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به منظور بررسی اثر کود ورمی کمپوست بر عملکرد و اجزای عملکرد گندم رقم چمران در شرایط تنش گرمایی آخر فصل، آزمایشی مزرعه‌ای به صورت اسپلیت پلات در قالب طرح پایه بلوک‌های کامل تصادفی با چهار تکرار در سال زراعی 97-1396 در مزرعه تحقیقاتی دانشگاه علوم کشاورزی و منابع طبیعی خوزستان اجرا شد. عوامل آزمایشی شامل سه تاریخ کاشت یک آذر، 20 آذر و 10 دی در کرت‌های اصلی و پنج سطح کود ورمی‌کمپوست (صفر، پنج، 10، 15 و 20 تن در هکتار) در کرت‌های فرعی بود. تجزیه واریانس نشان داد که اثر تاریخ کاشت و کود ورمی کمپوست بر صفات اندازه‌گیری شده معنی‌دار بود. مقایسه میانگین نشان داد که بیشترین عملکرد دانه (2356 کیلوگرم در هکتار) در تاریخ کاشت یک آذر و کمترین آن (1732 کیلوگرم در هکتار) در تاریخ کاشت 10 دی بود. همچنین در سطوح مختلف کود ورمی کمپوست، بیشترین عملکرد دانه (2593 کیلوگرم در هکتار) در مصرف 20 تن در هکتار ورمی‌کمپوست و کمترین آن (1566 کیلوگرم در هکتار) در عدم کاربرد ورمی‌کمپوست حاصل شد. به طور کلی تاخیر در کاشت و وقوع تنش گرمایی آخر فصل، باعث کاهش عملکرد دانه ولی افزایش میزان مصرف ورمی‌کمپوست در تاریخ‌های کاشت مختلف، موجب افزایش عملکرد دانه گندم شد.

به‌منظور بررسی واکنش گندم به مصرف کود دامی و زئولیت در شرایط تنش کم­ آبی، آزمایشی مزرعه‌ای به‌صورت اسپلیت فاکتوریل در قالب طرح پایه بلوک‌های کامل تصادفی با سه تکرار در پاییز سال زراعی 1396-1395 در مزرعه تحقیقاتی دانشگاه علوم کشاورزی و منابع طبیعی خوزستان اجرا شد. فاکتورهای آزمایشی شامل سه زمان قطع آبیاری (آبیاری کامل (شاهد)، قطع آبیاری از ابتدای مرحله شیری- خمیری تا رسیدگی فیزیولوژیک و قطع آبیاری از ابتدای مرحله گلدهی تا رسیدگی فیزیولوژیک) در کرت‌های اصلی و سه مقدار کود دامی (صفر، 15 و 30 تن در هکتار) و سه مقدار زئولیت (صفر، 6 و 12 تن در هکتار) به‌صورت فاکتوریل در کرت‌های فرعی بودند. مقایسه میانگین اثر برهمکنش کود دامی و زئولیت نشان داد که در شرایط آبیاری کامل، قطع آبیاری از مرحله شیری-خمیری تا رسیدگی فیزیولوژیک و قطع آبیاری از ابتدای مرحله گلدهی تا رسیدگی فیزیولوژیک، مصرف 30 تن در هکتار کود دامی و 12 تن در هکتار زئولیت نسبت به عدم مصرف آن‌ها، باعث افزایش قابل‌توجه عملکرد دانه شد. لذا در مناطق با کمبود آب آبیاری و یا عدم بارندگی از ابتدای مرحله گلدهی و یا مرحله شیری- خمیری دانه، می‌توان مصرف 30 تن در هکتار کود دامی و 12 تن در هکتار زئولیت برای حفظ و یا افزایش عملکرد دانه توصیه کرد.

