Iranian Journal of Field Crops Research
Year:2019 | Volume:16 | Issue:4|Papers Count:12

Introduction: Black cumin (Bunium persicum Bioss) is a small and perennial herbaceous plant. During the first year of the growth, this plant produces only cotyledon leaves and small root that becomes to underground tuber after growth. Lack of sufficient rainfall with irregular patterns over black cumin growing areas cause drought stress during different growth periods of plant, especially during the first and the second years of plant growth when tubers do not well formed. Therefore, this study was planned to evaluate moisture stress impacts on the growth of black cumin during the first year of its growth. Materials and Methods: In order to investigate the effect of moisture stress on black cumin, an experiment was carried out in a factorial experiment based on completely randomized design with three replications at College of Agriculture, Ferdowsi University of Mashhad during 2014. The factors were included plant population in three levels (Kuhbanan, Sirjan and Kalat) and three levels of moisture stress [100, 75 and 50% of Field Capacity (FC)]. During mid-April, seed dormancy was broken by the GA and chilling. Germinated seed were planted in pots (diameter 10 cm, height 15 cm) at a depth of 1-2 cm. Pots was irrigated at FC level for up to two weeks after seedling establishment. After that pots weighted, and if the weight decreased from FC, added water to reach the desired pot weight. At the end of the growing period (seven weeks after drought stress in mid-June) all plants in each pot were harvested. Plant height, root length, shoot and root dry weight, tuber diameter and tubbering percentage were measured. Samples of shoot and root were placed in oven at 75° c for 24 hours and then their dry weight were measured by a digital scale with accuracy of 0. 001 g. Statistical analysis was performed by using the software MSTATC and the means were compared by using the LSD test. Results and Discussion: The results showed that the differences between populations for all traits were significant, except for root length and shoot/root dry weight ratio, . The effects of moisture stress and population and their interactions were significant for all traits. Plants in all populations, at 50% FC were killed due to drought stress. Kalat population at 75% FC had the maximum length of roots and shoots. Also, at 75% FC Sirjan population had the most reduction in shoot dry weight. At 75% FC Kuhbanan and Sirjan populations had 15% reduction in height while this reduction in Kalat population was 24%. Root dry weight at 75% FC in all populations was less than 100% of FC. In all population the tuber was formed only at 100% FC and plants grown at 75% FC did not produce tubers. Conclusions: Results demonstrated that reducing the soil moisture from 100% FC had negative impacts on the growth traits of black cumin. Since the black cumin is a perennial plant, it would be useful to study the effects of moisture stress during different years.

Introduction: Roselle (Hibiscus sabdariffa ) is considered as a member of Malvaceae family which is cultivated across all tropical and warm areas. More than 300 species of Hibiscus are found in tropical and subtropical regions across the world. Roselle is annual and self-pollinated plant. This plant is very sensitive to cold and glacial, it is multipurpose plant and its various components are used. Severe water restrictions and the high water costs cause in some areas, the optimal level of water to become lower than the required level for maximum production. Nowadays, appropriate irrigation management and the cultivation of drought-resistant plants are regarded as strategies to deal with drought stress. Roselle is one of the few drought resistant plants. To study the effect of different levels of irrigation, planting date and fertilizer management on yield and yield components of Roselle, an experiment was contacted in Agricultural Research Station, 105 kilometers East of Bandar Abbas, Minab city, Iran. Materials and Methods: An experiment was conducted as split-split-plot based on a randomized complete blocks design with three replications. Treatments included irrigation levels in three levels (100, 80 and 60 percent evapotranspiration from reference crop) as main plots, planting date in three levels (June 15, September 10 and October 1th) as subplots and three levels of fertilizer (Cow manure, chemical fertilizer 50% and 50% cow manure and chemical fertilizers) are allocated as sub-sub plots. Results and Discussion: The results showed that the highest plant height (127. 7 cm) and stem diameter (1. 97 cm) were obtained in irrigation after 60 percent evapotranspiration from reference crop. The highest number of growing stems (3. 20 stems) and sepal dry weight (18. 48 g) were shown in 100 percent evapotranspiration from reference crop. The total number of stems, the number of generate stems, flower dry weight and plant dry weight were decreased by increasing the percent evapotranspiration from reference crop. Thus, the lowest total number of stems (7. 70), the number of generate stems (4. 52), flower dry weight (4. 28 g. per plant) and plant dry weight (377. 1 g. per plant) were shown in 100% evapotranspiration of the reference treatment. Most of the studied criteria were decreased by delaying sowing date. The lowest stem height (108. 2 cm), stem diameter (1. 