جستجوی مقالات مرتبط با کلیدواژه « خرفه » در نشریات گروه « زراعت »

Due to study the effect of ascorbate foliar application on photosynthetic pigments, phenols and flavonoids of purslane under salinity stress conditions, an experiment was carried out in 2016 at Islamic Azad University, Yadgar-e-Imam Khomeini (RAH) Shahre Rey Branch and Pakdasht city, as factorial design based on Completely Randomized design with 4 replications, in which salinity stress in 3 levels (0, 70, 140 and 210 mM) and ascorbate foliar application in three levels (0, 10 and 20 mM) were considered. The results showed that except for the simple effect of salinity on flavonoid and phenol and the effect of ascorbate on carotenoids and other effects on evaluated traits were significant. The double interaction effect of experimental factors was significant only on chlorophyll b and carotenoids. Base of the finding the mean  comparison results indicated that foliar spraying of 20 mM ascorbate led to the highest  chlorophyll content, but there was no significant increase in carotenoids. The mean comparison interaction effects demonstrated that 210 mM and non using of ascorbate gained to maximum leaves carotenoids content (0.72 µg/ml), while no use of salinity water and 20 mM of ascorbate solution with µg/ml 4.24 ml produced the highest leaves chlorophyll b.

To study the effect of herbicides on weed control in henna in south Kerman province, an experiment was carried out in randomized complete blocks design (RCBD) with 3 replications in 2014-2015 and 2015-2016. Treatments included trifluralin (Treflan, 48% EC) at 2 and 2.5 Lha-1, per-transplant, pendimethalin (Stomp, 33% EC) at 3 and 4 Lha-1 pre weed emergence and after transplanting, imazethapyr (Pursuit, 10% SL) at 0.5, 0.6, 0.7 and 0.8 Lha-1 + Cytogate at 1 Lha-1 at 2 to 4 leaf stage of broadleaf weeds + haloxyfop –R- methyl- ester (Gallant, Super 10.8% EC) at 750 ml ha-1 in the 3 leaf stage of narrow-leaf weeds, gramoxone (paraquat, 20% SL) at 3 Lha-1 and 10 -15 cm stage of weeds with protection cover over henna, hand weeding and weed free. Results of combined analysis in three-cutting henna showed that herbicide applications significantly reduced density and dry matter of amaranth (Amaranthus viridis), purslane (Portulaca oleracea) and Egyptian grass (Dactyloctenium aegypticum. The Best treatments for weeds control was the imazethapyr (0.8 ha-1), pendimethalin (4 Lha-1) and trifluralin (2.5 Lha-1) applications, respectively. Application of imazethapyr (0.8 ha-1) + haloxyfop decreased amaranth (69-76%), purslane (68-74%) and Egyptian grass (60-73%) biomass. Also, this treatment increased henna biomass in the first, second and third harvest by 90, 76 and 79 %, respectively. Therefore, this treatment is introduced as the superior treatment.

Salt tolerance at the germination stage is important, because salinity is usually severeat the soil surface.Especially in cases where the groundwater level is high.In order to investigate the effect of primingand salinity stress on the quantitative and qualitative traits of P. oleracea, this experiment was conducted in the Seed Technology Laboratory of the Faculty of Agricultural Sciences of Shahed University in 2019.Experimental agents included pretreatments (control (distilled water), hydro-priming, potassium nitrate and salicylic acid) in response to 6 salinity levels (no salinity as control and salinity of 30, 60, 90, 120 and 200 mM with Sodium Chloride).This experiment was studied as a factorial in a completely randomized design with three replications. The measured traits included germination indices, photosynthetic pigments, anthocyanin content, proline and soluble sugars.The results showed that the highest amount of germination components such as germination percentage (97%), germination rate (2.16 seeds per day), plantletlength (6.69 cm), plantletfresh weight (4 g), plantletlength index (324.69) and RWC (75.25%) were obtained in non-salinity stress and application of hydro-priming pretreatment.At salinity levels of 60 mM, the content of chlorophyll a, chlorophyll b and total chlorophyll in the hydropriming treatment increased and the highest content of proline, soluble sugars and anthocyanin was obtained at the highest salinity level.Among the studied priming levels, hydropriming at salinity stress of 200 mM had the highest percentage and seed germination rate, chlorophyll content, anthocyanin and proline.

