جستجوی مقالات مرتبط با کلیدواژه "ماده خشک" در نشریات گروه "اکولوژی"

Medicinal plants are one of the most valuable resources in Iran's wide range of natural resources, which can play an important role in society's health, job creation, and non-oil exports if they are scientifically recognized, cultivated, developed, and exploited properly. Iran is considered one of the world's best regions in terms of climate, geographical location, and medicinal plant growth, and it has been a source of production and consumption of medicinal plants in the past. Lemon balm is generally used in traditional medicine to treat digestive problems, pain, and mental disorders. Drought stress is one of the most serious and widespread problems that limit plant productivity because it negatively affects plant physiology. The effects of drought stress depend on the duration, intensity and stage of growth and the genetic tolerance capacity of plants, which can reduce the growth of plants. It causes a change in morphological and physiological structures and the pattern of biomass distribution or even death.

To study the effect of foliar different growth stimulants on the growth characteristics and essential oil of balm at different levels of drought stress, an experiment was carried out in the crop year 2021. The experiment was a split plot based on randomized complete blocks with four replications, where different levels of irrigation include irrigation after 80, 60, and 40 percent of the field crop capacity (FC) in the main plots and foliar application of different growth stimulants including control, melatonin, amino acid, and folic acid were placed in sub-plots. In this research, total chlorophyll, dry matter yield, relative water content, phenoline content, soluble sugars, essential oil content, essential oil yield, total phenol, and flavonoid were measured. The data obtained from the experiment was analyzed using SAS.9.4 software. The obtaineds averages were statistically compared using Duncan's method (LSR) and at the five percent probability level.

The results of variance analysis of the data showed that the effect of irrigation and foliar spraying on growth stimulants on all investigated traits were significant at the probability level of 1%. There was a significant difference between the interaction treatments in terms of chlorophyll content, proline content, essential oil percentage, essential oil yield, and flavonoid content at the probability level of one percent and in terms of relative leaf water content, dry matter yield, soluble sugars content and total phenol content at the probability level of five percent. The results showed the highest chlorophyll content (2.25 mg g-1 FW), relative leaf water content (88.12 percent), and dry matter yield (793.79 kg ha-1) was recorded in melatonin foliar application and irrigation of 80% of FC treatments. Also, the highest essential oil content (0.81%) and essential oil yield (6.46 kg ha-1) were observed in treating foliar application with melatonin under the irrigation treatment of 60% FC. This study allocated the highest total phenol content to melatonin foliar application at 40% of the FC conditions. In this study, 40% FC irrigation treatment increased the flavonoid content by 29.90% and 93.23%, respectively, compared to 60% and 80% FC. Furthermore, foliar application of melatonin, proline amino acid, and folic acid increased the flavonoid content compared to the control treatment by 17.64, 23.35 and 32.35%, respectively.

In this study, melatonin foliar application in all three irrigation conditions increased essential oil yield compared to the corresponding control. Under irrigation and foliar spraying of melatonin, the synthesis of secondary metabolites and essential oil has been accelerated and produced the maximum yield of essential oil. Therefore, foliar spraying of melatonin and mild water deficit stress can be recommended to achieve maximum economic yield in Lemon balm.

Tomato and cucumber are now produced by using a high amount of chemical nitrogen fertilizer and a variety of biocides. These are hazardous to human health and the surrounding environment. Intercropping these plants with a legume such as green bean not only improves nitrogen use but also helps to enhance environmental conditions. Based on these assumptions, the present investigation was carried out to determine the effect of intercropping bean with tomato and cucumber on yield and yield components, land equivalent ratio, and nutrient use efficiency in a triple intercropping system.

This experiment was conducted between 2015 and 2016 on a private farm adjacent to Shirvan in the Northern part of Khorasan Province. The experimental layout was based on a randomized complete block design with six treatments and three replications. Treatments were a different combination of single, double, and triple rows of cucumber, tomato, and green bean together with the pure culture of each one. Criteria measured were dry matter, yield accumulation, fruit weight, economical and biological yield, harvest index, land equivalent ratio, and also nitrogen, phosphorus, and potassium use efficiency.

As expected, dry matter yield accumulation in sole cucumber was higher than in other combinations, and a decreasing trend was observed when the ratio of cucumber was increased in intercropped. However, this was the reverse for tomato. Dry matter yield accumulation for green bean was higher in a single row intercropping than in others. Higher dry matter accumulation in intercropped seems to be associated with better resource use and lower interspecific competition and hence photosynthesis improvement. For cucumber, economic and biological yield in the pure stand was higher than the intercropped, while the harvest index was the highest in double rows intercropped. The economic and biological yield of green bean and tomato in pure culture was higher than in other treatments. In contrast, 1-row intercropping increased the green bean fruit in a plant by 18.42% and the tomato fruit weight in a plant by 62.38% compared to pure stand. Better light interception and efficient resource use seem to be the reason for better performance of intercropped compared with monoculture. However, nutrients use efficiency did not show a similar trend when nitrogen, phosphorus, and potassium use efficiency in single row planting was higher for bean and tomato; this was not a common trend in general. Single row intercropped showed a 27% increase in yield on the base of land equivalent ratio.

