جستجوی مقالات مرتبط با کلیدواژه « thyme » در نشریات گروه « گیاهپزشکی »

Fusarium root wilt by Fusarium solani f. sp. phsaeoli is one of the most import soil borne diseases of bean crops world-wide. Currently the control of the disease using fungicides is present in most of the technical recommendations, despite the environmental side effects. Therefore, this study was conducted with the aim of identifying healthy control solutions such as the use of plant essential oils and extracts. In this study, the inhibition effect of the essential oils of two plants was investigated in laboratory conditions on the pathogenic fungus. Iperidoine+Carbendazim fungicide, 1.5/1000 was used as a comparison criterion in experiments. The studied features were the speed growth rate of the fungus and the mycelial growth inhibition five concentrations of the studies plants. Results showed that MGI was 58.30 % for thyme in 100 ppm and 41.17 % for ajwain at 100 ppm. The fungicide showed the highest MGI rate at 78.53 % and thyme extracts at the highest concentration was not at the same Duncan group with the fungicide. According to the results, it can be concluded that thyme extract would be an alternative for the common fungicides to control Fusarium root wilt.

The Cucumber Mosaic Virus (CMV) belongs to the Cucumovirus that is one of the most important viruses that infect cucurbit plants in Iran and around the world. This study was accomplished in a completely randomized design by 6 repeats to survey spraying herbal extracts, salicylic acid, and distilled water as the control on resisting cucumber plants against CMV mechanical infection in a greenhouse at the Islamic Azad University of Jahrom Branch in 2015. It was planted 4 seeds of cucumber in each pot, and at the time of inoculation 2 plants were reminded. After treatments, (including spraying of 3% thyme and Rosemary extracts, 0.02% salicylic acid, and distilled water) the plants were inoculated mechanically by the sap of an infected plant. After that, pots were checked for a month. The infection of plants examined by the ELISA test. Data analysis was done using MSTAT-C. Results showed that the herbal extracts significantly were prevented the infection rate of CMV. According to the results in salicylic acid, thyme extract, rosemary extract, and distilled water treatments inoculation rates were 33.3%, 58.3%, 66.6%, and 88.3%, respectively. There wasn’t a statistically significant difference between treatments of salicylic acid and Thyme extract, as well as, spraying with Thyme and Rosemary extracts. Considering the result of this study, it can be concluded that by application of salicylic acid and then Thyme extract, the CMV can be controlled significantly.

The use of essential oils and extracts of medicinal plants is one of the environmentally friendly methods in the management of plant diseases caused by fungi and bacteria. The antimicrobial effect of essential oils and extracts of various medicinal plants such as thyme, cloves, savory, garlic, licorice and fennel has been proven and their active ingredient has also been identified. Based on these studies, the possibility of introducing, formulating and using essential oils and extracts of medicinal plants or any of their components with antimicrobial properties, as an alternative method of using chemical toxins in the management of fungal and bacterial diseases of plants can be provided.

Essential oils are hydrophobic, volatile and aromatic compounds that have been used as fragrances and flavors for a long time. Recent studies have shown that some plant essential oils have fungicidal effects against some important plant pathogens. For instance, the essential oil of thyme inhibits the mycelial growth of Penicillium italicum and the essential oil of lavender shows the fungistatic effect on ‎ Botrytis cinerea, Rhizopus stolonifer and Aspergillus niger. The essential oil of thyme has also been used to control the black rot of orange caused by Alternaria citri and grey mold of strawberry fruits caused by Botrytis cinerea. Antifungal activities of essential oils are mainly related to their effects on fungal cell wall, cell membrane, mitochondria and nitric oxide level. As a result of increased concern about harmful chemical pesticides, essential oils can have a good place in the market as natural fungicides. In this paper, application of essential oils as natural fungicides, their mode of actions and some safety aspects of their application have been discussed.