Nowadays, the side effects of using synthetic herbicides and fungicides have been identified as one of the most important environmental challenges in the world. Therefore, the use of natural materials with herbicidal and fungicidal power can be considered as an alternative to synthetic compounds. To evaluate the natural allelopatic and fungicidal properties of aqueous leaves and corm extracts of saffron on seed germination, plant growth of common pursalne, and antifungal effects on Penicillium sp, three separated factorial layout were conducted based on a completely randomized design with three replications in Seed Research Laboratory, Research Greenhouse and Plant Disease Laboratory of Birjand University of Agriculture during 2019. Experimental treatments in the lab and greenhouse consisted of two types of saffron tissues (leaves and corm) and six concentrations of aqueous saffron extract (0, 0.5, 1, 1.5, 2 and 4% m/v) and antifungal treatments consisted of two types of saffron organs (leaves and corm) and six concentrations of aqueous extract (0, 0.0078, 0.0312, 0.0625, 0.25, 1, 1.5, 2 and 4% m/v). The traits studied in the first experiment included germination percent, germination rate, root length, dry root weight, and dry shoot weight. In the second experiment traits included emergence percentage, fresh and dry weight of shoot and in the third experiment mycelium growth inhibition of Penicillium sp. The results showed that the extract concentrations and types had a significant effects on germination characteristics including germination percent, germination rate, mean germination time, germination, root length, shoot length, root dry weight and shoot dry weight. However the interaction effect of the type and concentration extracts on germination percent, germination rate seed viability and root length was significant. The mean germination time, root length, shoot and root dry weight were decreased up to 52.4%, 71.4%, 81.7% and 79.2%, compared to control at the highest extract concentration.

Plants in arid and semi-arid regions are constantly exposed to environmental stresses such as salinity. The sensitivity of different plants to salinity stress at different growth stages is quite different. In many plants, perhaps the most sensitive stage of the plant growth cycle to salinity, is germination and emergence stages. Germination and emergence of seeds are the first important stages in plant establishment which is affected by most environmental stresses. In South Khorasan, which has saline soil and water, conventional millet cultivation is common, and it’s most important weeds are lambsquarters, tumble pigweed and purslane. Since the irrigation of millet fields in this region of the country is performed with saline water, this experiment was conducted out to investigate the emergence response of millet and lambsquarters, tumble pigweed and purslane weeds, under sodium chloride salinity in Hoagland solution.

In order to evaluate the effect of salinity stress on quality and emergence rate of common millet, lambsquarters, tumble pigweed and purslane, four separate experiments were conducted out in a randomized complete block design with three replications in 2017 in the research greenhouse of agricultural faculty at Birjand University. Experimental treatments consisted of 10 salinity levels including Hoagland solution with 2 dS/m as control, 4, 6, 8, 10, 12, 14, 16, 18 and 20 dS/m (created sodium chloride in Hoagland solution). Hoagland formula was used for preparation of nutrient solution and sodium chloride was used for preparation of different salinity levels. After filling each pot with 1.5 liters of acid washed sand, 25 seeds from each species were placed at 1 cm depth from soil surface. Seedling emergence were counted daily. In order to investigate the response of each species to salinity stress, the emergence percentage in each species was analyzed in a randomized complete block design without considering treatments with zero emergence percentage. Data analysis was performed using SAS software. GLM procedure was used for analysis of variance and comparison of mean performed with protected LSD at 5% probability level.

