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

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.

Pistachio trees have different diseases. In the current study, the successful application of knowledge and experience of farmers for the control of pistachio gummosis disease was investigated. The data used is related to 286 pistachio orchards in Anar and Rafsanjan districts that were collected over a 9-year period (2010 to 2018) and during three cross times, in 2012, 2015 and 2018. The target sample was selected using a multi-stage random sampling method. To evaluate the effect of different management factors on reducing or increasing the severity of orchard disease and its effects on the quantity and quality of pistachio crop yield and profit, the methods of the correlation coefficient, mean comparison and regression were used. The results showed that 25% of pistachio orchards were always infected with gummosis and this disease could not be eliminated and should be controlled and managed. More than 97% of farmers have prior knowledge of gummosis but have failed to control and manage it. The results also showed that the only way to successfully control gummosis is to hire experts in plant pathology and they were active in the orchards and more investigation showed that this work is economical. Factors such as heavy irrigation, freshwater irrigation, use of mulch, and excessive use of machinery, especially tiller, increase the risk of gummosis. In contrast, regular and well-distributed irrigation, reducing irrigation terrace area, use of pressurized irrigation system, use of irrigation water from different wells, increase the width of the irrigation strip, use of poultry manure and enhance using macro and micro chemical fertilizers reduce the severity of gummosis in pistachio orchards.

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.

Today, fungicides are widely used to prevent or eradicate a variety of pathogenic fungi, but in some cases their use has destructive effects on beneficial microorganisms such as mycorrhizal fungi. Mycorrhizal fungi are among the beneficial microorganisms used in the production of biofertilizers. After mycorrhizal symbiosis, plant features included water and nutrient uptake as well as plant resistance to biotic and abiotic stresses improve. These microorganisms are also used to control soil pathogens. The present study was conducted to investigate the effect of concomitant use of fungicides including benomyl, roralthias, mancozeb and Tilt on the effectiveness of R irregularis in both wheat and corn plants under greenhouse conditions. The experiments were designed as a completely randomized design with five treatments and four replications. The effect of fungicides on the growth characteristics of wheat (Chamran cultivar) and corn (Zeamays, Single Cross 704) and their symbiosis relationship with R. irregularis were investigated. The results showed that the effectiveness of mycorrhizal fungus application was not affected by the concomitant use of fungicides. The application of fungicides also improved some growth characteristics in wheat and corn, although in most cases the differences with the control treatment were not significant. In general, two milliliters per liter of Tilt for wheat and two grams per liter of benomyl for corn can be recommended when using R. irregularis inoculum at the same time

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.

The effects of postharvest dip treatment in hot water and carbendazim fungicide on sensory, physicochemical, and antioxidant characteristics determining the internal and external quality of sweet lime (Citrus limettioides Tan.) fruit were studied. Treatments included a 4 min dip in 45 °C hot water, 0.5 g L-1 carbendazim solution and distilled water (control). Fruits were stored at 10 °C and 85% relative humidity for 90 days, with characteristics being measured at 30-day intervals. Compared to control fruits, treated fruits by hot water had lower weight loss and decay, better taste index, and higher content of total phenol in peel and ascorbic acid in the juice. After one month of the storage, they showed higher levels of enzymatic antioxidant activity (superoxide dismutase, catalase, ascorbate peroxidase, and guaiacol peroxidase) and more non-enzymatic antioxidants such as total phenol in peel and ascorbic acid in juice when compared to control. Afterwards, peel enzymatic antioxidant activity increased in control fruits while decreasing in hot water-treated fruits. Based on non-enzymatic antioxidants content and sensory evaluation after 3-months storage, hot water-treated fruits possessed the best internal and external quality, while fungicide-treated fruits with a pale appearance had the lowest quality in peel color and firmness. At this time, investigations on the peel content of hydrogen peroxide and enzymatic antioxidant activity revealed that fungicide-treated fruits experienced more stress and oxidative injury than control fruits. As a result, hot water dip treatment was recognized as a safe treatment for improving and extending the storability of sweet lime, as well as a suitable substitute for chemical fungicides.

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.

Usually, pomegranate fruit in humid areas is under attack from fungal diseases. In addition to skin damage to the fruit, fungal diseases also reduce qualities and visual charactristics. Fruit cracking is another physiological disorder that causes a lot of damages to the crop and causes irreparable damage to the gardeners. Control of these diseases is very difficult, and the use of recommended treatments also has yielded different outcomes. Finding the appropriate solution based on nutritional and chemical products is necessary to overcome this problem.

