علی نخ زری مقدم

One of the primary challenges contributing to low cotton yields in Golestan Province is the substantial yield gap the discrepancy between farmers' actual yields and the achievable potential yield. Estimating this gap and identifying its contributing factors require the application of robust analytical methods. This study aimed to document the production processes and estimate the yield gap associated with cotton agricultural management practices in the cotton-growing regions along the Caspian Sea coast, specifically in the cities of Kurdkoy and Bandarga. 

To investigate the management factors limiting cotton yield and to estimate the yield gap, a comprehensive study was conducted during the 2021-2022 growing season in the western Golestan Province. Data on agricultural management practices, from planting to boll harvesting, were collected through direct interviews with farmers. Comparative performance analysis (CPA) was employed to identify yield gap-inducing factors. The collected data were analyzed using stepwise regression and boundary line analysis in SAS software. Quantitative variables were further evaluated through simple and boundary linear regression. The contributions of individual limiting factors to the yield gap were determined using the derived production equation and model component values. 

The analysis of agricultural management variables using the production model revealed that the average and maximum potential yields were 2165 and 5358 kg/ha, respectively. Observed average and maximum yields in the field were 1988.5 and 4500 kg/ha, respectively. The total estimated yield gap, calculated using stepwise regression, was 3220 kg/ha. Among yield-limiting factors, the contributions to the yield gap were as follows: nitrogen fertilizer (1000 kg/ha; 31%), phosphorus fertilizer (277 kg/ha; 9%), and complementary element spraying (688 kg/ha; 21%). Yield increases were attributed to irrigation volume (490 kg/ha; 15%) and pest damage reduction (150 kg/ha; 5%). Irrigation during the budding and boll formation stages contributed an additional 149 kg/ha (5%) and 326 kg/ha (10%) to yield increases, respectively. Conversely, planting date and nitrogen top-dressing during flowering negatively impacted yields, with contributions of 69 kg/ha (2%) and 72 kg/ha (6%), respectively. When influential yield-related variables were included in the model, the estimated average and maximum yields were 2165 and 5358 kg/ha, closely matching observed field values of 1988.4 kg/ha and 4500 kg/ha, respectively. 

The observed yield variations among farms underscore the disparities in agricultural management practices. The use of boundary line analysis, alongside regression and performance comparison methods, proved effective in identifying production-limiting factors. The results indicate that optimizing key factors, as identified through stepwise regression and boundary line analysis, could significantly reduce the yield gap in farmers' cotton fields.

Soybean (Glycine max) is one of the important food crops, which is rich in protein and vegetable oil. Soybean is the only legume with ample amount of essential omega-3 fatty acid and alpha-linolenic acid. One of the primary challenges in soybean production in the central region of Mazandaran province, Iran, is the substantial difference between actual and attainable yields, referred to as the yield gap. In recent years, this gap has been noteworthy. Closing the disparity between actual and potential yield, achievable through proper management, necessitates a detailed investigation and analysis of its underlying causes. Thus, identifying soybean yield-limiting factors is crucial. This study was conducted in Babolsar, located in the central region of Mazandaran province, Iran, to simultaneously recognize the best management practices, assess the percentage of affected fields, and estimate soybean yield potential and gaps using the Comparative Performance Analysis (CPA) method. This study aimed to evaluate the factors limiting wheat yield in Babolsar County using the CPA method during the 2019-2020 period. Information collection, including planting dates, cultivation and harvesting activities, and soil physicochemical properties, was carried out through fieldwork and personal interviews with farmers. A total of 120 soybean fields within the geographical scope of the study area were monitored each crop year. Information related to soil characteristics, including EC, pH, percentage of organic carbon, absorbable phosphorus, absorbable potassium, percentage of clay, percentage of silt, percentage of sand, and soil texture class was obtained using soil tests and digital maps available in the agriculture organization of Babolsar. In the Comparative Performance Analysis method, stepwise regression was employed to examine the relationship between variables and yield. The yield gap rate, its causal factors, and the contribution of each factor to the yield gap creation were estimated. Among the investigated variables, a model with seven independent variables (farmer experience, plant density, frequency of nitrogen fertilization use, starter fertilizer, frequency of pesticides, and herbicides) was selected as the final regression equation. The results of the yield model indicated a difference of 1736 kg/ha between attainable (4059 kg/ha) and actual yield (2323 kg/ha). Notably, farmer experience, plant density, frequency of nitrogen fertilization use, starter fertilizer, frequency of pesticides, and herbicides use had the most significant influence on soybean yield gap in the study area, contributing 15.6% (261.71 kg/ha), 24.6% (426.58 kg/ha), 8.3% (143.4 kg/ha), 3.3% (57.97 kg/ha), 16.7% (288.79 kg/ha), and 31.5% (545.79 kg/ha) respectively. Every plant needs the right time for fertilization for more yield. If the best fertilization time is not chosen for the plant, later or earlier fertilization will cause harmful effects in the plant. Weed control emerged as a crucial factor for increasing crop yield, emphasizing the importance of selecting optimal plant density based on regional climatic and soil conditions. Pesticide use played a vital role in pest control, contributing to a considerable reduction in pest damage and increased yield. Although farmers' experience had a significant role in the yield gap (15.6%), it was underscored that experience alone, without scientific knowledge, might be insufficient. The study emphasized the need for farmers to adopt scientific principles to enhance productivity. Additionally, the proper use of fertilizers at the plant's critical stages was highlighted to increase soil nutrient levels and improve nutrient efficiency. This study employed the Comparative Performance Analysis to determine optimal requirements for various management factors in soybean cultivation, aiming to achieve the highest yield. Through proper agricultural management and modification of influencing factors, the study suggests that it is possible to reduce the disparity between attainable and actual yields, ultimately achieving desired results.

In order to study the effect of seaweed extract and amino acid application on plant height, number of secondary branches, number of inflorescences, flower yield and essential oil of German chamomile plant, a factorial experiment in the form of a basic design of randomized complete blocks with three replications in The research farm of Gonbad Kavoos University was implemented. Application of seaweed extract in three levels including no consumption (control), foliar application (at the rate of 1 kg per hectare), application with irrigation ( 2 kg per 10,000 liters of water) and application of amino acids in three levels including no consumption (control) ), foliar spraying of Amino Spark amino acids (1 kg/ha) and Azomine amino acids (1 kg/ha).The results of the variance analysis table showed that the effect of seaweed extract and amino acids consumption on plant height, number of sub-branches, number of inflorescences and flower yield was statistically significant at 1%. so that the use of amino acids under the treatment of algae consumption led to an increase in the performance of German chamomile flowers and essential oils. The results of the present study showed that the application of seaweed extract bio fertilizers and amino acids improves the morphological traits, flower yield and essential oil percentage as one of the most important goals of the economic production of the German chamomile medicinal plant.