The results showed that common millet, purslane, tumble pigweed and lambsquarters seeds had the ability to germinate up to 20, 16, 12 and 12 dS/m, respectively. The start of emergence for common millet seeds up to 10 dS/m and tumble pigweed up to 8 dS/m was 3 days after sowing. Meanwhile, the seeds of lambsquarters emergence up to 6 dS/m on the fourth day, and purslane in 2 dS/m on the second day after sowing. Millet plants were emergence up to 18 dS/m salinity in the first five days after sowing. The results also showed that for common millet and tumble pigweed, no significant difference were observed for single seedling dry weight at 2 and 4 dS/m. Increasing salinity from 2 to 4 dS/m led to a significant decrease in purslane seedling dry weight but with increasing salinity stress from 4 to 8 dS/m, the reduction in seedling dry weight was not significant. In this study, with increasing salinity stress from 2 to 8 dS/m, dry weight of common millet, purslane, lambsquarter and tumble pigweed decreased by 55, 73.8, 80.7 and 79.5%, respectively. In this study, after ensuring that the seeds did not emerge, to determine the viability of non-emerged seeds, the pots were irrigated with distilled water. Under this condition, non-emerged millet seeds in the pots were not able to germinate at any levels of salinity stress. Purslane had no germination under salinity stress of 18 and 20 dS/m, but there were 34% and 62% emergence percentage respectively, when the salinity were terminated. Under mild stress, the percentage of germinated purslane seeds was 18% after recovery, which decreased with increasing salinity up to 12 dS/m and then increased.

In general, the results showed that salinity stress caused a change in the emergence behavior of millet and purslane, tumble pigweed and lambsquarters weeds. Common millet had the ability to germinate at all levels of salinity stress, but tumble pigweed and lambsquarters had the potential to emerge up to 12 dS/m and for the purslane up to 16 dS/m. Also, with increasing salinity stress from 8 to 16 dS/m, dry weight of seedling of common millet, purslane, tumble pigweed and lambsquarters decreased by 66, 82, 100 and 100 percent, respectively. At the end, the results showed that occurrence of salinity stress and its removal, the purslane seeds had a greater ability to keep their viability, whereas the common millet seeds completely lost their viability.

Purslane (Portulaca oleracea L.) is one of the most valuable herbs of the Portulacaceae family, which can be used as herbs and medicinal purposes. Water deficit is one of the major abiotic stresses that have adverse effects on plant growth and yield. The application of growth regulators such as salicylic acid and abscisic acid increases the resistance of plants to stresses and is a strategy to prevent the destructive effects of environmental stresses. Due to the low water resources in the country and the widespread use of purslane in the pharmaceutical, cosmetic, health and food industries, this study was conducted to investigate the effects of salicylic acid and abscisic acid on yield, yield components and some quantitative and qualitative traits of purslane forage under water deficit stress.

Field experiment was carried out as split-plot based on randomized complete block design with three replications in 2018. Treatments were four levels of water supply (irrigation after 70, 100, 130 and 160 mm evaporation from class A pan) and three levels of foliar application (control (foliar application of water), foliar application of salicylic acid (1 μmolar) and foliar application of abscisic acid (50 μmolar). Irrigation and foliar application treatments were allocated to main and sub plots, respectively.

Decreasing water supply led to reduction in number of capsules per plant, number of grains per capsule, number of grain per plant, biological and grain yield. Foliar application of salicylic acid and abscisic acid caused significant increase in number of capsules per plant (13.2 and 10.9% respectively), biological (15.2 and 13.1% respectively) and grain (16.1 and 13.3% respectively) yield. Fresh and dry forage yield and crude protein percentage and yield decreased 66.8, 65.7, 35.4 and 80.8% respectively as a result of water deficit. Fresh and dry forage yield and crude protein yield significantly enhanced by foliar application of salicylic acid and abscisic acid.

There was no significant difference between salicylic acid and abscisic acid foliar application. Therefore, regarding to beneficial effects of salicylic acid and abscisic acid on grain and forage yield of purslane, foliar application of salicylic acid and abscisic acid recommended for the study area. This would become more important under conditions where water availability is limited.