Medicinal plants are rich resources for traditional medicines and in this regard play an essential role in the development of human culture. Basil (Ocimum basilicum L.) belongs to the Laminaceae family and can be found in tropical Asia, Africa, Central America, and South America. Basil is traditionally used worldwide as a medicinal herb to treat numerous ailments. The leaves and flowering tissues are traditionally used as antispasmodic, carminative, digestive remedies, to treat abdominal cramps, fever, poor digestion, migraines, insomnia, depression, dysentery, etc. Application of chemical fertilizers in order to eliminate residues of this chemichal substances from crop to ensure consumer health and environmental protection is one of the major challenges in sustainable production of medicinal crops. The application of organic fertilizers such as farmyard, vermicompose, and humic substances as an alternative to chemichal fertilizers to improve soil fertility in sustainable agriculture is currently being discussed. Application of organic fertilizers in addition to modifying soil physical and chemical properties, provides nutrients for the plant in long-term. Various studies have also shown the positive effect of organic fertilizers on increasing the quantitative and qualitative yield of medicinal crops. Therefore, the present study was conducted to investigate the effect of cow manure, vermicompost, and humic acid on some morphological traits, dry matter yield, and production of basil essential oil.

The experiment was conducted as a factorial based on a randomized complete block design with three replications at a farm in Oshnavieh city in the West Azerbaijan Province in 2014. The treatments included organic fertilizers (20 tons ha-1 farmyard, 7.5 and 15 tons ha-1 vermicompost, and control) and humic acid application (soil application, foliar application and not application as control). The measured traits included plant height, lateral stems number, lateral stems length, flowering stems number, leaf number per plant, leaf chlorophyll index, dry matter yield and essential oil percentage. Data analysis was done using MSTAT-C statistical software and means were compared using LSD test at 1% or 5 % probability levels based on the significance level in each trait.

The results showed that application of organic fertilizers significantly increased plant height, lateral stems number, lateral stem length, flowering stem number, and leaf number. The highest essential oil yield (2.94 g m-2) was obtained using 15 tons ha-1 vermicompost. Both foliar and soil application of humic acid treatments had the highest lateral stems number (13.1 per plant) and essential oil yield (2.75 g m-2) and humic acid foliar treatment had the highest flowering stem number (22.9) and essential oil percentage (0.59%). All treatments of organic fertilizer and humic acid increased leaf chlorophyll index compared to control. Application of 15 tons ha-1 vermicompost combined with or without humic acid produced the highest dry matter yield (with an average of 538.6 g m-2) that showed 99.6% increase compared to control (not application of organic fertilizers and humic acid). It seems that the application of humic acid and organic fertilizers increased the absorption and transport of nutrients such as nitrogen, phosphorus, potassium, calcium and magnesium as well as water absorption by the plant and by this way, the morphological and growth traits of plant increased. On the other hand, application of organic fertilizers not only increased the available nutrients to the plant, but also improved soil physical conditions and biological processes and provided a suitable environment for root growth. Consequently, organic fertilizers increased dry matter production and essential oil content and yield.

The findings of this study showed that organic fertilizers and humic acid application had significant effects on morphological traits, yield, and essential oil content of basil. So that, these treatments significantly increased the value of morphological traits. The highest dry matter yield was obtained by application of 15 tons ha-1 vermicompost combined with or without humic acid. The treatment of foliar application of humic acid had the highest essential oil content. The highest essential oil yield was obtained by the application of 15 tons ha-1 vermicompost. Finally, the application of organic fertilizers could be used in sustainable agriculture to improve of quantitative and qualitative yield of basil and reduce the application of chemical fertilizers.

This study was conducted to evaluate the forage yield and quality in the additive and replacement series of sorghum and Berseem clover intercropping.

The experiment was conducted in a randomized complete block design with three replications in the Research Farm of Seed and Plant Improvement Institute, Karaj, Iran, during two cropping seasons (2016 and 2017). Cropping systems included replacement series (S75C25: 75% Sorghum + 25% Clover; S50C50: 50%+50%; and S25C75: 25%+75%), additive series (S100C50: 100%+50%; S50C100: 50%+100%; and S100C100: 100%+100%), and sorghum and clover monoculture (S100C0 andS0C100, respectively).

The highest and lowest forage yields were obtained from S100C100 and S0C100 cropping systems, respectively. In addition, the highest content of digestible protein (11.48%), metabolizable protein (8.03%), digestible energy (2.77 Mcal.kg-1 DM) and relative forage quality (122.74%) was obtained in the S0C100. Also, the maximum yield of digestible and metabolizable protein (1956 and 1369 kg.ha-1, respectively) and the highest energy production for lactation (3.92 Mcal.m-2) were obtained in the S100C100. Among the additive series, only the S50C100 intercropping system was able to produce acceptable forage quality.