32 cm), total number of stems per plant (7. 3), the number of generate stems per plant (3. 94), sepals dry weight per plant (16. 15 g), flower dry weight per plant (3. 65 g), total dry weight per plant (212 g), were obtained on 1th October sowing date. The highest stem diameter (1. 85 cm), total number of stems per plant (10. 78), the number of growing stems per plant (7. 22), sepals dry weight per plant (21. 02 g), flower dry weight per plant (6. 59 g), total dry weight per plant (420. 02 g), were obtained under 100% chemical fertilizer treatment. The highest plant height (125. 1 cm) and the number of growing stems per plant (3. 61) were obtained under 100% chemical fertilizer treatment+100 percent evapotranspiration from reference crop under 1th of October treatment. The lowest stem diameter, the number of generate stems, the number of growing stems, sepals dry weight and total dry weight in each plant were obtained under 100% chemical fertilizer treatment+100 percent evapotranspiration from reference crop under 1th of October treatment. The highest stem diameter, the number of generate stems per plant and flower dry weight per plant were observed under 100% cow manure+60 percent evapotranspiration from reference crop. The highest number of stems per plant, the number of generate stems per plant, sepals dry weight per plant and dry weight of flower per plant were obtained under 100% cow manure on 15 July sowing date treatment. Conclusions: The results showed that most of the studied criteria were decreased by delaying sowing date from June to October. The highest dry weight of flower per plant and sepals yield were obtained under 100% animal manure+ June 15 sowing date treatment. The lowest dry weight of sepals per plant was shown under 100% of evapotranspiration irrigation of the reference crop.

Introduction: Potential production condition is defined as situation where water and nutrients are supplied in ample with no damage from weeds, pests and diseases. Under this situation potential yield (Yp) which is defined by solar radiation, temperature, CO2 concentration and genotypic characteristics of the crop species could be achieved. Closing the gap between Yp and actual yield (Ya) harvested by farmers is considered as the main challenge of agronomic sciences all around the world. Crop simulation models provide a powerful tool for prediction of Yp at regional and national scales. However, the accuracy of these models is highly dependent on the quality of input data which are usually not fully available even in developed countries. Simplified models designed based on few simple equations may be considered as an alternative where accurate data sets are lacking. In this research, Yp of wheat and sugar beet were estimated using some simple methods and the results were compared with those of complex simulation models under the same climatic and management conditions in Khorasan province, north east of Iran. Materials and Methods: Potential yields of wheat and sugar beet were estimated by three simple calculation methods including FAO method (FAO, 1981), modified FAO, FAO-M (Versteeg and van Keulen, 1986) and RUE-based method (Nonhebel, 1997) at three different regions (Torbat, Mashhad and Neishabor) in Khorasan province. In these methods total above ground dry matter (DM) is calculated using two equations and Yp is estimated as the product of DM and harvest index with minimum weather data requirements. In addition, Yp for both crops and at the same locations was predicted using LINTUL and SUCROS simulation models which were previously calibrated for yield estimation of wheat and sugar beet at regional level. The accuracy of predicted potential yields by five methods was compared statistically against the measured yields obtained from the field experiments and high yielding farms at the studied regions. Results and Discussion: Mean observed yield of wheat over the three studied regions was 7. 18 t ha-1 and the estimated potential yield in the same regions using two simulation models and three simplified models was ranged between 6. 92 and 7. 63 t ha-1. Prediction error for the simulation models was 1. 39 and for simple methods less than 5% (4. 64%). Relative root mean squared error (RMSEn) for the simple methods was higher than that of complex models. However, it was between 7. 11 and 10. 16 % of the mean measured wheat yield which could be statistically considered as reasonable. Calculated values of modeling efficiency (ME) were positive and higher than 0. 60 except for FAO-M method (ME=0. 48). Measured sugar beet yield averaged over regions was 82. 5 t ha-1 and estimated potential yield by different methods was between 89 and 91 t ha-1. Simple calculation methods had lower accuracy in predicting sugar beet yield compared to simulation models but RMSEnof simple methods never exceeded 11. 5% showing statistically acceptable prediction. Cross validation indicated significant correlation between the results of three simple methods and that of complex simulation models. Conclusions: Results of this study showed that potential yields of different crops can be estimated accurately using simple calculation methods with minimum weather data requirements. Such methods may be used as an alternative for agroecological zoning and yield gap analysis at regional level where calibrated simulation models and complete daily weather data sets are not available.

