• 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.

• Korean Journal of Agricultural Science
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• v.50 no.4
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• pp.723-734
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• 2023

Erwinia pyrifoliae, which causes black shoot blight in apple and pear trees, was first identified in Korea in 1995. Extensive measures are typically used to control the disease by eradicating trees in diagnosed orchards, owing to the detrimental impact of the disease on apple and pear production. However, despite governmental efforts, the disease has continuously spread. In this study, we analyzed the current status of the black shoot blight occurrence in apple and pear orchards between 1995 to 2022. Our findings reveal that over the past 28 years, black shoot blight has occurred in 26 cities and districts across five Korean provinces. The affected regions are predominantly concentrated in the northern part of Korea, including the Gangwon and Gyeonggi provinces. Furthermore, black shoot blight has gradually expanded to the northern provincial regions of Chungbuk, Chungnam, and Gyeongbuk, which are centrally situated in Korea. Furthermore, the occurrence pattern of black shoot blight differed between apple and pear orchards; in apple orchards, black shoot blight occurred consistently each year, with a sudden increase in cases in 2020; however, in pear orchards, it has considerably decreased since 2007. To the best of our knowledge, this is the first comprehensive report on the occurrence of black shoot blight in apple and pear trees in 28 years, and the results will provide valuable insights for future disease management strategies.

• Research in Plant Disease
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• v.27 no.3
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• pp.91-98
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• 2021

The current social demand for organic, sustainable, and eco-friendly approaches for farming, while ensuring the health and productivity of crops is increasing rapidly. Biocontrol agents are applied to crops to ensure biological control of plant pathogens. Research on the biological control of white root rot disease caused by a soil-borne pathogen, Rosellinia necatrix, is limited in pears compared to that in apple and avocado. This pathogenic fungus has an extensive host range, and symptoms of this disease include rotting of roots, yellowing and falling of leaves, wilting, and finally tree death. The severity of the disease caused by R. necatrix, makes it the most harmful fungal pathogen infecting the economical fruit tree species, such as pears, and is one of the main limiting factors in pear farming, with devastating effects on plant health and yield. In addition to agronomic and cultural practices, growers use chemical treatments to control the disease. However, rising public concern about environmental pollution and harmful effects of chemicals in humans and animals has facilitated the search for novel and environmentally friendly disease control methods. This review will briefly summarize the current status of biocontrol agents, ecofriendly methods, and possible approaches to control disease in pear orchards.

• Weed & Turfgrass Science
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• v.5 no.2
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• pp.51-59
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• 2016

The study was conducted to get a information on the dominance and distribution of weeds occurred in major orchards including apple, grape, peach, pear, and plum at 631 sites of Gyeongsangbuk-do during winter and summer season. The weeds classified by family and life cycle occurred in the five orchards were summarized as 36 family and 105 species in apple orchard, 34 family and 126 species in grape orchard, 34 family 126 species in peach orchard, 33 family 98 species in pear orchards, and 36 family 111 species in plum orchard. In addition to life cycle of weeds, most orchards except for pear orchard were dominant to biennial weeds. The most dominant importance value was observed in pear orchards as 6.57%. In winter's season, the weeds were summarized as 31 family and 89 species in apple orchard, 28 family and 71 species in grape orchard, 32 family 111 species in peach orchard, 27 family 68 species in pear orchards, and 33 family 83 species in plum orchard. In summer's season, the weeds were distributed as 31 family and 101 species in apple orchard, 27 family and 69 species in grape orchard, 29 family 91 species in peach orchard, 31 family 94 species in pear orchard, and 31 family 97 species in plum orchard. In winter season, the most dominant weeds in apple, grape, peach, pear, and plum orchard were Capsella bursa-pastoris, Laria media, Capsella bursa-pastoris, Capsella bursa-pastoris, and Erigeron canadensis, in turn. In summer season, the most dominant weeds in apple, grape, peach, pear, and plum orchard were Acalypha australis, Acalypha australis, Setaria viridis, Setaria viridis, and Setaria viridis, respectively.

• Korean journal of applied entomology
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• v.51 no.4
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• pp.479-484
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• 2012

The occurrence of plum fruit moth, Grapholita dimorpha, has been recently reported in apple orchards in Korea. It has been suspected that G. dimorpha and its related species, G. molesta, may occur simultaneously in other host plants. This study reports the occurrence of G. dimorpha in pear orchards of different localities in Korea. The identification of G. dimorpha was determined by morphological characters and the DNA marker. The cross-trapping of both species may be possible because the major sex pheromone (SP) compositions for the two species are similar. From the monitoring data, G. dimorpha and G. molesta were caught in SP lure traps of G. dimorpha and both species were also caught in SP lure traps of G. molesta. This cross-trapping of G. molesta to a SP lure of G. dimorpha varied significantly among pear orchards in different geographical localities. Furthermore, the occurrence peaks of the two species were not coincidental in all monitored orchards. These suggest that monitoring data obtained from each SP trap of both species in pear orchards may be mixed with two species, which would result in the over-estimation of population density and peak frequency on both species in pear orchards.

