• Life and Agrochemicals
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• s.280
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• pp.41-41
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• 2012

농촌진흥청(청장 박현출)은 최근 배 검은별무늬병 방제와 관련하여 농약안전사용기준을 철저히 준수해 줄 것을 당부하며 주의사항을 마련, 행정기관 및 관련 단체에 배포했다. 이는 최근 일부지역 배 재배농기에서 배 검은별무늬병 방제를 위하여 안전사용기준이 정해지지 않은 수도용 살균제 등을 오남용한다는 언론보도에 따른 것으로써, 관련기관 및 단체에 각종 농약안전산용 교육 홍보를 강화해 줄 것을 요청한 것이다.

• Korean Journal of Plant Resources
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• v.32 no.4
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• pp.296-302
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• 2019

This study was accomplished to select breeding materials among the pear germplasm 6 species 43 accessions and check out the expression of scab incidence of inter specific hybrids of 5 crosses 609 seedlings for scab resistance breeding. Fruitlets scab incidence of P. pyrifolia, P. bretschneideri and P. ussuriensis were 59.5, 73.4 and 63.0% respectively, and also fruitlets scab incidence of interspecific hybrid cultivars between P. pyrifolia and P. bretschneideri were 77.7%. However, fruitlets scab incidence of P. communis and interspecific hybrid accessions between P. pyrifolia and P. communis were significantly less than 15%. As a result of the Duncan test, scab resistance of pear accessions were classified into two groups: P. communis and their hybrid were resistance and P. bretschneideri, P. pyrifolia, P. ussuriensis, and among their hybrid were susceptible. Also, it showed the same trend in the seedlings. Scab incidence of 'Seolwon' ${\times}$ 'Chuwhangbae' and 'Supergold' ${\times}$ 'Mantienhong' in P. pyrifolia seedlings showed more than 80%, while that of interspecific hybrid between P. pyrifolia and P. communis showed about 2%. It showed scab resistance of P. communis transferred to hybrid seedlings and expressed to be dominant in their seedlings. Namely, P. communis was good breeding materials for scab resistance.

• Research in Plant Disease
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• v.24 no.1
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• pp.52-58
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• 2018

Pear scab and rust are the major diseases causing severe epidemics in organic cultivation of pear trees. Incidences of pear scab and rust were compared in organically managed plots and conventionally managed plots to obtain optimum application schedule of environment-friendly control agents in organically managed plots. Organically cultural practice with 10 time-applications of lime sulfur and Bordeaux mixture showed higher than 40% of control efficacies of pear scab and rust compared to conventionally cultural practice. Organically cultural practice with 8 time-applications of lime sulfur considering weather condition showed higher than 30% of control efficacies of pear scab compared to conventionally cultural practice. The results suggest that proper application of environment-friendly control agents such as lime sulfur considering weather condition will enable effective control of the major diseases for organic cultivation of pear.

• The Korean Journal of Mycology
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• v.13 no.4
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• pp.263-265
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• 1985

To identify a causal organism of pear scab in Korea, pathogens were isolated from pears of different varieties. Venturia nashicola was found to be the pathogen of the scab disease in Korea.

• The Korean Journal of Pesticide Science
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• v.18 no.4
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• pp.434-438
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• 2014

The mixture of fluxapyroxad plus pyraclostrobin or the 9 time-spray schedule with various fungicides was evaluated for their efficacy in controlling pear scab in field trials. It showed sufficient condition to evaluate the efficacy of fungicides for the control of pear scab since disease incidence of the untreated control plot was 58.4% or 100% on leaves or fruits, respectively. Pear scab on leaves was occurred by 6.3% at treated plot with the mixture of fluxapyroxad plus pyraclostrobin, resulting in the 89.2% of control value. Incidence of the fruit disease was 16.7% at treated plot with the mixture of fluxapyroxad plus pyraclostrobin, showing 83.3% of control value. When the 9 time-spray schedule was tested, pear scab was occurred by 5% or 13.3% on leaves or fruits, respectively. Their control values were the 91.4% on leaves or 86.7% on fruits. Although the 9 time-spray schedule showed slightly lower disease incidence than the mixture of fluxapyroxad plus pyraclostrobin, but there is no statistically significant difference. These results suggest that the mixture of fluxapyroxad plus pyraclostrobin can control effectively the pear scab.

• Research in Plant Disease
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• v.29 no.2
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• pp.101-107
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• 2023

Pear scab, caused by Venturia nashicola, is one of the most devastating diseases of Asian pears in Korea, Japan, China, and Taiwan. To manage this disease, growers mainly relied on chemical control. However, continuous use of chemical causes not only environmental contaminant but also the emergence of resistance to pathogens, so a more sustainable management plan is needed. Therefore, it is necessary to understand the life cycle and infection characteristics of V. nashicola and to set an active control strategy according to meteorological conditions rather than, as in the past, calendar-based control or continuous use of a specific fungicide system. Various results of the related research results were reviewed to summarize the race, infection characteristics, and control system of V. nashicola, a pear scab, and to discuss plans for a more effective control system.