Introduction: Low precipitation, high temperature and high evaporation along with excessive consumption of water sources have led to reduced quantity and quality of water sources (e. g. water salinization) in arid and semi-arid regions which ultimately affect crop growth. Environmental stresses such as salinity, cause alterations in a wide range of physiological, biochemical, and molecular processes in plants. So, identification of plants which are less affected by salinity could be of great importance in breeding programs. Kochia (Bassia scoparia) is such a crop which its high tolerance to salinity has been reported in previous studies. Since photosynthesis is the most fundamental and intricate physiological process in all green plants determining plant yield under salinity stress, the aim of this study was evaluation of the effects of salinity on photosynthetic characteristics of kochia. Materials and Methods: In order to study photosynthetic characteristics of kochia under salinity conditions, an experiment was conducted as split-plot based on randomized complete block design with three replications. Three masses of kochia including Birjand, Borujerd and Sabzevar were considered in main plots and three levels of salinity (5. 2, 10. 5 and 23. 1 dS. m-1) as sub-plots. Photosynthesis, evapotranspiration, stomatal conductance, Sub-stomatal CO2 concentration and quantum yield of PSII were measured in the youngest fully expanded leaf for seven weeks started from thirty days after imposing stress. Chlorophyll a, b and carotenoids and green area were measured at anthesis. Data were analyzed using Minitab 16 and means were compared by LSD test at a significance level of 0. 05. Results and Discussion: Results indicated that photosynthesis and evapotranspiration was decreased over the time after salinity imposed. Photosynthesis and evapotranspiration in different masses and salinity levels was almost the same in the 8th week after imposing salinity stress. At the end of the growth season, photosynthesis and evapotranspiration indicated too much decrease in all salinity levels and reached to a same level. In the 4th week after salinity was imposed, the highest photosynthesis was observed in Birjand, Sabzevar and Borujerd, respectively. Reduction intensity of evapotranspiration in time was more in Birjand compared to Borujerd and Sabzevar masses. CO2 sub-stomatal CO2 showed a pronounced increase in all masses and a salinity levels in the 8th weeks after salinity imposed. Results of chlorophyll fluorescence indices in the salinity imposing period indicated an improvement of these indices and finally the increase in quantum yield of photosystem II. Stomatal conductance showed a decreasing trend during time and reached to the lowest level in the 11th week after imposing stress. The lowest mean of this parameter was belong to Sabzevar mass. Stomatal conductance did not vary much till tenth week after imposing salinity while it got a steep slope decreasing trend in the other two salinity levels in week seven. Decreasing trend of stomatal conductance was stronger in treatments of 10. 5 and 23. 1 dS. m-1 compared to 5. 2dS. m-1. Leaf content of chlorophyll a, b, carotenoids and total pigments at anthesis were not affected by kochia masses and salinity levels. Interaction of salinity and mass indicated a lower green area in higher salinity levels. The highest and lowest green area was observed in Borujerd mass in salinity levels of 5. 2 and 23. 1 dS. m-1, respectively. Conclusions: Results of this experiment indicated that photosynthesis and quantum yield of PSII in kochia did not vary much as salinity intensity increased. Also, content of photosynthesis pigments was not affected by salinity stress. Generally, it could be concluded that photosynthesis system of kochia is capable to maintain its normal processes although being imposed to sever salinity stress and though could be used as a model crop in plant breeding programs.

Introduction: Drought is one of the major abiotic stress limiting plants growth and productivity across the world. Intercropping increased the efficiency of water utilization. In arid and semi-arid regions, intercropping can improve water use efficiency and water conservation in soil. Because intercropped plants use water efficiently and caused increasing of water use efficiency. Intercropping of legumes and cereals compared with corresponding sole cropping is common and might be beneficial in semi-arid regions particularly in resource limiting conditions. Do and Goutan (1987) reported that millet can be planted in mixture with some plants such as cowpea, sorghum, peanut and soybean. The aim of the investigation was to study the impact of intercropping on the growth and yield of millet and soybean under deficit irrigation. Materials and Methods: The experiment was carried out as a split-plot based on a randomized complete block design with three replications, at the Research Farm of Agricultural Faculty of Bu-Ali Sina University in 2015. The main factor included three levels of deficit irrigation (irrigation after 60 (well-watered), 90 (mild stress) and 120 (severe stress) mm by using of class A evaporation pan) and five levels of replacement intercropping consisted of monoculture of soybean, monoculture of millet, 67% soybean+ 33% millet (67S: 33M), 50% soybean+ 50% millet (50S: 50M) and 33% soybean+ 67% millet (33S: 67M) as subplot. Results and Discussion: Water stress decreased chlorophyll concentration of millet and soybean. In all intercropping ratios, the chlorophyll concentration of soybean was higher than its monoculture. The rate of increase in chlorophyll concentration in (67S: 33M), (50S: 50M), and (33S: 67M) ratios compared to monoculture of soybean, were 8. 43, 8. 57 and 8. 76 percent respectively. The highest total chlorophyll content of millet was obtained in (50S: 50M) and (33S: 67M) ratios, that was 12. 34 and 12. 