• Korean Journal of Agricultural Science
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• v.46 no.1
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• pp.103-111
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• 2019

Gray mold caused by Botrytis cinerea on strawberry plants is an economically significant disease in Korea. The rates for diseased fruits are high during the strawberry harvesting period from December to February, especially in hydroponic cultivation. This study assessed the effect of the nitrogen type in the soil culture and the electrical conductivity (EC) of the nutrient solution in a hydroponic culture on the gray mold incidence in 'Seolhyang' strawberry plants. The nitrogen sources assayed included calcium nitrate tetrahydrate (CN4), calcium nitrate decahydrate (CN10), ammonium sulfate (AS), and commercial fertilizer 213 (213). The effect of the EC was tested at 0.5, 0.8, 1.0, and $1.5dS{\cdot}m^{-1}$. The occurrence of gray mold varied according to the nitrogen type. The disease incidence and nitrogen content for the main nitrogen type were higher compared to the non-treated control. The AS treatment showed the highest occurrence of tipburn and gray mold. The incidence of gray mold as well as the nitrogen and phosphorus content of the leaves increased as the EC level was increased. These results indicate that the incidence of gray mold in strawberry plants is related to the nitrogen content of the leaf and the EC of the nutrient solution.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.98.1-98
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• 2003

Antagonistic effect of bacterial strains isolated from phylloplane of strawberry plants grown In greenhouse was tested on Botrytis cinerea Among the promising bacterial strains, Bacillus sp. S1-0210 showed highest inhibition of mycelial growth of B. cinerea and a broad spectrum of antifungal activities against many plant pathogenic fungi in vitro. Bacillus sp. S1-0210 was identified as Bacillus subtilis based on the analysis of 185 rDNA as well as its biochemical characteristics. Application of wettable powder formulation of B. subtiiis S1-0210 significantly reduced the incidence of gray mold on trawberry fruits during storage. Results showed that treatment of B. subtilis S1-0210 decreased the incidence of gray mold by 4.8％ whereas the incidence in control was 77.9％, indicating that the formulation of B. subtilis S1-0210 will be practically applied on strawberry fruits as a biocontrol agent of gray mold during storage.

• The Plant Pathology Journal
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• v.30 no.1
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• pp.90-95
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• 2014

This study was conducted to evaluate the resistance of 212 accessions of lettuce germplasm to gray mold disease caused by Botrytis cinerea. The lettuce germplasm were composed of five species: Lactuca sativa (193 accessions), L. sativa var. longifolia (2 accessions), L. sativa var. crispa (2 accessions), L. saligna (2 accessions), and L. serriola (1 accession); majority of these originated from Korea, Netherlands, USA, Russia, and Bulgaria. After 35 days of spray inoculation with conidial suspension ($3{\times}10^7$ conidia/ml) of B. cinerea on the surface of lettuce leaves, tested lettuce germplasm showed severe symptoms of gray mold disease. There were 208 susceptible accessions to B. cinerea counted with 100% of disease incidence and four resistant accessions, IT908801, K000598, K000599, and K021055. Two moderately resistant accessions of L. sativa, K021055 and IT908801, showed 20% of disease incidence of gray mold disease at 45 days after inoculation; and two accessions of L. saligna, K000598 and K000599, which are wild relatives of lettuce germplasm with loose-leaf type, showed complete resistance to B. cinerea. These four accessions are candidates for breeding lettuce cultivars resistant to gray mold disease.

• The Korean Journal of Pesticide Science
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• v.19 no.3
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• pp.295-300
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• 2015

Currently, amount of export strawberry has been continuously increased to ship many south Asia countries, including Hong Kong and Singapore. In the distribution process, significant damage to the quality has been caused depending on the environmental conditions. Gray mold disease caused by Botrytis cinerea has been known as major damage to the export strawberry, and the disease was caused during shipping and distribution to the final consumers. This study was performed to assess the relationship between pathogen density in packing shed and disease incidence of gray mold during storage period. Maximum gray mold disease incidence in storage period was up to 16% with low temperature condition ($4^{\circ}C$). At room temperature condition, the disease incidence reached up to 100% even densities of the pathogen spore were recorded relatively low in the packing shed. As results of the study, the correlation between pathogen density in the air and disease occurrence clearly clarified.

• Research in Plant Disease
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• v.29 no.3
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• pp.295-298
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• 2023

During a disease survey conducted in April 2022, we observed severe gray mold symptoms on inflorescences of mango trees (Mangifera indica) grown in a vinyl greenhouse in Jeju, Korea. The symptoms occurred on the flowers and peduncles, on which a lot of gray molds were formed. The incidence of gray mold on the inflorescences in the vinyl greenhouse ranged from 10% to 40%. Three fungal isolates were obtained from the lesions and identified as Botrytis cinerea based on their morphological characteristics and phylogenetic analysis. All isolates of B. cinerea were tested for their pathogenicity to inflorescences of mango trees through artificial inoculation. The pathogenicity of the isolates was confirmed on the flowers and peduncles. The symptoms induced by the isolates were similar to those on the inflorescences of mango trees observed in the disease survey. This is the first report of B. cinerea causing gray mold in mango in Korea.