به منظور مقایسه ارقام بهاره گلرنگ (Carthamus tinctorius L.) با استفاده از شاخص‌های تحمل و حساسیت به تنش گرمای آخر فصل در اهواز، آزمایشی در مزرعه پژوهشی دانشگاه کشاورزی و منابع طبیعی رامین خوزستان در سال زراعی 96-1395 به صورت کرت‌های یک بار خرد شده در قالب بلوک‌های کامل تصادفی با چهار تکرار انجام شد. فاکتورهای آزمایشی شامل چهار تاریخ کاشت (20 آبان، 11 آذر، 15 دی و 14 بهمن) در کرت های اصلی و پنج رقم گلرنگ (سینا، گلدشت، صفه، محلی اصفهان (کوسه) و فرامان) بود. نتایج نشان داد که ارقام مورد مقایسه از نظر صفت عملکرد دانه از لحاظ شاخص‌های حساسیت به تنش (SSI)، شاخص تحمل (TI)، میانگین بهره‌وری (MP)، میانگین هارمونیک (HM)، شاخص پایداری عملکرد (YSI)، میانگین هندسی (GMP)، شاخص تحمل تنش (STI)، شاخص خسارت تنش (SDI)، شاخص تحمل تنش تعدیل شده برای شرایط مناسب (MSTI1)، شاخص تحمل تنش تعدیل شده برای شرایط نامناسب (MSTI2) و شاخص درصد کاهش عملکرد (YRI) تفاوت معنی‌داری داشتند. با این حال اختلاف ارقام مورد بررسی از نظر شاخص رتبه بندی (RI) و شاخص عملکرد (YI) معنی دار نبود. در شاخص تحمل تنش (STI)، رقم گلدشت (0.335) بیشترین تحمل (کمترین حساسیت) و رقم محلی اصفهان (کوسه) با میانگین (0.157) کمترین تحمل (بیشترین حساسیت) نسبت به تنش گرمای آخر فصل خوزستان را داشتند. به طور کلی شاخص تحمل تنش (STI) نسبت به سایر شاخص‌های مورد بررسی، جهت شناسایی ارقام متحمل و حساس گلرنگ نسبت به تنش گرمای آخر فصل در خوزستان مناسب است.

به‌منظور بررسی اثر دوره‌های رشد و نمو بر عملکرد دانه و اجزای آن در 20 رقم گندم نان بهاره در شرایط تنش گرمای آخر فصل اهواز، آزمایشی مزرعه‌ای در دو سال زراعی 87-1386 و 88-1387 در اهواز به‌صورت بلوک‌های نواری شامل چهار تاریخ کاشت (15 آبان، 15 آذر، 15 دی و 15 بهمن‌ماه) در کرت‌های افقی و 20 رقم گندم نان بهاره (اترک، اروند، اس8018، استار، اینیا66، بولانی، بیات، پیشتاز، چمران، چناب70، داراب2، دز، روشن، شعله، فلات،‌ کویر، مارون‌، هامون، هیرمند و ویریناک) در کرت‌های عمودی با سه تکرار اجرا شد. نتایج نشان داد که سال، تاریخ کاشت، رقم و اثر متقابل تاریخ کاشت در رقم اثر معنی‌داری بر صفات اندازه‌گیری شده داشتند. مقایسه میانگین‌ها نشان داد که با تأخیر در کاشت و افزایش میانگین دمای دوره رشد، تعداد روز از کاشت تا گرده‌افشانی، تعداد روز از گرده‌افشانی تا رسیدگی و تعداد روز از کاشت تا رسیدگی کاهش یافت درنتیجه تعداد دانه در مترمربع، وزن هزار دانه و عملکرد دانه کاهش یافت که به کاهش سرعت تشکیل دانه، سرعت پر شدن دانه و سرعت تشکیل عملکرد دانه منجر شد. ارقام زودرس- دیررس مارون و شعله با دوره کاشت تا گرده‌افشانی کوتاه، سریع‌تر گلدهی کرده و با دوره گرده‌افشانی تا رسیدگی طولانی، دوره پر شدن دانه طولانی‌تری داشتند.

To compare tolerance and sensitivity indices of sesame genotypes to water stress in Ahvaz (south-west of Iran) conditions, an experiment was conducted in Research Farm of Agricultural Sciences and Natural Resources University of Khuzestan, south-west of Iran, in summer 2018. The experimental design was split plot based on a randomized complete block design with four replicates. Experimental factors were three levels of irrigation (I1; fully irrigated, I2: changing altered irrigated and I3: fixed altered irrigated) in main plots and six sesame genotypes in subplots. The yield of studied genotypes showed a significant difference in different levels of irrigation. Genotype Shushtar produced the highest grain and oil yield and showed good performance in both normal and low irrigation conditions. The examined genotypes had significant differences in terms of Stress Sensitivity index (SSI), Tolerance Index (TI), Productivity Mean (PM), Harmonic Mean (HM), Yield Stability Index (YSI), Geometric Productivity Mean (GPM), Stress Tolerance Index (STI), Stress Damage Index (SDI), Modified Stress Tolerance for appropriate conditions (MSTI1), Modified Stress Tolerance for non-appropriate conditions (MSTI2), and Yield Reduction Index (YRI). In general, the best indicator for evaluation of tolerance and susceptibility of sesame genotypes was stress tolerance index (STI). The most tolerant and sensitive genotypes were Shushtar and Halil genotypes, respectively. [ABSTRACT FROM AUTHOR]

