• Korean Journal of Medicinal Crop Science
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• v.22 no.6
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• pp.483-488
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• 2014

Lime-bordeaux mixture (LBM) has been used instead of pesticides in ginseng field and orchard since the 1960's in Korea. In this experiment, LBM was made with different concentrations and sprayed in the field of ginseng for eco-friendly cultivation. Growth characteristics and disease such as alternaria blight, anthracnose, and gray mold were investigated in 4-5 year old ginseng after spraying LBM. LBM caused a little damage on leaf when it was sprayed at the time of leafing stage, late April and early May. Root weights of five-year-old ginseng were 43.1~51.5 g and 41.2~46.6 g in the plot of mid-April and mid-May treatments, respectively. These growth levels were further reduced as compared with that of the chemicals treatment plot. The rate of diseases in the plot of 6-6 and 8-8 ratio were 0.0~4.8% and 0.0~4.4%, respectively, which was similar with that in the plot of chemical control for alternaria blight and anthracnose. However, LBM had little effect on controling gray mold. It showed lower control effect in the plot of 4-4 ratio than that of chemical control. This result will be expected to be a useful guide that can be used in the field to the farmers of the ginseng.

• Research in Plant Disease
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• v.15 no.2
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• pp.127-129
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• 2009

Gray mold caused by Botrytis cinerea occurred on Astragalus sinicus in an experimetal rice field of Gyeongsangnam-do Agricultural Research and Extension Services in Korea from 2008 to 2009. The symptoms appeared on the leaves, petiole and stems of infected plants. and then started with water-soaked, rotted and eventually died blight on plants. The colony were grayish brown and the optimum temperature for sclerotial formation was $20^{\circ}C$ on potato dextrose agar. The conidia were one celled, mostly ellipsoid or ovoid in shape, and were colorless or pale brown in color. The conidia were $7{\sim}16{\times}5{\sim}10{\mu}m$ in size and conidiophores were $14{\sim}28{\mu}m$ in length. On the basis of mycological characteristics and pathogenicity test on host plants, the fungus was identified as Botrytis cinerea Persoon: Fries.

• Korean Journal of Organic Agriculture
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• v.21 no.3
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• pp.373-380
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• 2013

A severe pink mold rot on matured asian pear (Pyrus serotina Rehder) fruit occurred in the organic farmers' orchard in Jinju, Korea in October, 2012. Decay of pear fruit appeared as a softened water-soaked symptom that was easily punctured by pressure. Later pink mycelium appeared on the surface of pear fruit and produced a mass of powdery pink conidia spores. Optimum temperature for mycelial growth of T. roseum was $25^{\circ}C$. Conidia showed hyaline, smooth, 2-celled, thick-walled with truncate bases, ellipsoidal to pyriform, and characteristically held together zig-zag chains and $10{\sim}22(34){\times}6{\sim}10(12){\mu}m$ in size. Conidiophore was erect, colorless, unbranched type, and 4-5 ${\mu}m$ width. On the basis of mycological characteristics, pathogenicity test, and molecular identification with the ITS region, the causal fungus was identified as Trichothecium roseum (Pers.) Link ex Gray.

• The Korean Journal of Pesticide Science
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• v.11 no.3
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• pp.138-143
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• 2007

The relationships between three dimensional quantitative structure and activity relationships (3D-QSARs) for the selective fungicidal function between N-phenyl substituents of N-phenyl-O-phenyl-thionocarbamate derivatives analogues and their the fungicidal activities against resistant (RBC) and sensitive (SBC) gray mold (Botrytis cinerea) were studied quantitatively using CoMFA and CoMSIA methods. The statistical values of optimized CoMSIA (M7) model were better ($r^2$ & $q^2=CoMSIA{\gg}CoMFA$) than that of CoMFA (M5) model. And the factor influencing of the selective between the fungicidal activity against RBC and SBC was dependent on electrostatic field of CoMFA (M5) model. Therefore, it is predicted that, from the CoMSIA contour maps of CoMSIA (M7) model, the selectivity will be improved by the H-bond donor that is with negatively charged favored group at meta-position on the N-phenyl ring.