The experiment was conducted as a factorial in the form of a completely randomized design in three replications. The investigated factors included irrigation cycle (0, 7, 14 and 21 days), compost amount (0, 5, 10 and 15%) and water source (river water). In order to ensure uniformity in the growth of seedlings, the first watering was done immediately after planting for all treatments to establish the plant. According to the distance of the plants (1.5 meters apart), each row included 4 plants, which were randomly sampled. At the time of harvesting mucilage parameters, total nitrogen, quercetin was measured.According to the obtained results, the investigated treatments had a significant effect on the plant height, the number of sub-stems, the yield of flowering branches, the percentage and yield of essential oil and borage mucilage. The highest number of sub-stems, height, yield of flowering branch and production of mucilage and essential oil were obtained in non-stress conditions and with the use of 10% chemical + biological fertilizers, and the lowest values were obtained in the conditions of vegetative + reproductive stress and with the use of 50% chemical + biological fertilizers. The combined use of 10% chemical + biological fertilizers compared to the use of 11% chemical fertilizers improved plant height by 10% in vegetative stress and 30% in reproductive stress. The results showed that carotenoid and total chlorophyll decreased due to drought stress.

Intercropping, the agricultural practice of cultivating two or more crops in the same space at the same time, is an old and commonly used cropping practice which aims to match efficiently crop demands to the available growth resources. The practice of growing two or more crops simultaneously in the same field is called intercropping and it is a common feature in traditional farming of small landholders. It provides farmers with a variety of returns from land and labour, often increases the efficiency with which scarce resources are used and reduces the failure risk of a single crop that is susceptible to environmental and economic fluctuation. Intercropping of chickpea with linseed reduced the chickpea yield by 60.3%, although linseed occupied only 33% of the total area. The loss of chickpea yield was compensated by the additional yield of linseed, and thus the system productivity of chickpea + linseed intercropping was increased by 43.4% compared with sole chickpea. Of this increase in system productivity, 65.3 and 34.7% were contributed by higher seed yield and higher minimum prices of linseed, respectively as compared to chickpea. The objectives of the present study were to study the competition indices of chickpea and quinoa intercropping such as land equivalent ratio, relative crowding coefficient, aggressivity, chickpea equivalent yield and effects of nitrogen and different intercropping arrangements on yield of sole chickpea, sole quinoa and intercropping yield of two plants. The objectives of the present study was to determine the best appropriate treatment of sole cropped, replacement and additive series of chickpea and quinoa in terms of yield and investigation of competition indices in intercropping replacement and additive chickpea and quinoa.

In order to study the effect of planting pattern and nitrogen application on yield and competitive indicators of chickpea and quinoa, a factorial experiment based on randomized complete block design (RCBD) was conducted with three replications at Gonbad Kavous University farm during the 2020-2021 growing season. Nitrogen factor was included three levels of non-application and application of 25 and 50 kg N.ha-1 and the treatments of intercropping were included 9 levels of sole cropped of chickpea and quinoa, 67% chickpea + 33% quinoa, 50% chickpea + 50% quinoa, 33% chickpea + 67% quinoa, 100% chickpea + 33% quinoa, 100% chickpea + 50% quinoa, 100% chickpea + 67% quinoa and 100% chickpea + 100% quinoa. For analysis variance of data software of SAS Ver. 9.4 was used and treatment mean differences were separated by the least significant difference (LSD) test at the 0.05 probability level.

Results showed that the effects of planting pattern and nitrogen consumption on yield were significant at confidence level of 1%. The maximum total yield belonged to the treatment sole cropped of chickpea with 3529 kg.ha-1, which was not significantly different from the 67% chickpea + 33% quinoa treatment. With increase of nitrogen fertilizer consumption, total yield was increased. The lowest chickpea crop equivalent yield related to the treatment sole cropped of chickpea and mixed crop was 33% increase of quinoa to chickpea crop with 3529 and 3551 kg.ha-1, respectively, and the highest was related to sole cropped of quinoa with 8876 kg.ha-1. Land equivalent ratio was higher than one in all the additive mixed cropping treatments and alternative mixed cropping treatments. The maximum proportion of land belonging to the treatment of 100% chickpeas + 67% quinoa was 1.10. The relative coefficient of total density in all treatments was more than one, which indicates the desirability of mixed cultivation of chickpea and quinoa. The examination of the aggressivity index showed that quinoa was dominant in the mixed cropping treatments, increasing and replacing the plant. As a result, the dominance index of quinoa was positive despite the favorable yield of both plants.

Of the two plants of chickpea and quinoa, quinoa plant produced more yield than chickpea plant. The maximum total yield belonged to the treatment sole cropped of chickpea with 3529 kg.ha-1, which was not significantly different from the 67% chickpea + 33% quinoa treatment. With increasing of nitrogen fertilizer consumption, yield was increased. According to the results, it seems that it is not possible to increase the density of two plants in mixed cultivation to obtain the maximum yield.

In order to investigate the effect of nitrogen fertilizer and foliar spraying of humic acid and Vita free on phenological stages, remobilization indices and yield of sunflower in the second experimental planting in a factorial manner based on a randomized complete block design with with three replications in summer 2018 at Gonbad Kavous University farm research. Cultivar factor was included Haysan 25 and Oscar and combination of fertilizer factor was included no fertilizer application, 100 kg N/ha, 50 kg N/ha, 50 kg N/ha + 1.5 kg humic acid/ha, 50 kg N/ha + 0.5 kg Vita free/ha and 50 kg N/ha + 1.5 kg humic acid + 0.5 kg Vita free/ha. The results showed that the effect of cultivar and fertilizer on most of the measured traits was significant. The results showed that cultivar and fertilizer were significant on most of the studied traits. The maximum days from planting to 50% Flowering, the dry matter of vegetative organs in the flowering stage, the remobilization, current photosynthesis and seed yield were obtained from Oscar cultivar. The maximum remobilization and remobilization efficiency were obtained in the treatment of no fertilizer use. Days from planting to 50% flowering, days from planting to 50% maturity, current photosynthesis and seed yield in 100 kg N/ha treatment and 50 kg N/ha + 1.5 kg humic acid/ha + 0.5 kg Vitafree/h was higher than other fertilizer treatments. Based on results, in order to achieve the maximum seed yield of sunflower and to prevent excessive use of chemical fertilizers, the combined use of Nitrogen fertilizer, humic acid and vita free is necessary.