09 percent higher than monoculture of millet, respectively. The highest number of panicles per plant of millet was obtained from (50S: 50M) and (67S: 33M) ratios under well-watered, and the lowest one was observed in monoculture of millet under severe water stress. The highest number of seed per panicles of millet was observed at intercropping of 33S: 67M, 50S: 50M and 67S: 33M treatments under well-watered, and the lowest value was measured in monoculture of millet under sever water stress. Water stress decreased number of pods per plant, number of seeds per pod and 100-seed weight of soybean, compared to well-watered. Number of pods per plant, number of seeds per pod and 100-seed weight of soybean reduced in severe water stress were about 50. 58, 33. 68 and 26. 09 percent, respectively, compared to well-watered. The number of pods per plant of soybean plants in all intercropping patterns was higher than monoculture of soybean. The rate of increase in number of pods per plant in (67S: 33M), (50S: 50M), and (33S: 67M) ratios, were 6. 38, 11. 63 and 7. 75 percent respectively, compared to monoculture of soybean. The highest seeds per pod of soybean was obtained in (50S: 50M) ratio by 13. 78 percent higher than monoculture of soybean. Water stress reduced grain yield of millet and soybean by 46. 8 and 50. 05 percent, respectively. Under well-watered condition, the highest yield of millet was obtained in (67S: 33M) and (50S: 50M) ratios. The highest actual yield of soybean was observed in (50S: 50M) ratio by. Maximum value of LER (1. 14) was achieved in (50S: 50M) ratio intercropping in severe stress. Conclusions: The best planting pattern to obtain maximum yield of millet and soybean was (50S: 50M) ratio. The difference in rooting millet with soybean and better use of water in different soil depths could be reason to the high yield under water stress, the show millet and soybean intercropping were complementary.

Introduction: Availability of nutrients needed by plants and ambient light are important in the growth and synthesis of active substance of medicinal plants. Various nutritional combinations have been assessed to study their effect on improving field management and production of medicinal plants. Nitrogen is often a limiting nutrient in plant growth in most agricultural soils. Nitrogen is a major component of chlorophyll, proteins, nucleic acid, vitamins and other organic compounds by which plants use sunlight energy to produce sugars from water and carbon dioxide (i. e., photosynthesis). It is also a major component of amino acids, the building units of proteins. Phosphorus is another element which has an important role in nearly every plant process that involves energy transfer. High-energy phosphate, contained in the chemical structures of adenosine diphosphate (ADP) and ATP, is the source of energy that drives the variety of chemical reactions within the plant. Nitrogen and phosphorus can be supplied through fertilizers or animal manure. Various studies show that combined use of manure and chemical fertilizers (as N, P and … ) have positive effects on soil fertility and growth of plant as well as protecting the environment. Studies also show the effect of adequate nutrients on plant growth parameters, light absorption and biosynthesis in medicinal plants. Therefore, the present study was conducted to evaluate the effect of organic amendments enriched with chemical fertilizers (nitrogen and phosphorus) on effective traits in light absorption and alcoholic extract of hemp in two consecutive years in Birjand. Materials and Methods: To study the effect of different levels of animal manure and chemical fertilizers, a split factorial experiment, based on complete randomized blocks design with three replications was conducted at the research Farm of Faculty of agriculture, University of Birjand, during 2013-2014 growing seasons. Experimental factors include application of animal manure (well-rotted farmyard manure) at a rate of 0, 10, 20 and 30 ton ha-1 to the main plot. The sub plots were received nitrogen at rate of 0, 50 or 100 kg ha-1 (nitrogen in form of Urea) and phosphorus at rate of 0 or 80 kg ha-1 (P2O5 as triple superphosphate). Measured traits were shoot height and diameter, leaf area and leaf number, nitrogen percentage of leaf, canopy light absorption, shoot and leaf dry weights, percentage of extract of leaves and seeds. Nitrogen content of plants was determined by Kjeldahl method and light Absorption was measured by Sun scan. The data were statistically analyzed by SAS software (V. 9. 1). Comparison of the means was performed using FLSD test at the 0. 05 level of significant. Results and Discussion: The results showed that canopy light absorption highly correlated with the leaf numbers (0. 676**), shoot height (0. 621**), nitrogen percentage of leaf (0. 543**) and shoot diameter (0. 481**) respectively. Application of 30 ton ha-1 of animal manure resulted in less efficiency in increasing shoot height and diameter, leaf area and number and nitrogen percentage of leaf. The absorption of light by plant was higher in treatments with higher nitrogen content in leaf. The study showed that weight of shoot and leaf following treatment increased by animal manure, nitrogen and phosphorus supplements, which subsequently increased final weight of extract from leaves and seeds. Application of 30 ton ha-1 of animal manure and 100 kg ha-1 of nitrogen resulted in 20. 1% and 20. 2% increase in content of leaf extract respectively, while application of 100 kg ha-1 of nitrogen resulted in 20% increase in total weight of extracts from seeds. Seed extracts were also highly correlated with the dry weight of leaves. Therefore, the study suggests that adequate nutritional supplement to soil can increase plant growth and final weight of the leaf and seed extracts from plants. Most seed extract estimated in combined treatment of 30 ton ha-1 animal manure and 80 kg ha-1 of phosphorus. The rate of plant growth was lower in the first year compare to the second year, which can be due to higher salinity of soil and animal manure and temperature of germination in the first year. Overall, the findings of this study showed that application of 30 ton ha-1 of animal manure can provide the plants with adequate level of nitrogen and phosphorus resulting in increased level of extracts of leaf and seed in hemp plant and can reduce the need for nitrogen and phosphorus fertilizers use.

