جستجوی مقالات مرتبط با کلیدواژه « قارچ کش » در نشریات گروه « گیاهپزشکی »

South Khorasan province of Iran is the largest producer of common barberry (Berberis vulgaris L.) in the world. The production and quality of common barberry shrub are affected by broad range of abiotic and biotic causal agents. Witches' broom rust caused by Puccinia arrhenatheri is one of the most important diseases of common barberry shrubs in South Khorasan province. A two years' field experiment carried out to study the control of barberry witches' broom rust using the Falcon (Tebuconazole + Spiroxamine + Triadimenol) at concentrations 0.6 and 1 ml L-1, Folicur 1 and 1.5 ml L-1, Amistar Xtra (Azoxystrobin + Cyproconazole) 0.75 and 1.2 ml L-1 and Tilt 0.5 and 1 ml L-1 at two locations of South Khorasan during 2018-2019 at the time of disease symptoms initiation as randomized complete block design. There was significant difference in witches' broom rust severity scores between the different fungicides and rates of application and control treatment. The results of combined analysis of variance showed that one-time application of Folicur at concentrations 1 and 1.5 ml L-1 were determined as the most effective in controlling the disease at the time of disease appearance, followed by Folicur 1 ml L-1, 1.5 ml L-1, Falcon 0.6 ml L-1, Amistar Xtra 1.5 ml L-1, Amistar Xtra 0.75 ml L-1, Falcon 1 ml L-1, Tilt 1 and 0.5 ml L-1. The highest and lowest disease severity were obtained in control and Folicur (1 ml L-1) treatments, respectively. Based on our findings retrieved from results of this study and field trials, Folicur at concentrations 1 ml L-1 and Falcon at concentrations 0.6 ml L-1 at the time of disease symptoms initiation to achieve efficient control and application of rotation of them to mitigate fungicide resistance development are recommended. Application of treatments including Folicur at concentrations 1 and 1.5 ml L-1 and Amistar Xtra at concentrations 0.75 ml L-1 were also significantly effective in decreasing the number of witches' brooms.

Downy mildew disease caused by Plasmopara viticola (Berk. & Curt.) Berl. & Toni is one of the most important diseases of vine. Especially in wet areas, it causes qualitative and quantitative damage to the crop. Although all green parts of the grapevine are susceptible, the first symptoms of downy mildew of grapes are usually seen on the leaves as soon as 5 to 7 days after infection. Foliar symptoms appear as yellow circular spots with an oily appearance (oilspots). Young oilspots on young leaves are surrounded by a brownish-yellow halo. This halo fades as the oilspot matures. The spots are yellow in white grape varieties and red in some red grape varieties (e.g., Ruby Red). Under favorable weather conditions, large numbers of oilspots may develop and coalesce to cover most of the leaf surface. After suitably warm, humid nights, a white downy fungal growth (sporangia) will appear on the underside of the leaves and other infected plant parts. The disease gets its name "downy mildew" from the presence of this downy growth. In late summer and early fall, the diseased leaves take on a tapestry-like appearance when the growth of the pathogen is restricted by the veinlets. Confirmation of active downy mildew is made by the "bag test." To do this test, seal suspect diseased leaves and/or fruit bunches in a moistened (not wet) plastic bag and incubate in a warm (13-28ºC), dark place overnight. Look for fresh, white downy sporulation beneath suspect oilspots or on shoots or fruit bunches. Note that mature berries, although they may be symptomatic and harbor the pathogen, may not support sporulation even when provided with ideal conditions. Infected parts of young fruit bunches turn brown, wither, and die rapidly. If infections occur on the young bunch stalk, the entire inflorescence may die. Developing young berries will either die or, if between 3 and 5 mm in diameter, become discolored. Berries become resistant to infection within 2-3 week after bloom, although all parts of the rachis may remain susceptible 2 months after bloom. The pathogen survives the winter period as oospores embedded in dead leaves and other host tissue on the vineyard floor. Oospores may be released from the decaying plant material on the soil surface. Oospores typically produce sporangia. These sporangia, in turn, produce zoospores. Sporangia and zoospores are splashed by rain or carried by wind to the lower leaves and tissues of the grapevines. The conditions necessary for oospore germination are wet soils with temperatures above 10ºC. Sporangia for secondary infections are produced on sporangiophores that emerge through stomata of infected leaves and other grapevine tissues. Sexual reproduction occurs towards the end of the season. The resulting oospores are thick-walled and serve as survival spores.

