جستجوی مقالات مرتبط با کلیدواژه « essential oils » در نشریات گروه « کشاورزی »

Recently, the use of new packaging materials and natural additives for improving the durability and preservation of foods has been increasingly considered. Edible coatings containing plant extracts lead to increase the shelf life of food, do not cause environmental contamination, and do not endanger the health of the consumer. Fish is a food rich in amino acids, vitamins and minerals, and polyunsaturated fatty acids, especially omega-3, which has made it more and more popular in the human diet. However, the presence of a significant amount of polyunsaturated fatty acids as well as easily digestible proteins has turned fish into a highly perishable commodity. Fresh seafood spoils rapidly due to the enzymatic and bacterial activities that occur after death, as well as the spoilage caused by the oxidation of polyunsaturated fatty acids and the high concentration of hematin compounds and metal ions of fish muscle, such as iron, and their pH which is close to neutral. Therefore, the use of natural coatings that can increase the shelf life of food and attract the consumers should be given more attention. Iran is the largest fishery producer in the region, thus, providing new methods to increase the shelf life of these products until the time of consumption can guarantee the safety and be effective in the economic prosperity of this industry. Therefore, the present study was designed to investigate the effect of chitosan coating along with the volatile oil of ginger plant on the shelf life of salmon fillets stored in refrigerator to reduce microbial growth, reduce chemical reactions, and increase the storage life of salmon fillets in refrigerator.

Rainbow trout fish with an approximate weight of 600 grams were purchased from the market. Fish were washed with sterile distilled water, and cut into 60-gram pieces after separating the head and tail and eviscerating. The prepated fish were randomly divided into 4 groups. The control group was without any treatment but the treatment groups were immersed in chitosan containing different concentrations of Ginger essential oils. All the samples were kept in zipped bags at refrigerator (4°C) for 15 days. Microbial tests (Mesophilic, Psychrophilic, Coliform, and Lactic acid bacteria count), chemical tests (pH, TVN, TBARS), and sensory tests (color, smell, taste, texture, and overall acceptance) were performed on days 1, 4, 7, 12 and 15. The data obtained from the microbial and chemical tests were analyzed by one-way analysis of variance and the data obtained from the sensory tests were analyzed by the Kruskal-Wallis test in Sigma Stat 4 statistical software, considering P<0.05.

 The results of bacterial tests showed that chitosan coating with ginger essential oil had a significant effect on reducing the growth of mesophilic, coliform, lactic acid bacteria and psychrophilic bacteria compared to the control and chitosangroups during 15 days of storage in the refrigerator (P<0.05). During the storage period, chitosan-treated groups containing 1.5% and 0.75% of ginger volatile oil had the best microbial quality in terms of mesophilic bacteria, Psychrophilic bacteria, lactic acid- bacteria, and coliforms. Also, in samples immersed in chitosan coating with ginger essential oil, the pH, TVN and TBARS values at the end of the storage period were significantly lower than the control and chitosan group (P<0.05). The results showed that pH, TVN, and TBARS did not exceed the defined standard for fish meat at the end of the storage period in the groups treated with ginger volatile oil. Sensory characteristicsindicated that the groups treated with chitosan coating containing ginger essential oils showed better sensory characteristics in terms of color, taste, smell, texture, and overall acceptance than the control and chitosan groups during the storage period (P<0.05).

Based on the results of the present study using the chitosan coating combined with ginger volatile oils has antimicrobial and antioxidant properties, which can reduce the oxidation of fats and microbial loads, while maintaining the organoleptic quality and increasing the shelf life of fish meat at refrigerator temperature. In comparison between treated groups, the use of chitosan along with 0.75% volatile oil of ginger is recommended, because by using a smaller amount of volatile oil, the microbial, chemical, and organoleptic properties can be kept at the standard level until the 15th day.