In salt stress conditions, the use of moderating substances such as potassium-containing fertilizers can reduce the negative effects of saline on yield and yield components of crops. The objective of this study was to determine the effect of potassium amount on yield and yield components of Common Purslane (Portulaca oleracea L.) grown under salt stress. The study was conducted in pot experiments under greenhouse conditions in Sabzevar branch, Islamic Azad university in 2016. A factorial experiment was carried based on completely randomized design with three replication. Factors were: amount of potassium (0. 150 and 300 kg k2O ha-1) as Solopotash form and salinity levels (0, 6, 9 and 12 dS.m-1). The results showed that increasing potassium amount in salt stress conditions increased the yield and yield components of Common purslane and the highest plant height, number of lateral branches, number of capsule per plant, number of seeds per capsule, dry weight of plant, grain yield, potassium content and lowest amount of sodium was obtained by consuming 300 kg. ha-1. Salinity at 12 dS.m-1 level, 57.75% reduced plant height, 55.75% number of lateral branches, 37.27% capsules per plant, 68.56% seeds per capsule, 67.57% 1000 seed weight, 71% plant dry weight, 47.21% grain yield and 41.91% plant potassium content and increased 27.65% sodium content compared to control. In total, the results showed that till 9 dS.m-1 grain yield was not statistically significant and consumption of 300 kg.ha-1 was more suitable for reducing the effects of salinity stress.

Purslane (Portulaca oleracea) is one of the most widely used medicinal plants in the world that has many medicinal properties.To investigate the genetic variation in the second generation (M2) of purslane lines, a nested experimental design with two replication was conducted at the research farm of Shahed University, Faculty of Agriculture during 2017-8. Experimental treatments included M2 lines treated with dimethyl sulfate (DMS) at concentrations of 0, 0.08, 0.1, 0.12 and 0.14 %. The studied traits included plant height, number of branched stem, stem diameter (SD), stem fresh weight (SFW), stem dry weight (SDW), SDW/SFW, leaf fresh weight (LFW), leaf dry weight (LDW),  LDW/LFW, plant fresh weight (PFW), plant dry weight (PDW), PDW/PFW, leaf length, leaf width, leaf shape (LS), number of capsules (NC), chlorophyll content, leaf area, hectoliters. The differences among concentrations od DMS were significant at the level of 1%. The maximum amount for traits such as SD, SFW, SDW, NC, LDW/LFW, PFW and LS was observed at the concentration of 1%. Among the 190 incomplete correlation coefficients, 28 were significant (15%) while this value was 58% in the Pearson correlation coefficient. In factor analysis, 19 variables were reduced to 6 factors, which explained 71.86% of the data variation. In path analysis with repeated data, the direct effect of SFW on PFW was higher than the indirect effect, while this trend was reversed on LFW. In path analysis with mean of replications, the maximum indirect effect on PFW was from LFW and  LDW/LFW through SFW.

scisic acid Abstract Field experiment was carried out as split-plot based on randomized complete block design with three replications in 2018, to evaluate physiological performance and oil yield of common purslane, in response to water limitation and foliar application of salicylic acid and abscisic acid. Treatments were four levels of water supply (irrigation after 70, 100, 130 and 160 mm evaporation from class A pan) and three levels of foliar application (control (foliar application of water), foliar application of salicylic acid (1 μmolar) and foliar application of abscisic acid (50 μmolar). Irrigation and foliar application treatments were allocated to main and sub plots, respectively. Decreasing water availability resulted in decreasing chlorophyll content (34.2%). However, proline content of leaves enhanced under limited irrigation conditions. Mean leaf chlorophyll content significantly enhanced by exogenous spray of salicylic acid (9.6%) and decreased with foliar application of abscisic acid (5.4%), compared with control. Decreasing water supply led to reduction in anti-oxidant enzymes activity and grain yield. Foliar application of salicylic acid and abscisic acid caused significant increase in anti-oxidant enzymes activity and grain yield. Oil percentage in the grains of purslane increased (16.6%) as a result of water deficit, but grain oil yield decreased (70.1%) with increasing irrigation intervals. Oil yield significantly enhanced by foliar application of salicylic acid and abscisic acid. There was no significant difference between salicylic acid and abscisic acid foliar application. Therefore, regarding to beneficial effects of salicylic acid and abscisic acid on grain and oil yield of pursalane, …..

