mohamad javad seghatoleslami

Pulicaria gnaphalodes (Vent.) Boiss. is a medicinal plant perennial and herbaceous belong to Asteraceae family which grows in some parts of Iran. In order to investigate the effect of two sowing dates (May 3 and 23) and nitrogen rates (0, 80, 160, and 240 kg N/ha) on morphological traits, yield and yield components and essential oil yield of P. gnaphalodes aerial parts, a factorial experiment based on a randomized complete block design with three replications was carried out in research field of Birjand branch, Islamic Azad University, Birjand, Iran in 2018. The results of analysis of variance showed that the simple and interaction effects of sowing date and nitrogen rate significantly affected plant height, number of main branch, number of capitols per plant, seed yield, dry weight and percentage of essential oil produced by the aerial parts at 1% level. In addition, the number of secondary branches, canopy diameter, number of seed per capitols and 1000-seed weight were affected by the nitrogen content at 1% level. The effect of sowing date on the number of main branches and canopy diameter was significant at the 1% level and on 1000-seed weight was significant at 5% level. Means comparison of simple effect of sowing date showed that plant height, number of main branches per plant, number of secondary branches per plant, canopy diameter, number of capitols per plant, 1000-seed weight, seed yield, and dry weight of the aerial parts had a significant superiority in the sowing date of May 3 compared to May 23, by 15.7, 19, 12.1, 10, 51.4, 15.8, 88.3 and 33.1%, respectively. Increasing the application of nitrogen to 240 kg N/ha also significantly increased the mentioned traits by 24, 41.2, 17.6, 29.3, 82.6, 115.3, 36.2, and 187.3%, respectively compared to 0 kg N/ ha (control). Means comparison of interaction effect between sowing date and nitrogen rate showed that the maximum plant height (68.50 cm), number of main branches per plant (17 branches per plant), number of capitols per plant (170), seed yield (322.87 kg/ha) and dry weight of the aerial parts (1808.52 kg/ha) were obtained in the treatment of the sowing date of May 3 with application of 240 kg N/ha.

Safflower is a plant that has been considered due to its high medicinal and nutritional value, especially in the extraction of edible oils in developed countries. Drought is one of the most important harmful factors in arid and semi-arid regions of the world that affects plant production. Modifiers play an important role in plant adaptation to stress conditions. Among these compounds are the hormone gibberellic acid and the antioxidant ascorbic acid, which increase plant tolerance to adverse environmental conditions. The present study investigated the effect of gibberellic acid and ascorbic acid on seed germination parameters and some enzymatic indices of safflower under drought stress.

The experiment was conducted as a factorial based on a completely randomized design with three replications in the Agricultural Science Laboratory of Iranshahr University in 2020. Experimental treatments included three levels of control (pretreatment with distilled water), pretreatment with gibberellic acid and ascorbic acid, and four levels of drought stress (0, -3, -6, and -9 bar). Drought stress was applied using polyethylene glycol 6000. Seed germination was carried out inside a germinator at 25 ° C for 14 days in darkness. Germination traits and enzymatic indices were measured using standard methods.

The results of variance showed that most germination and growth indices of safflower seedlings decreased with increasing drought stress. Also, drought stress led to changes in the activity of antioxidant enzymes. Seed priming with gibberellic acid and ascorbic acid increased germination indices and seedling growth and improved enzymatic activity, including catalase, peroxidase, and superoxide dismutase in comparison with untreated seeds. Priming with gibberellic acid had a significant advantage. Seed priming in drought stress conditions has increased germination rate, protein content, and catalase, peroxidase, and ascorbic dismutase activity, respectively, compared to the control.

In general, seed priming of safflower using gibberellic acid changed the activity of antioxidant enzymes. These activities ultimately moderated the negative effects of drought stress and increased germination parameters.

The role of gibberellic acid and ascorbic acid on safflower seed germination traits was investigated.
The effect of gibberellic acid and ascorbic acid on the activity of antioxidant enzymes and soluble protein during seed germination was investigated.

The medicinal plant of Pulicaria gnaphalodes which belongs to Asteraceae family, is a perennial, herbaceous and growing in some regions of Iran. The aim of this study was to investigate the habitat and behavior characteristics of Pulicaria gnaphalodes in the ecosystem of Noferest region for 2 years to evaluate the feasibility of domestication of this species. Systematic random sampling was used to determine the percentage of canopy cover, frequency and density. Characteristics of climatic, soil, phenology, morphological and yield traits, essential oil percent and reproduction method and preference value of the plant were investigated. The results showed that this species grows in Noferest habitat with an average annual rainfall of 176 mm, an average annual temperature of 16.5°C, canopy cover of 27%, frequency of 76% and density of 1650 plants per hectare. Soil experiments showed that Pulicaria gnaphalodes prefered sandy loam soil and soil acidity and electrical conductivity were 7.9 and 0.33 dS/m, respectively.T he highest percentage of shoot essential oil (0.5%) was obtained in full flowering stage. Phenological studies also showed that the vegetative growth of Pulicaria gnaphalodes started in mid-April and continued until late September. Flowering startede in early June and continued until late September. Seed maturation also started in early July. After maturation, the seeds fell off and the stagnation period started in early October.

