• The Plant Pathology Journal
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• 제39권1호
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• pp.88-107
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• 2023

In the present investigation, bacterial isolates from infected apple trees causing apple canker during winter were studied in the northern Gyeongbuk Province, Korea. The pathogen was identified as Pseudomonas syringae pv. syringae (Pss) through various physiological and biochemical characterization assays such as BIOLOG, gas chromatography of fatty acid methyl esters, and 16S rRNA. Bioassays for the production of phytotoxins were positive for syringopeptin and syringomycin against Bacillus megaterium and Geotrichum candidum, respectively. The polymerase chain reaction (PCR) method enabled the detection of toxin-producing genes, syrB1, and sypB in Pss. The differentiation of strains was performed using LOPAT and GATTa tests. Pss further exhibited ice nucleation activity (INA) at a temperature of -0.7℃, indicating an INA⁺ bacterium. The ice-nucleating temperature was -4.7℃ for a non-treated control (sterilized distilled water), whereas it was -9.6℃ for an INA^- bacterium Escherichia coli TOP10. These methods detected pathogenic strains from apple orchards. Pss might exist in an apple tree during ice injury, and it secretes a toxin that makes leaves yellow and cause canker symptoms. Until now, Korea has not developed antibiotics targeting Pss. Therefore, it is necessary to develop effective disease control to combat Pss in apple orchards. Pathogenicity test on apple leaves and stems showed canker symptoms. The pathogenic bacterium was re-isolated from symptomatic plant tissue and confirmed as original isolates by 16S rRNA. Repetitive element sequence-based PCR and enterobacterial repetitive intergenic consensus PCR primers revealed different genetic profiles within P. syringae pathovars. High antibiotic susceptibility results showed the misreading of mRNA caused by streptomycin and oxytetracycline.

• 한국식물병리학회지
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• 제11권1호
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• pp.9-16
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• 1995

Undiluted neoasozin solution (6.5% a.i.), an arsenic fungicide, was sprayed on 169 cankers of apple trees from early March to September in 1987 twice at intervals of one week without scraping off the affected barks. Among the treated cankers, 79.9% ceased to grow within 1∼7 weeks, 13.0% showed partial development, and 7.1% grew continuously to girdle the branches. The partially developed cankers, however, could also be cured by an additional spray after slightly piercing at the edge of cankers to facilitate the penetration of the chemical. When the canker growth was blocked, cankers were encircled by cracks developed at the marginal area of the cankers. If the cracks developed once, very few cankers grew beyond them. The above results suggest that the crack development may be the consequence of the host defense activity to wall off the pathogen. In addition to the curative efficacy, the neoasozin solution inhibited sporulation of the pathogenic fungus almost completely. However, the pathogen survived for more than three months in some cankers that externally appeared to be cured, suggesting that an indirect mode of action of the chemical against apple Valsa canker seems to be still more persuasive than the direct fungicidal effect. In the final examination conducted in the mid April of the next year, 72.7% of the cankers were completely cured by the two successive neoasozin treatments. Moreover the cure rate became 83.1% if that of partially developed cankers which were also completely cured by an additional treatment was also taken into account. Since 1989 when this method was widely applied in apple orchards in Korea, apple Valsa canker has been effectively controlled to reach a tolerable level.

• Mycobiology
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• 제28권3호
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• pp.153-157
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• 2000

In this paper, the distribution, host restriction, and taxonomic position of Valsa mali are discussed.

• 한국유기농업학회지
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• 제6권1호
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• pp.35-43
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• 1997

For the purpose of acquiring microbial agents that can be utilized to billogically control the major airborne disease to apple trees, such as canker(Valsa ceratosperma), the effective microorgaisms were isolated, tested for antagonistic activity to the pathogen causing major disease to apple trees and identifed. Screening of more than 3, 000 species of microorganisms collected in nature for them antagonistic action to the pathogen, Valsa ceratosperma causing disease to apple tree resulted in selection of effective species. Out of the 11 species, one species designated as CAP141 demonstrated outstanding activity. The bacterial strain, CAP141 exerted antagonistic efficiency of 65% on Valsa ceratosperma. The CAP141 was identified as a bacterial strain to Bacillus subtilis based on morphology, culture conditions, and physio-biochemical characteristics.