 The experiment was conducted in grape orchards located in Hamadan, Bojnourd, and Faruj, which had a history of Downey mildew. Different cultivars of grapes were selected for the experiment. The experimental design used was a randomized complete block design (RCBD) with 8 treatments and 4 replications.The control treatments included plots without any spraying and plots sprayed with water. The remaining treatments involved the application of specific treatments at three different stages. The first spraying was done before flowering, the second spraying after fall petals, and the third spraying 10 days after the second spray. Ten days after the final spraying, samples were collected from the grape leaves, and the percentage of disease incidence and disease severity were calculated. The data obtained for disease incidence and severity were analyzed using statistical software, such as SAS, and the means of these traits were compared using Duncan's multiple range test at a significance level of one percent. This test helps determine significant differences between the treatment means.

 The analysis of variance conducted on the data obtained from the evaluation of treated grape leaves revealed a statistically significant effect of the treatments on reducing the percentage of disease severity and disease incidence. Among the treatments, Profiler® at concentrations of 3 ml L-1, 2.5 ml L-1, and 1 ml L-1, Mishocap® at 3 ml L-1, and Captan at 3 ml L-1 demonstrated high efficiency in controlling grape Downey mildew disease. The new fungicide Profiler® at a concentration of 3 ml L-1 exhibited an efficacy of 94% in Hamadan, 67% in Bojnourd, and 47% in Faruj. Profiler® at a concentration of 2.5 ml L-1 had slightly lower efficacy, but the difference was not statistically significant compared to Profiler® at 3 ml L-1. Interestingly, the control treatments, including water spraying and no spraying, did not show a significant difference in disease control compared to the treated plots. These results indicate that Profiler® at appropriate concentrations and Mishocap® and Captan at their recommended concentrations can be effective options for controlling grape Downey mildew disease.

 Because both Profiler® 3 and 2.5 ml L-1concentrations are effective in controlling the disease, therefore in order to protect the health of the consumer and the environment as well as reduction in costs, the preferred dose is 2.5 ml L-1.

Potato black scurf and rhizoctonia canker caused by Rhizoctonia solani is one of the most common diseases in all potato growing areas of Iran. Due to the importance of seed disinfection in the control of this disease, in this study, the effect of seed disinfection with fungicides Iprodione carbendazim WP52.5%, Thiabendazole WP60%, Thiophanate methyl WP70%, Carboxin thiram FL40%, Carboxin thiram WP75%, PencycuronWP25%, Fludioxonil FS2.5%, Mancozeb WP80% and Carbendazim WP50-60% in the laboratory and greenhouse was investigated. Iprodione carbendazim with concentration of 2.5/1000 with 71.5% had the highest of percentage inhibition on germination of sclerotia and with a concentration of 20 ppm and 77.5%, inhibited the growth of fungal mycelium on potato dextrose agar (PDA) medium. In greenhouse, the plants from seed treatment with Iprodione carbendazim, Thiabendazole and Carboxin thiram FL40% each with a concentration of 2.5/1000 had the highest daughter tubers production with about 260-270 g. This treatments without any canker on underground stem and zero percent of infected plant were the most effective treatments and there was no significant difference between them. In the study of the number of sclerotia on the surface of the tuber, Iprodione carbendazim, Thiabendazole and Carboxin thiramWP75% each with a concentration of 2.5/1000 with an average of three sclerotia had the greatest effect on reducing the number of sclerotia on the daughter tubers. In general, according to the results, all studied fungicides had a positive effect on disease control and yield increase but Iprodione carbendazim with a concentration of 2.5/1000 was the most effective fungicide for controlling potato rhizoctonia canker.