This research was conducted in a commercial orchard located in Sorak city, 10 km from Sari city with a longitude of 53 degrees and 17 minutes and a latitude of 36 degrees and 61 minutes, and a height of 9 meters from the sea level in summer of 2017. The research was carried out as a factorial test in randomized complete block design with the aim of investigating the effects of Copper, Silicon, Vermiwash and Rovral TS on the quality of pomegranate fruit of Shavar cultivar. Experimental factors consisted mineral nutrition (in four levels of control, Copper nano-chelate, Silicon, and Copper+Silicon) and Fungicide (in two levels of vermiwash and Rovral TS). Foliar application was performed 4 times at intervals of 15 days and fungicidal treatments were carried  out at 3 times intervals of 20 days. Then morpho-physiological studies were carried out.

The results of this experiment showed that the highest amount of flower conversion to fruit and the highest amount of dry weight (49.78 g) were obtained in Vermiwash and Silicon treatments. The least amount of infected fruit was observed in the application of Rovral TS+copper, Rovral TS+Silicon and Vermiwash+Si+Cu, and. Simultaneous treatment of Silicon and Copper significantly increased fruit size. The treatments of Silicon+Copper and Silicon alone led to a decrease in the number of cracked fruits compared to the control. The highest amount of anthocyanin pigment was observed in Vermiwash alongside with Silicon+Copper treatments. The percentage of free radical scavenger in all treatments was higher than the control. Overall, the results of this experiment showed that Vermiwash, Copper and Silicon alone improved the traits studied. Silicon is naturally present as a compound of the cell wall and hardly bonds with the cell wall mass, thereby elicits resistance against cracking. Silicon also has a fungicidal effect, as has been reported in plants such as rice and cucumbers that can delay the development of pathogens such as Rhizoctonia solani and Pythium ultimum after treatment with Silicon. It has also been reported that the use of Vermiwash in various plants did affect control up to 93% of the diseases.

Vermiwash alongside with Si+Cu caused the lowest fungal infection, highest anthocyanin and appropriate fruit set, so this treatment can be strongly recommended. Besides, the results indicated that adding Si and Cu to chemical fungicide can boost its efficiency and decrease cracking significantly.

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.

Phosphite is a reduced form of phosphate, wherein an oxygen replaces a hydrogen atom, and this substitution has a significant effect on its performance in living organisms. Phosphite is readily transfered into plant cells through phosphate transporters. However, plants do not have the ability to use phosphite as a phosphorus resourc such that this property has limited the use of phosphite as fertilizer; however, phosphite has been used as a fungicide and biostimulant in agriculture. Some bacteria are able to oxidize phosphite into phosphate to cover for various cellular functions. In the last decade, the molecular mechanism of this biological oxidation has been elucidated to occure by the enzyme phosphite oxidoreductase or phosphite dehydrogenase. Phosphite is produced in large quantities in various chemical industries as a by-product or waste that is not recycled. The identification of the enzyme phosphite dehydrogenase, that catalyses the oxidation of phosphite to phosphate, has opened a new path for the recycle of this waste. Recently, there have been reports for the production of transgenic plants expressing ptxD gene. In practice, ptxD gene can be used as a marker in the selection of transgenic plants. By producing these transgenic plants, phosphite can be used as a herbicide and even as a phosphorus fertilizer.

Integrated control is a program that uses several methods to reduce the consumption of high-risk chemicals and is cost-effective. The aim of this study was to investigate the combined control of trichoderma fungi and chemical toxins (carbendazim and mancozeb) in onion gray rot caries. For this purpose, isolation of Trichoderma from fungal onions in Kahnouj city was carried out on a specific medium and isolates were identified using Gaussian and Twenty keys. Also, gray rot fungi were isolated and identified from onion molds infected with gray mold from the warehouses of Kahnouj city. Then, combined control of gray rot fungi was investigated by Trichoderma and two Mancosb and Carbendazim toxins. The results showed that the average inhibition of growth of Trichoderma fungi against Botrytis was 51.61percent in vitro. The average inhibitory percentages for growth of volatile metabolites were 38.14percent and nonvolatile metabolites in two treatments of 5 and 10 ml, respectively. The results of the analysis of catalase and peroxidase enzymes in onion samples treated with trichoderma showed an increase in both. Simultaneous use of trichoderma and two carbendazim and mancozeb toxins 100percent inhibited the growth of Butrititis in laboratory and storage conditions. Whereas, application of Trichoderma alone 68.18percent inhibited the growth of Botrytis in laboratory conditions. In addition, the concentration of the pesticides used was 500 ppm, which is lower than that of the conventional pesticides. Therefore, the results indicate that the fungal control of gray rot factor by trichoderma and the two toxins carbendazim and mancozeb are successful.