Increasing the marketability of cut flowers is very important from an economic point of view and alstroemeria cut flowers are considered as one of the most important cut flowers in Iran and worldwide. To investigate the effect of different concentrations of sodium nitroprusside (0, 50, and 100 μM) and thymol (0, 50, and 100 mg L -1) on the morpho-physiological traits of alstroemeria, a factorial experiment was conducted based on a completely randomized design. The longest vase life (16.3 days) was observed in the treatment with 100 µM sodium nitroprusside with or without thymol. In the treatments without sodium nitroprusside, no changes were observed in flower longevity with increasing thymol concentration. The interaction effects of sodium nitroprusside and thymol on relative fresh weight on days 5, 7, 9, and 13 and solution uptake were significant in all days. For the treatments with 50 and 100 µM sodium nitroprusside along with 50 mg L-1 thymol, there was an upward trend in solution absorption and relative fresh weight until the fifth day and a downward trend thereafter. The lowest value for relative fresh weight and solution absorption was observed in the control treatment. The highest values of chlorophyll a (0.16 mg L-1), chlorophyll b (0.078 mg L-1), and total chlorophyll (0.238 mg L-1) were observed in the 100 µM sodium nitroprusside and 50 mg L-1 thymol treatments. In the treatments with 100 μM sodium nitroprusside without or with thymol, the lowest amount of bacteria (3.51-62.3 log10 CFU/ml) and the highest amount of this indicator (3.88 log10 CFU/ml) was detected in the control treatment. No significant difference in dry weight was observed in the treatments without sodium nitroprusside and 50 μM sodium nitroprusside with increasing thymol concentration, but the highest amount of dry weight was observed in the treatment with 100 μM sodium nitroprusside and 50 mg L-1 thymol. The results of this experiment suggested the use of 100 μM sodium nitroprusside with or without thymol to extend vase life and reduce chlorophyll degradation in alstroemeria cut flowers.

Studying and investigating the therapeutic effects of plants has recently attracted the attention of many researchers. Scientific researches have proven the effectiveness and safety of a number of complementary medicine methods, including medicinal plants, in the treatment of most diseases. This article aims to review the characteristics and medicinal properties of marjoram plant (Origanum vulgare L.) and using library resources and information available in ISI, Pubmed, Scopus, SID, Magiran and Web of Science databases. Oregano plant is a medicinal and aromatic compound that is recognized all over the world as an important medicinal plant that is usually used as a culinary spice and also in traditional medicine to treat various diseases. The various uses of this plant in the pharmaceutical and food industries are the reason for its significant commercial value in the world. Almost all parts including roots, leaves, stems and flowers are used in medical systems to treat various diseases. In clinical and experimental studies, antibacterial, antifungal, antiviral and anticancer properties, improvement of chronic rhino sinusitis, convulsive attacks, control of diabetes, regulation of menstrual cycle, prevention of inflammation and cardiovascular diseases were proven for this plant. A total of 50 chemical compounds have been observed in the analysis of marjoram essential oil, whose main compounds are Thymol (15.9%), Z-Sabinene hydrate (13.4%), γ-Terpinene (10.6%), p-Cymene (8.6%), Linalyl acetate (7.2%), Carvacrol methyl ether (5.6%) and Carvacrol (3.1%).

Cucumber is an economically important crop, containing vitamins, minerals, antioxidants, and flavonoids. However, due to loss of weight and firmness, microbial contamination, mechanical damage, and yellowing, the storage duration of cucumber is limited to 3–5 days at room temperature. Therefore, pretreatments are crucial for prolonging its shelf life. Chitosan is a cationic polysaccharide and can interact electrostatically with anionic, partially demethylated pectin. Besides, chitosan has inhibitory effects on fungal rot and prevents weight loss in fruits. Pectin can form excellent films. Because of increasing demand to reduce synthetic chemicals as antimicrobial agents, substances derived from plants, such as essential oils, can play a significant role in the future.  Several essential oils and essential oil components have shown antimicrobial activity against spoilage and pathogenic microorganisms during fruit and vegetable storage. Essential oils of thyme and cinnamon contained phenolic groups have been found to be most consistently effective against microorganisms, however, essential oils are volatile and irritant. Therefore, forming an inclusion complex using b-cyclodextrin can improve solubility, control volatile, and induce off-flavors and unpleasant odor of the essential oils. The objectives of this study were to develop the microencapsulated thymol (thyme) and trans-cinnamaldehyde (cinnamon) essential oils to produce antimicrobial agents and subsequently evaluate the effectiveness of edible coating made of chitosan and pectin containing microencapsulated trans-cinnamaldehyde or thymol essential oils to improve qualitative and quantitative characteristics and shelf life of cucumber.

