Essential oils are natural compounds, which have extensive applications in perfumery, food and pharmaceutical industries. Nowadays they are also used in preservation of foods and disinfectant production. Considering the undesirable effects of synthetic compounds on the nature and living beings, using natural compounds like essential oils have been noticed recently. Peppermint (Mentha piperita) belongs to Labiateae family and is originated from Mediterranean region. It is widely cultivated in the world. In this research, we studied composition and antifungal effects of Mentha piperita oil on Fusarium oxysporum f. sp. ciceri., Macrophomina phaseolina, and Dreschlera oryzea on the basis of agar dilution method. The test was caried out with factorial experiments based on the random complete block design with triplicates. 1- Essential oil analysis with GS/MS revealed that main compounds of oil include menthol (19.76%), menthan-3-one (19.31%), menthofuran+isomenthone (9.12%), 1, 8-cineole+beta phellandren (8.8%) and menthol acetate (5.63%). 2-Comparison of means by LSD (?=1%) revealed that inhibitory effect of essntial oil varied among different fungi. After 48 hours, results showed no significant difference between the growth of fungi at 800 and 1600 ppm neither did show between water and alcohol controls, but differences between 200 and 400 ppm were significant. The minimum inhibitory concentration (MIC) of A and C was observed in 800 ppm, where as it was 1600 ppm in the case of B. After 72 hours, investigation showed that the MIC for A increased to 1600 ppm, whereas for C it was 800 ppm yet. After 3 days, 1600 ppm treatment completely inhibited the growth of fungi. After 7 days, it was found that 800 and 1600 ppm on C fungy, and 1600 ppm on A fungy were completely inhibitory. 3-Investigations on the fungicide effect of pippermint oil, showed that peppermint oil in these concentrations have no fungicide properties. The results of our studies revealed that the Mentha piperita oil exhibited a significant antifungal activity. Compounds of essential oils depend on climatic condition, spieces and chemiotype.

In this study, thyme essensial oil was extracted by water distillation method and was analysed by GS/MS, then we investigated the antifungal effect of this essential oil on Fusarium oxysporum f.sp. ciceri. (A), Macrophomina phaseolina (B), Bipolaris spicifera (C) on the basis of agar dilution method with different concentrations (200, 400, 800 and 1600) The test was carried out with factorial experiment based on the random complete block design with triplicate. 1- The major compuonds of thyme essensial oil were found to be Terpinen (4.65%), Cymene (12.16%), Thymol (19.8%), Linallol (4%), and Caryophyllene (4.07%). 2- Analysis of data with LSD (?=1%) showed that inhibitory percentage between fungi was different. After 48 hours results showed no significant difference between the growth of fungi at 800 and 1600 ppm and also between water and alcohol controls, but differences between 200 and 400 ppm were significant. The minimum inhibitory concentration (MIC) of A and C fungi was observed in 400 ppm, where as it was 800 ppm in the case of B fungy. Concentrations of 800 and 1600 ppm were 100% inhibitor about all the fungi. After 72 hours investigation showed the similar results to the period of 48 hours growth time. The concentration of 400 ppm was inhibitor on A and C Fungi completely after 72 hours, but the minimum inhibitory concentration for B fungy was increased to 1600 ppm. After 3 days, 1600 ppm treatment was completely inhibitor for all fungi. After 7 days, it was found out that 800 & 1600 ppm on A fungy, 1600 ppm on B fungy and 400 ppm, 800 ppm, 1600 ppm on C fungy was inhibitor completely. 3- Investigation on thyme fungicidal effect showed that concentration of 1600 ppm was fungicide on B and C fungi but other concentrations have fungistatic property. The results of our studies revealed that the thyme essensial oil exhibited a significant antifungal activity. Thyme (Thymus vulgaris) belongs to Labiateae family. It is an important medicinal plant. The antifungal and antibacterial activity of this essential oil has been reported.Thyme antifungal activity is due to the persence of thymol that is the major compound of this essential oil.