Introduction: Wheat (Triticum aestivum L. ) is the prominent cereal food grain and major staple food in Iran. However, weed infestation is a major bottleneck to higher wheat productivity, and accounts for more than 48% loss of potential wheat yield. Weeds are omnipresent pests that compete with crops for water, nutrients, space, and light; host pests and diseases; and release allelochemicals into the rhizosphere. The magnitude of weed-related losses, however, depends on the type and density of a particular weed species, its time of emergence, and the duration of interference. Yield losses are most severe when resources are limited and weeds and crops emerge simultaneously. Crop yields decrease with increasing weed competition. A strong relationship exists between the duration of competition and the competition pressure exerted on the crop, which reduces yield. Stale seedbeds are a long-established practice that can be used with supplemental herbicides in conventional systems or without them in organic systems. The aim of the study was assessing the effect of various seedbed and wheat density on weed control, and growth and yield of wheat. Materials and Methods: The experiment was conducted in a split plot arrangement based on randomized complete block design with three replications. The seedbed (false, stale and conventional seedbed) were assigned to main plots and wheat density (150, 200 and 250 kg seed ha-1) were randomized in subplot. The spacing between the planting rows was 20 cm. The required fertilizers were applied based on the results of soil analysis and by phosphate di-ammonium (150 kg ha-1) and urea (250 kg ha-1). Also, other planting operations such as irrigation were applied uniformly to all treatments. Weed control was not carried out in growth stages. Results and Discussion: The results showed that dry weight and density of weed, plant height, number of tiller, 1000-seed weight, grain yield and seed protein contents were affected by interaction of seedbed and plant density. Simple effect of seedbed and plant density had a significant effect on number of spike and lodging percentage of wheat. Using false and stale seedbeds led to reducing weed density and dry weight, and increasing number of tiller, number of spike, biological and grain yield and protein contents rather than conventional planting conditions, significantly. Increasing plant density had a positive effect on weed control. It seems that increasing wheat density increased the competitiveness of plant species by decreasing access to enough light and nutrients, and led to eliminating the weeds. The highest grain yield (6. 95 t ha-1) was assigned to stale seedbed and density of 150 kg seed ha-1. Grain yield in densities of 150 and 250 kg seed ha-1 was higher than density of 250 kg seed ha-1. Conclusions: In general, application of false and stale seedbeds with planting 150-200 kg seed ha-1 is recommended.