 Due to Iran's location in the arid and semi-arid region of the world, the possibility of drought is high. Therefore, implementing low irrigation to increase the efficiency of limited water resources is a scientific solution to reduce water consumption. On the other hand, irrigation deficit in cotton  is the most important factor limiting production worldwide, which indicates the need for optimal use of water resources to determine the real water needs of cotton plants. Therefore, development and introduction of drought tolerant cultivars and useful method to improve water productivity and efficiency in the face of drought and water scarcity. The aim of this experiment was to evaluate cotton cultivars by measuring traits related to photosynthetic pigments and yield in order to select drought tolerant cultivars. The present study, evaluated physiological traits of 10 cotton cultivars that were known as tolerant cultivar under irrigation deficit based on the measurement of traits and mechanisms of drought tolerance split-plot arrangement using randomized complete blocks design with three replications in 2021 and 2022 years, in the educational and research farm of Gonbadkavos University (Golestan province), Iran. Experimental research includes two different irrigation regime The main factor of irrigation stress in two levels including low irrigation stress (two times of irrigation in the stages of bud formation and beginning of flowering) and no stress (four times of irrigation in the stages of bud formation, beginning of flowering, beginning of bud formation and beginning of bud opening) and the factor Sub-types of cotton were included in 10 levels (Shayan, Sahel, Sepid, Sajidi, Golestan, Latif, Armaghan, Parto, Mai and Lodos). The studied traits include physiological characteristics such as chlorophyll a, b and carotenoids, proline and boll yield. Photosynthetic pigments were measured by spectrophotometer and its concentration was performed by Arnon (1967) method. Based on the results of this experiment, cultivars with low irrigation stress treatments showed a significant difference in terms of traits related to photosynthetic pigments and non-enzymatic antioxidants and their yield. The study of compound analysis of interaction effect of cultivars in the stress of low irrigation during two crop years showed a significant difference in the yield of Vash and malendialdehyde. Most of the studied traits were affected by the intensity of low irrigation stress and growth stage. The amount of proline increased with the increase of stress so that at the medium stress level of two stages of irrigation (bud formation and beginning of flowering) it increased significantly compared to the condition of no stress. The amount of chlorophyll a was affected by the intensity of stress, but there was no significant change in the amount of chlorophyll b. In the first and second year, the highest yield of rice in non-stress conditions belonged to Sajidi variety with 4596 and 4593 kg/ha-1, respectively, and the lowest yield in water stress conditions in the first and second year belonged to Sepid variety, with 1649 and 1756 kg/ha-1, respectively. The decrease in the yield of cotton was due to the decrease in the number of bolls in the plant under the condition of low irrigation stress. The results of this study indicated the traits of  tolerance cultivars under irrigation deficit. Also, cultivars showed different reactions to the studied traits.  According to the results of the research and the correlation coefficients between the traits, among the water stress tolerant cultivars studied, Golestan and Sajidi cultivars are among the stress tolerant cultivars, Sahil and Sepid cultivars are the sensitive cultivars to water stress, and the other cultivars are the semi-sensitive cultivars. Water stress was introduced.

The practice of growing two or more crops simultaneously in the same field is called intercropping and it is a common feature in traditional farming of small landholders. It provides farmers with a variety of returns from land and labor, often increases the efficiency with which scarce resources are used, and reduces the failure risk of a single crop that is susceptible to environmental and economic fluctuation. There is another important way that without incurring additional costs and use of water and fertilizer could result in higher production. This approach is increasing agricultural production per unit area by growing more than one crop in a year. Intercropping will be successful when competition for sources is less than competition within a species. Plants in the mixture can be chosen in a way that a species benefits from environmental changes caused by other species in mixed cultures directly. Intercropping inhibits the growth and development of weeds and leads to increased production. Since the system will reduce pesticide use, environmental pollution will be also less proportionally. The objective of the present study was to study some traits of chickpea (plant height, number of pods per plant, number of seeds per plant, number of seeds per plant, 100-seed weight, and plant yield,) under application of nitrogen and planting pattern of chickpea and quinoa.

In order to study the effect of nitrogen and intercropping ratios of chickpea and quinoa on some traits of chickpeas, a factorial experiment based on randomized complete Block design (RCBD) was conducted with three replications at Gonbad Kavous University farm during the 2020-2021 growing season. Nitrogen factor was included three levels of non-application and application of 25 and 50 kg N/ha and the treatments of planting pattern were included 9 levels of sole cropping of chickpea, 67 % chickpea + 33 % quinoa, 50% chickpea + 50% quinoa, 33% chickpea + 67% quinoa, 100% chickpea + 33% quinoa, 100% chickpea + 50 % quinoa, 100% chickpea + 67% quinoa, 100% chickpea + 100% quinoa and sole cropping of quinoa. In sole cropping, the distance between the plants on the row for chickpea and quinoa was 10 cm. The operation of harvesting the entire plot was done by removing the border rows and half a meter from both sides of the middle rows. For analysis variance of data software of SAS Ver.9.1.3 was used and treatment mean differences were separated by the least significant difference (LSD) test at the 0.05 probability level.

The results of analysis variance showed that planting pattern and nitrogen had a significant effect on plant height, number of pods per plant, number of seeds per pod, number of seeds per plant, 100-seed weight, and plant yield chickpea and also plant height, number of seeds per plant, 1000-seed weight, and plant yield quinoa. Plant height in additive intercropping was more than in replacement intercropping but the number of pods per plant, number of seeds per pod, number of seeds per plant, 100-seed weight, seed weight per plant, and pods weight per plant in replacement treatments and sole cropping of chickpea was more than additive treatments. Nitrogen application increased all traits. Plant yield of quinoa in replacement intercropping of 33% quinoa instead of chickpea was greater than other treatments. However, the plant yield of chickpea in sole cropping of chickpea and replacement intercropping of 33% quinoa instead of chickpeas with 14.11 and 13.26 respectively, which was greater than other treatments.

Plant height in additive intercropping treatments was more than in replacement intercropping but the number of pods per plant, number of seeds per pod, number of seeds per plant, 100-seed weight, plant yield, and plant dry weight in replacement treatments and sole cropping of chickpea was more than additive treatments.