Objective: Considering that the compost of sugarcane residues softens the soil texture and the use of plant growth stimulating bacteria increases the plant's tolerance against abiotic stress, including heat stress. To assess the combined effect of nitrogen fertilizer with sugarcane residue and growth-promoting bacteria on the qualitative traits and yield of wheat grain under terminal heat stress conditions, an experiment was carried out as split-split plots in the form of a randomized complete block design with three replications in the cropping season of 2021-2022 at the research farm of Khuzestan University of Agricultural Sciences and Natural Resources. Methods: The experimental factors included three sowing dates: 22 November, 11 December, and 31 December in the main plots; six combination of nitrogen with compost including control, 100% nitrogen, 75% nitrogen+ 25% compost, 50% nitrogen+ 50% compost, 25% nitrogen+ 75% compost, and 100% compost in sub-plots, as well as two levels of application and without application of bacteria in the sub sub-plots. Results: Mean comparisons showed that the combined use of 50% nitrogen + 50% compost with bacterial application increased the characteristics of grain filling duration and grain filling rate, grain protein percentage, and wet gluten. Also, the highest seed yield (5864 kg/ha) was obtained on the first planting date and combined consumption of 50% nitrogen + 50% compost and the lowest amount (1115 kg/ha) was obtained on the third planting date and the control treatment. Conclusion: In general, the combined use of nitrogen fertilizer and compost with growth-promoting bacteria could reduce the negative effect of terminal heat stress on the measured plant traits. [ABSTRACT FROM AUTHOR]

Introduction Among the most common problems and stress in the conditions of Khuzestan province, heat stress at the end of the season and the deficiency of nutrients, which occurs in different periods of rapeseed growth, depending on their severity, causes physiological and metabolic disorders and ultimately reduces the yield of rapeseed plants with different intensity depending on the type of plant genotype, they affect Materials and Methods With the aim of evaluating the growth and yield response of rapeseed cultivars (Brassica napus) to boron element levels in late season heat stress conditions caused by late sowings dates, this study was carried out in a split-split plot arrangement in the form of a randomized complete block design with three replications. The expeiment was carried out in the crop year of 2021-2022 in the research farm of Agricultural Sciences and Natural Resources University of Khuzestan. Sowings dates (November 21, December 11, and December 31) in the main plots, four levels of boron (zero, 4, 8, and 12 kg/ha) in the subplots and rapeseed cultivars (RGS, Zafar, and Saffar) in the sub-sub-plots were investigated. Results and Discussion The results of the research showed that sowing date and end of season heat stress in Khuzestan conditions had a significant effect on most of the studied physiological traits, seed yield and biological yield. In addition, the effect of boron on traits such as leaf area index, leaf area ratio, and relative moisture content of leaf water, leakage of electrolytes, grain yield and biological performance was significant. The triple interaction effect of planting date, boron and variety was also significant on traits such as relative moisture content of leaf water, leakage of electrolytes, grain yield, and biological performance. So that with the delay in planting and the consequent increase in temperature and heat stress at the end of the season in the period of growth of the rapeseed plant, it causes a decrease in traits such as leaf area index, relative moisture content of leaf water, leaf area ratio, leaf specific area, seed yield and biological yield. And conversely, due to the heat stress at the end of the season, the leakage of electrolytes and the canopy temperature increased significantly. In general, the highest seed yield was obtained in Safar variety on the sowing date of December 11 and the boron level was 4 kg/ha with an average of 4590 kg/ha. Also, the highest average leaf area index was observed on the first sowing date and Safar variety with an average of 5.43 and the lowest value was observed on the third sowing date and Safar variety with an average of 2.11. It was also observed that the application of boron caused a significant decrease in the leaf area index in all three studied cultivars. This issue can indicate the lower need of boron consumption of the studied cultivars in this experiment. Conclusion In general, the heat stress at the end of the season, which occurs in different periods of rapeseed growth, especially the seed filling period, depending on its intensity, causes physiological disorders in the plant and finally affects the grain yield with different intensity and depending on the genotype of the plant. The analyzed rapeseed genotypes also showed tolerance to different levels of boron element in the heat stress conditions of the end of the season and showed different reactions with different amounts of boron consumption per hectare. [ABSTRACT FROM AUTHOR]

