• Research in Plant Disease
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• v.15 no.1
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• pp.8-12
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• 2009

Virus disease surveys of strawberries cultivated and preserved as germplasm resources in Korea was conducted during 2007-2008. Virus detection was conducted by RT-PCR using total RNAs extracted from strawberry samples. We detected the infection with Strawberry mild yellow edge virus (SMYEV), Strawberry mottle virus (SMoV), Strawberry vein banding virus (SVBV) and Strawberry pallidosis associated virus (SPaV) while no infection with Strawberry crinkle virus (SCV), Strawberry necrotic shock virus (SNSV), Strawberry latent ring spot virus (SLRSV) and Arabis mosaic virus (ArMV) was observed. The infection rate of virus disease on 4 cultivars including Seolhyang, Maehyang, Gumhyang, and Dahong, bred in Korea, was 0.1, 1.9, 0, and 0%, respectively. Surprisingly, however, cultivar Red Peal introduced from Japan in 1997 revealed 48.3% virus infection rate. SMYEV, SMoV and SPaV were also identified in strawberries growing in the farm fields of Korea. In the field, however, SMYEV was the most predominant virus (97.4%) among those 3 identified viruses. SVBV was detected only in strawberry kept as a germplasm.

• Korean journal of applied entomology
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• v.18 no.4 s.41
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• pp.183-188
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• 1979

The study has been carried to describe a new disease of strawberry in Korea, which was found in 1977 at Kimhae. Symptom of the disease occurred mainly on leaves as showing large annular brown spots or 'V' shaped brown lesions. Many of dark pycnidia were observed from the both side of old lesions. The pathogen was identified as Dendrophoma obscurans (Ell. & Ev) Anderson which has not been described in Korea as a pathogen of strawberry disease. The common name of the disease was given, temporaly, as Annular leaf blight of strawberry. In the laboratory study, light was necessary for the production of pycnidia and potato dextrose agar was the best media for tile pycnidia formation. There were some difference on resistance to the disease among 48 tested strawberry varieties though none of them shelved highly resistant reaction, and the older leaves showed more susceptible reaction than younger ones.

• Research in Plant Disease
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• v.20 no.1
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• pp.54-58
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• 2014

Anthracnose crown rot (ACR), caused by Colletotrichum fructicola, is a serious disease of strawberry in Korea. The primary inoculums of ACR were symptomless strawberry plants, plant debris, and other host plants. To effectively control anthracnose in symptomless transplanted strawberries, it is necessary to use disease-free plants, detect the disease early, and apply a fungicide. Therefore, in 2010 and 2011, we evaluated the efficacy of pre-plant fungicide dips by using strawberry transplants infected by C. fructicola for the control of anthracnose. Dipping plants in prochloraz-Mn for 10 min before planting was most effective for controlling anthracnose in symptomless strawberry plants and resulted in more than 76% control efficacy. Azoxystrobin showed a control efficacy of over 40%, but plants treated with pyraclostrobin, mancozeb and iminoctadine tris showed high disease severity. The control efficacy of the dip treatment with prochloraz-Mn did not differ with temperature and time. Treatment with prochloraz-Mn for more than an hour caused growth suppression in strawberry plants. Therefore, the development of anthracnose can be effectively reduced by dipping strawberry plants for 10 min in prochloraz-Mn before planting.

• Plant Disease and Agriculture
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• v.5 no.1
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• pp.8-13
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• 1999

Twenty two different disease on strawberry have been reported in Korea. Their occurrence patterns were depended on the varieties cultivated. Fusarium wilt occurred seriously on var. Hokowase, a variety used for the fields or semi-forcing culture. In recent years, however, anthracnose occurred remarkably as the acreage of forcing culture increases. Consequently, anthracnose reduced the stand rate and yield of the strawberry. Average occurrence rate of anthracnose was 36.9% on major strawberry cropping areas. Nyoho and Akihime, which are popular varieties for the forcing culture, are considered to be susceptible, but Holiwase and Suhong are resistant against this disease. Colletotrichum gloeosporioides and Glomerella cingulata have been reported as casual agents for this disease in Korea. C. gloeosporoides was recently reported, but C. fragariae, known to be a strong pathogen in foreign countries, has bot been found yet in Korea. These two fungal pathogens showed significant differences in some characteristics such as major infection parts of plant and responses to temperatures as well as benomyl resistance. In addition, C. gloeosporioides is more pathogenic than G. cingulata. Because vinly sheltering is effective for control of anthracnose to protect water disposal of the pathogen during the seedling stages, it is strongly recommend to use this method in conjunction with integrated control programs.

• 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.