Anethum graveolens L is used to treat colds, coughs, urinary problems, bloating, and spasms. Water deficit may cause significant changes in the yield and composition of essential oils of medicinal plants. In order to improve water stress tolerance of plants, various mechanisms have been proposed. The use of materials such as vermicompost, zeolite, superabsorbent and methanol can partially compensate for the lowering of yield from drought stress. Therefore, it is important to use methods that can tolerate plants under drought stress conditions.

To evaluate the effect of organic and chemical growth improvers application on yield and essential oil percentage of dill (Anethum graveolens L.) under water deficit stress conditions, a field experiment was conducted as split plot in randomized complete block design with three replications in Birjand, Iran, during 2017 growing season. The main factor included three levels of water stress (60, 120, 180 mm evaporation form class A pan) and the sub-factor included five levels of organic and chemical growth improvers; control (no application), zeolite (5 t.ha-1), vermi compost (6.5 t.ha-1), super absorbent polymer (100 kg.ha-1) and methanol (20 v/v).

The results showed that water deficit significantly reduced all studied traits except harvest index and essential oil percentage. Also, organic and chemical improvement agents had a positive and significant effect on plant height, number of umbrellas per plant, grain yield, biological yield and essential oil yield. Interaction of water deficit stress and organic and chemical improvement agents was significant on number of umbrellas per plant, number of seeds per umbrella, grain yield, biological yield and essential oil yield. By increasing the intensity of water deficit stress, the use of organic and chemical improvers increased the yield of seeds and essential oils. Under severe stress conditions and in comparison, with control treatment, super absorbent application increased the yield of seeds and essential oil to 34.43 and 37.27%, respectively, and methanol spraying increased the yield of seeds and essential oils by 34.17% and 42.85. The results of this experiment showed that the use of organic and chemical improvers reduced the damage to seed yield and essential oil yield under water deficit stress conditions. Also, the results revealed that when the plant is exposed to intensive stress, substances such as superabsorbent and methanol can be used to modify the stress. Using these materials under severe stress conditions increased the grain yield by 34% compared to the control. In order to achieve maximum yield of essential oil, use of organic and chemical improvers has been beneficial. Under severe stress conditions, methanol spraying and super absorbent application increased the essential oil yield of dill (Anethum graveolens L.) in Birjand region.

In order to achieve the maximum yield of essential oil, use of organic and chemical improvers has been beneficial. Under severe stress conditions, methanol spraying and super absorbent application increased the essential oil yield of dill (Anethum graveolens L.) in Birjand region.

Seed germination is the first and most sensitive developmental stage in the plant life cycle and the key process in seedling emergence. On the other hand, one of the major barriers to optimum use of medicinal plants outside the natural habitat is limited level of seed germination and seed dormancy. Hence in order to find the best priming and temperature treatment to dormancy breaking and seed germination of medicinal plant seed Pulicaria gnaphalodes (Vent.) Boiss a factorial experiment based on the completely randomized design with four replications and two factors was conducted in Islamic Azad University, Birjand branch in 2017. The first factor of priming type is 11 levels included in potassium nitrate 2% treatment at two times of 24 and 48 hours, gibberellic acid (0, 250 and 500 mg/ l) at two times of 24 and 48 hours, and stratification (7, 14 and 21 days). The second factor was temperature at three levels (15, 20 and 25 °c). The results showed that highest germination rate and percent germination were related to stratification at 7 and 21 days at 25 °c and maximum seedling length, plumule length, radicle length, radicle/plumule length ratio, wet weight of seedling, dry weight of seedling, percent germination, germination rate, longitudinal index seed vigor, weight index seed vigor related to 21 days wet temperature and 15°c. Therefore, 21 days stratification and temperatures of 15 and 25 °c were the best priming and temperature treatments to dormancy breaking and seed germination of medicinal plant seed Pulicaria gnaphalodes.

To study the effect of planting dates on yields, yield components and protein contents of seeds of millet varieties in Birjand region, an experiment was carried out as a split-plot based on randomized complete block design with three replications at the Research Field of Islamic Azad University, Birjand Branch, Birjand, Iran, in 2013. Planting dates with three levels (May 12rd, June 2nd and June 23rd) were assigned to main plots and millet varieties with 5 levels (Bastan, Chomaki, Pishahank, White Gavars and Yellow Gavars), to sub-plot was. The results of variance analysis showed that the effect of planting date× variety interaction significantly affected tiller number per plant, seed number per panicle, number of days to physiological maturity, seed yield, biological yield, harvest index and protein yield. Means comparison of simple effects showed that the highest of panicle number per m2 (736.97) obtained at planting date of June 2nd and highest 1000-seed weight (3 g) obtained at planting date of June 23rd. Also, the highest number of panicles per m2 (742.2) belonged to White Gavars and highest 1000-seed weight (4.2 g) to related to Pishahang varieties, respectively. Means comparison of simple effect showed that the highest seed and protein yields (323.2 and 37.1 g.m2) were obtained from Chomaki variety at planting date of June 2nd respectively, but the highest biological yield (1207.2 g.m2)belonged to Yellow Gavars variety at planting date of May 12rd. As a whole, results of this research showed that planting date of Jane 2nd for Chomaki variety and planting date of June 23rd for Yellow Gavars variety were found to be proper planting dates to grow these two varieties in Birjand.