Powdery mildew is one of the most important diseases of apple globally and is caused by the fungus Podosphaera leucotricha. The aim of this study was to determine the efficacy of the fungicides Boscalid + Pyraclovastrobin (Bellis®; WG, 38%) with the doses of 0.4, 0.7 and 1 ml L-1 compared with the fungicides Tri-floxystrobin + Fluopyram (Luna Sensation®; SC, 500) with the dose of 0.2 ml L-1, Tri-floxystrobin (Flint®; WG, 50%) with the dose of 0.2 ml L-1 and Tri-floxystrobin + Teboconazol (Nativo®; WG, 50%) with  the dose of 0.2 ml L-1 to control the apple powdery mildew disease. The experiment was carried out in Ardabil province in a randomized complete block design (RCBD) with 8 treatments and 4 replications in 2019-2020. Control treatments were with water spraying and without any spraying Treatments were applied in the spring in three stages (full green bud stage, pink flower stage and 10 days after the 2nd spraying). Ten days after the first symptoms of the disease were observed in the control treatments, samples were taken from the sheets and the disease incidence and disease severity percentages were calculated. The results showed that the highest rate of control (80%) of apple powdery mildew disease was related to Luna Sensation® (0.2 ml L-1). Then   the fungicide treatment of Bellis® (1 ml L-1) had the highest rate of control of the disease (76%) and the treatments of Flint® (0.2 ml L-1), Bellis® (0.7 and 0.4 ml L-1) and Nativo® (0.2 ml L-1) were ranked next in this regard. The efficacy of the new fungicide Bellis® at the rates of 1 and 0.7 ml L-1 was 76 and 60%, respectively. Since both the doses of Bellis® are effective in controlling the disease, therefore, to protect the health of the fungicide users, the consumers  of the products and the environment as well as reduction in costs, the preferred dose was chosen as 0.7 ml L-1.

Soil-borne fungus Sclerotinia sclerotiorum or white mold is the cause of the destructive disease of root and stem rot of many plants. Chemical control due to the lack of highly resistant cultivars is the most important method in the pathogen management program in various plants. However, the repeated use of fungicides leads to the development of resistant strains in pathogen populations. The use of fungicides with different modes of action, especially those with a synergistic effect, is one the most important anti-resistance methods.

In this research, the effect of different mixing ratios in pairs of carbendazim, iprodione, and tebuconazole fungicides and their possible synergistic activity on four S. sclerotiorum isolates were investigated in vitro conditions. For this purpose, the isolates were cultured on potato dextrose agar, containing different concentrations of fungicides mixtures, and EC50 values and the synergy factors were then determined for different mixtures ratios.

Tebuconazole: carbendazim mixture in 1:7 ratio, with a synergistic activity, inhibited all the isolates growth, and carbendazim: iprodione mixture in 1:9 ratio showed a synergistic effect on three isolates.

The mixture of tabuconazole: carbendazim in 1:7 ratio had the best synergistic activity, and inhibitory effect on the growth of all the pathogen isolates, so it has the potential to be used in the management program of S. sclerotiorum.

