• Korean Journal of Environmental Biology
• /
• v.38 no.4
• /
• pp.603-610
• /
• 2020

The problem of increased resistance to pesticides is caused by the management of Bemisia tabaci, which depends almost entirely on pesticides, and to solve this problem, we investigated the host preference of B. tabaci among herbal plants to develop a possible attractant for alternative control methods. Experiments were conducted in greenhouse tomatoes at the National Institute of Horticultural Science and Herbal Science in Wanju-gun. Major herbal plants such as lemon balm, chocolate mint, rose geranium, and apple geranium were installed 50cm from the ground and 30cm from the top of the tomatoes, then the density of B. tabaci was investigated. As a result of examining the density of B. tabaci by the location of the herbal plants, it was found that the lemon balm location showed the highest B. tabaci density while rose geranium and apple geranium were rather avoided. These results are expected to be helpful in the development of alternative B. tabaci control methods using herbal plants including attractants, repellents, and trap plants.

• Korean Journal of Heritage: History & Science
• /
• v.54 no.2
• /
• pp.194-215
• /
• 2021

Termites are important decomposers in the ecosystem. They are also economically significant structural pests. In this study, we reviewed the developments of termite control and recent research on termite management to provide information on the prevention and control of termites. In Korea, most of the damage to wooden historical buildings is caused by subterranean termites. Reticulitermes speratus kyushuensis is the main species, which is widely found throughout the country. In the early 1900s, inorganic insecticides, such as arsenic dust, were used for termite control. After the synthesis of chlorinated hydrocarbon pesticide in the 1940s, it was widely utilized and demonstrated high termite control efficacy. However, chlorinated hydrocarbon insecticides were later banned, disappearing from markets after reports emerged concerning environmental contamination and toxicity to humans. Therefore, the termite control industry sought a new termiticide; hence many pesticides were utilized for termite control. Organophosphate (1960s), carbamate (1970s), pyrethroid, and insect growth inhibitor (1980s) were newly synthesized and adopted. In the 1990s, the first commercial baits using chitin synthesis inhibitors (CSI) were developed, providing a means to eliminate an entire colony of subterranean termites around a structure. Many studies have been carried out on soil termiticides (liquid termiticides) and CSI baits to increase their efficacy, and different baits such as aboveground bait stations, fluid bait, and high-durability bait were also developed in the 2000s. In addition, the paradigm of termite control has shifted from localized treatments using soil termiticides to area-wide pest management using CSI baits to create termite-free zones and protect buildings over time. Termite infestations in wooden historical buildings in Korea have been reported since 1980, and considerable attention was drawn in the 1990s when several UNESCO world heritages such as the Jongmyo Shrine and the Janggyeong Panjeon Depositories of Haeinsa Temple were infested by subterranean termites. Since then, a survey of termite infestation in wooden architectural heritage has been conducted, and the National Research Institute of Cultural Heritage and Heritage Care Program regularly monitors those properties. Finally, we suggest termite management using primarily CSI baits, selective application of various soil treatments applied to the object, foundation soil treatment, research and development of durable termite baits, application of area-wide programs for wooden-building complexes, application of integrated termite management (ITM), and regular education for owners and managers to prevent and reduce termite damage.

• Research in Plant Disease
• /
• v.29 no.2
• /
• pp.188-192
• /
• 2023

Abiotic and biotic stresses have been a serious threat to crop growth and productivity in the agricultural system. In this study, four strains (HS1, H30-3, KJ40, and BC42), which have biological activities related to disease suppression or alleviation of salinity and drought stresses, were tested for broad-spectrum biocontrol activity against anthracnose caused by Colletotrichum orbiculare, a bacterial fruit blotch caused by Acidovorax citrulli, and Fusarium wilt caused by Fusarium oxysporum in cucumber plants. As a result of test, when the four strains were drenched into the soil, anthracnose in cucumber leaves significantly decrease; strain KJ40 suppressed disease incidence by A. citrulli; strain BC42 significantly reduced bacterial fruit blotch and Fusarium wilt compared to control. Therefore, strain KJ40 could be a biocontrol candidate for controlling anthracnose through induced systemic resistance and the disease caused by A. citrulli as well as alleviating drought stress; strain BC42 has broad-spectrum biocontrol activity against anthracnose, Fusarium wilt, and bacterial fruit blotch.