Drought stress is known as one of the most important factors limiting the growth and production of agricultural plants in most parts of the world and Iran. It is a multidimensional stress and affects plants at different levels. From a physiological point of view, drought stress causes several changes in the relative water content of leaves and photosynthetic pigments of plants, which in turn causes a decrease in the efficiency of photosynthesis and a significant reduction in plant growth parameters and ultimately grain yield. In Iran, drought stress usually occurs during the filling stage of wheat grains, and due to the limitation of irrigation, supplementary irrigation can play an important role in dealing with drought stress. Durum wheat (Triticum durum, Desf) is an important food product due to its heavy gluten properties and non-sticky dough, ideal for preparing pasta products such as macaroni and spaghetti.
To investigate the physiological characteristics, yield, and yield components of durum wheat cultivars under drought conditions and supplemental irrigation, 10 durum wheat genotypes were evaluated in the form of a split-plot design with the basis of randomized complete blocks in dryland and supplemental irrigation with 3 replications during Crop years 2017-2018 and 2018-2019 in Kohdasht city of Lorestan province. Grain yield and yield components (weight of 1000 seeds, number of seeds per spike, number of spikes per plant) as well as biochemical and physiological properties of photosynthetic pigments, greenness index, relative leaf water, leaf protein and light consumption efficiency were investigated.
Variance analysis showed a significant variation among the examined cultivars, moisture conditions, as well as the interaction of cultivar × humidity conditions for most of the traits except the interaction effect of cultivar × humidity conditions for chlorophyll b and leaf protein. The effect of year and interaction effects of year with other factors were not significant for most of the traits. Performing supplementary irrigation compared to rainfed conditions caused all traits to increase significantly, except greenness index and protein content. Mean comparison of interaction effect of cultivar × moisture environment with Duncan's method at 5% level showed that the genotypes reacted differently for the traits in two moisture conditions and in dry conditions, Omrabi3, Hana, Aria and Saji genotypes were superior to other genotypes in terms of agricultural and physiological traits, and with supplementary irrigation, these for genotypes maintained their superiority, and two genotypes, Shabrang and Behrang, were added to this group.
In general, it can be said that the results were almost the same in the two years studied. Supplementary irrigation compared to rainfed conditions improved the agronomic and physiological characteristics of the cultivars. Among the genotypes, there was a high diversity for all the examined traits and this diversity was different in two humidity conditions. Considering the two-year mean yield, the genotypes of Omrabi3, Saji, Arya and Hana for rainfed conditions and Omrabi3, Hana and Behrang for supplementary irrigation conditions of the studied area are recommended.

In order to study the effect of nitrogen splitting and supplemental irrigation on yield, yield components and oil percentage of sunflower a factorial experiment was conducted based on randomized complete block design on farm research of Gonbad University with three replications during crop year of 2019.

Treatments in this experiment included nitrogen splitting (none consumption of nitrogen (as control), 25% of nitrogen at planting time and 75% before flowering, 50% of nitrogen at planting time and 50% before flowering and 75% of nitrogen at planting and 25% before flowering and supplemental irrigation (none irrigation ((as control)), supplementary irrigation at flowering stage, supplemental irrigation at grain filling stage, supplemental irrigation at flowering stage and grain filling stages) in four levels.

The results showed that consumption of 25% nitrogen at planting time and 75% before flowering led to the highest increase in number of grains per row, number of grains per head, one thousand-grain weight, grain yield (4318 kg.ha-1) and harvest index. Consumption of 75% nitrogen at planting time and 25% before flowering increased the number of rows per capita. None consumption of nitrogen increased oil percent though oil yield decreased. Irrigation at flowering and grain filling stages increased the number of grain per capita, grain weight, and grain yield (4427 kg.ha-1).

According to the results, irrigation at flowering and grain filling stages as well as application of 25% nitrogen at planting time and 75% before flowering is suitable to achieve optimum sunflower yield.

Estimating the yield gap and determining the factors causing it require the use of appropriate methods. The Comparative Performance Analysis (CPA) method is a suitable option for quantifying the yield gap, as it can identify the main limitations affecting performance. By using multiple regression in a step-by-step approach, CPA can help in taking actions to eliminate or reduce these yield-reducing factors. 

In this research, the CPA method was employed to investigate the management factors limiting the yield of cotton and to estimate the yield gap in the western part of Golestan province (Kordkoi and Bandargaz counties). Data related to agricultural management, from planting to harvest (including quantitative and qualitative variables), were collected through face-to-face consultations and direct conversations. Nine variables were selected from the information collected during the monitoring of cotton fields. The relationship between these variables and the actual yield obtained from the fields was analyzed using step-by-step regression in SAS software. Finally, using the production equation and the values of the model components, the contribution of each limiting factor to the yield gap was determined. 

The results showed that out of 82 farm management variables, the final yield model included 9 independent variables: planting date, pure nitrogen consumption, pure phosphorus consumption, nitrogen at flowering time, foliar spraying with essential plant elements, irrigation water volume, pest damage, and irrigation timing at budding. These factors were identified as the main limitations to cotton yield in West Golestan. The yield gap was calculated as 3119.5 kg/ha, which is the difference between the actual average yield (1988.48 kg/ha) and the optimal yield (5108 kg/ha) estimated by the model. Factors such as nitrogen application, foliar spraying of essential elements, irrigation volume, and timing of irrigation at budding (283.8, 267.2, 177.3, and 175.3 kg/ha, respectively) had the most significant impact on the yield gap, contributing 30%, 19%, 15%, and 10%, respectively. 

The results indicate that by implementing effective farm management practices and controlling the key factors limiting cotton yield, it is possible to reduce the observed yield gap by 61% in the studied areas and significantly enhance cotton yield.

Sources of protein are the most expensive part of animal feed, and every year a large amount of these sources are imported from abroad for use in animal husbandry industry. One of the important steps in reducing the cost of feed is the optimal use of available resources and the recognition of new foods and their use in animal rations. On the other hand, every year, a huge amount of agricultural product residues are obtained, which can be used in animal nutrition. Optimum use of agricultural by-products and processing industries in feeding ruminants is important from economic and environmental aspects. Pea (Pisum sativum L.) is a cool-season crop and one of the most important legumes, in the temperate climatic regions and it has been widely consumed as a legume or vegetable throughout the world for the purpose of both human nutrition and animal nutrition. Peas are cultivated with the aim of producing green seeds, but after harvesting the pods containing seeds, its waste can be used by ruminants as high-quality bulk feed. The by-product after the harvesting of chickpeas (green chickpeas) which can be extracted and separated manually is the parts of the stem, leaves and pods that are free of green seeds. This research was conducted in order to investigate the effect using organic acid (acetic acid) and fibrinolytic enzyme and molasses on chemical composition, fermentation characteristic, gas production and digestibility parameters of pea silage.

