• Research in Plant Disease
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• v.19 no.1
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• pp.45-48
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• 2013

Rusts are plant diseases caused by pathogenic fungi of the order Pucciniales. Rusts can affect a variety of plants. Development of new effective and environmentally benign agents against rusts is of great interest. In this study, we investigated the disease control efficacy of the emulsion concentrate (EC10) and wettable powder (WP20) type formulations of the extract of Magnolia officinalis (Magjia90; containing honokiol and magnolol at 90%) against rust diseases of perilla and zoysiagrass in fields. The treatment of EC10 and WP20 of Magjia90 showed control values of 47.9% to 69.6% and Magjia90-WP20 reduced more effectively the development of rust symptoms on perilla plants than Magjia90-EC10. Magjia90-WP20 also highly suppressed zoysiagrass rust with control values of 65.7% to 80.5%. On the other hand, no harmful effect of Magjia90-EC10 and Magjia90-WP20 was observed on the perilla and zoysiagrass plants tested. The results strongly indicate that the extract of M. officinalis (Magjia90) can be used as a natural fungicide for the control of rust diseases.

• Research in Plant Disease
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• v.9 no.3
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• pp.174-178
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• 2003

Pseudomonas sp. antagonistic to Colletotrichum truncatum and C. gloesporioies was selected as a biological control agent for soybean anthracnose. Pseudomonas sp. inhibited the mycelial growth of pathogens effectively as the funhicides such as benomyl and fluazinam in vitro tests without any adverse effects on soybean. Seed treatment with Pseudomonas sp. increased emergence rate of soybean seeds significantly after inoculaton with C. truncatum. When the suspension of Pseudomonas sp. was sprayed on soybean plants, the control efficacy was not different from that of fungicides, benomyl and fluazinam two weeks after treatment, however the efficacy did not last long enough after three weeks.

• Research in Plant Disease
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• v.8 no.4
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• pp.234-238
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• 2002

In vitro and in vivo activities of a biocontrol agent, Bacillus stearothermophilus strain YC4194 was evaluated for the control of Pythium damping-off of cucumber. B. stearothermophilus YC4194 inhibited germination of cystospores and formation of zoosporangia of Pythium aphanidermatum in vitro. Incorporation of a bentonite and talc based formulation(10$^{9}$ cfu/g) of B. stearothermophilus YC4194 to the nursery soils (10 g/ι soil) resulted In a significant (p=0.01) reduction in the disease severity of cucumber damping-off after inoculation with P. aphanidermatum. The control efficacy of B. stearothermophilus YC4194 formulation was not different from that of the fungicides, dimethomorph, metalaxyl, ethaboxam. When the cucumber plants were transplanted to the soil inoculated with P. aphanidermatum zoospores, the B. stearothermophilus YC4194 maintained the high population density in rhizosphere soil upto 10$^{7}$ cfu/g until 15 days after treatment.

• Journal of Bio-Environment Control
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• v.22 no.4
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• pp.413-420
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• 2013

The purpose of this study was to evaluate the control efficacy of major environment-friendly control agents against powdery mildew, as affected by the application condition such as disease-developing stage and microclimate, as compared with the efficacy of pesticides in plug seedling of three Cucurbitaceae vegetables, including cucumber, melon, and oriental melon. Single or combined application of major six environment-friendly control agents was used in the experiment: two biofungicide (Ampelomyces quisqualis 94013 and Bacillus subtilis Y1336), two plant extracts (neem oil and extracts of Rheum undulatum), and two mineral materials (wettable sulfur powder and lime bordeaux mixture). These control agents were treated to the plug seedlings for preventing powdery mildew and curative applications for managing powdery mildew. In all treatments, the disease incidence declined as daily average temperatures increased to $30^{\circ}C$ for consecutive 6~8 days with maximum temperature over $40^{\circ}C$. In preventative application, the control efficacy against powdery mildew was the highest in the treatment of wettable sulfur powder, and lowest in the B. subtilis Y1336, with values of 20~40%. In cucumber seedlings, the preventive single application of neem oil or wettable sulfur powder was more effective than curative application of fungicides, while the control efficacy of these agents was similar to those of fungicides in melon seedlings. The single application of R. undulatum extracts was also effective in preventing the disease for both cucumber and melon seedlings, showing a higher control efficacy than those of biofungicides during seedling stage. The treatment of water spray was not effective and showed a higher disease incidence than the untreated control plot in the oriental melon and melon seedlings. The curative application with environment friendly control agents, after powdery mildew was first detected, could not successfully controlled the disease at the middle stage (5~10% of disease incidence) of disease development. The curative combined application of [R. undulatum extracts (1st application) + wettable sulfur powder (2nd) + neem oil (3rd)] showed the highest control efficacy among the other treatments, with control value over 80% at the early stage (less than 1% of disease incidence) of disease development.

