• Korean Journal Plant Pathology
• /
• v.1 no.2
• /
• pp.128-135
• /
• 1985

Responses to the 14 fungicides added in PSA of penicillium expansum isolated froms the four major apple growing areas in Korea were examined. Degrees of the fungal tolerance were various with little difference by area and with great difference by kind and concentration of fungicide. Fall isolates of the fungus grew at higher fungicide concentration than did the spring isolates. $ED_{50}$ and MIC to mycelial growth of genomyl, garbenda, polydong, polyoxin and thiophanate methyl were $0.1{\mu}g-41.7{\mu}g/ml\;and\;100{\mu}g-2,250{\mu}g/ml,$, respectively, indicating high fungicide effects on the fungus isolated from decayed apples in storages and infected apples in orchards with low fungal tolerance; of captafol, captan, iprodione and mancozeb were $2.6{\mu}g - 750{\mu}g/ml\;and\;638{\mu}g-40,500{\mu}g/ml$, respectively, indicating medium degree of both fungicidal effects and fungal tolerance; and of chlorothalonil, folpet, oxidong, propineb and triademefon were $27.8{\mu}g-8,354{\mu}g/ml\;and\;2,625{\mu}g-150,357{\mu}g/ml$, respectively, indicating low fungicide effects and high fungal tolerance. Fungicidal inhibitory effects on conidia formation exhibited a similar trend as on mycelial growth whereas those on conidia germination showed an opposite trend to the mycelial growth with the exception of polyoxin and triademefon.

• Korean Journal of Food Science and Technology
• /
• v.36 no.1
• /
• pp.50-57
• /
• 2004

Selection of yeast strains, optimum conditions for alcohol fermentation, sterilization methods, and additives for improving wine quality were investigated to manufacture watermelon wine. Eight yeast strains exhibited significant alcohol fermentation, among which KWS 06 was selected for watermelon wine fermentation, because watermelon wine made by this strain showed the best overall acceptability in sensory evaluation. Sucrose was determined as the best saccharide for alcohol fermentation among sucrose, corn syrup, glucose, fructose, and lactose. Optimum concentration of soluble solid and $(NH_{4})_{2}HPO_{4}$ of nitrogen source were $24^{\circ}Brix and 0.2%, respectively. Addition of raspberries and omija increased wine flavor and alcohol production, respectively, with optimum alcohol production, taste, and color achieved with addition of 20 g/L raspberries and 10 g/L omija. Best sensory quality was obtained by addition of 0.04 % watermelon flavorant to the juice.

• Food Science and Preservation
• /
• v.24 no.2
• /
• pp.312-319
• /
• 2017

In the present study, disinfection efficacy of slightly acidic electrolyzed water [SlAEW, 30 ppm of effective chlorine at $20{\pm}1^{\circ}C$, oxidation-reduction potential (ORP) $562{\pm}23mV$, pH 6.4] on 4 kinds of vegetables (lettuce leaf, endive leaf, perilla leaf and kale leaf) was evaluated to obtain a microbial reduction characteristics which are necessary to design a process control for non-thermal sterilization of fresh vegetables. Active chlorine, residual chlorine, microbial counts and residual microbial counts, which are the key factors in the non-thermal sterilization process were measured by dipping them in SlAEW three times for 30 minutes in order to analyze the relationship between factors. Total microbial count was decreased mostly during the first 10 minutes of washing, and the limit value that can be reduced by immersion treatment was 3 log CFU/g for the total microbial count surviving in 4 kinds of vegetables. The total number of microorganism that can be reduced by washing in SIAEW for 10 min was found to be about 2 log CFU/g on average. In addition, the active chlorine decreased in the initial 10 minutes in 2.2 ppm, 2.0 ppm, 1.7 ppm and 2.5 ppm in lettuce, perilla leaf, endive leaf and kale leaf, respectively, and about 50-80% of the chlorine was reduced in the initial 10 min appear.