Considering the quantity and quality of produced forage, the S50C100 intercropping system (with 24.28 t ha-1 dry forage yield and relative forage quality equivalent to 91.04%) is introduced as the superior treatment. In general, additive intercropping systems of sorghum and berseem clover increased the quantitative and qualitative yield of forage and could be a good alternative to monoculture systems of these crops.

In order to evaluate the effect of organic fertilizers, ascorbic acid and humic acid on dry matter yield, seed yield and essential oil production of dragonhead an experiment was conducted as a factorial based on completely randomized design with three replications at research farm of Faculty of Agriculture, University of Tabriz in 2017. Treatments were included as first factor, application of organic fertilizers (control, application of farmyard (30 t.ha-1) and application of vermicompost (15 t.ha-1) and the second factor was the spray of ascorbic acid and humic acid (control, ascorbic acid, humic acid and ascorbic acid + humic acid). Results showed that the highest amounts of morphological traits, plant dry weight, dry matter yield, grain yield and essential oil yield were obtained with vermicompost and combined application of ascorbic acid + humic acid treatments. The highest dry matter yield (2271 kg.ha-1), grain yield (645.9 kg.ha-1) and essential oil yield (12.3 kg.ha-1) were obtained with application of a combination of ascorbic acid + humic acid, which showed 36.5%, 18.1% and 72.8% increases as comparison to control, respectively. The highest 1000 grain weight was obtained with the application of humic acid and vermicompost (1.66g), combined application of humic acid + ascorbic acid and vermicompost (1.59 g) and combined application of humic acid + ascorbic acid and control (1.54 g), with 30.2%, 24.7% and 20.6% increases as comparison with non-application of organic fertilizers and without spray, respectively. The highest essential oil percentage (0.61%) was obtained with spray of humic acid + ascorbic acid and vermicompost application, which indicated 45.2% increases compared to control. Considering to positive response of the quantitative and qualitative performance of dragonhead to the use of the organic fertilizers, humic acid and ascorbic acid, it can be expected that application of farmyard and vermicomposte, humic acid and ascorbic acid increase the performance and essential oil of dragonhead.

Sunflower (Helianthus annuus L.) is one of the plants cultivated for oil or seed. Sunflower oil contains many useful fatty acids. One of methods to increase plant yield and decrease input consumption is transplanting. Transplanting can increase seed yield components such as head number per plant, seed number per head, 1000-seed weight. Transplanting increased seed yield and quality compared to direct seeding due to no frost at the beginning of growth season and increasing flowering length. By delaying transplanting, seed germination or transplant establishment is reduced. Time interval from seeding till beginning and terminating flowering length can be reduced by delaying at seeding, but by transplanting flowering duration length increases. Drought losses crop productions especially at plant critical growth periods such as seed filling stage. In arid and semi-arid areas like Iran, water shortage leads farmers to plant low- water crops. By transplanting of sunflower, water can be saved, because seedling can be grown by a little water in controlled condition. In addition, some plant growth stages coincide with cool and rainy weather in spring. Many farmers use transplanting for warm season crops, but transplanting of sunflower has not been well studied. This research was aimed to assess sunflower transplanting under common sowing date and early sowing in Kermanshah climate condition. An experiment was conducted at greenhouse and research field, campus of agriculture and natural resources, Razi University in 2015 and 2016. In the first year, factors included three planting methods (direct seeding, 4-week transplanting and 6-week transplanting) and sowing date (early sowing, common date sowing). In the second year, treatments included 4- week transplanting at early sowing (superior treatment in the first year) and direct seeding (control). At harvesting stage, four plants per plot were selected and traits such as plant height, stem height, stem diameter, leaf number, internode length, leaf width, leaf length, leaf fresh weight, stem fresh weight, seedling fresh weight, leaf dry weight, stem dry weight and biomass were measured. Leaf greenness was measured by SPAD device and stomatal conductance was measured by porometer device. Leaf area was determined by digimizer software. Leaf relative water content, chlorophyll a and b, seed yield and yield components also were measured. Data were analyzed by SAS software. Mean were compared using LSD test. Analysis of variance of 2015 data, showed that planting method and planting date had significant effect on plant height, leaf relative water content, dry matter and leaf area. 4-week transplant at early planting date had the highest dry matter production and leaf area selected for the second year. It seems that by delaying in transplanting, sunflower plant become more sensitive to cold air and low temperature damages plants, so lower dry matter production was produced. Results of the second year showed that transplanting increased green leaf number, leaf area, chlorophyll a, plant fresh weight, plant dry weight, leaf to stem ratio, stem length, plant height, seed number per head, dehulled seed weight, hull weight, seed yield and 100-seed weight. It seems in transplanting, maximum stem length, plant height, green leaf number and leaf area was occurred when sunlight was maximum, so plant had higher radiation use efficiency and dry matter production. In addition, transplanting had higher seed yield than seeding probably due to weed suppression, rapid establishment, shorter growth duration and faster flowering. Transplanting increased seed yield and weight due to lack of coincidence of plant critical stages to adverse environmental conditions, suitable plant cover, prolonging the grain filling period and store assimilates in grain. In conclusion, it is suggested to plant 4-week sunflower transplant at early date in Kermanshah climate condition.