The inclusion complexes of trans-cinnamaldehyde and thymol in beta-cyclodextrin (CD) were prepared separately by freeze-drying. Each essential oil was dispersed in 1000 ml of beta-cyclodextrin aqueous solution (16 mmol/L, 18.15 g) in molecular ratio 1:1 (2.4 gr thymol, 2.11 gr trans-cinnamaldehyde) and mixed in a laboratory stirrer for 24 hour at room temperature , then frozen (-70 ºc) and freeze-dried (<20Pa, 48 h). Lyophilized samples were stored inside a freezer (-20 ºc) until further use. Cucumbers cv. Nagene with uniform size, appearance, ripeness and without mechanical damage or fungal contamination were selected. Then They were then sanitized by immersion in chlorine solution (150 mg/kg) for 1 min and air dried. Edible coatings were prepared as three immersion solutions of chitosan, pectin, and calcium chloride (CaCl2). The fruits were coated with pectin (1%) and chitosan (0-0.5%-1%) containing beta-cyclodextrin microencapsulated trans-Cinnamaldehyde or thymol each (0-0.25%-0.5%). After coating by chitosan, the fruits were immersed in 1% Calcium chloride solution to induce crosslinking reaction. After dipping step, fruits dried for 8 minutes at room temperature to remove the excess solution attached to the surface .Uncoated fruits served as control. Then fruits were preserved in cold storage (temperature: 10ºc; relative humidity: 90-95%) for 15 days. chemical (total soluble solids, titratable acidity) and physical (total color difference, Hardness, and weight loss) Characterization of fruits were measured immediately after harvest and after 5, 10 and15 days. Microbial tests (total count, mold, and yeast) were done at the end of preservation time. Analytical data were subjected to analysis of variance and factorial adopted completely randomized design and a Duncan comparison test was used. 

The results showed that weight loss, total soluble solids, and the total color difference increased and hardness and titratable acidity decreased gradually in all samples during cold storage (<0.05). Chitosan and essential oils slowed down this rising or decreasing trends. Interactive effects of chitosan, essential oil type, essential oil concentration, and storage time had positive effects on these quality attributes. The fruits coated with the highest concentration of chitosan (1%) and thymol (0.5%) essential oils showed the least weight loss, loss of hardness, and color change throughout 15 days of storage. Besides thymol in comparison with trans-Cinnamaldehyde was more efficient to prevent yeasts and molds on the surface of cucumber. By increasing chitosan and essential oil amounts, the ability of inhibiting microbial growth by coating is enhanced. 

The results of chemical, physical and microbial tests, showed that multi-layer coating solution containing chitosan 1% with thymol 0.5% was effective in extending the shelf life of cucumber. The combined usage of microencapsulated thymol essential oil and chitosan-based coating on cucumber could be considered a healthy and effective treatment that reduces microbial spoilage and preserves quality and color characteristics in cucumber and represents an innovative method for commercial application. Therefore, this coating can be used as an alternative to chemical fungicides to prevent fungal rot of cucumber and other fruits, however, it is suggested that more studies should be done in this field.