• The Korean Journal of Pesticide Science
• /
• v.18 no.4
• /
• pp.409-416
• /
• 2014

This study was conducted to reduce the using amount of chemical fungicides for the control of red-pepper powdery mildew. Effect of combined application of three microbial fungicides and six chemical fungicides for the control of red-pepper powdery mildew was examined in vitro, in pot assay and under field condition. One chemical fungicide (Azoxystrobin+Chlorothalonil) among six chemical fungicides significantly suppressed three microbial fungicides (Bacillus subtilis Y1336, Bacillus subtilis DBB1501, Bacillus subtilis QST-713) registered for the control of pepper powdery mildew in vitro. In the pot assay, two mixed application such as B. subtilis DBB1501+Trifloxystrobin, B. subtilis QST713+Trifloxystrobin among nine mixed applications of three microbial fungicides and three chemical fungicides showed the highest suppressive effect against red pepper powdery mildew. Also, suppressive effect of the mixed application of B. subtilis QST713 and Trifloxystrobin was similar to that of single application of three chemical fungicides(Myclobutanil, Trifloxystrobin, Hexaconazole). In the field test, when the microbial fungicides (B. subtilis DBB1501, B. subtilis QST713) and the chemical fungicide (Trifloxystrobin) for the control of powdery mildew of red pepper were mixed foliar sprayed four times at 7 day-intervals, the control values were in the range of 70.3% to 70.9%. On the other hand, when each of the chemical fungicide (Trifloxystrobin) was foliar sprayed four times at 7 day-intervals, the control value was 72.7%. Consequently, the mixed application of the microbial fungicides and chemical fungicides could be recommended as a one of control measures for reducing the using amount of chemical fungicides.

• Research in Plant Disease
• /
• v.23 no.3
• /
• pp.268-277
• /
• 2017

Fusarium head bight (FHB) is a devastating disease on major cereal crops worldwide which causes primarily by Fusarium graminearum. Synthetic fungicides are generally used in conventional agriculture to control FHB. Their prolonged usage has led to environmental issues and human health problems. This has prompted interest in developing environmentally friendly biofungicides, including botanical fungicides. In this study, a total 100 plant extracts were tested for antifungal activity against F. graminearum. The crude extract of Pterocarpus santalinus heartwood showed the strongest antifungal activity and contained two antifungal metabolites which were identified as ${\alpha}$-cedrol and widdrol by GC-MS analysis. ${\alpha}$-Cedrol and widdrol isolated from P. santalinus heartwood extract had 31.25 mg/l and 125 mg/l of minimal inhibitory concentration against the spore germination of F. graminearum, and also showed broad spectrum antifungal activities against various plant pathogens. In addition, the wettable powder type formulation of heartwood extract of P. santalinus decreased FHB incidence in dose-dependent manner and suppressed the development of FHB with control values of 87.2% at 250-fold dilution, similar to that of chemical fungicide (92.6% at 2,000-fold dilution). This study suggests that the heartwood extract of P. santalinus could be used as an effective biofungicide for the control of FHB.

• Journal of Food Hygiene and Safety
• /
• v.31 no.3
• /
• pp.216-221
• /
• 2016

This study was performed to evaluate the bactericidal efficacy of a fumigation disinfectant containing 35% paraformaldehyde against Salmonella Typhimurium (S. Typhimurium). In this study, the efficacy test of a fumigant against S. Typhimurium was carried out according to French standard NF T 72-281. The S. Typhimurium working culture suspension number (N value), all bacteria numbers on the carriers exposed to the fumigant (n1, n2, and n3), the number of bacterial suspensions by the pour plate method (N1), the number of bacterial suspensions by the filter membrane method (N2), and the mean number of bacteria recovered on the control carriers (T value), were obtained from the preliminary test. In addition, the reduction number of S. Typhimurium exposed to the fumigant (d value) was calculated using the T value, the mean number of bacteria in the recovery solution (n'1) and the mean number of bacteria on carriers plated in agar (n'2). The N value was $5.5{\times}10^8$ colony forming units (CFU)/mL, and n1, n2, and n3 were higher than 0.5N1, 0.5N2 and 0.5N1, respectively. Additionally, the T value was $3.5{\times}10^6CFU/carrier$. In terms of the bactericidal effect of the fumigant, the d value was 5.25. According to the French standard for fumigants, the d value for an effective bactericidal fumigant should be greater than 5. The results indicated that the fumigant containing 35% paraformaldehyde had an efficient bactericidal activity against S. Typhimurium, and, therefore, can be used to disinfect food materials and kitchen appliances contaminated with foodborne bacteria.