Whole crop pea silage was harvested and chopped with a conventional forage harvester under farm condition to length of 2-3 cm. Representative of pea forage sample was packed manually, in triplicate into plastic bags. The filled silos were stored at ambient temperature and allowed to ensile for 45 days. The following treatments were applied to the forage samples: 1) pea forage without any additives (control), 2) control + fibrinolytic enzyme(2 grams per kg of dry matter), 3) control + organic acid(2%), 4) control + molasses(8%) and 5) control + (fibrinolytic enzyme+ molasses). Additives diluted in deionized water and applied with a hand held sprayer while forage samples were stirred manually. A similar quantity of deionized water was sprayed on the control forage. After designated ensiling times, silos were opened and the ensiled forage was mixed thoroughly and then were dried at a 60°C in oven for 48 h and then ground to pass through a 2 mm screen for later analysis.

Results showed that there were significant differences among treatments on NDF, CP and pH (P>0.05). Enzyme treated silages had lowest NDF content (46.50%) compared with other treatments (P<0.05). The lowest pH was related to treatment containing molasses. silage treated with organic acid improved aerobic stability, significantly. There were significant differences among treatments on gas production parameters(P<0.05) and molasses and enzyme treated pea silage had highest and lowest gas production potential than others (199.1 and 183.3 ml/g DM, respectively). Results showed that there were no significant differences among treatments on DMD and partitioning factor (P>0.05). Organic acid treated silages had lowest effect on DMD and OMD compared with other treatments (P<0.05).

Overall, results showed that using molasses and molasses + enzyme as additive can be improwed nutritive value of pea silage better than others. Anyway, green pea forage according to the appropriate level of crude protein similar to corn forage and its silage characteristics, has the potential of silage and can be used in livestock feeding.

Combining organic and chemical fertilizers is one of the most important ways to achieve sustainable agriculture. In order to investigate the effect of organic fertilizers with chemical fertilizers on yield, yield components, and quality traits of sunflower, a factorial experiment was conducted in a randomized complete block design with three replications in spring 2018 at Gonbad Kavous University farm research. Cultivar factor included Haysan 25 and Oscar and combination of fertilizer factor included no fertilizer application, 100 kg N/ha, 50 kg N/ha, 50 kg N/ha + 1.5 kg humic acid/ha, 50 kg N/ha + 0.5 kg Vita free/ha, and 50 kg N/ha + 1.5 kg humic acid+ 0.5 kg Vita free/ha. The results showed that the effect of cultivar and fertilizer on most of the measured traits was significant. Oscar cultivar produced higher grain yield, biological yield and oil percent and oil yield than Haysan 25 cultivar. Grain yield, oil yield, biological yield and plant height in 100 kg N/ha treatment was higher than other fertilizer treatments though not significantly different from 50 kg N/ha + 1.5 kg humic acid/ha + 0.5 kg Vita free/ha treatment. Based on the results, in order to achieve the maximum seed and oil yield of sunflower and to prevent excessive use of chemical fertilizers, the combined use of Nitrogen fertilizer, humic acid and vita free is necessary.

In order to investigate the effect of Cenocarpus extract on the resistance of spinach to drought stress, a factorial experiment was conducted in the form of a randomized complete block design with two replications in the crop year 2019-2020 in the research greenhouse of Gonbad Kavous University. Experimental treatments including 5 levels of drought stress (0.10, 0.20,0.30,0.40 and 0.50 MAD) and 5 levels of extract (0, 2%,4%, 6% and 8%) were applied. The results showed that the greatest increase in consumption efficiency in the growth period and total water consumption was obtained from the 6% extract concentration with values of 1.045 μg/mL and 0.235 μg/mL, respectively. The efficiency of water consumption based on dry weight and the efficiency of water consumption on wet weight of the treatment without extract were obtained as 603.2% and 695.8%, respectively. The results of the comparison of the average weight of aerial parts under water stress and from the treatment of 2% extract were obtained. The maximum root length was obtained with 8.17 and 8.07 cm for 20% and 30% drainage, respectively, and the minimum root length belonged to the 50% moisture drainage treatment. The highest amount of chlorophyll, efficiency of consumption during the growth period and total water consumption were obtained from the control treatment, and also the highest efficiency of water consumption per dry weight and efficiency of water consumption per wet weight were obtained from the 2% extract treatment.

Drought stress poses a significant challenge to crop production globally, including in Iran. Selecting drought-tolerant cultivars is crucial to mitigate adverse environmental conditions. This study aimed to evaluate the drought tolerance of various cotton cultivars using drought tolerance indices to identify the best cultivar adapted to low irrigation stress conditions. In order to investigate and determine the response of 10 cotton varieties to drought stress, an experiment in the form of a statistical design of randomised complete blocks under medium stress conditions and without stress with three replicates was conducted in 2021 and 2022 at the Teaching and Research Farm of Gonbad Kavos University. To evaluate the tolerance and sensitivity of the studied cotton cultivars to drought stress, TOL (tolerance index), MP (mean productivity index), SSI (stress sensitivity index), STI (stress tolerance index), GMP (geometric mean productivity index), YI (yield index), YSI (yield stability index), SDI (drought sensitivity index), K1STI (adjusted stress tolerance index under non-stressed conditions), K2STI (adjusted stress tolerance index under stressed conditions), SSPI (percentage sensitivity index to stress), SNPI (performance index of stress and non-stress conditions) were used. After the analysis of variance and comparison of means, correlation coefficients, principal component analysis and cluster analysis were performed to identify and introduce indicators of drought tolerance. The results of the composite Based on the analysis of variance and the significance of the simple effect and the interaction effects of year, variety and low irrigation, the comparison of the average data in two years was carried out separately, with the highest yield of Vash in the two years 2021 and 2022 under non-stressed (YP) and stressed conditions. Under low irrigation (YS), the Sajdi and Golestan varieties were the highest yielding. The varieties Mai, Shayan, Lodos, Armaghan and Latif achieved above-average yields under both non-stressed and low irrigation conditions. The analysis of the two-year correlation coefficients between the drought stress indices and rice yield under non-stress (YP) and low irrigation (YS) conditions showed the superiority of the STI, MP, GMP and K1STI indices. The results of the analysis by principal components showed that the first two components explained 99.51 and 96.50 per cent of the changes in the first and second year, respectively. The MP, GMP, STI and K2STI indices were the most suitable indices for selecting varieties tolerant under low irrigation stress, as they showed a high correlation with wash yield and more principal components under both conditions. The superior values and cluster analysis of Golestan and Sajdi cultivars were identified as the most tolerant and Sahel and Sepid cultivars as the most sensitive cultivars to low irrigation stress. It seems that production and presentation of varieties with high yield and tolerance to water stress is one of the effective solutions to reduce the harmful effects of water stress.