In order to investigate the effects of growth and immunity-stimulating additives based on medicinal plants with and without probiotics on the performance and physiological and metabolic parameters of broiler chickens, an experiment was conducted in a completely randomized design (factorial arrangment) with three types of additives (commercial Bioherbal additive, ASRI-I1 and ASRI-I2) and two levels of Gallipro probiotics (0, 200 g/ton), in 6 treatments and 4 repetitions and 15 pieces of mixed male and female chickens in each repetition.The effects of immune stimulants and probiotics on body weight, feed consumption, food conversion ratio, viability percentage and production index were not significant. Carcass percentage, thigh percentage, breast percentage, back and neck percentage, abdominal cavity fat percentage and relative weight of internal organs were not affected by immune stimulant and probiotic. The effect of herbal and probiotic immune stimulants on the response to sheep red blood cells, immunoglobulin G and immunoglobulin M was not significant.The effect of immune stimulants on the percentage of heterophils, lymphocytes and their ratio was significant (P<0.05). In the whole period, no significant difference was observed in most of the examined traits in broiler chickens fed with diets containing three different types of immune stimulants, but numerically, there were slight differences between them, and the addition of IASRI 1 had better effects. Among other additives, its use along with probiotics showed beneficial effects in improving the performance and immune responses of broiler chickens, therefore, IASRI 1 additive is recommended for additional studies and semi-industrial production.

The ever increasing population and global issue for food security have led us to use multiple approaches to overcome the weed problems that can reduce the crop productivity up to 70%. Chemical herbicides and mechanical and other biological approaches have overcome weed problem on one hand but also destroy the environment and caused some human health impacts on the other hand. Bioherbicides are biological control agents applied in similar ways to chemical herbicides to control weeds. Of the array of bioherbicides currently available, the most successful products appear to be sourced from fungi (mycoherbicides), with at least 16 products being developed for commercial use globally. Over the last few decades, bioherbicides sourced from bacteria and plant extracts (such as allelochemicals and essential oils), together with viruses, have also shown marked success in controlling various weeds. Despite this encouraging trend, ongoing research is still required for these compounds to be economically viable and successful in the long term. This review will explain the importance and impacts of the bioherbicides by elaborating the constraints which this approach is facing in its production and application.

 Humic acid as an organic matter, made during chemical processes in the soil leads to improved root growth and aerial part of the plant. It increases the penetration of elements in the plant and improves water permeability. Zinc is involved in the maintenance of root cell membranes, the activation of antioxidant enzymes, and the production of RNA and DNA. This study aimed to investigate the effect of applying humic acid and zinc sulfate on some morphological and phytochemical traits of Salvia officinalis L.
 
 In this regard, this experiment was conducted as a factorial based in a completely randomized design with two factors (concentrations of 0, 1.5, 3 and 4.5 g/l humic acids and concentrations of 0, 3, 6 and 9 g/l zinc sulfate) in five replications in 2021. The studied traits included plant height, stem diameter, fresh weight, and dry weight, number of sub-branches, chlorophyll, carotenoids, phenols, flavonoids and essential oils. Seedlings of the same size and age as sage were grown under equal. The properties of the soil used in the laboratory were examined. Treatments were sprayed with humic acid 6% and zinc sulfate 34% in five steps, every two weeks.
 