Sclerotinia sclerotiorum is an important phytopathogen causing tobacco collar rot which distributed worldwide and can impose high yield losses in tobacco growing countries. The disease management is possible by use of fungicides, resistant cultivars, biological control and use of plant extracts and essential oils. Crude extracts of catmint (Nepeta cataria), tobacco (Nicotiana tabaccum) and thyme (Thymus pubescens) were prepared by water, acetone, hexane, ethanol and methanol with concentrations of 1000 and 2000 ppm. The effect of those extracts against the fungus was examined in vitro in a factorial experiment based on completely randomized design with three replications. Minimal inhibitory concentration of extracts was determined by agar diffusion method. Crude extracts of tobacco, catmint and thyme had remarkable antifungal activity. Hexane, ethanol and methanol were the best solvents to extract antifungal compounds. Minimal inhibitory concentration of hexane, ethanol and methanol extracts of catmint, tobacco and thyme were 1 mg/ml as tested on the fungus. The most important components of extracts of catmint were menthanol, menthol, sailen, thymol, pipertenone, nonenal, carvacrol, camphor and limonene; in extracts of tobacco, globulol, phytol, nicotine, sailen, imidazole, limonene and thunbergol; and in extracts of thyme, thymol, anethole trans, sailen, carvacrol, imidazole and nonenal. Therefore, extracts of catmint, tobacco and thyme can be considered as natural fungicides for control of causal agent of tobacco collar rot.

Root-knot nematodes (Meloidogyne spp.) are important plant pathogens that make large damage to the crops. The activity of root-knot nematode and reaction of host plant results in the development of several knots on the root, which interrupts water and food absorption system of the plant. Among popular methods for controlling root-knot nematodes are physical methods (soil solarization and flooding), farming methods (crop rotation, weed removal, contaminated roots removal, fertilization, soil reinforcement, planting time adjustment, and use of resistant varieties), and chemical methods (disinfection with pesticide and foliar spray. Incomplete control, high cost and environmental problems (chemical compounds) have directed some researchers toward to use non-chemical methods such as herbs and herbal products for the management nematodes. Mankind has used medicinal plants throughout the history in both direct and indirect ways. Today, medicinal plants have a considerable share of medical products. The nematicidal effect of many plants has been demonstrated and the use of plant products has been considered as a safe method to control root-knot nematode. This method is cheap and easy to use, does not cause environmental pollution, and is able to improve the soil in structural and nutritional terms. Organic plants possess a wide range of secondary metabolites such as phenyls, flavonoids, coinons, tanons, essences, alkaloids, saponins, and sterols. These substances are biodegradable owing to their natural origin and do not pollute the environment. Today, active plant compounds are given much attention because they are less durable and do not have the negative impact on mammals and non-target organisms. Plant products including essences and extracts are usually used to control plant diseases nematodes. Therefore, due to the favorable impact of plants in controlling Root-knot nematodes, In this study, the presence of several herbs (thyme, hyssop, and savory) are pathogenic nematode damage in tomato was examined.
In this study, the effect of the medicinal plants of the mint family on root knot nematode, three herb thyme (Thymus vulgaris), savory (Sature jahortensis) and hyssop (Hyssopus officinalis) was used. In order to prepare the inoculum required for the test, root-knot nematode- contaminated tomato samples were collected from the farms or greenhouses of Chaharmahal Bakhtiari Province (one of the provinces of Iran). To separate and extract eggs and larvae, contaminated roots were chopped into 1-2 cm pieces by the method of Hussey & Jonsen were mixed in 10% hypochlorite sodium solution in a mixer for one minute. Then the mixture was put in the 400-mesh sieve under water current so as to remove hypochlorite sodium. Finally, the eggs were collected in distilled water. Furthermore, to prepare sufficient larvae, nematode egg masses were transferred to petri dishes and kept in the incubator for 24 hours until the eggs hatched. Finally, the obtained eggs and larvae were used to carry out the test. A greenhouse experiment was as factorial in a completely randomized design with single culture tomato and mixed with herbal hyssop (Hyssopus officinalis), thyme (Thymus vulgaris), and savory (Sature sp), in the presence and absence of nematodes.
The tomato growth parameters (dry weight of root, stem, leaf, root length, shoot length) and nematode pathogenicity (Number of galls, egg massesin1/g of root of ,the number of eggs in each egg masses, second instar larvae per 100 gr of soil and reproductive factors) were evaluated three months after nematode inoculations. Data were analyzed using SAS statistical software comparing MSTATC software and LSD test was performed. Statistical analysis of data showed the significance difference between treatments. ANOVA results demonstrated that the use of three species of medicinal plants of the mint family is a significant effect on the pathogenicity of nematodes. For example One of them main indicators of pathogenic nematode are galls on the roots. The savory (Sature jahortensis), gall formation by nematode was reduced. In other words among the plants under study, Savory (Sature jahortensis) was the most effectiveness in reducing damage and pathogenicity of nematode, and thyme and hyssop were in next grades respectively. This inhibition may be due to a direct effect on larvae and egg root secretion or indirectly by providing suitable conditions for growing tomato and defense against nematode attacks.
Collectively, the tested medicinal plants in this study, had good control effect against root knot nematode and can be used in nematode management programs. And their application in Natural conditions also is investigated.

