• Research in Plant Disease
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• v.12 no.3
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• pp.287-289
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• 2006

Since 2004, a gray mold on Aerides japonicum Lindenb. & Reichb. caused by Botrytis cinerea occurred in a few greenhouses at Goseong and Tongyeong, Gyeongnam, Korea. The disease mainly started on the basal part of leaves, and often lead to severe rots of whole plant. Abundant grayish mycelia and conidial mats were visible on the lesions under a humid conditions. The light gray conidia were one celled and mostly ellipsoid or ovoid in shape. The conidia were $6{\sim}21{\times}4{\sim}13{\mu}m$ in size and conidiophores were $15{\sim}34{\mu}m$ in length. The fungus formed abundant sclerotia on potato-dextrose agar after 18 days incubation at $20^{\circ}C$. The fungus was identified as Botrytis cinerea Persoon: Fries. based on its pathogenicity and mycological characteristics examined in this study. This is the first report of gray mold of Aerides japonicum caused by B. cinerea in Korea.

• Korean journal of applied entomology
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• v.21 no.2 s.51
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• pp.73-77
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• 1982

This experiment was carried out to study the effect of boron application on the physiological response and the outbreak of Granville wilt flue-cured tobacco. NC2326 and Coker 86(flue-cured tobacco) were transplante dand investigated in all field culture plots for this experiment. Elongation of shoots were retarded, and stem heights were shortened in all boron applied plots and the more boron applied, the greater these tendency was. The ratio of root branching and root discoloration, and contraction by Granville wilt were docreased markedly in boron plots. Amount of harvested loaves (yield) was increased greatly in 2 and 4kg plots of borax and boric acid per 10a, and the increasing tendency was greater in NC2326 variety than Coker 86. Phenol compounds content in harvested leaves were higher in boron applied plots than non-applied, and was higher in Coker 86, Granville wilt resistant variety, than NC2326. The more boron applied, the higher nicotine content in the harvested leaves was.

• Horticultural Science & Technology
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• v.33 no.6
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• pp.883-890
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• 2015

The soilborne fungus Fusarium oxysporum f. sp. lilii (Fol) is a serious threat to all lily cultivars, especially infecting bulbs and flowers. It has become increasingly important to develop varieties resistant against the bulb rot disease. Genetic diversity of cultivars and reliable screening methods are required for this purpose. Here, an efficient in vitro screening system for evaluating resistance to Fol in 38 in vitro-grown lily plants was investigated. Various factors including culture conditions of Fol, inoculum density, appropriate plant materials, inoculation method and duration, and incubation period of plant materials after inoculation were combined to optimize the screening method. As a result, we suggest optimal conditions for an in vitro screening system for the selection of Fol-resistant lily cultivars as follows. Fol was grown on potato dextrose agar (PDA) medium for 6 days at $25^{\circ}C$ in darkness and used as working inoculation. Spore suspensions were prepared (inoculum density: $1.0{\times}10^4$ $spores{\cdot}mL^{-1}$), and then leaf segments $1.5{\times}2.0cm^2$ were inoculated by dipping for 22 hours at $25^{\circ}C$ in dark. Later, leaves were cultured on 0.6% agar plates at $25^{\circ}C$ and 50% humidity with a photoperiod of 16 hours light/8 hours dark (fluence rate of $40{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$) to examine the progress of bulb rot. After 7 days, disease levels were classified into indices 1 (no symptom) to 6 (serious bulb rot). Soil inoculation of Fol carried out with resistant or susceptible lily cultivars that had been selected through in vitro screening confirmed the reproducibility of results. Therefore, the in vitro screening method established in this study is efficient and reliable for selection of lily cultivars resistant against bulb rot disease.

• Korean Journal of Environmental Agriculture
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• v.25 no.3
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• pp.276-283
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• 2006

To evaluate the effectiveness of the foliar spray of calcium on "Baekdo" peach fruit, we carried out experiments in the orchards. The sprays were applied with $CaCl_2\;(Ca:\;400mg.kg^{-1})\;and\;CaCl_2$ with adjuvants (amino acid, $2g.kg^{-1}$; phytic acid, $2ml.kg^{-1}$ and wood vinegar, $2ml.kg^{-1}$) for four times from June 12 through July 4 at weekly intervals. The fruits and leaves were evaluated for Ca content, firmness and incidence of Brown rot caused by Monilinia fructicola at harvest To evaluate fruit quality included Ca content, firmness natural decay during the storage, the fruits were stored at room temperature for 14 days. The Ca content in leaf and fruit flesh at harvest was significantly increased (P=0.05) in $CaCl_2$ + amino acid treatment among $CaCl_2$ treatments. However, there was not significant Ca content in fruit peel. The firmness of flesh increased significantly (P=0.05) in $CaCl_2$ + amino acid treatment. The natural decay (Rhizopus stolonifers) during storage at the room temperature for 14 days, the fruit treated with $CaCl_2$ + wood vinegar exhibited lowest (P=0.05) incidence. Also, the firmness of the fruit during storage was firmer with treated $CaCl_2$ than untreated fruit. In the treatments of $CaCl_2$ + phytic acid and $CaCl_2$ + amino acid, it was possible to reduce incidence of Brown rot caused by M. fructicola most effectively in the field. In addition, inoculation with M. fructicola in fruits was also the most effective treatment for inhibiting disease development in vitro. These results suggested that the foliar spray of $CaCl_2$ with adjuvants increased the content of Ca and firmness of the fruits positively. It also inhibited the natural decay and the Brown rot effectively.