Apple (Malus domestica, Borkh) is considered one of the most common popular and favorite deciduous fruit trees cultivated in Iran. Various harmful factors affect the performance of this fruit. Apple powdery mildew disease is one of the most important apple diseases that has a worldwide distribution and causes disease and is caused by the fungus Podosphaera leucotricha Ell. Et Ev. This fungus is an obligate parasite and it can attack to leaves, flowers, fruits and twigs. In the beginning of spring the disease appeared on leaves which are the most susceptible organs. The disease appears on the upperside of infected leaf as powdery white lesions and eventually the infected part of leaf turn brown and infections on the underside of infected leaf result in chlorotic patches. Infected leaves become crinkle, curl and drop prematurely. Although blossom and fruit infections are less common, they are important because infected fruits are small and stunted if they do not drop. P. leucotricha survives the winter as mycelium in vegetative tissues or in infected flower buds. The primary infection starts when infected buds break dormancy and fungus resumes growth and colonizes developing shoots. Spores growing on infected shoots spread nearby and initiate secondary infections. Also it causes early loss of leaves and stop the growth of diseased branches and as a result, the loss of yield. In heavily infected trees, rust can be seen on fruit surface. Powdery mildew infection usually occurs at relative humidity above 70%, and on days when humidity is low, the infection usually occurs at night or in the early morning hours when the humidity is high. Although the use of effective fungicides can control the disease well but appearance of resistant strains of pathogens to reduce fungicide efficiency in controlling disease and producers' access to effective fungicides from various chemical groups, while helping gardeners to reduce the economic damage caused by the disease, reduces the possibility of pathogen resistance to fungicides. The aim of this study was to determine the efficacy of Boscalid + Pyraclovastrobin (Bellis ® WG38%) (Manufactured by BASF Co.) (With doses of 0.4, 0.7 and 1 ml L-1) compared with Tri-floxystrobin + Fluopyram (Luna Sensation ®) (with a dose of 0.2 ml L-1), Tri-floxystrobin (Flint ® WG50%) (0.2 ml L-1) and Tri-floxystrobin + Teboconazol (Nativo ® WG50%) (With a dose of 0.2 ml L-1) to control apple powdery mildew disease.
For the experiment, the apple orchard of Golden Smooth cultivar with a history of powdery mildew in Ardabil province was selected. The experiment was carried out in a randomized complete block design (RCBD) with 8 treatments and 4 replications. Control treatments were without any spraying and with water spraying. Treatments were applied at three stages (full green bud stage and followed up at pink flowers stage and 10 days after the 2nd spraying). Ten days after the first symptoms of the disease were observed on the control treatments, samples were taken from the sheets and the percentage of the disease incidence and disease severity percentage were calculated. After calculating the incidence and disease severity of apple powdery mildew for each plot, the corresponding values in SAS statistical software were analyzed and the means of both traits were compared by Duncan's multiple range test at one percent probability level.
The results of analysis of variance of the data obtained from the evaluation of the leaves of the treated trees showed that the effect of treatments on reducing the percentage of disease severity and disease incidence is statistically significant. The results showed that Bellis ® fungicide with a concentration of 0.1 and 0.7 ml L-1, Luna Sensation ® 0.2 ml L-1, Nativo ® 0.2 ml L-1 and Flint ® with a concentration of 0.2 ml L-1 had a high efficiency of controlling apple powdery mildew disease. The efficacy of new Bellis ® fungicide with concentrations of 1 and 0.7 ml L-1 was 76 and 60 percent, respectively. According to the obtained results, Bliss fungicide with a dose of 0.4 per thousand had poor efficacy in controlling the severity and occurrence of the disease and was not statistically significantly different from the control treatments. The results also showed that there was no significant difference between the control treatments (treatment with water spraying and treatment without spraying).
Because both Bellis ® concentrations are effective in controlling the disease, therefore in order to protect the health of the fungicide users, the consumer of sprayed products and the environment as well as reduction in costs, the preferred dose is 0.7 ml L-1.