A field experiment was conducted to evaluate the effect of barley (Hordeum vulgare) and berseem clover (Trifolium alexandrinum) cover crops, and their cutting time on black seed (Nigella sativa) weed management in 2016-2017 at research field of the College of Aburaihan, University of Tehran. The experiment designe was randomized complete block design with 3 replications. Treatments were: T1, no cover plant-weed free; T2, no cover plant- weed infest; T3, barley-first cutting; T4, barley-second cutting; T5, clover-first cutting and T6, clover-second cutting. The first and the second cutting were done after Black seed establishment and before flowering stage of cover crops, respectively. Results showed that the highest weed biomass was 444 gr.m-2 obtained from T2 treatment at t the second sampling time and the lowest weed biomass was 28 gr m-2, related to first cutting clover treatment (T5), at the first sampling time. The highest grain yields were 527 and 446 kg.ha-1, observed in treatment (T5) and control treatment (T1) respectively and the lowest yield was obtained from control (T2) with a mean of 100 (kg ha-1). Overall, results showed that T5 treatment at the second sampling time reduced weed biomass 90.4% compared to without weeding control. In addition, the berseem clover plant not only did not compete with black seed, but also increased yield compared to the without cover plant control (T1).

Interference includes competition for environmental potentials and allelopathy. By releasing chemical compounds, usually of secondary metabolites, in various ways such as root exudation, decomposition, leaching and volatilization, allelopathic weeds may have positive, negative or even neutral effects on crops. Therefore, the purpose of this experiment was to evaluate the hetrotoxic potential of Sorghum halepense, Portulaca oleracea and Centurea depressa in characteristics of germination, chlorophyll content and carotenoid pigments of cress under laboratory conditions.

For bioassay experiments, various concentrations of 0, 20, 40, 60, 80 and 100% of the weeds such as S. halepense, P. oleracea and C. depressa were prepared with the help of distilled water and were subsequently separately applied on 50 certified seeds of cress. In this experiment, characteristics such as rate and germination percentage, content of chlorophyll a, b, total chlorophyll content and carotenoids were measured based on the chilled acetone method.

Regression model showed that rate and germination percentage of cress significantly decreased at concentrations higher than 80% of S.halepense only. For every unit increase in the concentration, radicle length, seed vigor, content of total chlorophyll and carotenoids of cress decreased about 0.08 cm, 8.68, 0.007 mg/g and 0.007 mg/g, respectively. According to the results, there was an exponential relationship between different concentrations of the P. leracea extract with germination characteristics and photosynthesis pigments of cress so that in most cases, these characteristics up to concentration of 40% had moderate decline, but beyond this concentration, they showed a steep decline. In case of C. depressa, rate and germination percentage, as well as the shoot length of cress decreased about 14.67, 14.67 and 29.81% respectively, using only a concentration of 100%. However, radicle length and seed vigor of cress decreased with increased concentrations of aqueous extract of C. depressa. The most reductive effects were obtained in the treatment of 100%, which were about 52.38 and 55.44% respectively. Amount of total chlorophyll of cress decreased about 14.37, 27.59 and 25.29% respectively in concentrations of 60, 80 and 100% of C. depressa extract, as compared with the control. On the other hand, concentrations of 20 and 40% of C. depressa had no significant effect on the pigment studied. The result of carotenoids content was the same as total chlorophyll.

Based on the results, the weeds studied, especially P. oleracea, with high concentrations, had strong hetrotoxic effect on germination characteristics and photosynthesis pigments. This requires further investigation in a natural environment where targeted plants grow in close proximity.

Hetrotoxic compounds of Portulaca oleracea, especially in high concentrations significantly decrease seed germination and photosynthetic pigments of cress as compared with Sorghum halepense and Centurea depressa. Given the evidence for the hetrotoxic effect of aqueous extract of the weeds studied, they could be introduced as candidates for production of bio-herbicides.

