• Korean journal of applied entomology
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• v.36 no.2
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• pp.179-184
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• 1997

This study was conducted to observe the effects of pesticides on the pathogenicity of entomopathogenic fungi, Beauveria bassiana and Metarhizium anisopliae isolated from Korea. Spomlation of entomopathogenic fungi in SMAY medium that mixed different concentrations of pesticides was similar to control in metalaxyl and tolclofos- methyl treatment but in half recommanded treatment of fenitrothion and mepronil very poor spomlation was showed. Pathogenicity of entomopathogenic fungi dipped in all tested pesticide solution for 1 to 5hr was 100% pathogenicity of M. aniropliae in the pesticide treated chinese cabage fields were similar to control, Bt, teflubenzuron, metalaxyl, and carbofuran treatment but alachlol was below 80%. Pathogenicity and persistence of entomopathogenic fungi in turfgrass when pesticides were posttreatmented were continued to 4 months in iprodione+thiram and tolclofos-methyl treated plots but those of B. bassiana and M. anisopliae was losted in fenitrothion pathogenicity and persistence of in mepronil were nil M. anisopliae from 3 months after treatment.

• Asian Journal of Turfgrass Science
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• v.13 no.3
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• pp.131-138
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• 1999

A synergistic effect of biocontrol agent and chemicals on control of the large patch on turfgrass caused by Rhizoctonia solani AG2-2 was evaluated. Chemicals; mepronil, toclofos-methyl and iprodione inhibited 90∼100% mycelial growth of R. solani AG1 and AG2-2 in vitro. While on the other, the chemicals inhibited only 0∼5%, 18∼46% and 30∼67% of mycelial growth of the antagonists, respectively. In field application, toclofos-methyl was the best to suppress the disease in single application, however, the combination of mepronil and T. viride 41D showed highest disease control effect among combinations of antagonists and chemicals. Effect of the combination of mepronil and T. viride 41D was similar to that of toclofos-methyl and T. viride 41D stage of disease development, but became higher in six week late. Results indicated that the combined application of selected antagonistic agent and chemical increased control efficasy of turgrass large patch.

• Journal of Ginseng Research
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• v.29 no.4
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• pp.185-191
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• 2005

In vitro and in vivo effectiveness of fungicides were evaluated for the control of damping off caused by Rhizoctonia solani on Panax ginseng. Fludioxonil(67 mg a. i./L), flutolanil(75 mg a. i./L), thifluzamide(35 mg a. i./L), and mepronil (750 mg a. i./L) were selected from 9 fungicides, which were based on inhibition of mycelial growth of R. solani (isolate Rh 9801) and duration of fungicidal effectiveness against the pathogen in vitro. Field trials were made twice in the year of 2003 and 2004. Experimental plots $(54m{\times}0.9m)$ of 4-year-old ginseng fields were artificially infested with 5kg and 14 kg in fresh weight of inoculum in 2003 and 2004, respectively. The fungicides were drenched at a volume of 8l in $3.6m{\times}0.9m$ with 3 replications. Fludioxonil, flutolanil, thifluzamide and mepronil reduced the incidence of damping off by $73\%,\;69\%,\;69\%\;and\;43\%$, respectively. In the 2004 trial, fludioxonil, flutolanil, and thifluzamide showed similar result as reducing the incidence by $85\%,\;84\%,\;and\;82\%$, respectively, in the plot where the inoculum was applied 2.8 times more than the 2003. The disease incidences in untreated control were $12\%$ in 2003 and $47\%$ in 2004.

• Asian Journal of Turfgrass Science
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• v.11 no.3
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• pp.173-183
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• 1997

This study was conducted to develop an integrated disease management system against large patch disease. Attempts were made to estimate the effect of calcium hydroxide, silicate fertilizer and urea on the mycelial growth of Rhizoctonia sotani AG2-2 and the development of large patch in vitro and in vivo and to establish the most promising combination of fertilizer, fungicide and antagonistic microbes. 1.The mycelial growth of Rhizoctonia sotani AG2-2 were completely inhibited at 2,000, 1,000 and 3,000ppm concentration by calcium hydroxide, silicate fertilizer and urea, respectively. Inhibition effect of silicate fertilizer was the highest, but that of urea was the lowest compared with other treatments. 2.Treatment of calcium hydroxide at rate of l00g /$m^2$ was the most effective, and control effect appeared from 30 days after treatment in spring, which was better in autumn than in spring. Silicate fertilizer treated at rate of l00g /$m^2$, 200g /m$^2$, in spring and 50g /$m^2$ in autumn were very effective. Urea at rate of 30g /$m^2$ was more effective than 60g /m$^2$ and 120g /m$^2$. 3.The efficacies of mepronil and toclofos-methyl, applied twice in spring and once in autumn, were 83.8% in spring, which persisted to 70% in autumn compared with untreated plot. 4.The efficacies of Trichoderma harzianum were the highest by 55% in spring, but those of Bacillus amyloliquefaciens BL-3 and Peudomonas putida were the highest by 80% in autumn among other antagonists tested, when two organisms were applied twice in spring and once in autumn.