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

IntroductionCompetition for nutrient sources, especially nitrogen, is one of the reasons of corn yield reduction in the presence of weed. Weeds compete with corn for nitrogen uptake and affect its growth and development. Thus management and optimum application of nitrogen fertilizer may help corn to compete against weeds. More consumption of nitrogen fertilizer would change the competition ability of weed and crop. Comparison of crop-weed growth-related characteristics is a way to assess their rate of competition. The main objective of the current study was to evaluate the effects of different weed densities and nitrogen levels on growth indices of corn, red root pigweed and millet.
Material and MethodsIn order to study the effects of different weed densities and nitrogen levels on growth indices of corn, red root pigweed (Amaranthus retroflexus) and millet (Panicum miliaceum), a field experiment was conducted in 2009 in the research fields of Tarbiat Modares University of Tehran with factorial arrangement of treatments based on Randomized Complete Block Design with three replications. Accordingly, three factors included different nitrogen fertilizers (75% optimum or 138 kg N/ha, optimum or 184 kg N/ha and 125% optimum or 230 kg N ha), weed species (redroot pigweed and millet) and weed densities (5 and 25 plants.m-1 for redroot pigweed and 7.5 and 37.5 plants.m-1 for millet) was considered as main plot. Destructive sampling was carried out in four stages (including mid-vegetative growth [35 days after planting], Tasseling [62 days after planting], milky stage [84 days after planting] and physiological maturity [130 days after planting]), to measure changing trend of the leaf area and dry matter in corn, red root pigweed and millet. Four plants were used at each destructive sampling. The OriginPro 9.1 software was used to fit equations and draw figures.
Results and DiscussionThe highest dry matter (2429.39 gr), CGR (38.38 gr m-1 day-1) and LAI (4.57) was achieved for the treatment of 230 kg N ha-1 and weed control. However, the highest RGR with 0.06 g.g-1 was obtained in at the treatment of 184 kg N ha-1 and weed control. Corn in competition with millet was achieved the maximum CGR in 138 kg N ha-1 and 7.5 millet m-1 and also the maximum RGR was obtained in 184 kg N ha-1 and 7.5 millet m-1. Corn in competition with redroot pigweed was achieved the maximum CGR (30.83 gr m-1 day-1) and RGR (0.055 gr) in 138 kg N ha-1 and 5 redroot pigweed m-1 and also the maximum TDW (1815.92) and LAI (5.1) belonged to in 184 kg N ha-1 and 5 redroot pigweed m-1. Generally, analyzing the trends of growth indicators shows that the corn growth indices are reduced more by increasing the weed density in high levels of nitrogen and as a result, the competitive ability of weeds is more in high levels of nitrogen. The Millet and redroot pigweed growth indices show that their maximum TDW, CGR and RGR (In all different levels of nitrogen and weed densities) occurred at 62 days after planting. However, they have different values and trends at different levels of nitrogen and weed densities.
ConclusionThe results of this study show that the species of weeds in the farm is a determinative factor impress on the role of increasing application of Nitrogen for improving dry matter production and growth indices of corn. Totally, the results indicate that increasing N application beyond the optimum rate not only do not increases corn growth but also reduces its yield, where nitrophile species are the dominants in farms, and leads to environmental pollution .