Background and objectives: In order to improve soil fertility, increase the capacity to hold water and nutrients in the soil, as well as improve the growth and yield of plants, the use of different organic fertilizers in the soil has great importance due to the problem of lack of organic matter in most soils of Iran. However, organic fertilizers alone are not able to meet the needs of plants and are not sufficiently available to farmers. On the other hand, the high consumption of chemical fertilizers causes environmental pollution and increases production costs. Therefore, in order to efficiently and effectively use organic and chemical fertilizers and achieve sustainable agriculture, combined use of organic and chemical fertilizers is recommended. Using the biological potential of the soil or beneficial microbial community, including bacteria and fungi, is considered as a promising solution in sustainable agriculture. Considering the effect of heat stress at the end of the season on the reduction of wheat production in Khuzestan, as well as the effect of reducing the use of chemical fertilizers and increasing the use of organic and biological fertilizers on the health of agricultural ecosystems, this experiment was designed and implemented with aim to investigate the effect of combined use of nitrogen chemical fertilizer with sugarcane residue compost and the application of plant growth promoting rhizobacteria in late season heat stress conditions on the growth and yield of wheat (cv. ‘Chmaran 2’). Materials and methods: The experiment was carried out in the form of split-split plots in the form of a basic design of randomized complete blocks with three replications in the crop year of 2021-2022 in the research farm of Agricultural Sciences and Natural Resources University of Khuzestan. The experimental factors include three planting dates on November 1, December 11 and December 31 in the main plots; Six levels of combined use of nitrogen chemical fertilizer (urea) with organic fertilizer, sugarcane residue compost, including control (without nitrogen and organic fertilizer), 100% nitrogen fertilizer, 75% nitrogen fertilizer+ 25% organic fertilizer, 50% nitrogen fertilizer+ 50% organic fertilizer, 25% nitrogen fertilizer+ 75% organic fertilizer and 100% organic fertilizer in sub-plots and two levels of application and non-application of biofertilizers in sub-plots. Each subplot was 3 meters long and 2 meters wide (with an area of 6 square meters) and included 10 crop lines at a distance of 20 cm from each other. The distance between the main and sub plots was half a meter and the distance between the blocks was considered to be two meters. After harvest maturity, the plants were harvested and grain yield and yield components were measured. Results: Analysis of variance showed that the effect of sowing date and the combined use of chemical fertilizer with organic fertilizer of sugarcane residue compost were significant on all measured traits. Also, the effect of plant growth promoting rhizobacteria was significant on all the measured traits except harvest index. The mean comparisons showed that on the first planting date (December 1), the highest grain yield (5663 Kg ha-1 ) was in the combined use of 50% nitrogen+ 50% compost and the lowest amount (2821 Kg ha-1 ) was in the control. On the second planting date (December 20), the highest grain yield (4874 Kg ha-1 ) was in the combined use of 50% nitrogen+ 50% compost, and the lowest grain yield (2179 Kg ha-1 ) was in the condition of not using nitrogen fertilizer and compost. Also, on the third planting date (December 10), the highest grain yield (3622 Kg ha-1 ) was in the combined use of 50% nitrogen+ 50% compost and the lowest amount (1155 Kg ha-1 ) was in the control. In general, the delay in planting and the occurrence of heat stress at the end of the season caused a decrease in grain yield, but in different planting dates, the combined use of 50% nitrogen fertilizer+ 50% organic fertilizer compared to the treatment of 100% nitrogen chemical fertilizer, increased the yield by 9 to 18 percentage of wheat grain yield. Conclusion: According to the results, in areas with heat stress at the end of the season, it is possible to consider the combined use of 50% nitrogen chemical fertilizer+ 50% organic fertilizer of sugarcane residue compost and plant growth promoting bacteria to increase the growth and yield of wheat. [ABSTRACT FROM AUTHOR]