• Research in Plant Disease
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• v.11 no.1
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• pp.39-42
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• 2005

Powdery mildew, caused by Sphaerotheca aphanis var. aphanis, is an economically significant disease of strawberry in Korea. When powdery mildew is not controlled adequately, it often spreads rapidly through strawberry plants and damage is associated with reduced yields. Proper timing of fungicide applications is, therefore, essential for effective disease control. This study evaluated the efficacy by application schedule of fungicides before harvest stage for preventing powdery mildew in 2001-2003. The systemic fungicides, azoxystrobin, kresoxim-methyl, and cupper fungicide DBEDC were applied preventively during the first part of the cultivating season. Preventative applications of DBEDC by dipping treatment before transplanting and kresoxim-methyl by foliar spray before blooming stage were one of the most effective control schedule tested to prevent and manage this disease. This research demonstrated the significance of application time to control of powdery mildew, particularly provided elimination unnecessary sprays of agrochemicals and reduction costs for strawberry growers.

• Korean journal of applied entomology
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• v.19 no.4 s.45
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• pp.221-227
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• 1980

A new disease of strawberry caused by Alternaria was found in Gim Hae, Gyougnam province, in July 1979. The symptoms of the disease occurred mainly on leaves as showing dark brown spots with circular to irregular, $5\~6mm$ in diameter. The pathogen was identified as Alternaria alternate (Fr.) Keissler which has not been described in Korea as a pathogen of strawberry disease. The common name of the disease was given as Gum un mum byung of strawberry. The conidia shape and size of this fungus varied considerably with culture media. The measurements of conidia and beak on corn meal agar were $20.1\times9.3{\mu}\;and\;4.0\mu$, respectively, which were shorter than those on strawberry leaf lesions in the field. Among 49 strawberry varieties tested, Morioca 16 and Robinson were highly susceptible to the disease by artificial inoculation and Catskill, Cyclone, Northwest, Merton princess, Juspa and Daehak I were moderately susceptible whereas 31 varieties were resistant. This fungus could also infect the leaf of Common garden sunflower, Double sunflower and Mexican sunflower among the 14 plants species tested.

• Research in Plant Disease
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• v.29 no.3
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• pp.205-219
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• 2023

Anthracnose caused by Colletotrichum spp. is a major disease of strawberry plants worldwide. The anthracnose of strawberries in Korea has occurred in most cultivated strawberry varieties since its first report in 1990. Although many studies and efforts have been made to control the disease, anthracnose continues to affect strawberry yields in Korea. In this review, we introduced various management methods to control anthracnose in strawberries, such as identifying pathogens and environmental factors involved in this disease, understanding the importance of latent infection, and developing diagnostic techniques and control methods. Through this review, we propose that researchers can elucidate a comprehensive and practical approach to control anthracnose by understanding this disease and developing strategies to prevent its spread, ultimately benefiting strawberry farmers.

• Journal of Microbiology and Biotechnology
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• v.30 no.5
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• pp.708-716
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• 2020

The purpose of this study was to identify strawberry wilt pathogens and evaluate the efficacy of Chlorella fusca CHK0059 for improving plant growth and suppressing Fusarium wilt. We identified 10 isolates of wilt pathogens of non-pesticide Seolhyang strawberry plant, including Fusarium oxysporum f. sp. fragariae, using morphological and molecular analysis. On the 15^th day after 0.4% CHK0059 treatment, the plant height of the untreated control strawberry plants was significantly greater than that of the CHK0059-treated strawberry plants. After 85 days, both treatments showed a similar tendency regarding the height of the strawberry plants. However, the thickness of strawberry leaves treated with the CHK0059 was found to be 1 mm thicker than that of the untreated control. The flowering percentage of the CHK0059 plants was also 40.2% higher on average than that of the untreated control. The chlorophyll content of strawberry leaves treated with the CHK0059 was also, on average, 6.63% higher than that of the untreated control. After 90 days of the CHK0059 treatment, the incidence of Fusarium wilt in the CHK0059-treated plants had reduced by 9.8% on average compared to the untreated control. The population density of F. oxysporum f. sp. fragariae was also reduced by approximately 86.8% in the CHK0059-treated plants by comparison to the untreated control at 70 days after treatment. The results indicate that the microalga C. fusca CHK0059 is an efficient biological agent for improving strawberry plant growth and suppressing Fusarium wilt disease in organic strawberries.

• The Plant Pathology Journal
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• v.39 no.6
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• pp.614-624
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• 2023

Botrytis cinerea is a major fungal plant pathogen that causes gray mold disease in strawberries, leading to a decrease in strawberry yield. While benzimidazole is widely used as a fungicide for controlling this disease, the increasing prevalence of resistant populations to this fungicide undermines its effectiveness. To investigate benzimidazole resistant B. cinerea in South Korea, 78 strains were isolated from strawberries grown in 78 different farms in 2022, and their EC₅₀ values for benzimidazole were examined. As a result, 64 strains exhibited resistance to benzimidazole, and experimental tests using detached strawberry leaves and the plants in a greenhouse confirmed the reduced efficacy of benzimidazole to control these strains. The benzimidazole resistant strains identified in this study possessed two types of mutations, E198A or E198V, in the TUB2 gene. To detect these mutations, TaqMan probes were designed, enabling rapid identification of benzimidazole resistant B. cinerea in strawberry and tomato farms. This study utilizes TaqMan real-time polymerase chain reaction analysis to swiftly identify benzimidazole resistant B. cinerea, thereby offering the possibility of effective disease management by identifying optimum locations and time of application.