In order to evaluate the effect of the Russian knapweed (Acroptilon repens) aqueous extract as a biological herbicide on the germination of weeds of purslane (Portulacaoleracea), common yellow mallow (Abutilon theophrasti), and wheat (Triticum aestivum), a factorial experiment (with a completely randomized design and four replicates) was conducted in 2016 in the laboratory and greenhouse of the Faculty of Agriculture and Natural Resources, University of Mohaghegh Ardabili, Ardabil, Iran. The experimental factors included plant types (purslane, common yellow mallow, and wheat) and concentrations of the Russian knapweed aqueous extract at 6 levels (0 (control), 5, 5.7, 10, 15, and 20%). The results showed that germination percentage, coleoptile length, radicle length, and total weight of the seedlings were significantly affected by different concentrations of the Russian knapweed aqueous extract, plant species, and their interactions. Russian knapweed aqueous extract had the least and the greatest inhibitory effect on the germination of common yellow mallow and purslane, respectively. It was observed that the reduction of the length of coleoptile under the effect of aqueous extract concentrations of Russian knapweed for all species was significant and with increase in concentration of aqueous extract of Russian knapweed to the fast slope decreased length of the coleoptile. In the case of the radicle length, the results showed that at concentration of 20% extract of Russian knapweed, the highest and lowest radicle length reduction was related to the common yellow mallow and wheat with amount of 99 and 21% compared to control treatments. Based on the test results, reduce of the dry weight of seedlings on 15 and 20% for concentrations of aqueous extract of Russian knapweed was observed for each of the three plants. The applied results of this research was includes the usability of Russian knapweed aqueous extract on concentrations of 15 and 20% and its impact on seed germination and growth of purslane and common yellow mallow weeds.

In order to study the effects of irrigation regimes and humic acid application on some of physiological and biochemical characteristics of Portulaca oleracea L., a greenhouse experiment was conducted as factorial based on completely randomized design with three replications at research greenhouse of plant production faculty of Gorgan University of Agricultural Sciences and Natural Resources, during of 2014- 15. The main factors were irrigation regimes including four levels: (25, 50, 75 and 100 percent of field capacity) and four concentrations of humic acid: (0, 200, 400 and 600mg/L). Traits evaluated were proline, RWC, total phenol, flavonoid, antioxidant, soluble carbohydrate and carotenoid content. The results showed the treatments had significant effects on the traits. As, Irrigation regimes had significant effect on proline, total phenol, flavonoid, antioxidant, soluble carbohydrate. The highest level of irrigation regimes (25 percent FC) increased proline and decreased RWC and carotenoid. Humic acid had significant effect on all traits except of carotenoid content that were the highest in 400 mg/L humic acid. Interaction effect of humic acid and irrigation regimes was significant for all traits except of total phenol. Irrigation regimes increased antioxidant, soluble carbohydrate, in 25% and 50% FC, respectively. Generally the best of treatments is 400mg/L humic acid and 25percent FC, economically. Because the highest yield achieved with low water and humic acid.

To investigate the effect of nitrogen and phosphorus nutrients from organic and chemical fertilizers sources, on their efficiency in purslane, a field experiment based on complete randomized block design was conducted at the Research Farm of Shahrekord University in 2014. Treatments were 13 t.ha-1 broiler litter (T1), 14.4 t.ha-1 broiler litter (T2), 39 t.ha-1 cattle manure (T3), 16.8 t.ha-1 cattle manure 150 kg.ha-1 urea (T4), four chemical fertilizer levels equivalent to organic manure treatments, 260 kg.ha-1 urea 뚸ꦕ super phosphate, respectively (T5), 287 kg.ha-1 urea triple super phosphate, respectively (T6), 260 kg.ha-1 urea triple super phosphate, respectively (T7), 260 kg.ha-1 urea triple super phosphate, respectively (T8) and control (T0). The results showed that T2 treatment produced 8345 kg.ha-1 of dry matter as compared with those of other fertilizer treatments (P