Rapeseed contains one of the highest quality oils with balanced components of saturated and unsaturated fatty acids. During the 2018-2019 academic year, the Bayekola Agricultural Research Station in Neka City conducted a randomized complete block design experiment with three replications. Factors included planting arrangement in two levels: one-row and two-row; and weed control in seven levels of application of herbicides: Treflan lontral herbicide 1 liter per hectare before planting and mixed with soil; butisan star 2.5 liters per hectare before planting and before emergence of rapeseed and weeds; lontral herbicide 1 liter per hectare in stages of 2 to 4 leaves of weeds; paraquat herbicide 2 liters per hectare in stages of 4 to 6 weed leaves; weed control and without weed control. The results showed that changing the arrangement of planting and application of guided herbicide in two rows increased canola seed protein percentage by 21.31%, linoleic acid by 24.22%, linoleic acid by 10.08%, oil yield and yield of canola by 78.46% and 78.48%, respectively. Also, palmitic acid decreased by 11.06% when application of this treatment was made. Therefore, by managing canola agronomy and adjusting the row spacing to utilize guided herbicide paraquat, in addition to weed control, canola also increased protein content, unsaturated fatty acids, oil yield, and rapeseed grain.

Wheat is considered a strategic crop that provides food for half of the world's population. Therefore, increasing wheat yield per unit area seems necessary due to the limited area of cultivation. Nitrogen is an essential mineral element in plant tissues, which is necessary for plant growth and metabolic processes. In the lack of nitrogen, the plant is unable to complete a normal life cycle. Nitrogen deficiency in plants will lead to slow or stopping growth, chlorosis and necrotic spots. Basically, biofertilizers not only increase yield of the crops, rather, they affect the effectiveness of most chemical fertilizers. Also, the use of supplemental irrigation increases crop yield and improves water use efficiency. So, research on increasing wheat yield per unit area will be necessary. The purpose of this study was to evaluate the effect of supplementary irrigation, alkazot biofertilizer and nitrogen fertilizer on the qualitative and quantitative characteristics of wheat.

This experiment was carried out as factorial based on randomized complete block design with three replications at the research farm of Gonbad Kavous University in growing season during 2016-2017. Alkazot biofertilizer in two levels of non-consumption and 100 kg ha-1 and into brush seed and nitrogen fertilizer in four levels of non-application and application of 50, 100 and 150 kg per hectare as first factor and supplemental irrigation in two levels (non-irrigation and irrigation in seed filling stage) as second factor. In this study, the Gonbad cultivar of wheat was used. Planting and harvesting dates were December 25, 2016 and June 1, 2017, respectively. In the present study, half of nitrogen fertilizer and biological fertilizer were applied in sowing date. The rest of the nitrogen fertilizer was applied after emergence of spikes before rainfall. In this study, the measured traits included plant height, number of spikes per square meter, number of seeds per spike, 1000-grain weight, grain yield, protein percentage and protein yield.

In the present experiment, alkazot fertilizer significantly affected plant height, number of grain per spike, 1000-grain weight, grain yield, protein percentage and yield. Overall, all of these traits under application treatment of alkazot fertilizer were more than non-application treatment with value of 4.16, 8.11, 12.04, 21.72, 3.74 and 26.40%, respectively. Supplemental irrigation also significantly affected 1000- grain weight, grain yield, protein percentages and yield. 1000-grain weight, grain yield, protein percentage and protein yield in irrigation treatment was 37.35 g, 5103 kg ha-1, 14.40% and 739.8 kg ha-1, respectively. In contrast, in non-irrigation treatment the amounts of these traits were 29.4g, 3787 kg ha-1, 15.00% and 573.8 kg ha-1, respectively. Effect of nitrogen on plant height, number of spikes per square meter, number of seeds per spike, 1000-grain weight, grain yield, protein percentage and yield were significant. Plant height, spikes per square meter, grain per spike, 1000-grain weight, grain yield, protein percentage and yield in non-application of nitrogen was 69.62 cm, 354.6 spike, 31.3 grain, 31.63 gr, 3502 kg/ha, 14.07% and 492.1 kg ha-1, respectively. The maximum amount of plant height, spikes per square meter, grain per spike, 1000-grain weight, grain yield, protein percentage and yield with value of 73.95 cm, 440.4 spike, 35.74 grain, 34.59 gr, 5364 kg ha-1, 15.54% and 831.8 kg ha-1 belonged to application of 150 kg N ha-1, respectively.

According to the results, 150 and 100 kg per hectare of nitrogen had a significant effect on all measured traits of wheat cultivar except grain per spike in case of alkazot biofertilizer. While irrigation in reproductive stage affected just 1000-grain weight, seed yield, protein percentage and yield. According to the results, it can be concluded that the amount of rainfall and temperature at the time of vegetative growth in Gonbad Kavous County was sufficient that in the reproductive stage, once supplementary irrigation with the use of alkazot and nitrogen resulted in good quantitative and qualitative yield.