• The Plant Pathology Journal
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• v.36 no.6
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• pp.579-590
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• 2020

Botrytis cinerea, which causes gray mold disease in more than 200 plant species, is an economically important pathogen that is mainly controlled by synthetic fungicides. Synergistic fungicide mixtures can help reduce fungicide residues in the environment and mitigate the development of fungicide-resistant strains. In this study, we screened microbial culture extracts on Botrytis cinerea to identify an antifungal synergist for tebuconazole. Among the 4,006 microbial extracts screened in this study, the culture extract from Schizophyllum commune displayed the most enhanced activity with a sub-lethal dosage of tebuconazole, and the active ingredient was identified as schizostatin. In combination with 5 ㎍/ml tebuconazole, schizostatin (1 ㎍/ml) showed disease control efficacy against gray mold on tomato leaf similar to that achieved with 20 ㎍/ml tebuconazole treatment alone. Interestingly, schizostatin showed demethylation inhibitor (DMI)-specific synergistic interactions in the crossed-paper strip assay using commercial fungicides. In a checkerboard assay with schizostatin and DMIs, the fractional inhibitory concentration values were 0.0938-0.375. To assess the molecular mechanisms underlying this synergism, the transcription levels of the ergosterol biosynthetic genes were observed in response to DMIs, schizostatin, and their mixtures. Treatment with DMIs increased the erg11 (the target gene of DMI fungicides) expression level 15.4-56.6-fold. However, treatment with a mixture of schizostatin and DMIs evidently reverted erg11 transcription levels to the pre-DMI treatment levels. These results show the potential of schizostatin as a natural antifungal synergist that can reduce the dose of DMIs applied in the field without compromising the disease control efficacy of the fungicides.

• The Korean Journal of Pesticide Science
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• v.16 no.4
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• pp.364-368
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• 2012

In vivo experiments were carried out to investigate the effect of microbial agents on tomato disease occurrences in a sustainable tomato farm in Gong-ju, Chung-nam during 2 years (2010-2011). Two kind of commercial microbial agents (EXTN-1 and Cillus suspension concentrate) and 2 kind of microbial agents (Bacillus subtilis strain 'B4' and 'B17') developing by National academy of agricultural science were used in this study. In the 1st experimental year, the microbial agents were sprayed on leaves for 2-4 times at 1-2 weeks interval from 3 weeks after transplanting, and then disease occurrence were observed. As a result, the control efficacies of commercial EXTN-1 and Cillus suspension concentrate (SC) against gray mold were 59.6% and 50.5% in the treatment of 4 times foliar application at 1 week interval from 3 weeks after transplanting, and the control efficacy of commercial EXTN-1 SC against gray mold was 55.4% in the treatment of 3 times foliar application at 1 week interval from 4 weeks after transplanting. However, the control efficacies of EXTN-1 and Cillus SC were not enough for tomato crop protection against powdery mildew. In the 2nd experimental year, the microbial agents were treated following by the planned combination schedule of transplanting stage drip-watering, early stage root irrigation and early blooming stage foliar application. The control efficacies of EXTN-1 SC and B17 treatment following by transplanting stage drip-watering, 2 times root irrigation at 2 weeks interval root irrigation and 4 times foliar application at 1 weeks interval for gray mold management were 57.0 and 55.1%, respectively. In the case of same treatment for gray mold management mentioned at above, the control efficacies of EXTN-1 SC, B4 and B17 treatment for powdery mildew management were 50.5, 51.3 and 52.5%, respectively.

• Research in Plant Disease
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• v.8 no.3
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• pp.184-188
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• 2002

An antagonistic bacteria, Bacillus licheniformis Nl strain which effectively inhibited mycelial growth of gray mold rot pathogen, Botrytis cinerea was isolated from the rhizosphere of perilla crop. Powder soy formulation by B. lichentfomis Nl strain as a biocontrol agent was developed far the first time and estimated its control effect on perilla leaves in this study. First of all, far the mass production of antifungal metabolites of B. lichentfomis Nl strain in flask liquid culture, the most effective carbon and nitrogen source were selected as glucose and tryp-tone, respectively, For the formulation, vegetative biomass of B. licheniformis Nl strain from 5-day-old liquid culture in nutrient broth added glucose and tryptone was mixed with soy flour, rice flour glucose, FeSo$_4$~7$H_2O$, and MnCl$_2$. 4$H_2O$, and dried and pulverized. In plastic house test, powder soy formulation effectually controlled gray mold rot as the control value of 93.1 %, was more effective than chemical fungicide, benomyl showing the control value of 86.1%. Thus, development of powder soy formulation of B. lichentfomis Nl will aid large-scale application of biological control in field trials.