Result showed that application of humic acid and zinc sulfate had no significant effect on plant height and only their simultaneous use had a significant effect on this trait and the highest plant height was observed for treatment of 1.5 g/l humic acid and 9 g/l zinc sulfate (66.50 cm). In stem diameter analysis, the use of humic acid (p≤0.01) and the application of zinc sulfate (p≤0.05) and the interaction of these two treatments(p≤0.05) affected the stem diameter. According to the results, the highest stem diameter was 8.69 mm, which occurred in the treatment of 4.5 g/l humic acid and 3 g/l zinc sulfate. Application of humic acid significantly (p ≤ 0.01) affected the fresh weight of the plant. Application of zinc sulfate also had a significant effect (p ≤ 0.05) on fresh weight. The effect of simultaneous use of humic acid and zinc sulfate on the fresh weight of this plant was significant at the level of 1% probability and the highest fresh weight was 87.26 g.plant-1, which achieved at a concentration of 4.5 g/l humic acid and 6 g/l zinc sulfate. Compared to the control plant, it has increased by 12.56 grams. The effect of humic acid on dry weight was significant at the level of 5% probability, while the effect of zinc sulfate application on this trait was not significant. The combined use of humic acid and zinc sulfate was significant at the 1% probability level. The maximum dry weight reached 29.73 grams per plant, achieved with a concentration of 4.5 grams per liter of humic acids and 3 grams per liter of zinc sulfate. Both humic acid and zinc sulfate exhibited a significant effect (at the one percent level) on the number of branches. Furthermore, the combined application of humic acid and zinc sulfate proved to be highly effective (p<0.01). The greatest number of sub-branches was observed at the 1.5 grams per liter level of humic acid. Humic acid had a substantial impact on chlorophyll a, b, total chlorophyll, and carotenoids (p≤ 0.01). Similarly, the application of zinc sulfate showed significant effects on chlorophyll a, b, and carotenoids (p≤ 0.01), as well as on total chlorophyll (p≤ 0.05). In the end, the simultaneous application of humic acid and zinc sulfate significantly influenced chlorophyll a, b, total chlorophyll, and carotenoids (p<0.01). The most significant effects on photosynthetic pigments (carotenoids, chlorophyll a, and total chlorophyll) were observed with concentrations of 4.5 grams/liter of humic acid and 6 grams/liter of zinc sulfate. The highest chlorophyll b content was obtained with the treatment of 3 grams/liter of humic acid and 6 grams/liter of zinc sulfate. The effect of humic acid and zinc sulfate application as well as their simultaneous use on the amount of phenols and flavonoids was significant at the level of 1% probability. The highest amount of phenol was 0.372 (mg gallic acid per gram of fresh tissue) which was obtained at a concentration of zero zinc sulfate and 3 g/l humic acid. The highest flavonoid content was 0.527 (mg quercin per gram of fresh tissue) which was observed in the treatment of 4.5 g/l humic acids. The use of humic acid had significant effect on the amount of essential oil. The percentage of essential oil reached the highest levels at the concentrations of 1.5 and 3 g/l humic acids.
 
 Based on the results, the use of humic acid alone and in combination with zinc sulfate, had the greatest effect on most of the studied traits.

Varroa destructor Anderson & Trueman is one of the most perilous pests of honey bee colonies around the world. So, natural products such as plant essential oils are considered as a suitable replacement for chemical compounds in pest control. This study was planned to check the respiratory killing effect of essential oils of four perennial Satureja species on Varroa destructor and Apis mellifera meda in an apiary. The sensitivity of the mite to four essential oils was according to the following, S. khuzestanica Jamzad, S. rechingeri Jamzad, S. mutica and, S. bachtiarica Bunge. The calculated LC50 values for S. khuzestanica Jamzad and S. rechingeri Jamzad were 151.6 and 161.77 ppm for Varroa mite and 328.22 and 337.7 for honey bee, respectively. Qualitative analysis of essential oils showed that the major component of the oils for all species was carvacrol. Satureja khuzestanica Jamzad and S. rechingeri Jamzad had the highest amount of carvacrol with 93.5% and 88.8%, respectively. In general, the essential oil of S. khuzestanica Jamzad and S. rechingeri Jamzad had a high ability to control Varroa mites.

 Drought is one of the most important environmental stressors that adversely affects agricultural products, especially in arid and semi-arid regions. Using Trichoderma fungus along with biopolymers such as chitosan is one of the ways to reduce drought stress. Trichoderma fungus as plant growth-promoting fungus is the most common fungal and soil-modifying species that are able to directly with plant roots in the rhizosphere and improve growth as well as biological control of living stresses such as pathogenic fungi and non-living stresses such as drought, salinity and heavy metals. On the other hand, one of the effective ways to protect the plant in conditions of low irrigation is the use of anti-transpirants, including the biostimulant of chitosan, which markedly limits transpiration from the plant surface. The anti-transipirants action of chitosan can be attributed to the involvement of chitosan in the abscisic acid pathways, which closes the stomata and thus reduces transpiration. Chitosan is readily soluble in water and organic acids. Therefore, it can be used in various methods such as mixing with soil, foliar spraying and impregnation with seeds in agriculture.

