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

• Design & Manufacturing
• /
• v.13 no.1
• /
• pp.31-35
• /
• 2019

For manufacturing upper housing product of mechanical control valve, the progressive drawing process was conducted experimental. Then, the center of the product was cut to measure the thickness of the product. As a result, the following conclusions were obtained. By means of a stand-alone pad provided with sufficient pressure, it is possible to prevent the occurrence of wrinkles in the die pad product of the drawing process. As a result of the experiment, it was considered that the flange bottom of the product and the lower edge of the product are made thick in thickness, the top edge and the top surface are thin. It is considered that this is due to the size and roughness of the entrance edge radius of the die in the drawing process, and the inflow of the material by the die pad.

• Korean Journal Plant Pathology
• /
• v.14 no.6
• /
• pp.668-675
• /
• 1998

These surveys were conducted to check the occurrence of disease in various horticultural crops in alpine areas, especially Daekwallyong areas, Pyongchang-Gun, and Hyeongseong-Gun in Kangwon province. TuMV on Chinese cabbage was one of the most serious diseases, especially in 1994 and 1997. The incidence of soft rot and clubroot has been increased gradually. Brittle root rot on Chinese cabbage was significantly decreased. Soft rot, gray mold, downy mildew, powdery mildew, bottom rot and Alternaria leaf spot were the common diseases on most vegetable crops. Gray mold (Botrytis cinerea) on celery, cercospora leaf spot (Cercospora sp.) on melon, powdery mildew (Erysiphe cichoracearum) on lettuce, and clubroot (Plasmodiophora brassicae) on parsley are newly found in Korea. The most common and predominant diseases were viruses, especially CMV, TMV, TuMV, BBMV, and gray mold, wilts, and cercospora leaf spot on many flowers in alpine areas. Fusarium oxysporum f. sp. eustomae causing wilting on lisianthus (Eustoma grandiflorum), Turnip mosaic virus causing mosaic and color breaking on stock, Cercospora spp. causing cercospora leaf spot on various wild lily, Cladosporum echinulatum causing leaf spot on carnation, and phytoplasma causing witches' broom on statice (Limonium sinuatum) and blazing star (Liatris spp.) were newly found during these surveys in Korea.

• Research in Plant Disease
• /
• v.20 no.4
• /
• pp.275-282
• /
• 2014

The occurrence of post-harvest diseases and their pathogens in 'Campbell Early' which is the most produced grape in Korea was investigated. The 'Campbell Early' grapes produced in 3 main grape-producing areas were stored in a cold room ($0-4^{\circ}C$) for 2 weeks then at room temperature for 4 weeks prior to investigation. The major post-harvest diseases occurred were gray mold, blue mold, ripe rot, new decay 1, and new decay 2. Pathogens isolated from the symptoms were identified as Botrytis cinerea for gray mold, Penicillium sclerotiorum for blue mold and Collectrichum acutatum for ripe rot. Pathogens for new decay 1 and new decay 2 were not identified yet. Incidences of new decay 1 and new decay 2 were much higher than the other 3 decays in all grapes produced from 3 areas. Gray mold and blue mold occurred at much lower frequencies than these two decays, and ripe rot occurred least.

• Korean Journal Plant Pathology
• /
• v.11 no.4
• /
• pp.380-382
• /
• 1995

Yellow spot or blotch symptoms on the upper surface of leaf, without the production of velvet-like fungi on the lower surface of leaf as in the gray mold of tomato caused by Cladosporium fulvum, were observed in tomato (cv. Seokwang) plants in May, 1995, in a vinyl-house of the experimental plot of Gyeongnam Provincial Rural Development Administration, Chinju, Gyeongnam, Korea. We identified this disease as powdery mildew of tomato caused by Oidiopsis taurica (L v.) Arnaud (=Leveillula taurica), which was new to Korea. Conidia of the fungus were borne on uni- or bi-septated conidiophores which were developed through the stomata of the tomato leaf. The conidia were slender, clavate and variable in size (31~111.6$\times$13.1 ${\mu}{\textrm}{m}$). The fungal conidia isolated from tomato leaves were inoculated to tomato plants, and the occurrence of the same disease was confirmed based on the symptomatology and the morphology of the pathogen reisolated.