• 한국유기농업학회지
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• 제25권1호
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• pp.125-134
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• 2017

본 연구는 친환경 유기과원의 부란병 방제를 위한 유황토분의 효과를 검증코자 2년간 수행되었다. 제조된 유황토분의 사과 부란병 치유효과를 검증하기 위해 유기과원에는 석회유황합제의 처리와 비교하였으며, 관행과원에서는 석회유황합제, 유황토분 및 네오아소진을 처리하였다. 유기과원의 유황토분의 부란병 치유율은 대조구에 비해 뚜렷하게 유의성이 인정되었으나, 2013년 봉현 과원을 제외하고는 석회유황합제와는 큰 차이가 없었다. 유기과원의 과실품질조사 결과, 과피의 붉은 색은 대조구에 비해 석회유황합제 처리구에서 다소 높게 나타냈으며, 과실의 경도에서는 유황토분 처리구가 대조구에 비해 유의적으로 높게 나타났다. 관행과원에서의 유황토분, 석회유황합제 및 네오아소진 처리는 대조구에 비해 통계적 유의적으로 높게 조사되었다. 유황토분의 부란병 치유율은 유기사과과원 및 관행사과과원에서 87.5~97.5%인 것으로 조사되었다. 관행과원에서의 유황토분 처리는 신초생육에 있어 네오아소진에 비해 통계적 유의성이 있게 증가하였다. 과실품질의 경우 유황토분처리는 과실의 붉은 색의 증가를 보였으나, 다른 과실품질인 무게, 경도, 당도 및 적정산도에서 통계적 유의성을 나타내지 않았다.

• 한국응용곤충학회지
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• 제9권2호
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• pp.81-84
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• 1970

1) 본 보고는 사과나무 부란성병의 발생상황에 대하여 주산지인 충북, 충남, 경북등 3개도에서 1967년부터 1970년까지 4년 간 조사한 것이다. 2) 피해상황은 각지방에서 $30\%$ 내외가 감염되어 사과재배에 큰 위협을 주고 있다. 3) 수령별로는 대체로 수령이 많아질 수록 발병이 심한 펀이었다. 4) 품종간에는 홍옥의$6.1\%$가 가장 발병이 많았고 그 외는 Golden Delicious, 인도, 국광, 축의 순위였다. 5) 시비관계는 질소다량시비구가 $21.9\%$로 소양시비구에 비하여 약 1/3정도 발병이 많았으며, 붕소를 사용한 과원은 대조과원보다 약 1/4-1/6 정도로 발병률이 감소되었다. 6) 재배지대별로 보면 충북에서는 하천지대에 발병이 심했으나 경북지방은 대체로 하천, 평야, 구릉지대 어디서나 비슷한 경향이었다.

• 한국유기농업학회지
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• 제5권1호
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• pp.137-147
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• 1996

For the purpose of acquiring microbial agents that can be utilized to biologically control the major airborne diseases to apple trees, such as canker(Botryosphaeria dothidea), bitter rot(Glomerella cingulata), alternaria leaf spot(Alternaria mali), root rot(rosellinia necatrix), canker(Valsa ceratosperma) and gray mold rot(Botrytis cinerea), the effective microorgaisms were isolated, tested for antagonistic activity to the pathogens causing major diseases to apple trees and identifed. Screening of more than 5,000 species of microorganisms collected in nature for them antagonistic action to the pathogens causing 5 major diseases to apple trees resulted in selection of effective species. Out of the 11 species, one species designated as CAP134 demonstrated outstanding activity. The bacterial strain, CAP134 exerted antagonistic efficiency of 57% on an isolated strain and 40% on a donated strain of Botryosphaeria dothidea., 52% on an isolated strain and 46% on a purchased strain of Alternaria mali, 60% on Valsa ceratosperma 25% on Glomerella cingulata, and 64% Rosellinia necatrix. The CAP134 was identified as a bacterial strain to Bacillus subtilis ATCC 6633 based on morephology, culture conditions, and physio-biochemical characteristics.