• Asian Journal of Turfgrass Science
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• v.13 no.4
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• pp.213-222
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• 1999

The toxic effects of four pesticides on the entomopathogenic nematodes. Heterorhabditis bacteriophora NC strain, Steinernema glaseri NC and Dongrae strain were tested by checking the mortality of infective juveniles(Ijs) in aqueous solution of pesticide. Mortality of Ijs was influenced by pesticide and concentration and soaking time. The herbicide alachlor and insecticide fenitrothion were toxic to Ijc of three entomopathogenic nematodes. But, the fungicides mepronil and tolclofos-methyl were nontoxic to Ijs. Tolclofos-methyl showed significantly very week toxicity at 28 days after soaking for S. glaseri NC strain. H. bacteriophora NC strain was more highly sensitive to high temperature condition then were the other nematodes.

• Asian Journal of Turfgrass Science
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• v.9 no.3
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• pp.199-206
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• 1995

This study is aimed to clarify on the influence of cultivated conditions and fungicides on development of Rhizoetonia diseases of zoysiagrass and creeping bentgrass and results are as follows. Infection rates of disease were observed more serious when inoculum amounts were higher than low. Effects of the watering intervals on the severity of disease with artificial inoculating conditions, infection rates were higher when two days watering interval for creeping bentgrass and one day interval for zoysiagrass. Disease severity of creeping bentgrass incited by Rhizoetonia solani AG 1 (1A) was grater under conditions of double amounts of nitrogen fertilization. A posi- tive correlation was founded between the pH and disease development. The pots with pH 5 and 8 were significantly more diseased grass than those in which the pH was in 6.5. Mepronil and myclobutanil were extremely effective against brown patch of creeping bentgrass and large patch of zoysiagrass and followed by capro, and tebeonazole. Fenari was inferior effect to both diseases.

• Asian Journal of Turfgrass Science
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• v.21 no.2
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• pp.147-154
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• 2007

In March of 2004, gray snow mold (Typhula blight) caused by Typhula spp. occurred on perennial ryegrass (Lolium perenne L.) and Kentucky bluegrass (Poo pratensis L.) at MuJu golf courses in Jeonbuk Province. Leaves in the affected areas were matted together and frequently covered with white to grayish mycelia. Sclerotia were formed on the leaf blade, leaf sheath, or crown regions. The fungus isolated from the diseased leaf formed whitish mycelium, clamp connections, and light pink to brown, irregular-shaped small sclerotia of less than 1.4 mm in diameter, which are characteristic to Typhula incarnata. Optimum temperature ranges for mycelial growth were $5^{\circ}C$ to $15^{\circ}C$. The causal organism was confirmed to be T. incarnata as the partial sequence of its ribosomal RNA ITS1 (internal transcribed spacer) region was 91% homologous to those of T. incarnata in GenBank database. Out of the 14 fungicides tested fur antifungal activity in vitro, 10 fungicides including iprodione, tebuconazole, polyoxin D, flutolanil, hexaconazole, tolclofos-methyl, fosetyl-Al, mepronil, pencycuron+tebuconazole, and fenarimol completely inhibited fungal growth at their recommended concentrations. In the field test, these fungicides and others such as thifluzamide and thiram effectively controlled the gray snow mold of turfgrass with some variable degrees of control efficacies.

• Asian Journal of Turfgrass Science
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• v.15 no.1
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• pp.1-8
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• 2001

Antifungal activity of 20 chemicals registered to turfgrass diseases was evaluated. Among the chemicals, iprodione, benomyl, iprodione+thiram, pencycuron+tebuconazole, hexaconazole, and iprodione+thiophanate-methyl exhibited high antifungal activity to the dollar spot fungus. All isolates were greatly inhibited by the chemicals at the concentration over 32ppm($\mu\textrm{g}$/ml). However, sensitivity of the isolates to chemicals was varied at the lower concentration as 8 and 16 ppm as follows. The isolate originated from Ora golf course was resistant to iprodione and iprodione+thiophanate methyl, Gonjiam isolate to iprodion, Youngpyung isolate to iprodione+thiram, and Dogo isolate to iprodione+thiram, pencycuron+tebuconazole, and tebuconazole. It was found from this study that the varied chemical resistance among the isolates was positively related to the application time of the chemical in the golf course. Consequently, when a chemical was applied more often times than the others to the golf course, the fungal isolates originate from the field showed higher resistance to the former chemical. Effects of the chemicals on control of the dollar spot was evaluated in the field. All tested chemicals revealed over 70% disease control efficacy, however, mepronil+propiconazole was the best showing 83% control efficacy and followed by fenarimo, iprodione, terbuconazole, thiram, and thiophanate-methyl.