IntroductionPurslane (Portulaca oleracea L.) is one-year and C4 plant of the family Portulacaceae. Purslane is a drought- and salt-tolerant plant, which contains high amounts of beneficial omega-3 fatty acids and antioxidant vitamins. Make it a prime candidate to form edible landscape in areas with dry conditions and salty soils, which are often present together where land is irrigated. Purslane seeds provide nutritional value, and have beneficial health effect on body specially in preventing cardiovascular, cancer and hypertension (high blood pressure) diseases, because it contains omega-3 and omega-6 fatty acids and other nutrients such as antioxidants, tocopherols and dietary fibre.
Materials and MethodsThis study was conducted in the 2011 growing season at Agricultural Research Station of Islamic Azad University, Birjand (Latitude: 32°53'N; Longitude: 59°13'E and Elevation above sea level: 1480 m), Iran. Climate in this area is semi-dry to dry (annual rainfall is about 176 mm, maximum and minimum temperature are 39.1 and -17 degrees centigrade, respectively). The soil of the field was Sandy clay loam with pH 8.38 and with an EC of 2.74 m. mohs.cm-1. In this study, the effect of four sowing dates (4 April, 21 April, 5 May and 20 May) and three plant densities (5.5, 8.3 and 16.6 plants m-2) were investigated as main plot and sub plot, respectively in a split plot design based on randomized complete blocks with 3 replications. Each plot was 2.4m×6m with six planting rows. The space between rows, plots and replications was 0.4, 0.8 and 2 m, respectively. The field had been left fallow in the previous year. Sowing was done manually and was wet planting. Irrigation was employed with an interval of 4 days immediately after planting for uniform emergence until establishment of seedlings and after that continued weekly. To achieve the desired density, the seed was planted with high density, then the operation in two stages six and eight-leaf thinning, the density was obtained. According to the results of soil test, 100 kg/ha Triple superphosphate and 100 kg/ha soleplate potassium was applied to the soil before final disking. Nitrogen fertilizer was applied 300 kg/ha (as 1/3 at sowing, 1/3 at first harvest and 1/3 at second harvest) in the form of urea. Weed control was done manually in three stages. There was no specific pests and diseases during the growing season. In this study, we evaluated traits such as number of capsules per plant, number of seeds per capsule, 1000 seed weight, seed yield, biological yield, harvest index and forage yield. All statistical calculations were carried out by MSTATC software and the means of the studied traits were compared by Duncan’s Multiple Range Test at 5% probability level.
Results and DiscussionThe results showed that delay in sowing date, reduced the number of capsules per plant, number of seeds per capsule, 1000 seed weight, grain yield and forage yield. For each 15-day delay in planting, seed yield reduced by 12.6%, 49.7% and 31.8% respectively. In planting 15 April, optimum environmental conditions such as light, temperature and longer growing period, resulted in hgher plant photosynthetic and thus biomass and grain yield increased. Effects of plant density on all measured traits (with the exception of 1000 seed weight) were significant. Increasing plant density decreased all measured traits with exception of number of capsules per plant and number of seeds per capsule. The planting density of 16.6 plants m-2 compared to 8.3 and 5.5 plants m-2, reduced the grain yield 55.6 and 67.4 % respectively. In the low densities, due to low leaf area, photosynthetic rate and biomass decreased and the seed yield was low. Interaction between sowing date and plant density on biological yield and dry matter yield were significant. Highest biological yield was of sowing date 15 April and plant density 16.6 plants m-2 and the lowest, in plant density of 5.5 plants m-2 in all sowing dates studied. Highest dry matter yield obtained from sowing date 15 April and plant density of 16.6 plants m-2 and the lowest, was for sowing date 21 April and plant density of 5.5 plants m-2.
ConclusionsSowing date of 4 April and plant density of 16.6 plant m-2 can be recommended to obtain high seed and biomass yield of purslane.