Chickpea is the third most important cereal crop in the world after beans and peas. European scientists found that studying 542 plant species in 26 European countries, including 125,000 time series, found that in 78% of the time between 1971 and 2000, the rate of development increased due to rising temperatures and shorter stages. The shortening of the growth period caused by the increase in temperature in most crops reduces yield because it absorbs less radiation and has less time for dry matter accumulation. The purpose of this study was to identify the effects of climate change on phenological traits of chickpea in Gonbad city in order to adapt and improve yield for future conditions.Materials and MethodsFirst, meteorological data from the Dome Synoptic Weather Station from 1993 to 2017, including daily data on maximum and minimum temperatures, sunshine hours and rainfall, and then processed and converted to DOY using the Srad -calc program (Soltani & Sinkler, 2012) Solar radiation was calculated based on sunny hours and days of the year. Then, new changes were made to the meteorological data based on climate change scenarios. The SSM-iLegume-Chickpea model was implemented for both rain and water conditions and each scenario. Planting type was selected according to the climatic conditions of the region, autumn and the type of free cultivar. Simulations For each rainfed and irrigated condition, three different planting dates (December, January and February) were selected and simulations were performed for 25 years (1993-2017). Results Planting date and climate change scenarios were significant at 1% level for all phenological traits in both rainfed and irrigated conditions, while the interaction effects of planting date and climate change except day to emergence were significant at 1% level. As the temperature rises in the future climate, the length of the phenological stages, ranging from day to flowering, day to pod start, day to physiological maturity, and day to harvest maturity will be reduced compared to normal conditions. Maximum decrease in phenology length was related to increase in temperature of 6°C and combined effects of doubling Co2 concentration, two percent decrease in precipitation and increase of 6°C under normal conditions, and minimum decrease in temperature increase scenario by 2°C. Co2 is a two percent decrease in recipitation and an increase of two degrees Celsius in both rainfed and irrigated conditions. Therefore, due to unchanged phenological stages under Co2 doubling scenarios and 2% reduction in rainfall compared to normal conditions, and reduction in phenological stages under the influence of temperature rise scenarios and similarity of the results of the temperature rise scenarios alone compared to the combined effects of Co2 doubling and 2% decrease in precipitation and an increase in temperature can be deduced that only an increase in temperature reduces the length of the phenological stages.ConclusionSimulation results in Gonbad city showed that increasing Co2 concentration in both rainfed and irrigated conditions and different planting dates had no effect on the phenological stages of chickpea but increasing temperature would significantly decrease the chickpea growth period, although this decrease in the length of chickpea growth is greater in the vegetative growth stage. As a result, the chickpea plant enters the reproductive stage faster, enjoys better temperature and humidity conditions in the reproductive stages, and causes premature and eventually evaporation of drought and late-season heat, and ultimately increases yield under conditions that will be dry. But delay in chickpea planting will shorten the chickpea growth period, depletion of available resources such as radiation, optimum humidity and temperature, dealing with end-season heat and drought, and ultimately yield loss.

In order to investigate the effect of planting pattern and nitrogen and megafol on grain yield, yield components, and seed protein of chickpea (Cicer arietinum L.) under rainfed conditions, a factorial experiment has been conducted in a randomized complete block design with three replications in Gonbad Kavous University farm during growth season of 2017-2018. The planting pattern is in three levels of 30×11, 45×7.4, and 60×5.5 cm (30 plants. m-2) and the factor of use of fertilizers in five levels of non-consumption and consumption of 50 and 100 kg nitrogen and one and two liters of megafol per hectare. The results show that the highest seed yield is related to 30×11 and 45×7.4 and the lowest is related to 60×5.5 cm. Seed per plant and seed yield in application of 100 and 50 kg N ha-1 has been higher than others. The highest and the lowest protein percentage of seeds is related to 60×5.5 and 30×11 cm. 1000-seed weight in application of 100 and 50 kg N ha-1 and 2 liters of megafol has been more than other treatments. The harvest index in application of fertilizer is the maximum and in treatment of non-application of fertilizer is the minimum. In addition, because of more effect of nitrogen on seed yield compared to megafol and non-significant differences between consumption of 100 and 50 kg N ha-1, it seems that consumption of 50 kg N ha-1 and planting pattern of 30×11 is the most appropriate advice for planting of rainfed chickpea in Gonbad Kavous condition.

The main goal of conventional agriculture is to maximize both production and income. Intercropping, the agricultural practice of cultivating two or more crops in the same space at the same time, is an old and commonly used cropping practice that aims to match efficiently crop demands to the available growth resources and labor. The most common advantage of intercropping is the production of greater yield on a given piece of land by making more efficient use of the available growth resources using a mixture of crops of different rooting ability, canopy structure, height, and nutrient requirements based on the complementary utilization of growth resources by the component crops. Mixed cropping of cereals with non-cereal plants, in addition to the optimal and fair use of resources such as land and labor, increased productivity per unit area and strengthened total productivity per unit area and time. In mixed cropping of bean and sesame, treatments including 25:75, 50:50 and 75:25 had 1000-seed weight, number of capsules or pods per plant, number of seeds per pod and harvest index were higher than other treatments. 

An experiment was carried out as factorial based on a randomized complete block design with three replications in Gonbad Kavous University farm from 2017-to 2018. The intercropping ratios were in nine levels, including sole crop of chickpea and lettuce, replacement intercropping of 33, 50, and 66% lettuce instead of chickpea, and additive intercropping of 100% cicer + 33, 50, 67, and 100% lettuce and pure nitrogen consumption in three levels of 0, 50 and 100 Kg-ha. Row distance was 30cm, and row lengths were 3m. The distance between plants in rows was 20 cm for lettuce and 10 cm for chickpeas. The number of rows in sole cropping of chickpea and lettuce was four, 50% lettuce + 50% chickpeas 4 (chickpea-lettuce-chickpea-lettuce), 33% lettuce + 67% chickpea 5 (chickpea-lettuce-chickpea-chickpea–lettuce), 33% chickpea + 67% lettuce 5 (lettuce-chickpea-chickpea- lettuce-chickpea) and in additive treatments was 8 (lettuce-lettuce-lettuce-lettuce-lettuce-lettuce-lettuce-lettuce-) with 15 cm from together. In additive treatments distance of plants was 60, 40, 30, and 20 cm for 33, 50, 67, and 100% increase, respectively. SAS Ver. 9.4 was performed for statistical analysis of data, and the least significant difference test (LSD) at the 5% probability level was employed for mean comparisons.   

The results showed that the highest dry weight, number of pods per plant, number of seeds per plant, 1000-seed weight, seed weight per plant, and chickpea harvest index were obtained from replacement series of 33% chickpea and 67% lettuce. This was due to reduced external competition, which provided more space for the plant and produced more photosynthetic material. Also, the lowest dry weight, number of pods per plant, number of seeds per plant, seed weight per plant, and 1000-seed weight of chickpea were obtained from an increase of 100% lettuce to chickpea. With increasing nitrogen consumption, plant weight, the number of pods per plant, number of seeds per plant, seed weight per plant, 1000-seed weight and chickpea harvest index, and lettuce plant height and weight were increased. By increasing of nitrogen, plant growth, yield components, and consequently, chickpea seed yield increased. 

Among the two pea and lettuce plants, lettuce plant weight was higher. The higher weight of lettuce can be attributed to the genetic characteristic of the plant (harvest of the whole plant and high level of water content of the plant). The weight of both species increased with increasing nitrogen consumption. The highest harvest index resulted from the treatment of 50 kg nitrogen per hectare, and the lowest harvest index was obtained from the treatment of non-consumption of nitrogen. Chickpea plant dry weight was reduced due to increasing density which in turn resulted in high competition between plants. Seed weight and yield components of chickpea decreased with increasing density.