IntroductionSummer Savory (Satureia hortensis L.) is the representative plants of Lamiaceae family, which has high significant nutritional and taste values. Its pharmacopoeial raw material is herb (Satureiae herba), which contains many different biologically active compounds beside essential oil and minerals like calcium, potassium, magnesium, iron, and zinc. Sustainable agricultural systems has became an important issue throughout the world. It is obvious that intensive cultivation has led to a rapid decline in organic matter and nutrient levels as well as affecting the physical soil properties . The biofertilizers practice (such as vermicompost and biological nitrogen fixing bacteria) has been recognized for a long time as an effective means of improving the structure and fertility of the soil, increasing the microbial diversity, activity and population, improving the water storage capacity of soils and crop yield.
Materials and MethodsThis investigation was conducted at agricultural research fields of RAN Company at Firouzkuh, Iran in 2015. Factorial experiment based on randomized complete blocks design with two factors and three replications were chosen as an experimental design. The factors were biological nitrogen fertilizer at three levels of Control, Nitroxine and Supernitroplus, and vermicompost at four levels 0, 5, 10 and 15 ton per hectare. Measured traits consisted of fresh and dry plant weight, flowering shoot yield, essential oil content, nitrogen, phosphorus and potassium percentage in aboveground shoots. All data were subjected to statistical analysis (one-way ANOVA) using SAS software. Duncan’s multiple range test (DMRT) at 5% probability level were performed to calculate means of comparison. Data were transformed when necessary before analysis to satisfy the assumptions of normality.
Results and DiscussionResults showed that the highest fresh and dry plant weight (41.10 and 12.93g/plant, respectively) and essential oil content (2.01%) were obtained by using 10 ton per hectare of vermicompost. Applying 15 ton per hectare of vermicompost caused maximum flowering shoot yield (2237.82kg/ha), nitrogen (2.21%) and phosphorus (0.52%) content in the aboveground shoot. Mean comparison indicated that seed inoculation with Supernitroplus had significant effects on all measured traits except for nitrogen content in aboveground shoot. The maximum fresh and dry plant weight (40.21 and 14.42g/plant), flowering shoot yield (2406.21kg/ha), essential oil (2.05%), phosphorus (0.49%) and potassium (1.34%) were obtained by applying Supernitroplus. The maximum nitrogen content (2.23%) was obtained by using Nitroxine. Results of interaction effects showed that using supernitroplus and 15 ton per hectare of vermicompost caused maximum potassium content (1.50%) in Savory shoots.
Several types of studies have shown a beneficial effect on crop plants by inoculation of seeds with Azospirillum and Azotobacter strains. Inoculation of plants with Azospirillum and Azotobacter can results in significant changes in various plant growth parameters. Positive effects of inoculation have been demonstrated on including increase in root length and nutrition (NO3- , NH4, P042- , K , Rb and Fe) uptake. Nitrogen and phosphorus are the two major plant nutrients and combined inoculation of nitrogen fixers and PSM may benefit the plants better than either group of organisms alone. Interaction studies have been done both in vitro and in vivo. Nitrogen fixers and PSM when inoculated together colonized the rhizosphere and enhanced the growth of crops by providing it with nitrogen and phosphate, respectively. Vermicompost contains most of the plant nutrients such as nitrate, phosphates, exchangeable calcium and soluble potassium, and microelements which result in improved plant growth and development and is responsible for increased qualitative and quantitative yield of many crops.
ConclusionThe results of current experiment showed that vermicompost and nitrogen fixing bacteria have stimulatory effects on the yield, essential oil and mineral elements (N, P and K) uptake by summer Savory and have thus considerable potential for providing nutritional elements in Savory production, especially for the sustainable production systems.

In order to evaluate the effect of chemical and biological fertilizers and irrigation regimes on yield and yield components of sesame (Sesamum indicum L.)a field experiment was performed using a split plot experiment based on completely randomized design with three replications at Agricultural Research Station, Ferdowsi University of Mashhad, Iran during growing season of 2013 and 2014. Main plots were three levels of irrigation (%100, %75 and %50 of sesame water requirement) and sub plots were eight different biological and chemical fertilizers (nitrogen, phosphorus, nitrogen phosphorus, nitroxin, biophosphore, nitroxin渪⦆謩蚊, biosulfure and control). Results showed that for all fertilizer and biofertilizer treatments reduction in irrigation levels was the major factor in reduction of yield and yield components. Under stress free conditions (100 percent of sesame irrigation requirement), chemical fertilizer exhibited more yield and yield components than biofertilizers. According to the results in 100% irrigation treatments, the highest plant height, number of seed in capsule, 1000 seed weight and capsule in plant resulted from nitrogenꘚⲦᨫ뫇 and nitrogen. In general, biofertilizers particularly nitroxin and nitroxin渪⦆謩蚷 inoculation, improved plant height, seed yield, yield components of sesame, under 50% water requirement supply, the same as or better than chemical fertilizers.Recent study showed significant correlation of yield components (seed number in capsule, 1000 seed weight and capsule in plant) with yield. In stress free conditions (100% irrigation) highest grain yield resulted from nitrogenꘚⲦᨫ뫇 (3.14 ton.ha-1) and nitrogen (2.99 ton.ha-1) in 2013 and 2014 respectively. In stressful conditions (50% irrigation) highest grain yield (2.42 and 2.31 ton.ha-1) were obtained from nitroxin and biosulfure in 2013 and 2014 respectively.It can be concluded that application of biofertilizers provide a most desirable solution to drought stress conditions.