Introduction: Oilseed canola plant (Brassica napus L. ) is an important agricultural crop grown primarily for its edible oil. It is well known that abiotic stresses especially drought stress are very restrictive factors for agricultural production around the world. Drought stress affects a vast range of morphological, physiological and biochemical characteristics in plants. However, exogenous application of materials such as salicylic acid (SA) has been regarded as a good alternative to counter the adverse effects of various environmental stresses on plant functions. Salicylic acid is a naturally occurring plant hormone that controls plant growth and induces water deficit tolerance in plants. Material and Methods: The experiment was carried out as a split split plot layout with three replications in East Azarbaijan Research Center for Agriculture and Natural Resources. Treatments included three level of drought stress (well-watered, drought stress at flowering and podding stages) (as main plot), two level of SA spraying (0 and 150 ppm) (as sub plot) and four cultivars of spring canola (Zafar, Zarfam, Dalgan and RGS003) (as sub-sub plot). The studied traits were included number of pods, number of seeds per pod, 1000 seed weight, grain yield, chlorophyll a, b and total, carotenoid, H2O2, MDA, proline, total sugar contents and seed oil percentage. The collected data were analyzed using SAS 9. 1 software and means were compared with Duncan test at the 5% and 1% level of probability using MSTATC software. Results and Discussion: Results indicated that withholding irrigation from flowering stage had a more negative effect on yield components and physiological traits compared to withholding irrigation from podding stage. Withholding irrigation in both stages reduced the content of chlorophyll a, b and total and increased the content of H2O2 and MDA. Also, Zarfam and RGS003 cultivars had the highest content of chlorophyll and the lowest content of H2O2 and MDA. Salicylic acid (SA) spraying increased 31. 79%, 41. 1% and 7. 33% of proline content, leaf soluble carbohydrate and seed oil, and decreased the content of MDA and H2O2 by 16. 1% and 18. 67% respectively. The results also showed that SA spraying led to 31. 96% increase in grain yield under drought stress from podding stage. SA may compensate the negative impacts of drought stress on plant yield and other parameters. Conclusions: In general, in this experiment, the use of salicylic acid not only improved the morphological and physiological traits of the plant under drought stress, probably through the effect on the antioxidant system but also increased the yield and quality of the cultivars.

Introduction: Sesame (Sesamum indicum L. ) is considered as the queen of oilseeds for its high oil quality. Sesame oil is rich in micronutrients, antioxidants and essential amino acids as well as polyunsaturated fatty acids. It has been well documented that agronomic practices such as time and rate of planting will have a direct effect on sesame grain yield, oil content and quality. Therefore determining the optimum plant density is very important in sesame production. Material and Methods: In the current experiment, the effect of different planting densities (20, 40 and 60 Plants per m2) was investigated on agronomic traits of six sesame cultivars (Halil, Dashtestan 2, Darab 1, Oltan, Yellow White and Naz Tak Shakhe). The field experiment was carried out as factorial layout based on randomised complete block design with three replicates in research farm of Seed and Plant Improvement Institute, in 2016. Each experimental plot consisted of four adjacent rows, 5 m in length and 0. 3 m apart. To achieve the above-mentioned planting densities, sesame seeds were sown 16, 8 and 5 cm apart on each row on 6th June. If required, the seedlings were thinned at 2-3 leaf stage. The crop was irrigated according to the conventional schedule for the region. Weeds were manually removed throughout the growing season. At physiological maturity stage, two middle rows of each plot were harvested for determination of yield and yield components. Data analysis was performed using SAS 9. 1 and means were compared by the Least Significant Difference (LSD) test at the 5% probability level. Results and Discussion: The results showed that all measured traits except 1000-seed weight and harvest index significantly affected by planting density. Also, the interaction between planting density and cultivar was significant on the number of capsules per plant, seed yield, harvest index and oil concentration. At planting densities of 20 and 40 plants per m2, the maximum grain yield were related to Dashtestan 2 cultivar. At planting densities of 60 plants per m2, Naz Tak Shakhe was found to be the best cultivar regarding grain yield. Although the increase in planting density from 20 to 40 plants per m2, could increase grain yield in all cultivars, the highest grain yield was related to Naz Tak Shakhe cultivar. Furthermore, increase in planting density up to 60 plants per m2, caused severe grain yield loss in all cultivars except Naz Tak Shakhe cultivar which showed 18% increase in grain yield. Conclusions: In general, it can be concluded that cultivars characteristics could be considered as essential parameters to determine the optimum planting density. Therefore, if the plant density is adjusted in such a way that plants could be able to use the environment and agronomic inputs factors with the minimum intra-specific competition, maximum economic yield will be obtained.