Stem rot caused by Sclerotinia sclerotiorum, is one of the important diseases of rapeseed, and fungicides are applied for its control. In Iran, carbendazim and tebuconazole are often used for chemical control of the disease. In order to introduce other effective fungicides against the disease, seven fungicides were studied in laboratory conditions and then six of them were applied in the field. In the laboratory conditions, different concentrations of the fungicides showed significant differences (P<0.01) with control (without fungicide) and caused inhibition of pathogen radial growth on potato dextrose agar medium except chlorothalonil (Daconil®). Effective concentration (EC50) and minimum inhibitory concentration (MIC) of the fungicides including iprodione + carbendazim (Rovral TS®), propiconazole (Tilt®), thiophanate methyle (Topsin M®), trifloxystrobin+ tebuconazole (Nativo®), tebuconazole (Folicure®) and spiroxamine+ tebuconazole+ triadimenol (Falcon®) was calculated. The EC50 values of these fungicides were 0.10, 0.11, 0.12, 0.22, 0.36 and 0.60 ppm, and MIC values were 1, 5, 1, 10, 10 and 10 ppm respectively. In the field conditions, all fungicides, had significant difference (P<0.01) with control  and decreased the rate of the disease infection and increased the crop yield about 300 to 700 Kg/ha. Nativo® was the most effective fungicide. The duration of plant protection in Nativo® treatment was longer and occurrence of disease symptoms after spraying was later than other treatments. Therefore, these fungicides can be used in rotation with common fungicides.

Tomato (Lycopersicum esculentum Miller) is one of the most popular crops in the world. The cultivation of this plant is always exposed to harmful factors, especially blight caused by the fungus Botrytis cinerea, which in favorable environmental conditions (high humidity and temperature up to 15˚C) in cultivars and tomato hybrids are common. Fungicides can prevent disease by controlling germination and spore infiltration, but due to the pathogen's resistance to fungicides, it is necessary to alternate spraying programs with the appropriate doses and at the appropriate times. This study examined the effect of several fungicides on the pathogenic mycelial growth.
For this purpose, various fungal isolates were collected from greenhouses and tomato farms. Purification and proof of pathogenicity and pathogenicity of fungal isolates were performed on disease-sensitive cultivars named PETOERLI with fungal spores suspension at 2 × 105 spores per ml on leaves in greenhouses. The severity of the disease index was determined after 15 days and to determine the effect of fungicides on mycelial growth, Captan, Ipirudion + Carbendazim, Thiram, Agrofar and Thiophanate -methyl fungicides were used at a rate of one per thousand in the culture medium. Among the used fungicides, Iprodione + Carbendazim with 89.5% inhibition and then Agrofar with 83.76% with a concentration of one per thousand were successful in controlling mycelial fungal growth control, respectively.

Sulfur (S), as a promoter of plant defense system and fungicidal effect, can have a critical role in organic farming. Presence of sulfuric defense compounds including elemental sulfur, H2S, glutathione, ÇÓیÏیÊåytochelatins, secondary metabolites and S-rich proteins are vital under stress conditions. As a soil disinfectant, carbon disulfide is widely used against soil-borne pathogens. This is used for controlling the root and crown rot disease caused by Armillaria. Sulfur fumigation is used against powdery mildew in greenhouse production. Fumigation and application of sulfur pad are methods for controlling the grape and some other fruits rot in storage. Besides, sulfur is effective in control of mites, psyllids, and thrips.

The present paper tends to assess the inhibitory impacts of the three isolates of Trichoderma harzianum obtained from the commercial products of Trianum-P, Trichomix-HV and TricofungS and the two native isolates of T. harzianum, Th1 and Th2, applied to control melon Fusarium wilt using seed coating method under both laboratory and greenhouse conditions. Melon seeds were infected with pathogen and treated by T. harzianum isolates were assessed for germination in vitro. Research results showed that Trianum and Th1 were the most effective treatments for germination (with 95 and 92.5%, respectively), in comparison with the control sample 25% and they indicated significant difference. In greenhouse, disinfected seed by tested treatments were planted in pots containing soil infected by pathogen. Treatments included the three mentioned commercial products and two propagated isolates in bran at three concentrations of 0.5, 1.5 and%0 2.5 and two fungicides of Rovral TS and Thiabendazole in concentrations of 1.5,2 and %02.5. plant growth parameters and disease severity were measured. Trianum, Tricofung, Trichomix and Rovral in concentrations of 2.5, 1.5, 2.5 and %2 reduced disease severity by 80% and 67.5%, 67.5%, 67.5% respectively. In control samples, the percentage of plants with no wilt symptoms was 7.5%. For growth parameters, the plants treated by Rovral %ₒ2, Th1, Th2 and Trianum %ₒ2.5 were the most effective seed coatings. Research results indicated that commercial and native isolates of T. harzianum had the potential of controlling Fusarium wilt in melon using seed coating method as well as tested chemical fungicides. However, different isolates of T. harzianum had different biological effects.

