• Research in Plant Disease
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• v.24 no.3
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• pp.175-181
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• 2018

Incidence rates of bacterial canker, bacterial leaf spot and postharvest fruit rot on the Korean yellow-fleshed kiwifruit cv. Haegeum were compared with those on the most popular green-fleshed kiwifruit cv. Hayward grown in several naturally infected kiwifruit orchards in 2013 and 2014. The percentages of diseased leaves caused by bacterial canker were 18.5% and 17.3% on Hayward in 2013 and 2014, but those on Haegeum were 1.2% and 0%, respectively. The percentages of diseased leaves caused by bacterial leaf spot on Hayward were 63.5% and 16.2% in 2013 and 2014, respectively, but no bacterial leaf spots were observed on Haegeum in both years. The average percentages of diseased fruits caused by postharvest fruit rot were 24.2% and 20.5% on Hayward in 2013 and 2014, while 6.3% and 4.4% and Haegeum, respectively. Botryosphaeria dothidea was turned out to be the major pathogen of postharvest fruit rot on both cultivars.

• Korean journal of applied entomology
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• v.21 no.4 s.53
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• pp.222-226
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• 1982

Changes in levels of phenolic compounds such as total phenols, flavonols and anthocyanins in Macrophoma-infected apples were studied at various developmental stages of apple fruits. The amounts of total phenols in apple fruit flesh and peel drastically decreased as apples became mature. Apple rot resulted in concentration of total phenols somewhat lower than those of healthy apple flesh. The decline in amount of total phenols was distinct in infected fruit flesh of the cultivar Fuji, which was more susceptible to Macrophoma sp. than the cultivar Miller. Higher amounts of total phenols were found in infected than in heathy fruit peel. In the case of the cultivar Miller, increased accumulation of total phenols was pronounced in infected peel. Apple rot resulted in concentrations of flavonols much higher than those of healthy apples. In particular, the drastically increased accumulation of flavonols was detected in infected peel at the first collection on 10 July, when the cultivars tested were completely resistant to Macrophoma sp. Production of anthocyanins was increased considerably by apple rot: anthocyanins in infected fruits of the cultivar Miller increased markedly as compared with their concentration from healthy fruits. These results suggest that the altered phenolic metabolism in apple fruits may be associated with the development of apple rot.

• Korean Journal Plant Pathology
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• v.11 no.1
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• pp.98-99
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• 1995

A disease causing fruit rot and leaf and vine blight on watermelon was found in Euseong in July, 1991 and in Bonghwa, Kyungpook province in August, 1993. Abundant zoosporangia characteristics of Phytophthora capsici were formed on the surface of the infected fruits. The zoosporangia were ovoid to ellipsoid, tapering to the base and with conspicuous papilla. The fungus isolated from the infected fruits was pathogenic on seedlings of watermelon, pumpkin, and pepper. The morphological characteristics and host range agreed with those of P. capsici. The watermelon disease caused by P. capsici was reported long time ago in Japan and America but rot yet in Korea. Thus, the disease on watermelon caused by P. capsici is reported as a new record in Korea.

• Mycobiology
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• v.38 no.2
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• pp.113-117
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• 2010

Trichoderma strains were evaluated under field conditions to assay their efficacy in suppressing Alternaria fruit rot disease and promoting chili plant growth. The experiment was conducted at the Botanical Garden, Rajshahi University, Bangladesh from July 2006 to March 2007. Application of Trichoderma harzianum IMI 392432 significantly (p = 0.05) suppressed the disease compared to Alternaria tenuis (T2) treatment and improved both growth and yield. The treatment T4 (T. harzianum IMI-392432 + A. tenuis) was most effective in reducing disease percentage (72.27%) compared to A. tenuis (T1) treatment. The highest seed germination rate (85.56%) and the highest growth and yield (12.5 g/plant) was also recorded in the same treatment (T4), followed by T5 (T. harzianum IMI-392433 + A. tenuis), T6 (T. harzianum IMI-392434 + A. tenuis), T2 (T. virens IMI-392430 + A. tenuis), and T3 (T. pseudokoningii IMI-392431 + A. tenuis) treatment, while single treatment with A. tenuis significantly decreased these values.

• The Plant Pathology Journal
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• v.25 no.4
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• pp.429-432
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• 2009

An unreported disease of apricot was observed in orchards in Zhejiang province, China. Symptoms started as water soaked lesions on the fruit surface. Later, water-soaked areas developed and spread to the entire fruit, resulting in soft rot of the whole fruit. The causal organism isolated from symptomatic fruits was identified as Burkholderia cepacia based on its biochemical and physiological characteristics and confirmed by the cellular fatty acid composition and Biolog data as well as 16S rRNA gene sequence analysis. The bacterial isolates caused similar symptoms when inoculated onto fruits of apricot. In addition, European plum, Japanese plum, nectarine and kiwifruit were susceptible to the B. cepacia pathogen. However, the B. cepacia pathogen failed to cause any visible symptoms when it was inoculated onto 16 other fruits. This is the first report of a bacterial disease of apricot caused by B. cepacia in China.

