index (HI) also increased by 2.3 and 1%, respectively. The increased dry matter production and HI can be due to temperature increase during the cold seasons, and more amount of precipitation during the reproductive growth. The simulated wheat growth during the near future period (2018-2047) showed that wheat growth cycle will reduce from 5 to 7 days under different emission scenarios. In the different soil textures, wheat yield under RCP2.6, RCP4.5, RCP6, and RCP8.5 scenarios will increase by 24.4, 19.9, 24.9 and 25.2%, respectively. Furthermore, the highest and the lowest yield were obtained from clay and sandy clay loam soils, respectively. Under the different emission scenarios, the mean incident light and light use efficiency during the growth period would be increased by 20.8-24.6% and 5.5-8.3%, respectively, in projected climate change as compare to baseline period. Reducing irrigation water as amount of 300 m3 ha-1 and simultaneous increase in irrigation water use efficiency are possible incident scenarios for the near future. Based on these scenarios, simulations showed that grain yield increased 26.3, 19.6, 27.2 and 25.6 % under RCP2.6, RCP4.5, RCP6, and RCP8.5 emission scenarios, respectively.  The increased temperature and atmospheric CO2 concentration during the next 30 years will decrease wheat growth cycle, but increase the potential biomass and grain wheat yield under the different emission scenarios. The results showed that the increased yield production will occur under climate change conditions, even if the available irrigation water would decrease by 300 m3 ha-1.

Agronomic approaches to weed management are effective, low-cost, environmentally-friendly options without adverse effects on human health. These approaches should be emphasized to develop a sustainable agriculture (Zimdahl, 2007). A living cover crop can affect weed competition by competing for growth resources and the residue of cover crops may affect weed growth and competition with their allopathic potential (Karbalaei-Khiavi et al., 2016). Fenugreek plants, with their shallow root system, ability of nitrogen-fixing as well as allopathic potential, were chosen as a cover crop to study the effects of various densities of fenugreek on growth and weed competition.
An experiment was conducted in a randomized complete block design with six treatments and three replications at the experimental station of Torbat-e Jam University in 2016. The treatments included the seeding of 0, 10, 20, 30 and 40 fenugreek plants per square meter as a cover crop and a control treatment. The destructive sampling was taken to determine the dry matter production in sunflower, fenugreek and weed from 60 cm of rows. After examining the residuals for normality, analysis of variance was done using SAS software.
The highest and lowest weed dry matter were obtained from the densities of 0 and 20 fenugreek plants per square meter, respectively. The results showed that the planting of fenugreek, regardless of its density, at the same time as the sunflower planting reduced growth of competing weeds by at least 50%. This reduction can also be increased by up to 78% by establishing the appropriate density of fenugreek. The highest and lowest leaf area, dry matter production and seed yield in the sunflowers was obtained from densities of 20 and 40 cover crop plants per m-2, respectively. The presence of cover crops in all densities, except for 20 fenugreek plants per m-2, significantly reduced sunflower yield compared with the control. Regression analysis also showed that the response of sunflower growth and yield to increased cover crop density follows a quadratic trend. The sunflower growth and yield was reduced at lower and higher densities of cover crop compared to its optimum density. The role of cover crop densities higher than the optimum level, however, was greater than the lower one in reducing competing weeds. Thus, the establishment of a suitable plant density of fenugreek would occupy an existing vacant niche, reduce available growth resources, and ultimately reduce the growth of competing weeds (Mohammadi et al., 2015).
Due to the reduction of competing weeds in the presence of fenugreek and the economic value of fenugreek production, this plant can be used as an effective cover crop in sunflower fields as an option in a comprehensive weed management system.