Plants may be exposed to various stresses and water deficit is the most important limiting factor of growth and yield in many parts of the world and Iran. Stress induced growth decrement can be because of cell development decrease due to decrement of turgor pressure and meiosis and photosynthesis decrease due to stomata closure. Determination of desired planting density is one of the success factors of plant growth and production. Garlic (Allium sativum) has been an important medicinal plant over centuries in human life. According to the importance of medicinal plants and studying the effects of drought stress on them, the goal of this research is to investigate the effect of drought stress and planting density on growth and morphological characteristics of two ecotypes of garlic and determining the preferable ecotype and density from the perspective of these traits.
This experiment was performed in 2012 in a farm in south east of Semnan. It was conducted on a split-plot factorial arrangement based on randomized complete blocks design with three replications. Three levels of drought stress with 60, 80 and 100 percent of crop evapotranspiration (ETc) were the main plot factors and factorial combination of three planting density (30, 40 and 50 plants.m-2) and two ecotypes of Tabas and Toroud were the levels of sub plot factors. To estimate water requirement of garlic, daily measured meteorology parameters of Semnan synoptic station were used and water requirement was calculated based on FAO-56 instructions. From mid-January, the sampling of leaf area, bulb and leaf fresh and dry weight was started with destructive method every other week and continued until middle of Jun. three plant were selected randomly from each plot in each turn. From middle of May, height and number of leaves were measured. Leaf area measurement was done by leaf area meter (Delta-T). To estimate growth indices, dry weight of aerial and underground organs and leaf area from measured samples of treatments were used.
The results showed that the highest value of maximum leaf area index (LAI), maximum total dry matter accumulation (TDM), maximum crop growth rate (CGR) and maximum of net assimilation rate (NAR) were observed at 100% ETc with the value of 5.537, 387.53 gr.m-2, 10.47 gr m-2day-1 and 4.92 gr.m-2leaf.day-1 respectively; and by applying the irrigation treatment of 80% ETc these values decreased to 3.745, 262.60 gr.m-2, 6.31 gr.m-2day-1 and 3.71 gr.m-2leaf.day-1 respectively. Drought stress can decrease cell development and division and plant photosynthesis, and thus, it can decrease leaf area index and consequently decrease light absorption, photosynthetic area, dry matter and crop growth rate. Difference between ecotypes in terms of number of leaves, maximum total dry matter accumulation and maximum crop growth rate was significant. Maximum crop growth rate (CGR) in Toroud ecotype was higher than Tabas ecotype but number of leaves and maximum concentration of total dry matter (TDM) in Tabas ecotype were higher than corresponding values in Toruod ecotype. The effect of planting density on maximum leaf area index (LAI), maximum total dry matter (TDM) and maximum net assimilation rate (NAR) was significant. The highest value of maximum leaf area index (5.017) and maximum total dry matter (358.57 g.m-2) concentration were obtained from 50 plant.m-2 density. The highest value of maximum net assimilation rate (4.61) was obtained from 30 plant.m-2 density. It could be because of having leaves exposed to more light and less shading.
Applying drought stress at the irrigation treatment of 80% ETc decreased studied growth characteristics of garlic. Therefore, it is recommended that garlic should be avoided from facing drought stress and its water requirement must be met as much as possible. In general, under drought stress, two studied ecotypes did not have any preference related to the studied growth characteristics. Higher planting density, due to higher active photosynthetic area over unit area, increased the dry matter in unit area.

IntroductionIndustrialization has been the cause of environmental pollution and one of significant pollutant is that of heavy metals. These hazardous elements can cause to water and soil pollution. These metals can accumulate in the food chain and create damages for human and livestock. Researchers revealed that increasing Cd, Pb, Cu, Mn and Zn concentrations caused to decreasing of shoot fresh weight and essential oil yield. Scavroni et al (2005) indicated that peppermint was able to accumulate the heavy metals in shoot tissues but did not enter into essential oil. Therefore study the effect of heavy metals on morphological and quantitative traits of medicinal plants is essential.
Material and MethodThe experiment was done in the research greenhouse of the Agricultural Faculty of Ferdowsi University of Mashhad in 2011.The treatments were arranged basis on a randomized block design with three replications. Treatments were included T1:0, T2:10 ppm cd , T3:20 ppm cd,T4:40 ppm cd,T5:60 ppm cd,T6:80 ppm cd cd,T7:100 ppm cd,T8:100ppm pb, T9:300 ppm pb, T10: 600 ppm pb, T11: 900 ppm pb, T12: 1200 ppm pb and T13: 1500 ppm pb. Peppermint was cultivated with uniform weight rhizomes harvested from the research farm of Ferdowsi University of Mashhad. Every rhizome had two buds and six rhizomes were planted in pots of dimensions 30×50×35 cm. Treatments were irrigated with cdcl2 and pbcl2 with the administered doses and control was irrigated with distilled water. Plants were harvested two times at the first stages of flowering. The essential oil percentage was measured with 30 grams of dried leaves by Clevenger device.
Result and DiscussionIncreasing cadmium and lead concentrations caused a decline of fresh and dry weight, main stem height, leaf area per plant, leaf number per plant, number of nodes per plant and essential oil percentage compared to the control. At the first harvest, increasing doses of Cd caused a decrease of fresh weight. This decline was 18.16% at 100 ppm Cd and was 24.55% at 1500 ppm Pb compared to the control. At the second harvest, fresh weight declined by 15.24% and 32.72% compared to the control at 100 ppm cadmium and 1500 ppm lead, respectively. At the highest concentrations of Cd and Pb, dry weight of peppermint was dropped 22.92% and 25.88% at the first harvest. For the second harvest, decreased dry weights were 39.01% and 26.77% compared to the control, respectively. Stancheva et al (2010) revealed that increasing cadmium and lead concentrations caused to the shoot and root weights of sage (salvia officinalis L.) declined by 15 and 10%, respectively. They mentioned the glutathione-ascorbate cycle plays a vital role in neutralizing the destructive effects of ROS in sage. In this cycle, guaiacol peroxidase, ascorbate peroxidase and catalase enzymes increase and lead to diminish the ROS activity. In the same doses of cadmium and lead (100 ppm), cadmium had a more reductive effects than lead for all traits except for essential oil at the first harvest. This event is due to more toxicity of cadmium compared to lead. The toxicity threshold of cadmium and lead was reported 5 and 30 mg kg-1. Tirillini et al., (2006) reported that hypericin content in essential oil of hypericum perforatum L. was not affected by chrome stress.
ConclusionEssential oil, fresh and dry weight of peppermint did not show any significant change when the concentrations of cd and pb were maximum, so it seems that peppermint can be cultivated in polluted water or soil with cadmium and lead.