• 한국응용곤충학회지
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• 제11권1호
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• pp.19-23
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• 1972

1. 사과나무 부란성병해를 일으키는 병원균을 사과 주산지인 충남북, 경북등 3개도에서 조사하였으며 살균제의 효과를 실내에서 검정하였다. 2. 병윈균은 Valsa mali (부란병) 및 Botryosphaeria ribis(동부병)은 경북, 충남. 충북 등 3개도 모두 분포하며 Phomopsis truncicola (동고병)만은 충북에서는 없었다. Valsa mali는 어느 지역에서나 가장 많이 발견되었으나 천원지방에서는 Botryosphaeria ribis가 더 많앗다. 3. 저지대에 의한 Valsa mali의 산균효과나 병원균을 접종한 수피의 침투효과에서 수은제 , 석회유황합제의 효과가 좋았고 다음으로 황산옥시키노린제, 유황제가 좋았고 알콩등의 효과는 인정되지 않았다.

• 한국응용곤충학회지
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• 제23권2호
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• pp.82-88
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• 1984

사과나무의 과실 부패현상과 가지 사마귀현상의 평원균 및 그 병원성을 조사한 결과 다음과 같다. 1. 사과나무와 배나무의 가지 및 과실, 벚나무${\cdot}$복숭아나무${\cdot}$자두나무${\cdot}$능수버드나무 및 자작나무의 가지 등 7종의 병든식물에시 분리된 것은 Dothierella mali (Botryosphaeria berengeriana 의 불완전세대)가 대부분이었고 사과의 썩은 과실에서는 Alternaria sp.와 Pencicillium expansum도 분리되었으며, 배의 썩은 과실에서는 Phomopsis sp.도 분리되었다. 2. B. berengeriana의 10개 분리균을 4종 재배에 배양한 결과 균사생장, 균총의 모양 및 색깔의 차이에 따라 2가지로 나눌 수 있다. 공시된 분리균은 배지에 특이한 색깔을 나타내지 않았다. 병자각은 자좌속에 형성되었으며, 모양은 구형 또는 편구형으로 흑갈색이었고, 크기는 사과 병조직의 것이 $103.5-287.5\mu\times92.0-287.5\mu$사이었다. 병포자는 보통 무색, 단포, 타원형-방추형으로써 사과나무 가지에서 분리한 균의 크기의 범위는 $4.3-7.2\mu\times20.0-31.5\mu$(평균 $5,9\times25.4\mu$)이었다. 병포자는 발아전후에 1개, 2개 또는 3개의 격막이 생기는 것도 있었다. 배지 또는 접종부위에 형성된 병자각 안에는 소형포자도 형성되었다. 접종식물의 잎과 과실에는 겹무늬의 갈색-흑갈색 병반이 나타났고 사과나무와 배나무의 햇가지에는 사마귀상 돌기가 접종부위에 생기는 것이 있었으며, 복숭아나무 및 벚나무의 가지에는 조피형 동고성 병반이 나타났다.

• 한국환경농학회지
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• 제41권4호
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• pp.328-334
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• 2022

BACKGROUND: The low temperature at flowering period break the balance between vegetative and reproductive growth of apple tree. Summer pruning has been used to control vegetative growth. So, this study was conducted to investigate the effect of summer pruning time on shoot growth and fruit quality of 'Fuji'/M.9 apple trees damaged by the low temperature at flowering period. METHODS AND RESULTS: The following treatments were applied to tree : a) control (no summer pruning), b) pruned 26 June, c) pruned 30 July, d) pruned 28 August, and e) pruned 26 September. The summer pruning significantly increased light penetration and fruit red color by reducing the total shoot growth compared with control. And the summer pruning control the outbreak of apple valsa canker. But the summer pruning at the end of June increased regrowth of shoot and pruning weight compared with the summer pruning at the end of August. The summer pruning at 30 July had the highest fruit weight, but return bloom was the highest in the summer pruning at 28 August. CONCLUSION(S): These results indicated the optimum summer pruning time of 'Fuji'/M.9 apple trees damaged by the low temperature at flowering period were the end of August.