• Research in Plant Disease
• /
• v.17 no.3
• /
• pp.302-310
• /
• 2011

Elsinoe fawcettii is one of major pathogenic fungi which cause citrus scab diseases, resulting in fruit blemishes that reduce the economic value of fruit. By increasing interest to safe products of crops, the alternative methods of disease control is highly required. We investigated whether the 215 bacterial strains isolated from Jeju Island possess antifungal effect or suppression effect on the symptom development by Elsinoe fawcettii on citrus. Among them, three bacterial strains THJ 609-3, MRL408-3, and TRH423-3 that exhibited antifungal capacity against Elsinoe fawcettii were selected. To illustrate the disease suppression mechanism, pre-inoculation with the selected bacterial strains was carried out whether could suppress the citrus crab on the leaves. The observation with a fluorescence microscope revealed that the selected bacteria could decrease the number of fungal spores. The ratio of germ tube formation was also decreased by the selected bacterial strains at one day after fungus challenge. The strain THJ 609-3 was identified as Pseudomonas putida as a result of analyzing the internal transcript spaces of the rhizobacterial rDNA. The strains MRL 408-3 and TRH 423-3 were identified as Burkholderia gladioli. Our results may be valuable when the selected rhizobacterial strains used as the environment-friendly microbe for biological control on citrus scab caused by Elsinoe fawcettii.

• The Korean Journal of Mycology
• /
• v.41 no.2
• /
• pp.112-117
• /
• 2013

Phytophthora capsici is one of major limiting factors in production of pepper and other important crops worldwide by causing foliage blight and rot on fruit and root. Increased demand for the replacement of fungicides has led to searching a promising strategy to control the fungal diseases. To meet eco-friendly agriculture practice, we isolated microorganisms and assessed their beneficial effects on plant health and disease control efficacy. A total of 360 bacterial strains were isolated from rhizosphere soil of healthy pepper plants, and categorized to 5 representative isolates based on colony morphology. Among the 5 bacterial strains (GJ-1, GJ-4, GJ-5, GJ-11, GJ-12), three bacterial strains (GJ-1, GJ-11, GJ-12) presented antifungal activity against P. capsici in an fungal inhibition assay. In phosphate solubilization and siderophore production, the strain GJ-1 was more effective than others. The strain GJ-1 was identified as Bacillus sp. using 16S rDNA analysis. Bacillus sp. GJ-1 was also found to be effective in inhibiting other plant pathogenic fungi, including Rhizoctonia solani, Pythium ultimum and Fusarium solani. Therefore, the Bacillus sp. GJ-1 can serve as a biological control agent against fungal plant pathogens.

• Microbiology and Biotechnology Letters
• /
• v.32 no.4
• /
• pp.312-316
• /
• 2004

In oder to select the powerful rhizophere-dorminatable biocontrol agent, we had isolated an indigenous antagonistic bacterium which produced antibiotic and siderophore from a disease suppressive local field soil of Gyungsan, Korea. And we could select the Pseudomosp. 4059 which can strongly antagonize against Fusarium oxysporum and Phytophthora capsici by two kinds of antifungal mechanism that can be caused by the antibiotic of Phenazin, a siderophore and a auxin like subThe selected strain was identified as Pseudomonas fluorescens (biotype A) 4059 by biochemical tests, API $\textregistered$ test, MicroLog TM system and 16S rDNA analysis. The selected antagonistic microorganism, Pseudomosp. 4059 had an antifungal mechanism of antifungal antibiotic and sidrophore. And we were confirmed the antagonistic activity of P fluorescens 4059 with in vitro antifungal test against Phytophthora capsici and in vivo by red-pepper.