Three separate experiments conducted to survey the response of two populations of common purslane weed collected from Karaj and Ahvaz on germination and early growth. The first experiment was based on 4 levels of flooding, including 1, 2, 4, 8 days plus non-flooding treatment as a control. Second experiment addressed the impact of various acidity levels, such as 4, 5, 6, 7, 8, 9, 10 and finally third experiment considered the influence of high temperatures of 60, 80, 100, 120, 140, 160, 180, 200, 220 centigrade on germination rate, germination percentage, radicle length and plumule length as well as fresh weight of the aforementioned population of common purslane (Karaj and Ahvaz). Analysis of variance revealed that in both weed populations, all germination indices were impressed by flooding periods, acidity levels and high temperatures. Extending the flooding periods resulted in reducing all measured parameters in both weed populations, so growth of common people was completely inhibited less than 8 consecutive days of flooding. Germination rate and percentage improved gradually by increasing the acidity value from 4 up to 7. An adverse relation was observed between the measured parameters and temperature variations in both Karaj and Ahvaz weed population. Germination rate and percentage, radicle and plumule length as well as fresh weight of seedling decreased significantly in response to increasing the oven temperature. Overall, it can be concluded that boosting our knowledge about both ecology and biology aspects of common person can pave the way for introducing new ways in line with expanding long term strategies, improving management systems and predicting the mode of germination and growth of the this important weed.

In order to evaluate the effect of different sources and rates of nitrogen the growth and biomass production of purslane, a randomized complete block design was conducted with three replications at the agricultural research farm of Shahrekord University in 2012. Fertilization treatments were consisted of control (no N amendment), 30 and 90 kg N ha-1in the form of urea fertilizer, 30 and 90 kg N ha-1 in the form of cow manure, 60 kg N ha-1 as urea fertilizer+ cow manure in 2:1, 1:1 and 1:2 ratios. The results showed that the greatest leaf area index was observed from the second cutting with integrated treatments and 90 kg N ha-1 as cow manure. In the first cutting, the greatest aboveground fresh weight (76.04 Mg ha-1) was obtained in 90 kg N ha-1 as cow manure and it didn’t have a significant difference with that of the integrated treatment (1:1). In second cutting, aboveground fresh weight in integrated treatment (1:1) has a significant decline compared to that of the 90 kg N ha-1 as urea and/or cow manure. The leaf fresh weight from the first cutting was significantly greater than that of the second cutting. In general, the application of combined organic and chemical fertilizer (1:1) is effective in reducing nitrogen of single cutting of purslane production and future research should focus on top dress nitrogen for or increasing production of purslane second cutting treated with integrated fertilizer.

This present research was arranged to determine economic thresholds of three weed species in corn field including redroot pigweed، purslane and Johnsongrass. The control methods were chemical، mechanical and integrated method. The statistical design was a randomized completely block with eleven treatments in 3 replicates. The experiment was conducted at the experimental station of Agricultural and Natural Resources College of Darab، Shiraz University، in 2004 and 2005. The treatments included the application of Atrazine plus Alachlor at 1+2. 5 and 0. 5+1. 25 kg ai ha-1 used as broadcast and band application alone and in combination with rotary or sweep cultivators and mechanical weeding alone. The Results indicated that the economic thresholds in Johnsongrass was controlled by chemical، mechanical and integrated methods were 4. 371، 7. 270 and 10. 164 weed/m2 respectively. The economic thresholds of Purslane were 1. 185، 2. 104 and 1. 624 weed/m2 respectively and for the Redroot pigweed were 2. 816، 4. 886 and 3. 932 weed/m2 respectively. Furthermore’ based on the economic threshold، mechanical weed control which is an early control method should be applied. Otherwise another appropriate control method based on the plant density as envisaged by economic threshold should be considered for each weed specie.

In order to study the effect of different drought levels on germination of purslane)Portulaca oleracea L.) seeds, an experiment was conducted under eight negative water potentials (0, -0,25, -0,5, -0,75, -0,1, -1,25, -1,5 and -17,5 MPa) using a completely randomized design with five replications. Increasing water potential significantly decreased percentage and rate of germination, length and dry weight of radicle and plumule, ratio of root to shoot length and seedling vigor index and increased the mean germination time. But these changes occurred after a threshold, e.g. negative potential more than -0.75 MPa negatively affected germination percentage and ratio of root to shoot length. In addition rate of germination and average germination duration decreased after in potentials more than -0.5 MPa. Ratio of root to shoot length was not significant different up to -1.25 MPa, and then significantly decreased. As a result, purslane germination can be extremely tolerable to drought conditions so it seems that this plant can be established in arid and semi-arid regions.