• Korean Journal of Organic Agriculture
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• v.26 no.2
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• pp.245-257
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• 2018

The efficacy of different control techniques against the large black chafer, Holotrichia parallela Motschulsky (Coleoptera: Scarabaeidae), in organic pear (Pyrus pyrifolia) orchards was evaluated. In this study, field trials were conducted in three locations in Korea-Naju, Hampyeong, and Boseong-to evaluate different techniques to suppress these beetles. Pheromone traps, bio-insecticides (Hongmengye and Melchungdaejang), and a combination of the two were applied as treatments. In Naju, Hampyeong, and Boseong, the highest number of adult H. parallela were caught in the control plots (n=45, n=39, and n=20, respectively), while the fewest were caught in the pheromone plus bio-insecticide plot (n=19) in Naju and in the combined treatment plot in Hampyeong (n=10). In Naju, the greatest leaf damage was observed in the control (66%), and in all locations (Naju, Boseong, and Hampyeong), the least damage occurred in the combined treatment plots (42%, 36%, and 24%, respectively). Regarding the tree canopy, the greatest leaf damage was observed in the upper canopy, and less damage was observed in the lower canopy. These results demonstrate that the combination of sex pheromone traps and bio-insecticides can be used to manage H. parallela in organic pear orchards.

• Korean journal of applied entomology
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• v.53 no.3
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• pp.209-215
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• 2014

This study was performed to monitor the seasonal occurrence of Pseudococcus comstocki (Kuwana) by using pheromone traps and to test a mating disruption technique to control this pest in pear orchards. We compared the attractiveness of rubber septa loaded with 1.5 and 3.0 mg of the pheromone, 2,6-dimethyl-1,5-heptadien-3-yl acetate. A total of 1,021 and 1,431 males were caught in traps baited with 1.5 mg and 3 mg of the pheromone, respectively. The numbers of males caught were not affected by trap color, although yellow traps were more attractive than white traps. In 2012, P. comstocki males were captured between June and October, with peaks in late June, early August, and late September. In 2013, the males were trapped between June and October, with peaks in middle June, late July, and late September. In pheromone mating disruption tests, catches were reduced by 17.7, 65.3, and 62.9% in orchards treated with 450, 900, and 1,350 mg per 10 a of the pheromone, respectively. At harvest, 3.4, 2.9, and 4.8% of fruits in orchards treated with 450, 900, and 1,350 mg per 10 a were damaged by P. comstocki, while 9.5% were damaged in the control orchard.

• Research in Plant Disease
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• v.25 no.2
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• pp.89-93
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• 2019

Fire blight disease caused by the bacterium, Erwinia amylovora, was observed in apple and pear orchards in Korea in 2015. Since then, it has spread, sometimes over long distances to other orchards. Therefore, we examined the ability of E. amylovora to survive in soils and on the surfaces of common materials such as T-shirts, wrist bands, pruning shears, and rubber boots by both conventional PCR (cPCR) and quantitative PCR (qPCR) methods. E. amylovora was detected in all materials tested in this study and survived for sufficiently long periods to cause fire blight disease in new sites. Thus, based on the results of this study, sanitation protocols must be applied to equipment during orchard work.

• Korean Journal of Organic Agriculture
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• v.19 no.1
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• pp.93-107
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• 2011

This research was carried out to investigate invertebrate fauna with organic and conventional pear orchards, which used four collected methods; soil sampling for soil microorganism, pitfall, malaise, and black light trap for over ground species. Collected species were 37 species, 1,184 individuals in organic and 28 species, 501 individuals by soil sampling in conventional pear fields. Those were 38 species, 646 individuals and 29 species, 440 individuals by pitfall trap, 55 species 650 individuals and 47 species, 508 individuals by malaise trap, and 23 species, 201 individuals and 9 species, 42 individuals by black light trap. Collembola was collected 389 individuals in organic which was 5 times than in conventional in soil sampling. In pitfall trap, that was 183 individuals which was 3 times. The diversity indices of organic pear orchards were 1.956 in May, 2.638 in August and those of conventional was 1.426 in May, 2.011 in August in soil sampling. In pitfall trap, the dominant species were spiders, collembollan, and coleopteran. Among Coleoptera, indicator insects for the evaluation of agricultural environment suggested were Eusilpha jakowelewi as organic pear orchard and Anisodactykus punctatipennis and Pheropsophus jessoensis as conventional. Malaise trap was collected dominant species as Diptera and Hymenoptera of Braconidae and Ichneumonidae. The diversity indices of organic pear orchards were 2.952, 3.120, and 2.010 in pitfall, malaise and black light trap in over ground invertebrate sampling. The highest diversity was in malaise trap. The higher diversity indices, the lower dominance indices.

• The Korean Journal of Mycology
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• v.51 no.4
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• pp.471-490
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• 2023

Soil is a rich source of saprobic and pathogenic fungi in crop cultivation areas. Compared with that of the fruit trees, scarce information is available regarding the fungi present in orchard soils in Korea. We sampled rhizosphere soils of apple and pear trees from several orchards in Cheongju, Anseong, and Cheonan, Korea. During the processing of soil fungi, seven unrecorded species of the phylum Ascomycota were isolated. These included Acrocalymma walkeri, Clonostachys krabiensis, Coniella vitis, Cosmospora diminuta, Lasiobolidium spirale, Penicillium vallebormidaense, and Pseudothielavia arxii. All the species were identified and described based on morphological characteristics and molecular analysis of the ITS1-5.8S-ITS2 region and the large subunit of nuclear ribosomal RNA gene and partial β-tubulin gene (BenA) sequences. Descriptions and illustrations of the morphological characteristics are provided.