Phytophthora stem and root rot of tomato, Phytophthora parasitica L., is one of the most important soil-borne diseases of tomato. This disease has been spreading in greenhouses located in east-south of Tehran province (Varamin) through the last decade. The disease control by fungicides has not been successful; In spite of success of biological control or using resistant varieties to reduce disease, it seems that studying and application of natural compounds especially plant essences including a wide range of secondary metabolites can not only reduce disease but also it has beneficial effects on the environment. In this case study, efficacy of eight plants including thyme, cumin, savory, pennyroyal, mint, tarragon, ajwain and fennel with Ridomil-mancozeb fungicide as control were evaluated on colony growth rate and inhibitory growth of causal agent in five concentrations of 60,120,180, 240 and 300 ppm on PDA medium based on completely randomized block design in vitro conditions. Greenhouse experiments were carried out with ten treatments including successful essences of thyme, pennyroyal and fennel at 0.2 and 0.3 with Ridomil-mancozeb fungicide at 1 and 1.5 ppm and check and control infected with P. parasitica in completely randomized block design in four replications. Essences and fungicide were added into root substrate of tomato seedlings in two leaves stage. Recording disease severity percentage was performed according to Quesada-Ocampo and Hausbeck scale, four weeks after inoculation. Essences with highest inhibitory growth percentage in laboratory were respectively thyme (79.28%), pennyroyal (72.85%), cumin (69.95%), mint (60.70%), tarragon (60.70%) and ajwain (60%) and thyme and pennyroyal essence by concentration of 180 ppm showed minimum inhibitory concentration, EC50 of mycelial growth. Results of variance analysis in greenhouse demonstrated that all treatments were significantly different at 1% confidence level. Mean comparisons by Duncan multiple range test showed that thyme essence respectively with disease severity index of 1.65 and 1.31 were classified statistically in e, d that were the closest index with fungicide treatments of Ridomil-mancozeb and cheek (18% DSI) and it has been proved the best efficacy on disease reduction.

Root rot is one of the important diseases of bean in Zanjan province and two fungal pathogens، Rhizoctonia solani and Fusarium solani are the major causal agents of this disease in the region. In this research، the inhibitory effect of N-hexane، di-ethyl-ether، chloroform and ethanol extracts of five plant species، hermel (Peganum harmala)، thyme (Thymus kotschyanus)، yarrow (Achillea wilhelmsii)، pennyroyal (Mentha pulegium) and garlic (Allium sativum) on mycelial growth of R. solani and F. solani was studied using poisoned food technique at four levels of 100، 250، 500 and 1000 ppm with three replications. After laboratory experiments، the most effective extracts، were applied against bean root rot under green house conditions. According to the results from in vitro studies، N- hexane extract of thyme and pennyroyal (both at the level of 1000 ppm) had the most inhibitory effect against both pathogens and also caused cytoplasm granulation and leakage of intracellular compounds of hypha of both fungi. At greenhouse experiments، hexane extract of thyme and menthe not only significantly reduced the root rot percentage، but also had significant increasing effect on most plant growth parameters (P = 0. 05).