• The Korean Journal of Mycology
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• v.51 no.4
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• pp.259-263
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• 2023

During crop disease surveys in 2019 and 2021, we observed gray mold symptoms on the leaves of wasabi (Eutrema japonicum) plants grown in vinyl greenhouses in Taebaek and Pyeongchang, Gangwon Province, Korea. The symptoms appeared at the edges of the leaves, where the infected areas turned black and rotted, and many gray molds formed on the lesions. The incidence of gray mold on the leaves in the vinyl greenhouses at the two locations ranged from 1 to 30%. Four fungal isolates were obtained from leaf lesions and identified as Botrytis cinerea based on morphological characteristics and phylogenetic analysis. Two isolates of B. cinerea were used for pathogenicity tests on the leaves of wasabi plants by artificial inoculation. The pathogenicity of the isolates was confirmed in leaves. The symptoms induced by the isolates were similar to those observed in wasabi leaves in the vinyl greenhouses investigated. This is the first report of B. cinerea causing gray mold in wasabi in Korea.

• Research in Plant Disease
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• v.23 no.4
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• pp.372-378
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• 2017

In this study, we identified the causative agent of post-harvest gray mold on broccoli that was stored on a farmers' cooperative in Pyeongchang, Gangwon Province, South Korea, in September 2016. The incidence of gray mold on broccoli was 10-30% after 3-5 weeks of storage at $3^{\circ}C$. Symptoms included brownish curd and gray-to-dark mycelia with abundant conidia on the infected broccoli curds. The fungus was isolated from infected fruit and cultured on potato dextrose agar. To identify the fungus, we examined the morphological characteristics and sequenced the rDNA of the fungus and confirmed its pathogenicity according to Koch's postulates. The results of the morphological examination, pathogenicity test, and sequencing of the 5.8S rDNA of the internal transcribed spacer regions (ITS1 and ITS4) and three nuclear protein-coding genes, G3PDH, HSP60, and RPB2, revealed that the causal agent of the post-harvest gray mold on broccoli was Botrytis cinerea. To our knowledge, this is the first report of post-harvest gray mold on broccoli in Korea.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.104.2-105
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• 2003

Bacterial isolates, CC178, PTC25, HC39 and KY165 originally obtained from the leaves of cucumber or tomato were selected for biocontrol agents against gray mold of cucumber and tomato by in vivo cucumber seedling assay. Each suspension of the selected epiphytic bacteria were sprayed three times at seven-day interval from early stage of cucumber in a field. Incidence of gray mold on cucumber fruits treated with isolates CC178, PTC25, HC39 and KY165 was 15.3％, 18.2％, 23.6％, and 10.4％, respectively, whereas that of control was 38.0％ after 7 days of final spray. On the other hand, treatment with the selected isolates, CC178, PTC25, HC39, and KY165 on tomato showed 2.2％, 1.3％, 2.9％, and 3.5％ in the incidence of gray mold on leaves, whereas that of control was 9.3％. All selected isolates had strong antagonistic activity against Botrytis cinerea on dual culture plate assay.

• Korean Journal of Medicinal Crop Science
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• v.23 no.6
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• pp.473-479
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• 2015

Background : To control ginseng gray mold, farmers have mainly used inorganic chemical based fungicides. The recent emergence of fungicide resistance has reduced the effectiveness of such control methods. Such pesticides also carry additional problems, such as diffuse pollution. Methods and Results : Six treatments of organic agricultural materials were tested for control of ginseng gray mold, CAPW (Chrysophanic acid + Phytoncide + Wood vinegar), EmEWV (Emodin + Ethanol + Wood vinegar), CEWV (Curcumin + Eugenol + Wood vinegar), Bacillus subtilis, soybean oil and sulfur. The control effect for gray mold by a single application of the agrochemical fungicide industrial Fenhexamid wettable powder (WP) was 84.4%. The control effect by CAPW, EmEWV and CEWV varied between 52.7 - 64.9%. The control effect by B. subtilis, soybean oil, and sulfur were 32.9 - 59.2%. Conclusions : In the field tests, CAPW showed the highest control effects when used before, and at first stage of disease incidence, against ginseng gray mold.

• Korean Journal Plant Pathology
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• v.14 no.5
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• pp.467-472
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• 1998

Gray mold rot of perilla was epidemic at Kangdong, Pusan and Miryang, Kyungnam in 1997 and 1998. The incidence of this disease ranged form 21.3 to 68.1% at Kangdong area. Leaf necrosis initially appeared on the edge of the infected leaves, and it was developed to the center of the leaves forming typical V-shaped brown necrotic lesions. Under high moisture condition, abundant mycelia of the pathogen was formed on the surface of the lesions. Infected stems became slender and were completely blighted up to the top of the plant. Two isolates, LVF12 and SD7, were isolated from diseased lesions showing typical symptoms, and the pathogenicity was tested using mycelial disks and conidial suspension inoculation. The developed symptoms were same as the naturally produced ones. These two pathogenic fungi were identified as Botrytis cinerea based on the morphological characteristics using a microscope and a scanning electron microscope, and cultural characteristics. This is the first report of gray mold or perilla in Korea.