Introduction: The negative effects of heat stress on plants are serious problems, which often cause damage to crops throughout the world. In addition, the issue of global warming increases the importance of the heat stress. Currently, to increase the resistance of plants to environmental stresses, some chemical compounds are used that improve the metabolic activity of the plant. Calcium chloride is one of them and finding the appropriate time to use it is important. For this purpose, the present experiment was conducted to investigate the effect of calcium chloride application on reducing the effects of heat stress on yield and yield components of wheat in Ahvaz. Materials and Methods: This experiment was carried out on wheat (Chamran cultivar) plant in a factorial experiment based on a complete randomized block design with three replications at the experimental farm of Shahid Chamran University of Ahvaz during a growing season 2016-2017. The solution type was used as the initial factor: 1-foliar application with distilled water, 2-foliar application with calcium chloride (10 mM). The application time was used as the second factor: 1-15 days before flowering (A), 2-flowering (B), 3-15 days after flowering (C), 4-15 days before flowering and flowering (A*B), 5-flowering and 15 days after flowering (B*C), 6-15 days before flowering and 15 days after flowering (A*C) and 7-15 days before flowering, flowering, 15 days after flowering (A*B*C). Results and Discussion: Regarding the mean comparison of traits, a calcium chloride foliar application on traits such as plant height, number of spikelet’ s per spike, grain yield per plant and harvest index were not significant (P≤ 0. 05). The 1000 grain weight increased under different time traits of calcium chloride foliar application. The highest 1000 grain weight belonged to the calcium chloride foliar application during two weeks before flowering. Foliar application of calcium chloride at the flowering time as well as flowering and two weeks later increased the shoot dry weight. Grain weight per plant was increased in all treatments with calcium chloride except for foliar application at flowering and two weeks before and after flowering. The highest amount of grain weight per plant was obtained in the calcium chloride foliar application during two weeks before flowering and flowering, but no significant difference was observed with other treatments with calcium chloride. Conclusions: Looking at the research, the positive effects of the use of calcium chloride in some plants have been shown under stress conditions, but there is no consensus on the best time or best type of it. Induction of heat stress at the onset and during the flowering period by decreasing pollen and ovarian grain yields prevent fertility and thus decrease grain yield. On the other hand, when the plants were in the post-flowering stage and in the grain filling stage exposure to high temperatures, heat stress accelerates this stage and reduces the grain filling period, thus reduces yield. Under heat stress conditions, the use of calcium chloride improved some properties such as number of spikes per plant, seed weight per plant and 1000-grain weight, and the destructive effects of heat stress on the plant. According to the results of this study, application of 10 mM calcium chloride concentration two weeks before flowering is recommended to reduce the damaging effects of heat stress in wheat.

Introduction: Artichoke (Cynara scolymus L. ) is an herbaceous perennial plant belongs to the Asteraceae family (Ziai et al., 2004). Artichoke silage quality was less than alfalfa silage but it is as much as corn silage with lower seed contents and was more than sorghum silage and the palatability of this plant increased after ensiling. Application of Integrated Nutrition Systems (IPNS) based on the use of biofertilizer is one of the most important factors affecting the sustainability of food production and soil fertility. Researches have shown that biological or chemical fertilizers alone cannot be used for sustainable agricultural production, and in most cases, bio-fertilizers as a supplement to chemical fertilizers can ensure the sustainability of production in agricultural systems. Regarding the importance of nutrition management in plants, the present experiment was conducted with the aim of investigating the effect of different fertilizer sources (bio-fertilizers, chemical fertilizers and their integration) on yield and artichoke silage quality in Isfahan climate conditions. Material and Methods: This experiment was conducted as a factorial based on RCBD design with three replications at the Research Station of Isfahan Agricultural and Natural Resources, Iran, during 2014-2015. The first factor consisted of chemical fertilizers at levels of 100% chemical fertilizer (200 and 100 kg ha-1 NP), 50% chemical fertilizer (100 and 50 kg ha-1 NP), and control (no fertilizers). The second factor comprised bio-fertilizer at levels of 1 liter ha-1 Nitroxin (include Azotobacter, Azospirillium, and Pseudomonas), 100 gha-1 Barvar 2 (include Pseudomonas potida and Bacillus lenthus), 1 liter ha-1 Nitroxin +100 gha-1 Barvar 2 and control (without inoculation). Seeds were sown on 26 April 2014. Chemical fertilizer (urea and triple superphosphate) applied based on soil analysis results. The first half of the nitrogen fertilizer was utilized as strip takes under seed before sowing and the rest at 7-8 leaf stage of the crop. The plants were harvested at vegetative rosette stage. The harvested material was chopped and stored for about 75 days in laboratory silos. Wet and dry forage yield and Silage quality indices as crude protein (CP), crude fat (CF), ash, neutral detergent fiber (NDF), water soluble carbohydrates (WSC), organic matter digestibility (OMD), metabolizable energy (ME) and net energy for lactation (NEL) were measured. Analysis of variance was done using SAS ver. 9. 1 software and comparison of the means was conducted using by Duncan at 5% level. Results and Discussion: The results showed that soil fertilizer management systems significantly affected forage yield and silage quality of artichoke. Increasing the levels of chemical fertilizer increased wet and dry forage yield. Among the bio-fertilizer levels, combined fertilization with Nitroxin and Barvar 2 and application of Nitroxin alone had the highest forage yield. The effect of integrated fertilizer management on silage quality was higher than the single application of chemical fertilizer or bio-fertilizer. The highest CP percent (19. 25 %) and lowest CP (7. 68 %) were obtained by 100% chemical fertilizer + Nitroxin+ Barvar 2 and control treatment, respectively. NDF reduced with the application of chemical and biological fertilizer and 100% chemical fertilizer + Nitroxin+ Barvar 2 had the minimum values of them. The highest amount of WSC was related to 50% chemical fertilizer at all levels of bio-fertilizer. Application of bio-fertilizers increased the OMD, ME and NEL compared to control level. Also, these traits increased by the increment of chemical fertilizer application. Conclusions: Based on the results of this research, using 50% chemical fertilizer + Nitroxin+ Barvar 2 can be recommended to improve the silage quality of artichoke.