Brown rot disease of citrus fruits caused by Phytophthora citrophthora and Phytophthora parasitica is one of the most threats to citrus plantation in northern Iran. In evaluation of different methods to control of citrus brown rot, an experiment was achieved in Northern Iran based on Randomized Complete Block Design (RCBD) in factorial test with five replications. In reciprocal effects study of fungicides (metalaxyl, cupper oxychloride and burdux mixture) and skirt pruning, a significant difference was observed among the treatments. The results showed that the best treatment was obtained from the application of cupper oxychloride skirt pruning in August. In reciprocal effects study pruning and fungicides application time, no significant differences were observed among treatments, however maximum and minimum percent of decay were depended on "no pruning spraying in September and pruning spraying in May" respectively. There were also differences among spraying time and fungicides application, as maximum and minimum percent of decay were related to application of metalaxyl and cupper oxychloride in September.

Tan spot disease incited by Pyrenophora tritici-repentis, is an important disease of wheat throughout the world, including Iran. The disease inflicts considerable losses to the crop in the epidemic conditions. Application of fungicides is a quick method for control of the disease in epidemic years. In this study, the effect of some registered fungicides was evaluated on growth inhibition of the causal agent as in vitro, and also for control of the disease in greenhouse and field conditions on a susceptible wheat line (N-80-19). The experimental design was carried out as completely randomized in in vitro condition and as split plot in greenhouse and field conditions with 3 replications. Main plots were included the fungicides Cyproconazole, Cyproconazoleপ�睚츩 (Altocombi), Flusilazoleপ�睚츩 (Alert), Iprodioneপ�睚츩 (Rovral T-S), Propiconazole, Tebuconazole, Carbendazim and Benomyl), and sub-plots were consisted of the spraying times (flag leaf, head appearance and flag leafꖩ appearance stages). The treatments were evaluated by recording the infection index, 10 days after the last spraying simultaneously with disease development on control plots. The grain yield was also calculated after wheat harvesting. The results demonstrated Rovral T-S (73.83%), Altocombi (71.92%) and Alert (69.42%) had maximum in vitro growth inhibition of the fungus. The three fungicides showed considerable advantages on reduction of infection index and increase of yield in greenhouse and field tests, compared to other fungicides. For infection index, no-significant difference was recorded among spraying times. The highest thousand grain weight was respectively obtained by spraying at flag leaf head appearance (increasing 10.11 and 9.94 grams), flag leaf (increasing 9.26 and 9.18 grams) and head appearance stages (increasing 9.15 and 8.68 grams, respectively, for greenhouse and field), compared to their control.