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Background and objectives: Drought stress, reduces physiologic, qualitative and yield traits of triticale. Also, using compost fertilizer has beneficial effects on physical, chemical and biological conditions of the soil and reducing the negative effect of environmental stresses like drought stress on physiologic and qualitative traits of crop plants. This study designed and carried out with aim to study the effect of sugarcane residue compost fertilizer on physiologic and qualitative traits of triticale under drought stress conditions in Ahwaz weather conditions in Agricultural Sciences and Natural Resources University of Khuzestan. Materials and methods: In order to investigate the effect of sugarcane residue compost fertilizer on physiologic and qualitative traits of triticale under drought stress conditions, a field experiment using a split-plot arrangement accomplished in a randomized complete block design with four replicates in the research farm of Agricultural Sciences and Natural Resources University of Khuzestan during 2018-2019 growing season. Experimental factors include four levels of drought stress (complete irrigation, drought stress from spike emergence stage, drought stress from pollination stage and drought stress from milky-dough stage) in main plots and five amounts of sugarcane residues compost fertilizer (0, 10, 20, 30 and 40 t ha-1) in sub-plots. Results: Analysis of variance showed that the effect of drought stress, sugarcane residue compost fertilizer and their interaction on the most of measured traits (SPAD, chlorophyll a, chlorophyll b, carotenoids, relative water content, cell membrane stability, canopy temperature, redistribution, grain yield, and grain protein, Fe and Zn content) were significant. Mean comparison of above measured traits in interaction effects of drought stress and sugarcane residue compost fertilizer showed that drought stress decreased these traits and the maximum amount of these traits was obtained in full irrigation and the lowest amount was observed in drought stress from spike emergence to complete maturity. Also, in different drought stress levels, with increasing the amount of sugarcane residue compost fertilizer, the amount of traits increased and reached a maximum at the level of 40 t ha-1. Therefore, the maximum amount of these traits was under full irrigation and 40 t ha-1 of sugarcane residue compost and the lowest amount of them was obtained in drought stress from spike emergence and non-use of sugarcane residue compost. Conclusion: Generally, drought stress from irrigation cut off decreased physiologic and qualitative traits of triticale. Also, in different drought stress levels with increasing the amount of sugarcane residue compost fertilizer, the amount of above traits increased. Therefore using sugarcane residues compost fertilizer decreased the negative impact of drought stress from spike emergence conditions on physiologic and qualitative traits of triticale between 6 to 46 percent. [ABSTRACT FROM AUTHOR]

In order to increase the quality of agricultural products and improve healthy food production systems, application of organic fertilizers has become very important in agroecosystems. To investigate the effect of different concentrations and time of humic acid foliar application on the qualitative characteristics and shoot and grain micronutrients content of Triticale, an experiment was conducted at the Research Field of Agricultural Sciences and Natural Resources University of Khuzestan during the 2017-2018 growing season. The experimental design was a split plot based on the randomized complete block design with four replications. Treatments included the time of foliar application at four levels (tillering, stem elongation, flag leaf, anthesis) in the main plot and spraying concentrations at four levels (0, 200, 400 and 600 mg L-1) in the sub plots. The results showed that the foliar application of humic acid at the flag leaf and anthesis stages had the greatest impact on the plant physiological traits. The highest chlorophyll b content, leaf area index and total chlorophyll (SPAD) were obtained from the application of 600 mg L-1 humic acid and the highest chlorophyll a content was gained from the spraying of 400 mg L-1. The maximum grain iron (40.44 mg kg-1) was related to the spraying of 200 mg L-1 of fertilizer at the tillering stage. The highest protein yield (745.65 kg ha-1) was obtained from the foliar application of 200 mg L-1 humic acid in the flag leaf stage. The highest amount of manganese (30.73 mg kg-1) was related to the application at the stem elongation stage and the concentration of 200 mg L-1. Based on the findings of this study, humic acid foliar application can increase the accumulation of micronutrients in plant and improve the qualitative traits of triticale. [ABSTRACT FROM AUTHOR]

Among soil and agronomic factors affecting growth, nutrition and plant density have a great effect on the growth and yield of crops such as Flax (Linum usitatissimum L.). In order to study the effect of different levels of nitrogen and plant density on yield and yield components, oil percentage and yield of Flax, a split plot experiment was conducted in a randomized complete block design with four replicates at the Research Farm of Agricultural Sciences and Natural Resources University of Khuzestan, Iran in 2016-2017. Experimental factors included different levels of nitrogen (0, 75, 150 and 225 kg/ha) in main plots and four plant densities (50, 100, 150 and 200 plants/m2) in sub plots. Analysis of variance showed that nitrogen, plant density and their interaction effect was significant on all measured traits. The highest grain and oil yields were obtained in 150 kg/ha nitrogen level and the density of 200 plants/m2. The mean comparison of interaction effect showed that the highest grain yield (1348 kg/ha) and oil yield (349 kg/ha) were achieved in 150 kg/ha nitrogen level and the density of 200 plants/m2. The lowest grain yield (570 kg/ha) and oil yields (188 kg/ha) were observed in 0 kg/ha nitrogen level and the density of 150 plants/m2. [ABSTRACT FROM AUTHOR]