Tamarix aphylla is used as a windbreaker, shade tree and ornamental plant in gardens and urban landscape. The browning phenomenon is an important inhibitory factor in various stages such as disinfection and regeneration of Tamarix aphylla. To optimize the disinfection conditions and control the browning process of the explants, experiments were carried out with disinfectants and eugenol compound to disinfect the current and annual stem explants. Then, callus induction was studied in a medium complemented by two types of auxins (2,4-D and NAA). In the third experiment, the optimization of shoot induction medium was investigated on current and one year old shoots explants. The best disinfection treatment to control fungal and bacterial contamination and phenol secretion from the current explants was obtained using a 60-second ethanol application combined with 10 minutes of 20% sodium hypochlorite disinfection. Spraying of donor plants with thiophanate methyl fungicide was also able to reduce fungal contamination by almost 50% compared to the control. Application of 0.01% eugenol in the medium by injection reduced the contamination and phenol secretion from the explants. The highest survival and callus induction was acquired at the concentration of 1 mgL-1 2, 4-D, in the shortest time. Shoot induction in the explants of current and one year old shoots was obtained in the culture medium containing 2 mgL-1 BA and 0.5 mgL-1 IBA In conclusion, the application of younger plant materials, spraying of donor plant with fungicides and the use of 0.01% eugenol in the medium can reduce the browning phenomenon and proper control of contamination and finally could provide micropropagation of Tamarix aphylla shrubs using appropriate growth regulators

To investigate the effect of yellow rust disease on some agronomic and physiological characteristics of bread wheat cultivars, two field experiments were conducted in Agricultural Research Station of Miandoab in West Azerbaijan, Iran, in 2013-2014 and 2014-2015 cropping seasons. Experimental treatments were arranged as factorial in randomized complete block design with three replications. Treatments included; non-sprayed and sprayed of Tilt fungicide with six winter and facultative bread wheat cultivars (Zarrin, Alvand, Pishgam, Oroum, Zareh and Mihan). Environmental conditions was inductive and yellow rust disease occured naturally in both cropping seasons. The results showed that Zarrin and Alvand cultivars had the highest disease infection (63% and 57%, respectively) in the non-sparyed treatment. However, Pishgam, Orum, Zareh and Mihan cultivars were resistant to yellow rust disease. Yellow rust decreased grain filling duration in sausceptible cultivars (Zarrin and Alvand) by 10 days. Leaf chlorophyll content of susceptible cultivars decreased in non-sprayed treatment from the milky to hard dough stage with a steepy slope. However, in the sprayed treatment leaf cholorophyll content decreased with slower rate. Yellow rust disease in non-sprayed treatment caused the highest proportion of reserved carbohydrtaes remobilization in Zarrin and Alvand by 30%, but 1000 grain weight loss in susceptible cultivars was about 26%. Despite of 29% increase in grain yield of susceptible cultivars in the sprayed treatment, the higher grain yield was obtained from resistant cultivars, Pishgham and Mihan (7877 and 7593 kg.ha-1, respectively). It can be concluded that integrated disease management by using resistant/ moderately resistant cultivars and fungicide application would be the best crop management practice to control yellow rust disease and reduce environmental pollution by application of less fungicide and reducing production costs.

The global trend has shifted towards the reduction of synthetic pesticide application in agriculture in general and in postharvest in particular. Currently there is a growing interest in using natural antifungal compounds, like plant extracts for the preservation of foods. In order to develop fungicide formulation of natural origin as postharvest treatments, this study was conducted on the antifungal activity of pomegranate (Punica granatum L.) extract against Penicillium italicum and P. digitatum. The experiment was set up according to a completely randomized design with 4 replications using ‘Satsuma’ mandarin. The experimental factors included extract concentration (0, 25%, 50%, 75% or 100%) and the effect of treatments (preventive or curative). The fruits were wounded on the outer surface on four locations to a depth of 2 mm and a diameter of 1 mm. Preventive treatments were carried out by dipping wounded fruit into the formulations of extract and thereafter, each wound site was infected by inoculating 20 μL of the inoculum of P. italicum or P. digitatum. For curative treatments, fruits were wounded as above, and then inoculated with P. italicum or P. digitatum (20 μL of inoculum per wound site). The results showed that the 75% or 100% pomegranate extract applied to ʻSatsuma mandarin produced a significant antimicrobal effect, reduced spore or mycelium diameter, decay severity and infection index and increased sporing time and healthly fruit percentage. Our study showed that 100% pomegranate peel extract application could decrease weight loss rate during storage of “Satsuma” mandarin fruit inoculated with spores of P. digitatum or P. italicum. The obtained results showed that the tested pomegranate extract can be effectively utilized for controlling and curing infections caused by P. italicum and P. digitatum.

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.