In order to evaluate the effect of application of biological and chemical fertilizers on purslane and dragon’s head intercropping, a factorial experiment conducted on the basis of completely randomized block design with three replicates at Agricultural Research Station of Hamedan in the spring of 2014. The first factor had five levels including: pure culture of purslane, pure culture of dragon’s head, intercropping of 25% dragon’s head + 100% purslane, intercropping of 50% dragon’s head + 100% purslane, intercropping of 75% dragon’s head + 100% purslane; and the second factor had four levels including: no fertilizer treatment, application of nitrogenous chemical fertilizer (urea), application of bio-fertilizer (nitroxin) and the mixture of 50% nitrogenous chemical fertilizer + bio-fertilizer (nitroxin). Evaluation of total canopy showed that the most of intercropping systems had more leaf area index and dry matter compared to pure cropping. The maximum amount of total leaf area index was observed in additive intercropping of 50% dragon’s head + 100% purslane and the mixture of 50% nitrogenous chemical fertilizer + bio-fertilizer (nitroxin). Intercropping systems did not have any significant effect on essential oil of dragon’s head; however application of fertilizers significantly affected this trait. Thus, in a purslane-dragon’s head intercropping, the practice of 50% dragon’s head + 100% purslane and also the usage of a mixture of nitrogenous chemical and biological fertilizers can improve the growth indexes of these plants.

Nowadays in order to produce healthy foods، application of compost and other organic fertilizers has received more attention as a suitable alternative for utilization of chemical fertilizers. It’s due to the fact that excess use of chemical fertilizers can cause threats to human health and lead to salinity or pollution of agriculture soils. Due to low organic-matter content in most soils in arid and semi-arid regions of Iran، application of organic-wastes’ like compost can increase water-holding capacity of the soil. In order to evaluate the effect of licorice compost application on decreasing of water stress in greenhouse cucumber (cv. Negin)، an investigation was conducted in a research greenhouse of Fasa in 2012. The experiment was factorial in a randomized completely block design with four replications. Treatments were composted root residue of licorice in four levels (0، 10، 20 and 40 percent of pot soil) and three irrigation regimes (50، 75 and 100% of field capacity moisture). Results showed that increasing in the amount of waste Licorice significantly increased shoot dry and fresh weight of cucumber. By reduction in moisture content of the soil and the amount of licorice residue، number of flower and fruit، plant height and internode length were reduced significantly. But 100% of field capacity moisture and 40 percent of licorice residue increased fruit weight and yield per plant significantly. The result of this study showed that water stress in cucumber can be controlled using licorice residue.

One of the problems of potato breeding in Iran like the most other countries is the lack of enough genetic diversity due to asexual propagation and the availability of just foreign imported commercial cultivars. In order to evaluate the potential of yield and also selecting promising clone for use in breeding programs an experiment using 6 families of true potato seed including Fanta op، selected Andigena (Adg)، hybrids of Agria × Caeser (Agr × Cas)، Agria × Savalan (Agr × Sav)، family of the BC1 of S. stoloniferum× S. tuberosum (sto × tbr) with the cultivated parent (tbr) and families of inter-mating between sto × tbr hybrids (HS - sto × tbr) were compared with using a randomized complete block design with three replications. The results has been showed significant difference between families for the total tuber yield، plant height، leaf area، pollen stainability (p ≤ 0. 01) and tuber and haulm dry weight، and number of stem per plant (p ≤ 0. 05). According to mean comparison results family Agria × Savalan with 526. 66 grams per plant had the highest tuber yield but its difference with the families of Adg; (HS - sto × tbr) were not significant. The BC1 of sto × tbr family with 19. 7 tubers per plant had the maximum tuber number but its difference with the families of the Adg، Agr × Sav and (HS - sto × tbr) were not significant. The (HS - sto × tbr)، BC1 and Fanta OP had the highest and hybrids of (Agr × Sav) lowest pollen fertility.