• Research in Plant Disease
• /
• v.11 no.2
• /
• pp.167-172
• /
• 2005

An isolate of Ampelomyces quisqualis 94013 was selected as an effective parasite for biological control against cucumber powdery mildew. Temperature range for the parasitism of A. quisqualis 94013 against cucumber powdery mildew was $12\~30^{\circ}C$, and optimal temperature for that $20\~28^{\circ}C$. In $20\~35\%$ humidity of the greenhouse, parasitic ability of A. quisqualis 94013 against Sphaerotheca fusca was not good. Inoculation tests revealed that A. quisqualis 94013 can parasitize on six species of Sphaerotheca in the 12 crops and Ersiphe cichoracerum in tomato. As host rang of A. quisqualis 94013 was broad and it may be used effectively as a biocontrol agent for powdery mildew of 13 crops.

• Korean Journal of Environmental Biology
• /
• v.40 no.3
• /
• pp.325-334
• /
• 2022

Paspalum distichum and P. distichum var. indutum are perennial weeds of the family Poaceae that prefer moist environments such as waterfronts and waterways. The origin of both species is North America. P. distichum is distributed all over the world. However, P. distichum var. indutum occurs only in the United States, Japan, and Korea. For this reason, in many countries, P. distichum and P. distichum var. indutum are classified as the same species. In other words, P. distichum var. indutum is a different ecological type of P. distichum. Both species can reproduce and spread mainly by rhizome fragments rather than seeds. This rhizome has a characteristic that it does not germinate if it is buried in the ground with depth of more than 3 cm. As a management method for P. distichum and P. distichum var. indutum in agricultural lands (paddy fields), it is effective to combine cultural control and chemical control methods. In other words, combining deep plowing and harrowing can suppress the budding of water sparrow that has invaded paddy fields or fallow paddy fields. After that, these two species that germinate can be controlled by spraying soil treatment herbicides such as butachlor and thiobencarb or foliar treatment herbicides such as cyhalofop-butyl and fenoxaprop-p-ethyl.

• Korean Journal of Environmental Biology
• /
• v.41 no.1
• /
• pp.31-40
• /
• 2023

In 2022, the Korean Ministry of Environment designated Parthenium hysterophorus as an ecosystem-disturbing plant. The purpose of this study was to present a management plan for P. hysterophorus considering its distribution, morphological, physiological, and ecological characteristics, and to introduce various control techniques. P. hysterophorus is native to Central America and occurs in about 45 countries worldwide. However, in Korea, it only grows in some areas of Tongyeong and Changwon, Gyeongsangnam Province. P. hysterophorus is an annual plant and spreads by seeds, moves between countries in the process of importing and/or exporting agricultural seeds, and spreads by agricultural machinery and vehicles after introduction. P. hysterophorus releases parthenin, an allelochemical that suppresses the occurrence of the surrounding vegetation, from its stems and roots. In addition, P. hysterophorus causes damage to humans and livestock through various allergens. P. hysterophorus can be controlled by physical methods, such as cutting its stems or pulling roots, and by treatment with non-selective herbicides, such as glyphosate. Many biological control research studies have been conducted and, unfortunately, there is no a practical solution so far.

• Korean Journal of Environmental Biology
• /
• v.38 no.3
• /
• pp.486-495
• /
• 2020

We surveyed disease outbreak status that has recently become a problem in organic tomatoes and cucurbit in plastic greenhouse that were grown without spraying pesticides during the plastic greenhouse growing season of 2015 to 2019. It was found that the incidence of leaf mold, tomato spotted wilt virus, and tomato chlorosis virus disease was severe in tomato, and disease incidence of powdery mildew and zucchini yellow mosaic virus were severe in Cucurbit. The disease outbreak was found to be faster and more severe in crops grown in pesticide-free cultivation plastic greenhouses than in plastic greenhouses that are cultivated in general using pesticides. In particular, the occurrence of viral diseases mediated by thrips and aphids was found to be severely damaged. Therefore, in order to produce good organic products, it is important to effectively control pests, and in order to minimize the damage caused by disease, sanitation and physical blocking, and comprehensively utilize organic materials or microorganisms to prevent them.