• The Korean Journal of Pesticide Science
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• v.5 no.1
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• pp.61-67
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• 2001

Five hundred sixteen isolates of Botrytis elliptica were isolated from infected leaves of Lilium longiflorum from Kangwon alpine areas in Korea during tile seasons from 1998 to 2000 and resistance of these isolates against some fungicides were examined. The isolation frequency of phenotypes resistant to benomyl, procymidone, and diethofencarb were 90.1, 32.4, and 40.9%, respectively. The isolates were divided into six phenotypic groups; RSS, RRS, SSR, SRR, RSR and RRR, representing sensitive (S) or resistant (R) to benzimidazole, dicarboximide, and N-phenylcarbamate fungicides in order. The percentage of six phenotypes were 40.7, 8.5, 7.2, 2.7, 19.8, and 21.1%, respectively. The RSS phenotype was the most frequently isolated, and tile SRR consisted of the extremely minor populations. In comparison studies on tile overwintering ability of each phenotype in relation to the others, the most frequently isolated RSS and SSR had the higher fitness ability than the less frequently isolated RSR, SRR, and RRR. Recently, population increase of tile RSR and RRR phenotypes may have resulted from the increased applications of the mixture of carbendazim and diethofencarb to control benzimidazole-resistant B. elliptica since 1998. The results of this study indicate that careful application of the fungicides is necessary to achieve effective control of leaf blight on lily in Korea.

• Korean journal of applied entomology
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• v.11 no.2
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• pp.101-107
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• 1972

This experiment was conducted in order to determine the fungi associated with ear blight of rice and their chemical control. 1, Pyricularia oryzes, Helminthosporium oryzne, Epicoccum purpurascens, Curvularia lunata, Cladosporium cladosporoides and Alternaria tenuis et al. were mainly detected in large quantities from the discolored seeds of recommended varieties but Trichoconis padwickii, Fusarium dimerum, and Nigrospora oryzae were mainly detected from Tongil. 2. Pyricularia oryzae, Nigrospora oryzae, and Curvularia lunate et at. were from the necks; Helminthosporium oryzae, Trichoconis padwickii, Stemphylium sp. , Cladosporium cladosporoides, and Alternaria tenuis et at. were from the branches of ear; and Phoma spp. was mainly detected from the kernels. 3. In the laboratory Difolatan WP $0.13\%$ gave good control of Helminthosporium oryzae, Cladosporium cladosporoides, and Alternaria tenuis, et al.; and Dithane M-45 WP $0.2\% gave especially good control of Pyricularia oryzae, Trichoconis padwickii, and Curvularia lunate. 4. In field experiments, the appropriate date of chemical spray was milk ripening stage or panicle emergence stage. Under these conditions Hinosan Ec and Kasugamin Ec were more effective than Difolatan WP and Dithane M-45 WP. However, the assessment of ear blight was complicated by a severe outbreak of neck blast.

• Applied Biological Chemistry
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• v.47 no.3
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• pp.339-343
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• 2004

Anionic surfactants such as sodium dioctyl sulfosuccinate (SDSS) and sodium dodecylbenzene sulfonate (NaDBS) and a nonionic surfactant, polyoxyethylene oleyl ether (OE-7) were tested for their protective, curative, and persistent activities on tomato late blight (TLB, Phytophthora infestans), red pepper blight (RPB, P. capsici), and cucumber downy mildew (CDM, Pseudoperonospora cubensis). They exhibited a strong protective activity on TLB, RPB, and CDM. Among them, $NaDBS\;(500\;{\mu}g/ml)$ showed the most in vivo antifungal activities(1-day protective activity) with control values of 99%, 100%, and 85% against TLB, RPB, and CDM, respectively. However, the three surfactants represented a weak disease controlling efficacy on TLB, RPD, and CDM in a 1-day curative application. SDSS and NaDBS exhibited a good persistent activities on TLB and RPB. Especially, NaDBS, at $500\;{\mu}g/ml$, showed control values of more than 88% on TLB and RPB in a 7-day protective application. The results indicate SDSS and NaDBS have a potential for the control of TLB, RPB, and CDM in the fields.