• The Korean Journal of Ecology
• /
• v.23 no.4
• /
• pp.315-321
• /
• 2000

The occurrence and distribution of Dictyostelid cellular slime molds on Mt. Mukak soils with two different vegetation types were investigated. Two plating methods were used for the isolation of dictyostelids following Dr. Hagiwara's method. Dictyostelium and Polysphondylium were isolated in these soils. D. purpureum (subtropical form ) and D. giganteum were observed in both Quercus variabilis and Pinus thunbergii communities soils. D. delicatum, B. sp-1 (D. brefeldianum complex). D. sp-2 (D. brefeldianum complex), D. minutum and P. pallidum complex occurred only in Q. variabilis soil. D. macrocephalum, D. purpureum (temperate form ), D. robustum, D. polycephalum, P. violaceum, and P. pallidium occurred only in P. thunbergii soil. P. pallidium complex is being identified.

• Journal of Mushroom
• /
• v.5 no.1
• /
• pp.25-28
• /
• 2007

Green mold of Phellinus baumii mushroom caused by a species of Penicillium was observed in Daegu on August, 2000. The causal fungus was identified as Penicillium rubrum based on its cultural and morphological characteristics. Conidiophores of the fungus were one-stage branched and terminating in a whorl of 3~5 metulae. The metulae were mostly 5.2~7.8 ${\mu}m$ in size. Phialides were flask-shaped and $5.7{\sim}7.5{\times}2.2{\sim}2.7{\mu}m$. Conidia were subglobose and 1.8~2.3 ${\mu}m$. Colonies on Czapek's agar growing, attaining a diameter of 23 mm within 8 days at $25^{\circ}C$. The optimum temperature for growth of the fungus was about $20{\sim}30^{\circ}C$. This is the first report on the occurrence of green mold of P. baumii caused by P. rubrum in Korea.

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

• Horticultural Science & Technology
• /
• v.31 no.6
• /
• pp.740-747
• /
• 2013

Leaf mold symptoms were found on commercial tomato cultivars carrying the Cf-9, a resistance gene to leaf mold pathogen Fulvia fulva in 2012 at Buyeo, Chungnam in Korea. Fifteen-fungal isolates were obtained from four Cf-9 cultivars of tomato including 'Cutie', 'otaerangdia', 'Unicorn' and 'Rapito'. Due to their same morphological appearances and colony color, nine isolates were selected and identified as F. fulva based on molecular analysis of the internal transcribed spacer rDNA sequence. Pathogenicity of the 15 isolates on five commercial cultivars carrying Cf-4, Cf-5, and Cf-9 were tested. All the isolates showed strong pathogenicity on Cf-9 cultivars, 'Cutie' and 'Dotaerangdia', and Cf-5 cultivar, 'Yoyocaptain'. In contrast, on Cf-4 cultivar, 'Superdotaerang', five isolates were virulent and the other isolates were not. In addition, two fungal isolates, infecting Cf-9 cultivar and non-infecting Cf-4 cultivar, were selected and their pathogenicity was tested on 17 commercial cultivars reported as tomato having Cf-9 resistance gene. Among them, 15 cultivars were susceptible and 2 cultivars were resistant. It is likely that the two cultivars include other resistance gene. To our knowledge, this is the first report on the occurrence of Cf-9 infecting F. fulfva strains in Korea.

• Research in Plant Disease
• /
• v.25 no.1
• /
• pp.16-21
• /
• 2019

Botrytis cinerea is the pathogen for a gray mold generating problems during the cultivation and transportation of roses. But there is little information about the difference of the symptom severity caused by gray mold on rose varieties and pathogen strains. 16 strains were collected from the rose cultivation area to confirm the degree of disease occurrence against strains and each variety. Collected 16 strains were identified based on the sequences analysis of ITS region of ribosomal DNA by using specific primers. The sequence analysis was performed by comparing the sequences to find a difference. To confirm the difference in disease occurrence for each strains, the difference was classified from 0 to 5 stages using charmant variety as a control. The data was confirmed through Kruskal-Wallis ANOVA. The result showed the significant difference in the pathogenicity caused by strains. WNG6_5 showed the lowest pathogenicity with 0.24 and WNG6_3 showed the highest with 3.20. The difference between two strains were almost 3.0. In addition, nine varieties of roses were more investigated with three strains such as the strains of WNG6_5, Hwa_1, and WNG6_3. The result showed that the Love Letter variety showed resistance and the Ice Bear variety was sensitive to three strains. Taken together, this study showed the significant difference by the interactions of rose varieties and gray mold strains.