In order to evaluate the yield and some morphological characteristics of two faba bean (Vicia faba L.) local and foreign cultivars to different sowing dates in Ahwaz region، an experiment was conducted during 2013-2014 year in Khouzestan Ramin Agriculture and Natural Resources University. The Experiment was as split plot based on complete randomized block design with four replications that included sowing date as main plot (October 10، October 25، November 10، November 25 and December 10) and two faba bean varieties Hystal (foreign) and Saraziry (local) as sub plots. The results showed that cultivars had significant difference in terms of number of grain per pod، number of pods per plant، plant height and grain weight. Also interaction effect of sowing date and cultivar on grain yield، biological yield، was significant. The mean showed that Hystal cultivar has more grains per pod and saraziry cultivar had more number of pods per plant. The Highest grain yield related to sowing date of October 25 and November 10 with average 3979. 3 and 3849. 4 kg per hectare، respectively and the lowest grain yield to December 10 with average 1806. 2 kg per hectare. In general، results of experiment showed that Hystal cultivar in sowing date of November 10 and Saraziry cultivar in sowing date on October 25، produced highest grain yield and dry matter.

Field studies were conducted in the research field of the Agricultural Faculty of Islamic Azad University-Astara branch in 2010 and 2011 year in order to evaluate the effect of redroot pigweed (Amaranthus retroflexus L.) on yield and dry matter of corn (Zea mays L.) under different levels of nitrogen application. The experiments were established as a split plot arranged in randomized complete block design with three replications. The main plot was with nitrogen (N) at different rates (0, 100, 160 and 220 kg ha-1) and the sub plot was redroot pigweed in different densities (0, 5, 10 and 20 weeds m-2; 0, 3, 5, 7 and 14 plants m-2 in a corn row, respectively). The results showed that the highest number of seed rows per ear, grain number per ear, 1000 grain weight, grain yield per plant and harvest index of corn were, respectively, 15.6, 691.3, 247.7 g and 41.2% at 160 kg N ha-1 in a weedfree condition and the presence of 5 weeds per m-2 had no significant effect on them. The highest dry matter and grain yield of corn were 15.9 and 12.3 t ha-1 at 220 and 160 kg N ha-1 under weed-free conditions.

Proper application of herbicides is a major concern in sustainable agriculture. This issue depends on our knowledge about weed plants، especially weed-crop competition. Therefore، In order to evaluate the effect of weed competition on some dry bean’s traits an experiment was conducted in 2011. The experiment was a randomized complete block design with 3 replications. Treatments included weed-infested and weed-free periods until 0، 10، 20، 30، 40 and 50 days after crop emergence. In order to evaluate trends of dry bean’s traits Boltzmann model was fitted to the data. Crop height had a descending trend in weed-infested treatments، while it had an ascending trend in weed-free plots. Increase in duration of weed interference reduced main stem’s node formation of the crop. Weed interference affected crop’s number of branches. This trait had a descending trend in weed-infested plots، while it was ascending in weed-free treatments. Weed competition influenced pods length as well، so that the minimum value of this trait (6. 56 cm) was observed in full season weed-free treatment. Regression analysis revealed a significant negative relationship between weed biomass accumulation and evaluated dry bean’s traits (height، number of nodes in main stem، number of branches and pods length) at 1% probability level. Therefore، weeds are able to restrict dry bean’s development and growth through constraining environmental essential resources in which consequently lead to a final yield reduction.

Climate change, especially an increase in CO2 concentration and soil pollution due to heavy metals, has changed plant growth and metal uptake by them. This research was carried out in order to investigate the impacts of increasing atmospheric CO2 concentrations on Fe, Cu and Zn uptake and the growth parameters of wheat and sorghum at two levels of CO2 (400 and 900 μL L-1) and four levels of cadmium (0. 10, 2 and 40 mg kg-1). After 60 days, the plants were harvested, and the results showed that increasing CO2 concentration led to significantly increased plant height, leaf area, root and shoot dry weight (p< 0.01). Increasing CO2 concentration caused increase concentration and uptake of Cd, Fe, Cu and Zn in sorghum shoot and root. In contrast, uptake of these elements in wheat decreased. Among nutrients, the greatest increase in concentration for shoots of sorghum was in Zn (14-25%) and in root was related to Fe (16-25%). For wheat, Cu showed the greatest decrease in concentration in shoot (19-25%) and root (10-15%). Decreasing the uptake of Cd in wheat can be a factor for higher stress tolerance but, on the other hand, a decrease in micronutrient concentrations, especially of Zn, in crops such as wheat that has been used widely, can create problems associated with plant growth conditions and food production. For sorghum, although an increase in the uptake of nutrients was seen, increased Cd uptake is a problem that must be noted within the context of human and food safety.