In order to study the response of morphology, yield and yield components of spring safflower (Carthamus tinctorious L.) cultivars to different sowing dates, an experiment was carried out using a split-plot design on the basis of a randomized complete block design with four replications, in Agricultural Sciences and Natural Resources University of Khouzestan, south-west of Iran at 2016-2017. Experimental factors were four sowing dates (11 November, 2 December, 5 January and 3 February) in main plots and five safflower cultivars (Sina, Goldasht, Soffeh, local Esfahan (Kooseh) and Faraman) in sub plots. The analysis of variance showed that the interaction effect of sowing date and cultivar was significant on all measured traits except plant height and grain oil percent. The mean comparisons showed that the highest grain yield (3722 kg/ha) and oil yield (837 kg/ha) were produced in sowing date of 11 November by Goldasht cultivar, and the lowest grain yield (351 kg/ha) and oil yield (71 kg/ha) were observed in sowing date of 3 February by Faraman cultivar. The highest amount of measured traits were achieved in the first sowing date (November 11) and delays in sowing date and, hence, occurrence of a terminal heat stress in flowering and grain filling phase decreased the grain yield and oil yield. [ABSTRACT FROM AUTHOR]

To evaluate the effect of different concentrations of humic acid on guar (Cyamopsis tetragonoloba L.) yield and nutrient uptake in different sowing densities, an experiment was carried out by using a split plot design with three replications based on a randomized complete block design, in Agricultural Sciences and Natural Resources University of Khuzestan, Iran at summer 2016. Experimental factors consisted of four levels of humic acid (0, 5, 10 and 15 kg/ha) as the main plots and four plant densities (35, 55, 75 and 95 plants/m2) as sub plots. The density of 35 plants/m2 and 15 kg/ha humic led to increase in nitrogen, phosphorus, zinc and iron content of the plant. Moreover, the highest nitrogen harvest (295 kg/ha) was obtained from density of 95 plants/m2 and 15 kg/ha of humic acid. The lowest plant protein content (8.84%) was obtained from density of 95 plants/m2 and without application of humic acid. The highest grain yield and dry matter (4209 and 17955 kg/ha, respectively) were obtained from density of 95 plant/m2 and application of 15 kg/ha humic acid. Generally, it seems that high levels of plant density (greater than 95 plant/m-2) must be evaluated for cultivation of guar in Khuzestan province. In addition, application of humic acid may lead to significantly increase of guar yield in the region. [ABSTRACT FROM AUTHOR]

Terminal heat stress in hot and dry conditions like Ahwaz reduces the quantitative and qualitative yield of wheat. In order to study the effect of terminal heat stress on grain filling period duration, grain filling rate and quantitative and qualitative yield of 20 spring bread wheat cultivars, a field experiment was conducted in Research Farm of Agricultural Sciences and Natural Resources University of Khuzestan, Iran in 2008-2009 as stripe block design and included four sowing dates (6 Nov., 6 Dec., 5 Jan. and 4 Feb.) in horizontal plots and 20 spring bread wheat cultivars in vertical plots with three replications. The analysis of variance showed that sowing date, genotypes and their interaction had a significant effect on measured traits. The mean comparison of interaction effect showed that in sowing date of 6 Dec. the highest grain yield (7254 kg/ha) was related to Chamran cultivar and the lowest grain yield (5445 kg/ha) belonged to Maroon cultivar. In terminal heat stress condition (sowing date of 4 Feb.), the highest grain yield (2323 kg/ha) was related to Maroon cultivar and the lowest grain yield (1258 kg/ha) belonged to Hamoon cultivar. Generally, in early (6 Nov.), timely (6 Dec.) and late (5 Jan) seeding, Chamran cultivar was suitable and in very late (4 Feb.) sowing, cultivars of Maroon, Virinak, Arvand and Atrak were suitable. [ABSTRACT FROM AUTHOR]