The effect of soil amendment by brown, green and red seaweeds was studied in controlling the root rot infecting fungi of okra seedlings in the greenhouse. The soil amendment with seaweeds Stokeyia indica, Padina pavonia (brown), Solieria robusta (red), at 1% w/w reduced Macrophomina phaseolina, Rhizoctonia solani and Fusarium solani infection on okra roots. Codium iyengarii (green) at 0.5 % w/w was effective against F. solani, while at 1% w/w was found phytotoxic. S.robusta showed better control of F. solani infection when used with Pseudomonas aeruginosa than either used alone. S. robusta produced better plant height and fresh weight of shoot than P. aeruginosa. Results of the present study suggest that the use of brown seaweeds S. indica and P. pavonia alone and S. robusta alone or in combination with P. aeruginosa have great potential to control root-infecting fungi of okra with enhancement of plant growth. These seaweeds alone or in combination with P. aeruginosa may be utilized as biological control of root infecting fungi of okra.

Many fungi cause sugar beet root rot during various stages of the plant growth. Among them Rhizoctonia spp. induce crown rot, dry rot and violet root rot on sugar beet (Whitney and Duffos, 1986). Root rot caused by Phytophthora drechsleri has been observed in fields with excessive moisture (Habibi, 1975). Pythium aphanidermatum has been recognized as one of the causal agents of sugar beet, damping-off, root rot and seed deterioration (Ahmadinejad and Okhovat, 1976). Rhizopus arrhizus has been also reported as one of the fungi involved in crown rot of sugar beet (Habibi, 1977). In order to determine pathogenic fungi involved in sugar beet root rot and their distribution in Kermanshah province, this investigation was carried out during 1998-1999. Forty-one fields in different parts of the province were surveyed. At every field some information about previous crop in rotation, method of irrigation, source of irrigation water and disease severity was recorded. From each field, 2-5 root samples showing root rot symptoms were collected and transferred to laboratory. A soil sample was also collected and analyzed in the laboratory. Ninty eight isolates belong to Fusarium spp., Rhizoctonia solani, Binucleate Rhizoctonia, Phytophthora drechsleri, Pythium aphanidermatum, Rhizopus arrhizus, Rhizopus stolonifer, Macrophomina phaseolina, Phoma betae, Mucor spp. and Geotrichum sp. were isolated. In this study, although the majority of the isolates belonged to Fusarium spp., they could not induce root rot symptoms in pathogenicity tests. The most severe symptoms of root rot were induced by R. solani, P. drechsleri, P. aphanidermatum and R. arrhizus. Among soil specifications, only soil saturation percent had a weak relationship with disease severity and other factors showed no distinct relation with disease symptoms. Figure 1 shows distribution of the fungi involved in sugar beet root rot in Kermanshah province.

Twenty-five soybean cultivars from different maturity groups were evaluated in artificial infection conditions with two isolates of Tiallosporella phaseolina, in a factorial experiment on the basis of RCBD with two replications in greenhouse, to determine their reactions to the above pathogenic fungus. In order to establish infection in soybean cultivars, autoclaved soil (10 min, 121) was contaminated with inoculums propagated on 50 ml corn meal and sand medium in a 250ml flask. The mixture of sand and corn meal was autoclaved for two successive days and then inoculated with 4-5 agar plugs of the 4 day-old fungus grown on PDA (potato-dextrose agar) at 30oC. Ten gr of inoculums was mixed thoroughly with the soil in each pot. Each soybean cultivar was six times planted in six pots, five seeds in each pot. Two pots were contaminated with isolate I and the other two with isolate II, while the last two pots being used as control (without any contamination). Microsclerotial propagules in lower stem and taproot tissues at growth stage R7 were used to determine infection percentage in cultivars. Analysis of variance showed that there were significant differences among cultivars as to the disease. Some cultivars were susceptible, while some being moderately resistant to T.phaseolina. Based on Duncan's multiple mean comparison test, cultivars NE 3297, Gorgan 3, M58, and Calhoan suffered the highest, while cultivars L93-3258, Macon, Probest and Salin the lowest infection percentage. Cluster analysis, performed on cultivars for infection percentage, placed cultivar NE3297 in a separate cluster.