• Applied Biological Chemistry
• /
• v.29 no.2
• /
• pp.164-174
• /
• 1986

도열병균에 의한 벼의 목 및 잎도열병에 효과가 좋은 새로운 살균제의 개발을 시도하였다. 농약으로 예상되는 몇몇 3-oxo-1, 2-benzisothiazole-1, 1-dioxide의 새로운 유도체들을 합성하고, 이들 유도체들의 도열병균 (Pyricularia oryzae)에 대한 항균성을 agar medium dilution 방법에 의해 측정하였다. 3-oxo-1, 2-benzisothiazole-1, 1-dioxide의 5 원자 고리의 3개 구조 단위중에서 가장 항균성이 큰 단위는 $R-S-C=N-SO_2-$단위이며, 3개 구조 단위의 항균성 순서는 $RS-C=N-SO_2-\;{\geq}\;RO-C=N-SO_2-\;>\;-CNR-SO_2-$였다. 30개 후보화합물 가운데서 14개의 유도체가 도열병균에 효능이 좋은 것으로 알려진 oryzemate 보다 우수한 항균성을 나타냈다.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.37 no.10
• /
• pp.1337-1342
• /
• 2008

This study was conducted to investigate effects of chemical sanitizers on inhibiting foodborne pathogens, such as Listeria monocytogenes (L. monocytogenes), Salmonella Typhimurium (S. Typhimurium), and E scherichia coli O157:H7 (E. coli O157:H7), on cabbages. Cabbages were inoculated with the culture cocktail of pathogens and treated with water, 100 ppm commercial chlorine, and 50, 100, and 200 ppm chlorine dioxide ($ClO_2$) for 1, 5, and 10 min at room temperature ($22{\pm}2^{\circ}C$). Treatments with water did not significantly reduce levels of three pathogens whereas other treatments with chemical sanitizers significantly reduced levels of three pathogens. Treatment with 200 ppm $ClO_2$ for 10 min was the most effective at inhibiting pathogens and reduction levels were 1.90, 1.92, and 1.98 log CFU/g for L. monocytogens, S. Typhimurium, and E. coli O157:H7, respectively. Levels of reduction were increased with the increase of $ClO_2$ concentrations. When chemically injured cells were investigated, there were no significant differences on the levels of injured cells between before and after treatment with commercial chlorine and $ClO_2$. These results suggest that $ClO_2$ can be used as an alternative sanitizer for reducing pathogens on fresh produces.

• Research in Plant Disease
• /
• v.14 no.2
• /
• pp.102-106
• /
• 2008

The single application of Bacillus subtilis QST713(BS QST713) mixed application with fungicides and alternate application were treated to examine the control of alternaria leaf blight of Panax ginseng. Control value of alternaria leaf blight by single application of BS QST713 at 10 days interval was 83.3%, and those of single application at 10 days interval was $80.4{\sim}83.7%$ by azoxystrobin, chlorothalonil copper sulfate basic, copper sulfate basic, kresoxim-methyl, difenoconazole, mancozeb. When mixture of BS QST713 and fungicides were applied at 14 days interval, the control value of alternaria leaf blight were 83.6% by BS QST713 and mancozeb, and 82.6% by BS QST713 and azoxystrobin. However, mixture of BS QST713 with difenoconazole, kresoxim-methyl, copper sulfate basic and chlorothalonil copper sulfate basic exhibited the disease control values from 61.1% to 76.4%, which showed slightly lower control efficacy. In Daejeon, the alternate application of BS QST713 followed by copper sulfate basic with 14 days interval was 85.9% in control value, which showed the best control efficacy. The alternate application with other tested fungicides slightly decreased to $55.5{\sim}78.2%$ in control value. However, the alternate application of BS QST713 followed by fungicides showed very high control efficacy, which were approximately 90% in Muju, Jeonbuk Province. Consequently, the single, mixed or alternate application of BS QST713 and fungicides could be recommended as a control method to reduce the amount of fungicides.

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