• Research in Plant Disease
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• v.10 no.4
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• pp.319-323
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• 2004

This study was conducted to investigate the effect of U. atrum treatment on control of Botrytis leaf blight of lily and Botrytis gray mold of cucumber, and to evaluate the U. atrum as the biological control agent of Botrytis diseases. The antagonistic isolates CNU 9037 and CNU 9054 isolated from tomato leaves were identified as Ulocladium atrum Preuss based on morphological characteristics. This is the first record of U. atrum in Korea. In bioassays on dead leaves of tomato and cucumber, treatment of U. atrum colonized the dead leaves and suppressed sporulation of Botrytis as compared with the untreated control. The suppression of spoulation of Botrytis on dead leaf segments by U. atrum was higher when U. atrum was treated before Botrytis was treated. The effect of treatments with conidial suspension of U. atrum on leaf blight of lily and gray mold of cucumber caused by Botrytis elliptica and B. cinerea, respectively, was investigated under greenhouse conditions. Spraying U. atrum ($1{\times}10^6$ conidia per ml) at intervals of 1 week for three times resulted in a significant reduction of natural infections of lily leaves caused by B. elliptica. Protective value of U. atrum treatment was higher than that of the fungicide (procymidone) treatment. Spraying U. atrum also resulted in a significant reduction of cucumber gray mold caused by B. cinerea. Our results show that U. atrum has a potential for biological control against diseases caused by Botrytis spp, in lily and cucumber.

• Research in Plant Disease
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• v.16 no.3
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• pp.316-319
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• 2010

The gray mold disease occurred on tuberous roots of yacon in storage facilities in Gangneung, Korea, in March 2010. Symptoms typically appeared as in the form of dark brown discoloration on the surface of tuberous roots and water-soaked brown lesions in cross sections of the affected portions. A total of five isolates of Botrytis sp. were obtained from the symptomatic portions. All isolates on potato-dextrose agar (PDA) produced abundant conidia which were pale brown, one-celled, mostly ellipsoid or ovoid in shape and $8.2{\sim}14.8{\times}6.5{\sim}9.9\;{\mu}m$ in size. Large numbers of round to irregular, smooth, black, hard sclerotia were produced on PDA over time. The optimal temperature for mycelial growth and sclerotia formation of the fungal isolates was $20^{\circ}C$. On the basis of morphological and cultural characteristics, all the fungal isolates were identified as Botrytis cinerea. Pathogenicity test on host plants showed that the fungus could infect not only tuberous roots but also leaves and petioles of yacon. This is the first report on gray mold of yacon (Smallanthus sonchifolius) caused by Botrytis cinerea in Korea.

• Research in Plant Disease
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• v.10 no.3
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• pp.159-166
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• 2004

This study were carried out to identify pathogens and determine the seasonal occurrence and chemical control of safflower (Carthamus tinctorius) diseases from 2000 to 2002 in Gyengbuk province, Korea. Major diseases of safflower were, anthracnose caused by Colletotricum acutatum in open field, and gray mold by Botrytis cinerea in rain sheltered plastic house. Other diseases occurred were powdery mildew caused by Sphaerotheca fuliginea, collar rot by Sclerotium rolfsii, leaf spot by Alternaria carthami and A. alternata, rust by Puccinia carthami, root-rot and stem-rot by Phytophthora cactorum, root-rot and wilt by Fusarium oxysporum and damping-off by Pythium ultimum. Seasonal occurrence of anthracnose on safflower has begun from late April, and increased until harvesting, especially rapid increased after rainfall during stem elongation season that is from May to June. In open fields, maximum incidence of anthracnose was 67 ％ in late July. But in rain-sheltered plastic house, it was very low, about 5％ in July. Gray mold caused by Botrytis cinerea was most important disease in rain-sheltered plastic house cultivation. Maximum incidence of gray mold on floral head was 27.4％, whereas other diseases occurred below 1 ％. In the test of the chemical control of the safflower anthracnose, metiram WP, carbendazim$.$kasugamycin WP and iminoctadintris$.$thiram WP were the highest controlling chemicals. In chemical control of gray mold, iminoctadintris$.$thiram WP, fluazinam WP and iprodion WP showed highest controlling effects.