Application of proper rates of nitrogen fertilizer and plant density are important factors for medicinal plants yield. To study the effect of nitrogen rates and plant densities on yield and yield components of coriander, an experiment was carried out in split-plot based on randomized complete block design with three replications at the Research Field of Islamic Azad University of Birjand, Iran, in 2013. The main plots were nitrogen rates with four levels (0, 40, 80 and 120 kg N per ha) and the sub-plots with three levels (30, 40 and 50 plants per m2). The results showed that nitrogen rate had significant effect on number of umbel per plant and per m2, fruit number per umbel, fruit yield, biological yield, fruit weight of single plant, biomass yield of single plant and percent and yield of essential oil. Changes in plant density, also had significant effect on all traits except fruit number per umbel, 1000-fruit weight and percent of essential oil. Moreover, interaction effect between nitrogen rate and plant density affected all traits except umbel number per plant, fruit number per umbel and percent and yield of essential oil. Mean comparisons showed that as N fertilization rate increased from 0 to 80 kg N ha-1, umbel number per m2, fruit yield, biological yield and essential oil yield increased by 62.5, 74.1, 74.3 and 186.8%, respectively. Results also revealed that increasing plant density from 30 to 50 plants per m2, increased these traits by 25.6, 31.4, 21.8 and 37.4%, respectively. The conclusion is that application of 80 kg N ha-1 and use of 50 plants/m2 produced highest fruit and essential oil yield for coriander in Birjand region.

In order to study the effect of sowing date and plant density on essential oil, yield and water use efficiency (WUE) of fennel, an experiment was conducted in research field of Islamic Azad University, Birjand branch, Iran as a split-plot experiment based on a randomized complete block design with nine treatments and three replications. The main plot was sowing date at three levels of March 19, April 9 and April 20. The sub-plot was plant density at three levels of 6.7, 10 and 20 plants m-2. According to the results of analysis of variance, seed, biological and essential oil yield and WUE were significantly affected by sowing date, plant density and their interaction at 1% probability level, but the interaction between sowing date and plant density did not significantly affect essential oil percentage. As means comparison showed, delay in sowing from March 19 to April 20 led to 85.6 and 85.6% loss of seed yield and biological yield, respectively. Despite higher essential oil percentage at delayed sowing, the highest oil yield was obtained at sowing date of March 19 with the average amount of 20.96 L ha-1 which was 5.82 times as high as that at the sowing date of April 20. The sowing date of March 19 had higher water use efficiency (WUE) for seed and oil production than the sowing date of April 20 by 5.5 and 3.67%, respectively. However, it increased biological yield and WUE for seed, biomass and essential oil production by 71.8, 64, 44.9 and 74.9%, respectively. The highest seed yield with the average amount of 726.90 kg ha-1 was obtained at the density of 20 plants m-2 which was 16 and 62% higher than that at the densities of 10 and 6.7 plants m-2. Lower densities had lower essential oil yield despite higher oil percentage. In general, it is recommended to use sowing date of March 19 with the density of 20 plants m-2 for the cultivation of fennel because of having the highest seed and essential oil yield and WUE.

In order to study the effect of water deficit stress and different nitrogen levels on flower yield, yield components and water use efficiency of Calendula officinalis L., an experiment was conducted as split plot based on randomized complete block design with three replications, at research field of Islamic Azad University, Birjand branch in 2009. In this experiment, irrigation treatments (irrigation after 60, 120 and 180 mm cumulative evaporation from pan class A) set as main plots and nitrogen rates (0, 60,120 and 180 kg N ha-1) set as sub plots. The results showed that increasing irrigation interval from 60 to 180 mm cumulative evaporation reduced flower number per m-2, biomass yield and plant height 65.6, 69.3 and 8.3%, respectively. Also in comparison with control, irrigation after 120 and 180 mm evaporation reduced flower dry yield 16.2 and 72%, respectively. However, the highest WUE was related to irrigation after 120 mm evaporation (0.161 and 0.788 kg m-3 for dry flower and biomass, respectively). Nitrogen fertilizer utilization significantly increased flower yield, flower number, biological yield, WUE and plant height, but there was not any significant difference between 120 and 180 kg N ha-1 treatments. Interaction of irrigation and nitrogen on all traits was not significant. Totally, the results indicated that treatment of irrigation after 120 mm evaporation with 120 kg N ha-1 application is suitable for marigold cultivation in Birjand.