Sclerotinia sclerotiorum (Lib.) de Bary is a major plant pathogen that plays a crucial role in yield reduction of economically important crops. Most of the conventional methods are not effective in management of S. sclerotiorum. The Biological control by fungal antagonists could be useful in reducing disease. In the present research, antagonistic effects of indigenous Trichoderma species on S. sclerotiorum were determined in vitro. Dual culture technique, production of volatile and non-volatile compounds were used to determine the percentage of mycelial growth inhibition. The mycelial growth inhibition of S. sclerotiorum by Trichoderma strains ranged from 35.5-53.4, 0-33 and 0-100 percent in dual culture, volatile compounds and non volatile metabolites tests, respectively. Trichoderma harzianum (A10) showed the highest impact on mycelial growth inhibition in dual culture and T. harzianum (A2 & A10) had the highest effect on the inhibition of mycelial growth by the production of volatile compounds and non-volatile compounds. On the whole, antagonist T10 (T. harzianum) was most effective in controlling pathogen isolates under laboratory conditions. Also effects of three fungicides including thiophanate- methyl, Rovral TS and Benomyl were studied in laboratory conditions. Results showed that thiophanate-methyl (10 ppm) and the other two fungicides at concentration of 100 ppm were able to completely inhibit the mycelial growth. Comparison of effectiveness of chemical and biological control methods in greenhouse conditions indicated that inoculation of soil with antagonist prior to infection with the pathogen had better effect than chemical control did. This study has shown that the use of biocontrol agents at the right time is more efficient in prevention of the disease than chemical fungicides.

Gray mold, caused by Botrytis cinerea, is one of the most important diseases of grape worldwide. Although, it has recently become a major problem in West Azarbaijan province causing significant yield losses, no fungicide has been registered to control the disease. In currentstudy, susceptibility of 103B. cinerea isolates collected from vineyards in different regions of the province was assessed to three fungicides including benomyl, iprodione and fenhexamid using discriminatory doses of fungicides in in vitro conditions. Results indicated that isolates resistant to benomyl and iprodione were widely distributed across the surveyed regions at different frequencies, whereas the isolates resistant to benomyl were not detected in the samples collected from Salmas. Isolates resistant to fenhexamid were detected at low frequency in six sampling locations. The results also showed that the isolates with multiple resistances to two fungicides were widely distributed in the studied regions. It is likely that application of benomyl and iprodione or fungicides with similar mode of action to control fungal diseases in grape other than gray mold, have resulted in selection of B. cinereastrains resistant to these fungicidesas non-target pathogen leading to increase in their frequencies. The results revealed that the use of benomyl and iprodione or fungicides with similar mode of action would be ineffective to control the disease, while fenhexamid seems to be an alternative and effective fungicide to be registered and used to control the disease.

Sclerotinia sclerotiorum (Lib.) de Bary is a major plant pathogen that plays a crucial role in yield reduction of economically important crops. Most of the conventional methods are not effective in management of S. sclerotiorum. The Biological control by fungal antagonists could be useful in reducing disease. In the present research, antagonistic effects of indigenous Trichoderma species on S. sclerotiorum were determined in vitro. Dual culture technique, production of volatile and non-volatile compounds were used to determine the percentage of mycelial growth inhibition. The mycelial growth inhibition of S. sclerotiorum by Trichoderma strains ranged from 35.5-53.4, 0-33 and 0-100 percent in dual culture, volatile compounds and non volatile metabolites tests, respectively. Trichoderma harzianum (A10) showed the highest impact on mycelial growth inhibition in dual culture and T. harzianum (A2 & A10) had the highest effect on the inhibition of mycelial growth by the production of volatile compounds and non-volatile compounds. On the whole, antagonist T10 (T. harzianum) was most effective in controlling pathogen isolates under laboratory conditions. Also effects of three fungicides including thiophanate- methyl, Rovral TS and Benomyl were studied in laboratory conditions. Results showed that thiophanate-methyl (10 ppm) and the other two fungicides at concentration of 100 ppm were able to completely inhibit the mycelial growth. Comparison of effectiveness of chemical and biological control methods in greenhouse conditions indicated that inoculation of soil with antagonist prior to infection with the pathogen had better effect than chemical control did. This study has shown that the use of biocontrol agents at the right time is more efficient in prevention of the disease than chemical fungicides.