 This research was conducted in a split factorial arrangement based on randomized complete block design. The main plot factor was irrigation interval in three levels (two days as normal irrigation and three and four days as deficit irrigation conditions) and sub-plots were inoculated with T. longibrachiatum at two levels (inoculation and uninoculated control) and chitosan at three levels (0, 0.2 and 0.4 g/L). Each experimental plot consisted of three planting lines two and a half meters long and one meter wide .T. longibrachiatum was obtained from Tabarestan Agricultural Genetics and Biotechnology Research Institute. The first irrigation was done simultaneously with planting basil. Up to one month after sowing the seeds (six to eight leaf stage of plants), the plots were irrigated evenly with tubes and from this stage onwards, irrigation treatments were applied. Pesticides and herbicides were not used during the experiment and weed control was done manually. Chitosan was prepared from Sarina Teb store and prepared in three levels of zero, 0.2 and 0.4 g/l and sprayed in three stages: vegetative, before flowering and 50% flowering.

 The results showed that with increasing the irrigation period from two to four days, the morphological traits of basil, such as root length and stem length, leaf dry weight, root, stem and dry matter yield decreased. Also, physiological traits of basil such as carotenoids and chlorophyll meter increased while chlorophyll a, b and total chlorophyll decreased. Application of 0.2 g/L of chitosan inoculated plants increased chlorophyll b content by 68%. The highest percentage and yield of essential oil in both normal and irrigation deficit conditions were obtained when plants inoculated with Trichoderma and foliary sprayed by chitosan. The highest percentage and yield of essential oil were observed with an average of 0.88 and 42.87% in normal irrigation conditions, application of Trichoderma and zero level of chitosan, respectively. According to the results, increasing the irrigation cycle along with chitosan application and fungal inoculation increased the percentage and yield of essential oil. However, by increasing the irrigation cycle, chitosan alone decreased the percentage and yield of essential oil and only in the three-day irrigation cycle, it increased the percentage of essential oil compared to the control.

 Overall, the findings showed the positive effect of concomitant use of Trichoderma fungus and chitosan on improving the growth of sweet basil and increasing drought resistance.

Coriander (Coriandrum sativum L.) is an annual plant of the Apiaceae family. The used part of this plant is its seeds and leaves. In addition to oral consumption, coriander is a blood sugar lowering, blood lipid lowering, blood pressure lowering, hypnotic, sedative and anti-anxiety. This plant has shown antispasmodic, antidiarrheal, antioxidant, sedative and antimicrobial activities. The basic requirement for plant breeding programs is a germplasm diversity that provides necessary facilities for breeding species with desirable features. Therefore, accurate identification of genotypes is considered as a prerequisite in this manner. The phenotypical characteristics are the first markers that have been used for diversity researches.

In order to evaluate the genetic diversity of some coriander Populations in Iran based on morphological and physiological traits, 26 ecotypes were collected from different regions of the country and the experiment was conducted based on a randomized complete block design with 3 replications in field conditions Mohaghegh Ardabili University in 1398. Some morphological and phytochemical characteristics such as Stem diameter, Leaflet Number, Leaf Number, Stem, root and internode length, Total plant height, flower and Leaf fresh and dry weight,Total plant and Root dry weight, Anthocyanin, Total Phenol and essential oil components were studied. The measurements began after the 50% of flowering stage.