This study is conducted to investigate the influential factors on rice yield gap in the Joibar Region, located in Mazandaran Province, by means of two methods of boundary line analysis and comparative performance analysis, in the cropping years of 2017-18 and 2018-19. It is carried out through fieldwork and face-to-face interviews with farmers, for which purpose, totally 120 rice fields located in the studied geographical area in each crop year have been selected in such a way that they had sufficient diversity in terms of location and time. In the comparative performance analysis method, the relation between yield and all measured quantitative and qualitative variables are examined, using multiple regression method. According to the suggested protocol in the boundary line analysis method, a boundary line is fitted to the data in the data distribution diagram. Results show that according to the yield comparative performance analysis model, the yield gap of Joibar rice fields has been 1842 kg/ha, and the harvest date has played the most important role in rice yield gap. Also, according to the findings of border line analysis, the yield gap of rice fields in this region has been 874 kg/ha with the biological control being the most important factor in rice yield gap. Therefore, continuous monitoring and evaluation of crop management on farmers' fields and its identification is essential to eliminate yield gaps along with the management factors causing them.

Fertilizer use is cost-effective until the higher yield supply the cost of consuming more fertilizer. In other words, like any other investment, fertilizer use should have a reasonable return because the law of diminishing returns also applies to fertilizers (Khajehpour, 2008). Application of nitrogen increased Seed yield and Protein percentage but nitrogen agronomic efficiency decreased (Doaei, 2018). In many crops, topping reduces vegetative growth and transfers more and better photosynthetic materials to specific organs, especially seeds. This increases the penetration of light into the canopy and the lower leaves of the plant can use more light. Therefore, increases the photosynthesis of the lower leaves, transfers more photosynthetic materials to growing organs and as a result, productivity will increases. It seems that earlier topping will reduce the number of pods per plant and will improve the conditions for photosynthetic material to be transferred to the pods. Thus, more seeds per pod will be produced. Furthermore, the flowers that will be set in late, have no opportunity to form a large pod and consequently, the fewer seeds will be set in the pod. Delay in topping will reduce the number of seeds per pod of faba bean (Nakhzari Moghaddam, 2013).

In order to study the effect of topping, nitrogen and supplemental irrigation on green pod yield, protein percentage, proline rate and agronomic efficiency of nitrogen in faba bean, a factorial experiment based on Randomized Complete Block Design was conducted with three replications at research farm of Gonbad Kavous University during growing season of 2016-2017. Planting date was 11.13.2016 and harvest date was 5.6.2017. Topping factor was in three levels of non- topping, topping at beginning of flowering and topping at beginning of seed filling, nitrogen in three levels including 0, 50 and 100 kg nitrogen per hectare and supplementary irrigation in two levels of non irrigation and irrigation at the filling stage. Each plot had four rows with 50 cm width and four meter length. Seed planted in depth of three cm. one third of nitrogen were used in sowing date, one third in branching and other one third in seed filling stage. Supplemental irrigation was done in 5.24.2017, first topping in 4.30.2017 and second in 5.13.2017.

The results showed that the effect of topping on green pod yield, proline rate and agronomic efficiency of nitrogen was significant but on protein percentage was not significant. Effect of nitrogen and supplementary irrigation on green pod yield, proline rate, protein percentage and agronomic efficiency of nitrogen were significant. Green pod yield in none topping treatment, topping at the beginning of flowering and seed filling stages was 21523, 29118 and 27737 kg.ha-1, respectively. The highest yield of green pod with 29118 kg.ha-1 was related to consumption of 100 kg N.ha-1 and the least was related to treatment of non application of nitrogen with 22149 kg ha-1. Although application of nitrogen increased green pod yield but agronomic efficiency of nitrogen was decreased. Reducing of nitrogen use efficiency was due to increasing nitrogen loss through leaching and sublimation and the lack of effective absorption by the plant. Supplemental irrigation increased green pod yield 5143 kg ha-1 (21.83%). Topping by reducing top dominance transfered more nutrients into pods and therefore pod yield increased. Agronomic efficiency of nitrogen in treatment of topping at beginning of seed filling was 89.85 and at beginning of flowering was 55.96 seed grain/kg nitrogen. Nitrogen consumption increased protein percentage of the seed so that in treatment of 100 kg Nha-1 protein percentage was 22.65 (7.65% more d the protein cont than non consumption). Proline rate and protein percentage in none irrigation treatment was greater than irrigation treatment but green pod yield and agronomic efficiency of nitrogen was lower.

Topping, nitrogen consumption and irrigation increased green pod yield. Therefore, for obtaining more yield of faba bean it is nessesary to remove head of plant, use enough nitrogen and irrigate plans at least one time in reproductive stage.

Quinoa is a plant of Amaranthus family, a genus of Chenopodium. Having a wide variety of genetic variations and flexibility allows the plant to adapt to different environments. One of the factors that should be considered when planting a plant in the pattern of cultivation in each region is the planting date of the plant. This factor can affect grain yield and quality by affecting vegetative and reproductive growth period in Quinoa. Sowing date is one of the most effective factors in completing different stages of plant growth. Since observing proper sowing dates will result in higher economic performance without any additional expense and will allow the plant to show its full potential.

In order to study the effect of planting date on phenological, morphological, yield and yield components of Quinoa, a study was conducted on different planting dates on the Quinoa. This study was carried out at a greenhouse complex of Agricultural Jihad in Khalilabad, Khorasan Razavi province, during 2018in a randomized complete block design with three replications and 12 different sowing dates. The cultivation was carried out on March 5 and at intervals of 15 days.

The results showed that the sowing date was significant for the number day of planting to emergence, planting to four leaves, planting to emergence of inflorescence, planting to change the color of inflorescence and planting to harvesting. The results showed that the time from sowing to emergence was reduced by increasing the environment temperature. The results of the experiment showed that the effect of sowing date at 1% probability level was significant on number of seeds per plant, 1000 seed weight, and seed weight per plant, grain yield, biological yield and Harvest Index. The highest grain yield was obtained in sowing date on March 5(2387 kg.ha) and the lowest in sowing date on May 20th (75 kg.ha). The highest biological yield was related to the sowing date of March 5 (10964 kg.ha) and the lowest was related to the sowing date of August 21 (3739 kg.ha), which did not show any significant difference with the sowing date of August 6.

In general, the results showed that different sowing dates due to changes in temperature and day time could affect the morphological, phenological, yield and yield components of the Quinoa under the experimental conditions. The results showed that the flowering stage and seed filling in the Quinoa was one of the sensitive growth stages of the plant to temperature, because the increase in temperature, especially in the flowering and pollination stage, led to a sharp decrease in the number of seeds and, finally, a significant reduction in the grain yield of this plant. In sum, the best sowing date for the Quinoa was obtained based on the information obtained from this study for March 5 and March 21.