• Korean Journal of Breeding Science
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• v.41 no.3
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• pp.354-357
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• 2009

"Wonkyo Na-heukseong 2" was selected from a cross between "Kiyomaro", late season European cultivar with highly resistance and "Mansoo", late season Asian cultivar with long storability, large size and low susceptibility to pear scab made in 1997 at the National Institute of Horticultural & Herbal Science of Rural Development Administration in Korea. "Kiyomaro", released cross between "Taiheiyo" and "Bartlett" with scab resistance caused by Venturia nashicola in Japan, with no visual symptoms on any leaves was used as scab resistant source after field investigation and artificial inoculation test during 1997~1999. "Wonkyo Na-heukseong 2" blooms 1 day earlier than "Mansoo" and 3 days later than "Kiyomaro" in 2008. It is strong in tree vigor and upright-spreading in tree habit. It is classified as highly resistant to pear scab as "Kiyomaro" and "Bartlett", and cross-compatible with parental variety and Korean major pear varieties such as "Niitaka" and "Wonwhang". The average optimum harvest time of "Wonkyo Na-heukseong 2" was approximately 180 days after full bloom and it matured about 20 days shorter than parental varieties. The fruit is spindle in shape and yellowish greenish brown in skin color. Average fruit weight was 484 g and soluble solids content was $13.2^{\circ}Brix$. The flesh had medium to high juice and negligible grit. Its fruit was crisp like Asian pear.

• Korean Journal of Organic Agriculture
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• v.21 no.4
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• pp.617-627
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• 2013

This study was conducted to survey the current pest occurrence and grower's pest management practices, and to investigate biodiversity including birds, snakes, rodents, and amphibians in organic pear orchards. From the questionnaires and field survey of 22 organic orchards in 2010, the materials such as lime sulphur, plant extracts and their mixtures with microorganisms, and oils were preferred over insecticides. Scab, mealybugs, woollybugs and barkminers were the major pests for organic pear growers. Environment-friendly fungicides and insecticides were applied 9 to 10 and 5 to 6 times respectively. Incidence and severity of scab on Niitaka pear fruits in organic orchards was higher than in conventional ones. Whereas for mealybugs there was no significant difference between organic and conventional orchards. Pear fruits in organic orchards were significantly smaller than those of non-organic orchards. For the biodiversity of amphibians, snakes, pheasants, and rodents, there was no significant difference between organic and conventional orchards, but Rufous turtle doves were monitored more in organic areas than in conventional ones.

• The Korean Journal of Pesticide Science
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• v.14 no.4
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• pp.401-406
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• 2010

This study was conducted to investigate the control effects of the environmental-friendly materials against major diseases of pear and to elucidate factors related to spore disperse of pear scab and pear rust. Spore disperse was deeply related ambient temperature in the early stage of disease occurrence and the maximum spore disperse was affected greatly by the air humidity, Percent of infected leaves of pear scab in plot treated with Trichoderma harzianum-YC459 was 29.3% and 43.3% in plot treated with Sulfur-80%. Two formulations above-mentioned were less effective to control pear scab than the chemical pesticide, hexaconazole. Control effect in plots single- and mixed-treated with Trichoderma harzianum-YC459, Sulfur-80% and hexaconazole against pear scab were compared with that in plot treated with chemicals by conventional application schedule in pear orchard. The incidence of pear scab was lower in plot treated with the environmental-friendly materials than that of untreated plot. However there was no significant difference among the treatments at the 5% level. Application of Sulfur-80% reduced significantly the incidence of pear scab (7.8%) compared to that (10.3%) in plot treated by conventional application schedule in organically cultivated pear orchard. Alternative application of Trichoderma harzianum-YC459 and Sulfur-80% (4.3%) suppressed the incidence of pear rust than that (7.1%) in plot treated by conventional application schedule in organically cultivated pear orchard.

• Research in Plant Disease
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• v.16 no.1
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• pp.48-58
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• 2010

In Korea, EBI fungicides which are highly effective for control of pear scab and rust but of high risk for development of resistance have been frequently sprayed by majority of pear growers. To detect any possible resistance or reduced sensitivity in the field strains of scab fungus to five EBIs, difenoconazole, fluquinconazole, flusilazole, fenarimole and hexaconazole, sensitivity tests were conducted with fungal specimens collected in Ulsan and Naju where scab usually occurs and EBIs have been intensively sprayed for many years. As the strains for which $EC_{50}$ values of the EBIs were largely shifted from those of base-line were occasionally found, the resistant or less sensitive strains were supposed to be distributed. In the activity test for the EBIs by artificial inoculation, in which EBI-treated pear leaves on the potted seedlings were inoculated with fungal spores collected in the two regions, development of resistances to EBIs were confirmed. Since the fungal spores collected at 4 and 2 orchards in Naju and Ulsan, respectively, produced much higher disease incidence on the leaves treated with hexaconazole than those on the untreated control, those fungal specimens were determined as resistant to hexaconazole. Similar results were also obtained with two specimens from Ulsan for flusilazole.