The analysis of variance of the data showed a significant difference between the studied traits, which indicates the existence of genetic diversity between coriander populations. there are significant differences between the populations in traits of plant height, stem and root length, nodes, internodes, leaves and leaflets numbers, stem diameter, plant dry weight, root dry weight, stem dry weight, leaf fresh weight, flower fresh weight and total phenol. Comparison of mean traits in total showed that Siahkal and Kashmar populations were superior to other populations in stem diameter (1.74, 1.63 mm), leaf fresh weight (0.57, 0.50 g), number of leaves (11.66, 15.70) and anthocyanin content (0.27, 0.37 mg/g FW). Based on Cluster analysis, divided the studied populations into three major groups. Main purpose of this study was determination of genetic diversity among Coriander accessions from Iran. Significant differences were found among the accessions in almost every parameter measured.

The range of vegetative and flower values obtained in this study was more than those of reported in previous researches about Coriander. With increasing leaf number and leaf fresh weight that is the main place to trap sunlight for photosynthesis and consequently provides the condition to produce secondary metabolites. Thus, Kashmar accessions with having high values of leaf can be considered for in view point of cultivation and breeding programs.

Saffron or red gold is a strategic agricultural product with a very high non-oil export potential. Considering the ban on the use of synthetic chemical poisons against saffron pests and the growing trend of planting this product in the country, as well as the importance of producing certified seeds of agricultural products, it is inevitable to find non-chemical ways to control the pest and produce certified saffron onions. Meanwhile, the saffron mite Rhizoglyphus robini Claparède is one of the most important pests of saffron, which causes great damage to onions and saffron crops every year. In the present study, the toxicity of four plant essential oils from the Asteraceae family, including Artemisia sieberi Besser, Acroptilon repens (L.), Cichorium intybus L. and Achillea millefolium L., was evaluated on the adult female species of the saffron mite in laboratory conditions. Bioassay was performed by fumigation method inside a 5 cm petri dish in total darkness, with a relative humidity of 70% and a temperature of 26 degrees for 24 hours. For each essential oil, 6 concentrations and 3 repetitions were considered for each concentration. The results of the bioassay by fumigation method showed that the essential oil of A.sieberiwith LC50 = 160.09 ppm has the highest and C. intybus essential oil with LC50 = 440.12 ppm has the lowest toxicity on saffron bulb mite. Also, the highest concentration slope was observed in A. repens essential oil (5.801±0.719) and the lowest was observed in the essential oil of A. sieberi and A. millefolium. Based on the starting point of toxicity, the essential oil of A. sieberiwith the highest intercept (-2.177±0.323) caused the fastest initial toxicity on bulb mite at a concentration of 33.21 ppm.

The lesser grain borer, Rhyzopertha dominica F. is an important pest of the stored products, which causes severe economic damage on grain. Regarding necesity of using alternative methods to chemical insecticides, in the present study the lethal and sublethal effects of the essential oils of Ajwain (Carum copticum L.) and fennel (Foeniculum vulgare Mill) along with diatomaceous earth were evaluated against R. dominica. The chemical compositions of the essential oils were determined by gas chromatography-mass spectrometry. The major components of Ajwain were phenol, benzene, and γ-terpinene and those of the fennel were propanal, trans-anethole, γ-terpinene, benzene, and cyclohexene. The toxicity of fennel essential oil (LC50 = 103.83 µl/l air) against the adults of R. dominica was higher than Ajwain essential oil (LC50 = 167.46 µl/l air). The LC50 for the diatomaceous earth was obtained 0.052 g/kg. Results of the experiment of sublethal effects (LC30) showed that males and females’ longevity and the fecundity of females were significantly lowest in the combination of Ajwain essential oil along with diatomaceous earth. Furthermore, the net reproductive rate (R0), intrinsic rate of natural increase (rm), and finite rate of increase (λ) of the pest, in both the combination of Ajwain essential oil along with diatomaceous earth and fennel essential oil along with diatomaceous earth were significantly lower (P < 0.05) than other treatments. The results of this study indicated that the essential oils of each of these plants in combination with diatomaceous earth can be used in the management programs of R. dominica.