• Research in Plant Disease
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• v.10 no.4
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• pp.313-318
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• 2004

Internal fruit rot of cucumber was observed in several locations in Korea. Incidence of the disease reached up to 21.5% and averaged 4.2% in the fields surveyed. The disease started at blossom ends of cucumber fruits. Internal tissues of infected fruit tips showed brown discoloration over 2 cm in length and 2 mm in diameter. Subsequently, the brown discoloration was extended into the carpels, and the surface of the infected fruit tips was rugged. Fungal isolates from the internal tissues of diseased fruits were identified as Didymella bryoniae based on mycological characteristics. Temperature for mycelial growth of isolates ranged $5{\sim}32^{\circ}C$ with optimal temperature between $26{\sim}28^{\circ}C$. Similar symptoms were developed in the internal part of the cucumber fruit when conidial suspensions of the isolates were inoculated to the flower of cucumber. Furthermore, Didymella bryoniae isolates from other plant parts of cucumber, watermelon, oriental melon, melon and pumpkin also showed the similar symptoms in the internal part of cucumber fruits by inoculation tests. Temperature range for occurrence of internal fruit rot of cucumber was $10{\sim}32^{\circ}C$ with optimal temperature of $25{\sim}28^{\circ}C$.

• Research in Plant Disease
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• v.24 no.4
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• pp.321-327
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• 2018

In 2018, symptoms of black rot on apple (Malus pumila var. dulcissima KOIDZ) cv. Fuji were observed in Yeongcheon-si, Korea. The fruit decay symptoms consisted of purple pimples spots, black rot around the seed cavity (calyx end), mummified fruit. To isolate the causal agent, small fragment (2 to 3 mm) of decayed tissue from the lesion margin were placed on WA or PDA. Fungal colonies on PDA produced dense white aerial mycelium, becoming dark gray with age. Pycnidia and conidia were observed under a light microscopy. The shapes of conidia were aseptate, ovoid, rounded at both ends, and $21.7-28.3{\times}9.9-15.3{\mu}m$. Based on morphological and cultural characteristics, this fungus was identified as Diplodia seriata. To confirm its identity, two loci (ITS and ${\beta}$-tubulin) were sequenced for molecular identification. BLAST searches indicated 100% identity with D. seriata. A pathogenicity test was conducted with isolates on Fuji apples. The apples were inoculated with mycelial plugs (5 mm) from 7-day-old cultures of the putative pathogens. All inoculated apples developed rot symptoms identical to the original symptoms, from which D. seriata were reisolated, fulfilling Koch's postulates. This study is the first report of black rot caused Diplodia seriata on apple.

• Korean journal of applied entomology
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• v.16 no.4 s.33
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• pp.245-247
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• 1977

Penicillium digitatum SACCARD, P. italicum WEHMER, Botrytis cinerae PERSOON and Sclerotinia sclerotiorum MASSE. were the main storage diseases on the cold injured mandarin at Jeju in 1975. The losses observed through the materials used were $18.3\%$ which consists of $8.1\%$ by diseases and $10.2\%$ by water rot as the result of cold and snow damages at harvest stage in Jeju. The total amount of damages estimated at shipping stage were 915M/T in value of 135 million Won from the rot waste of 675M/T by the end of 1975. Since cold injury is known as the main factor of the fruit rot, shipping and storage process as well as disease control measures are discussed.

• Journal of Bio-Environment Control
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• v.3 no.1
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• pp.36-41
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• 1994

The major objective of this study is to develop a method of zone cooling during summer day using heat pump for year- round cultivation. The efficiency of cold water cooling and fog cooling was investigated. In order to prevent the occurrence of blossom - end rot in tomato, cooling was induced together with air flow of the fruit treatment as well as promoting air circulation in the plant treatment was induced. The following results were obtained : 1) The temperature in the cold water cooling district was 1$0^{\circ}C$ lower than greenhouse temperature and the temperature in the fo8 cooling district was about 5$^{\circ}C$ lower than the greenhouse. 2) Regardless of cooling method, the treatment of air flow on fruit did not affect the fruit but prevent blossom-end rot. There was 34.5% occurrence rate of blossom -end rot in non-air flow district of cold water cooling 54.5% in non-air flow district of fog cooling and 78% in fog circulation cooling district. The cooling efficiency using cold water cooling method induced enough cooling at critical temperature for growth and development and the occurrence of blossom -end rot was lower than fog cooling. Fog cooling in culture district with air circulation did not induce and difference in temperature but caused an Increase in humidity resulting in 24% increase in the occurrence of blossom-end rot. Thus the occurrence of blossom-end rot in tomato caused by environmental factors can be attributed more to humidity than to temperature.

• Horticultural Science & Technology
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• v.19 no.3
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• pp.362-366
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• 2001

This survey was carried out to investigate the effect of flooding by heavy rain on growth characteristics and disease incidence of 'Fuji'/M.26 mature apple tree in 1998 at Kyongbuk province. The surveyed regions were Andong, Uisung, and Gunwi area. The six orchards were selected from one area, totally 18 orchards were surveyed. The flooded depth of surveyed orchards was from 70 to 350 cm, and the flooded duration was from 6 to 72 h. Defoliation ratio, number of abnormal budding, and flowering per tree were increased along with the increment of flooded depth and duration. Rooting ratio was decreased rapidly with the increment of flooded duration, and dead root ratio was 16.2% in flooded orchards. Marssonia blotch (Diplocarpon mali), white rot (Botryosphaeria dothidea) of fruit, and phytophthora fruit rot (Phytophthora cactorum) incidence were increased in flooded orchards. The analysis results of pearson correlation coefficient among surveyed items showed that higher relationship of abnormal growth characteristics and increment of disease incidence of 'Fuji'/M.26 apple trees with flooded duration than with flooded depth. With these results, the flooded depth was found to be the main factor for the abnormal growth characteristics and disease incidences of 'Fuji'/M.26 apple trees.