• Korean journal of applied entomology
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• v.4
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• pp.25-28
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• 1965

The study was carried on a new disease of rice seedling which named 'Black rot of rice seedling'. None of papers on this disease was reported recently. The symptom of this disease was quite different from other seedling rot of rice plant. Submerged mycelial growth in water was black colored and it was surrounded whole surface of seed. Soil on which diseased seedlings were placed was black colored by this disease and the seedlings, finally stopped to grow within 3 em in height, and appeared with black rot symptom. Sporulation of the pathogen does not occurred under both of natural and artificial conditions. The mycelium appeared in dark color and with distinguished septation under the microscope. With those results it is easily recognized that the pathogen does not belong to those which causal organism:; of other seedling rot of rice plant like as Phycomycetes or Fusarium species. The study should be continued on identification of the causal organism. Favorable environments for the disease did not differ from other seedling rot of rice plant, and varietal resistance also did not significantly differ among the varieties used in this experiment. Dissemination of the disease was carried out not by planted seeds but by infected soil.

• Research in Plant Disease
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• v.13 no.3
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• pp.216-219
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• 2007

Gray mold caused by Botrytis cinerea occurred on Prunus mume Sieb. & Zucc. in an experimetal orchard of Gyeongsangnam-do Agricultural Research and Extension Services in Korea from 2005 to 2007. The symptoms usually started with water-soaking lesions and hollow depression on the fruit surface. The conidia of the pathogen appeared on the surface fruits. The conidia were one celled and mostly ellipsoid or ovoid in shape and were colorless or pale brown in color. The conidia were $6{\sim}17{\times}4{\sim}10{\mu}m$ in size and conidiophores were $15{\sim}30{\mu}m$ in length. The sclerotial formed abundantly on potato-dextrose agar, They were flat or irregular in shape and black in color The optimum temperature for sclerotial formation was $20^{\circ}C$. On the basis of mycological characteristics and pathogenicity test on host plants, the fungus was identified as Botrytis cinerea Persoon: Fries. This is the first report on gray mold of P. mume caused by B. cinerea by in Korea.

• Research in Plant Disease
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• v.12 no.1
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• pp.58-61
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• 2006

Ggray mold caused by Botrytis cinerea occurred on Balsam pear (Momordica charantia) at Daesan-myon, Changwon city, Gyeongnam province in Korea from 2004 to 2006. The disease symptoms usually started with water-soaking lesions on the fruits tip and stem, and then the infected plants became withered and eventually died. The conidia of the pathogen appeared on the surface of fruit and stem of infected plants. The conidia were one celled and mostly ellipsoid or ovoid in shape and were light gray in color, The conidia were $6{\sim}20X4{\sim}12{\mu}m$ in size and conidiophores were $14{\sim}30{\mu}m$ in length. The sclerotia formed abundantly on potato-dextrose agar 18 days after incubation. The optimum temperature for sclerotial formation was $20^{\circ}C$. Pathogenicity of the causal organism was proved according to Koch,s postulates. The causal organism was identified as Botrytis cinerea Persoon: Fries based on the mycological characteristics. This is the first report on gray mold of M. charantia caused by B. cinerea in Korea.

• Research in Plant Disease
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• v.7 no.2
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• pp.112-115
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• 2001

Blossom blight of petunia caused by Choanephora cucurbitarum was found in greenhouses around Jinju area, Gyeongnam province, Korea in April 2001. The disease started with water-soaked lesions on the flower which rapidly withered and was rotten. Calyces developed water-soaked, dark-green lesions, and then were rotten. Whitish mycelia and monosporous sporangiola were produced on the lesions. The fungus isolated from the lesions produced white to pale yellowish brown mycelia with scattered monosporous sporangiola on potato-dextrose agar (PDA) plates. Size of sporangium was 37.2~135.8 um. Monosporous sporangiola were elliptic, fusiform or ovoid, and brown in color and their size was 10.4~22.4$\times$7.4~12.9 um. Sporangiospores were elliptic, fusiform or ovoid in shape, dark brown or brown in color and were 13.7~23.5$\times$8.7~13.8 um in size, and had appendaged appressorium of 3 or more. Zygospores were black, and 40.8~61.5 um in size. The fungus grew on PDA at 15-4$0^{\circ}C$, and optimum temperature was 3$0^{\circ}C$. This is the first report on the blossom blight of petunia caused by C. cucurbitarum in Korea.

• Research in Plant Disease
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• v.11 no.2
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• pp.204-207
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• 2005

A Rhizopus soft rot caused by Rhizopus stolonifer occurred on Momordica charantia at Daesan-myon, Chang-won city, Gyeongnam province from 2003 to 2005. The disease usually started from wound on fruit with water-soaking lesions. The lesion rapidly expanded and softened. The fungal mycelia grew vigorously and sporangia, sporangiophores, and stolons were formed on surface of the fruit. Spoyangiophores were $15\~30{\mu}m$ in width. Sporangia were globose or hemispheric and $90\~180{\mu}m$ in size. The color of sporangia was white and cottony at first and turned to brownish black with many spores at maturity. Columella were hemispheric and $80\~150{\mu}m$ in size. Sporangiospores were irregular round or oval, brownish-black streaked and $7\~18{\times}6\~12{\mu}m$ in size. The optimum temperature for mycelial growth of the fungus on PDA was $25^{\circ}C$. On the basis of mycological characteristics and pathogenicity to host plants, the causal fungus was identified as Rhizopus stolonifer (Ehrenberg ex. Fr,) Lind. This is the first report of Rhizopus soft rot on M. charantia caused by R. stolonifer in Korea.

• 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.