• The Korean Journal of Pesticide Science
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• v.8 no.1
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• pp.71-78
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• 2004

A promising hyperparasite, Ampelomyces quisqualis 94013(AQ94013) was selected as a biological control agent to cucumber powdery mildew caused by Sphaerotheca fusca. Effect of agrochemicals on mycelium growth and spore germination of AQ94013 and effect of spread stickers on hyperparasitical activity of AQ94013 to powdery mildew pathogen were evaluated. Finally it was confirmed that mycelial growth and spore germination of AQ94013 on potato dextrose agar amended with two fungicides for controlling powdery mildew, triadimefon and pyrazophos; five fungicides for controlling downy mildew, dimethomorph, kasugamycin+copper oxychloride, dichlofluanid+copper oxychloride and tribasic copper sulfate; three fungicides for controlling gray mold, iprodione, vinclozolin and procymidone; and six insecticides immidacloprid, teflubenzuron, bifenthrin, ethofenprox, deltamethrin and phenthoate were slightly reduced. Addition of mineral oil in the spore suspension of AQ94013 enhanced 7.9% control value to cucumber powdery mildew.

• Asian Journal of Turfgrass Science
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• v.25 no.2
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• pp.237-242
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• 2011

The 2011 Japanese Society of Turfgrass Science was divided in oral presentation, sectional meeting and small symposium, and the total 55 subject was announced. The oral presentation was reported physiological ecology of turf, disease and weed; field management; pesticidal activity and spectrum of new turf pesticides. Above all, there was presentation that investigated control method of necrotic ring spot of new turf disease and Cyperus brevifolius, annual bluegrass and mouse-ear chickweed. In addition, the control effect of new registration fungicide (Furametpyr) and herbicides (S-metolachlor, Flucetosulfuron and Foramsulfuron) were announced. There was various information interchange through 4 kinds of subjects of a golf course, ground turf, a urban park greens and ground cover plants greening by the sectional meeting, and the genetic resource of turfgrass discussed by small symposium. Specially, park greens sectional meeting was announced about the radioactive material contaminated on mechanism and effectively removal method of the radioactivity contaminant from public park, school ground and domestic lawn.

• Korean Journal Plant Pathology
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• v.12 no.3
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• pp.307-315
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• 1996

토마토 잎에 집적된 triflumizole 잔류량 동태에 미치는 온도 영향과 Cladosporium fulvum에 대한 triflumizole의 살균효과를 구명하였다. 8주간 키운 토마토 식물체에 triflumizole을 분무 살포한 후 식물생장용 항온실에서 키우면서 4가지 온도 조건을 처리하였다. 주기적으로 토마토 잎을 채취하여 HPLC 방법을 이용하여 triflumizole의 잔류량을 조사하였다. Triflumizole 잔류량의 경시적 동태는 약제살포후 적산온도를 독립변수로 사용하는 지수적 감소 몸형으로 나타낼수 있었으며, 이는 triflumizole의 잔류성이 온도 영향을 크게 받는다는 것을 뜻한다. 경기도 농촌진흥원에 위치한 토마토 비닐하우스에서 수행한 실험에서 얻은 자료를 이용하여 평가한 결과 이 모형의 타당성이 인정되었다. Triflumizole의 약효에 대한 in vitro 실험 결과, 이 살균제는 C. fulvum의 균사 생장과 포자형성을 뚜렷이 억제하였으며, 잎곰팡이병 방제를 위해서는 토마토 잎에 집적된 triflumizole 잔류량이 최소한 10 ppm 이상이 되어야 할 것으로 추측된다. 본 연구에서 연구된 지수적 감소 모형은 토마토 잎에 집적된 triflumizole 잔류량을 추정하는데 활용될 수 있으며, 실용적인 측면에서 볼 때, 토마토 잎곰팡이병을 효과적으로 방제하는데 필요한 triflumizole의 최소 잔류량을 식물체에 유지하기 위하여 triflumizole을 살포해야 할 시기를 결정하는데 활용될 수 있다.