Introduction: The necessity of using sustainable agricultural systems, especially in agricultural fields, is more important than the development of arable land. Sustainable agriculture is based on the efficient management of the elements of production to improve soil quality and one of the main problems in sustainable agriculture is the lack of organic matter and its consequences. One of the possible, inexpensive and feasible ways to increase organic matter in agricultural lands is to return crop residues to the soil. In sustainable agriculture, the use of compost and vermicompost increases the microbial activity of the soil, which increases the nutrient requirements of the plant, especially the consumed elements, which leads to increased crop yields. In order to evaluate integrated fertilizer management and harvest time on the quality and quantity of corn forage, this experiment was conducted in the research farm of Zabol University in 2016-17 crop year. Materials and Methods: An experiment was conducted as factorial based on a randomized complete block design with three replications in the research farm of Zabol University during 2016-17 cropping year. The first factor included 10 fertilization levels: (without fertilization, 30% wheat residue, 60% wheat residues, 90% wheat residues, 30% vermicompost, 60% vermicompost, 100% vermicompost, 10% vermicompost + 90% wheat residues, 40% of vermicompost + 60% of wheat residues and 70% vermicompost + 30% of wheat residues) and the second factor of harvesting time were at two levels: (harvest in milky and dough stages). The studied traits included leaf dry weight, stem dry weight, dry matter digestibility, water-soluble carbon hydrates, crude protein and protein yield, crude fiber, insoluble fiber in acid detergent, insoluble fibers in neutral detergent and ash. Results and Discussion: The results of analysis of variance showed that the effect of interaction between harvesting stage and combined fertilizer management systems on leaf dry weight, stem dry weight, dry matter digestibility, the percentage of water-soluble hydrocarbons and insoluble fiber in acid detergent was significant. As the plant mature and the stems grow, the ratio of leaf to stem decreases in forage. The highest leaf dry weight (146 g) and stem dry weight (185. 33 g) were obtained in milk militias and in the application of 70% vermicompost and 30% of wheat residues. Mean comparisons showed that the highest digestibility of dry matter (69. 72%), the highest percentage of water-soluble carbohydrate (21. 17%) was observed in dough stage with the application of 60% of wheat residues. The highest non-soluble fiber in acid detergent (34. 85 g / kg dry matter) was obtained in the milky stage of grain and in the application of 70% vermicompost and 30% of the wheat residues. Insoluble fiber in acid detergent was the most important determinant of forage quality. The results of the analysis of variance showed that the effect of harvesting stage on the percentage of crude protein and ash content was very significant; the effect of harvesting stage and the effect of combined fertilizer management systems on the percentage of CF was significant; and the simple effect of combined fertilizer management on the non-soluble fiber (CF) in neutral detergent was meaningful. Comparison of means showed that the highest percentage of crude protein (9. 32%) was observed in the milky stage; the highest percentage of crude fiber in the grain dough stage (35. 45%) and in the application of 70% vermicompost + 30% wheat residues (36. 85%); The most NDF (52. 58 g / kg dry matter) in terms of application of 70% vermicompost + 30% of wheat residues; and the highest percentage of Ash (7. 21%) in milky stage was obtained. The optimal quality is obtained when the plant has a digestibility of dry matter, crude protein, WSC, and more ash content. In general, using 60% and 100% vermicompost ratios and 60% of wheat residues improved the quality of forage at harvest time from the milky stage. The results of this study confirmed the importance of soil organic matter in improving forage quality. Conclusions: The results of this study confirmed the importance of soil organic matter in improving forage quality. According to the results of this study, the combined application of vermicompost with wheat residues has improved the quantitative and qualitative traits studied in corn. So that application of 70% vermicompost plus 30% wheat residues increased 2% protein percentage compared to control. Therefore, the application of the combined fertilizer system in the long term increases the content of nitrogen and organic carbon in soil. In general, 70% and 100% vermicompost ratios and 60% of wheat residues improved the quality of forage at harvest time from milking stage. The growth stage at harvest time, the most important determinant of forage quality, is a definite species. Forage quality decreases with the advancement of growth stages.