Early blight is one of the most common and important disease that causes damage to most Solanaceos plants. At the present time, the most practicable way of control of the disease is using fungicides. Due to the importance of alternarios and excessive use of chemical compounds, this study was conducted to evaluate the effectiveness of non-toxic compounds in controlling the disease and comparing them with common fungicides. In this study, the effect of NaHCo3, CaCl2 salts, biological compound of Bacillex, clove oil, Rovral Ts and Dakonil fungicides on growth of fungal species Alternaria solani and A. alternata in vitro and the disease severity of resulting them in greenhouse have been investigated. The results showed that all the compounds inhibited the mycelium growth of two species of fungi in vitro except Daconil. The maximum growth inhibition was done with Rovral Ts and sodium bicarbonate at concentration of 30 ppm and 35 mg/ ml respectively. Greenhouse experiments indicated that tested compounds were effective in the disease severity reduction. Maximum reduction of disease severity in greenhouse due to Rovral Ts, Daconill, sodium bicarbonate, calcium chloride, Bacillex and clove oil were 33/88, 93, 33/92, 93, 33/70 and 74%, respectively.

Fungal diseases of plants are major treats for agricultural products. Lots of fungicides are widely used to control the plant pathogens. Incidence of resistance to the fungicides in the pathogenic fungi is a main limitation in their use. With some exceptions, in general, there are more reports on the resistance of fungi to systemic fungicides than the non-systemic ones. This review discusses the mechanisms of resistance to chemical fungicides (e.g. altering the target site, reducing the fungicide uptake, fungicide removal, detoxification or metabolism of the fungicide) in some phytopathogenic fungi at the molecular level and describes the methods (e.g. RFLP-PCR, and allele specific real-time PCR) used in molecular detection of resistance to the fungicides.

Rhizoctonia canker, also known as stem canker and black scurf of potato, Rhizoctonia solani Kuhn, causing serious economic losses by canker on under ground stem, roots, stolens, blanding of tubers and black scurf on potato surfacee in Isfahan. In this manscript, the effects of green chitting and or disinfection of potato seed tubers and soil were considered on this disease in the fields. The laboratory trails on R. solani isolates indicated that, almost all the sclerotinia are pathogenic. The seed tubers of four potato cultivars were selected and kept under room temperature along with normal light and high humidity for two months. Then, they were sown in the highly infested soil to the disease. The results indicated that the green chittings reduced Rhizoctonia stem canker severity effectively. In comparison to the above experiments, the fungicide screening, Rovral in the form of seed, soil and simultaneous seed and soil applications were carried out in the same fields. The results showed that the stem canker severity was reduced effectively compared to chittings and that of control. Increased growth response was observed in only green chitted potato seed tubers compared to other treatments.

Early blight is an important and ubiquitous disease which attacks many herbaceous plants Specially Solanaceae family. Already this disease threaten the potato fields In Iran. The experiments were conducted in order to study the effects of rovral, Chlrotalonil, Mancozeb fungicides in 1 ppm against flint in 1, 2, 5, 10 ppm on different culture media, including PDA and CMA for two species Alternaria alternata & Alternaria solani. The result indicated that, all of tested fungicides could prevent the growth of two species with the various levels, as far as the growth rates are concerned. Also flint fungicide in various concentrations, 1,2, 5, 10, 20, 50, 10, 200, 500 and 1000 ppm indicated that it could effectively inhibit the growth of two fungal species, as the dosages are increased, indicating the reductions in the growth correspondingly. The highest inhibitions were flint 500 and 1000 ppm and the lowest in flint 1 ppm. This fungicides had a very significant effects on the sporulation of A. alternate, indicated that, with the increased in fungicides concentrations, the sporogenesis decreased, in which the highest sporulation was in Mancozeb treatment and the lowest was in flint with 1000 ppm Also, the results indicated, that the fungicides had effective reductions on the dry and wet mycelial growth weights on zapeks culture media, where the highest wet weights were observed in Mancozeb fungicide, and the lowest was in flint, 1000 ppm.