• Journal of Mushroom
• /
• v.14 no.3
• /
• pp.100-104
• /
• 2016

Mushroom flies are one of the most serious threats to mushroom production and cultivation in Korea, and they cause significant losses in yield and quality. In this study, we investigated the occurrence and control of mushroom flies in farms where Agaricus bisporus was cultivated in Chungnam. The cultivation period was more than 7 years in the 32 mushroom farms examined; about 28% were environment-friendly cultivation farms, and 72% were conventional cultivation farms. Mushroom flies were a major pest in about 84% of the examined farms. Most of the mushroom flies were sciarids and phorids (71% and 24%, respectively). The adult flies were found throughout the year, but their occurrence was the highest in September when the temperature increased. In general, the occurrence of mushroom flies in the examined farms was high; however, insect nets and post-crop steaming programs used as basic control methods were not implemented properly. Our findings show that integrated pest management of mushroom flies is urgently required for A. bisporus cultivation in Korea.

• Korean journal of applied entomology
• /
• v.54 no.2
• /
• pp.83-89
• /
• 2015

This study was conducted with n-hexane extracts of sensitive plant Mimosa pudica, mexican poppy Argemone mexicana, panimarich Leucus aspara, water pepper Polygonum hydropiper and shialmutra Blumea lacera weeds against pulse beetle Callosobruchus chinensis (Coleoptera: Bruchidae) for protection of mung bean Vigna radiata grains. The $LC_{50}$ values of the weed extracts ranged from 4.5 to 6.4, 4.1 to 5.6 and 3.6 to 5.5 g/100 mL at 24, 48 and 72 hours of post treatment, respectively. The extracts showed 35 to 69% fecundity and 33 to 63% adult emergence inhibitory effect on the pest, and revealed 13 to 49% grain protection of mung beans. Insect mortality, fecundity and adult emergence inhibitory effects, and grain protection activity increased with increased concentration of the extracts. The shialmutra followed by water pepper extracts revealed better performances in fecundity and adult beetle emergence inhibitory effect compared to the other weeds. The findings proved that the n-hexane extracts of the five weeds are sources of botanical insecticides which may be used in the integrated management of C. chinensis.

• Microbiology and Biotechnology Letters
• /
• v.33 no.1
• /
• pp.9-15
• /
• 2005

Chitin deacetylase (CDA; EC 3.5.1.41) catalyzes the hydrolysis of N-acetamide bonds of chitin, converting it to chitosan. Chitosan has several applications in areas such as biomedicine, food ingredients, cosmetics, pharmaceuticals, and agriculture. In this paper, occurrence, assay and purification protocols, enzymatic characteristics, substrate specificity, and mode of action of microbial CDAs have been described. Several lines of evidence have substantiated the biological roles involved in cell wall formation and plant-pathogen interactions for fungal CDAs. The gene structure of CDAs has been compared with other family 4 carbohydrate esterases which deacetylate a wide variety of acetylated poly/oligo-saccharides. The use of CDAs for the conversion of chitin to chitosan, in contrast to the presently used chemical procedure, offers the possibility of a controlled, non-degradable process, resulting in the production of well-defined chitosan oligomers and polymers. Insect pathogen that can secrete high levels of chitin-metab­olizing enzymes including CDA can be a possible alternative for new pest management tools.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.15 no.4
• /
• pp.201-209
• /
• 2013

The spread and expansion of pests and pathogens due to climate change have caused considerable reduction of rice yield in agricultural landscapes. This study was conducted to quantitatively analyze the spread of rice pathogens carried by insect pests on spatial network in South Korea using graph-theoretic methods. We identified the connectivity "backbone" of pathogen spread network among the cities along the coastal area of West Sea. In addition, we graphically represented 1) the core areas that can cause local and regional outbreaks of pathogens; and 2) the areas that act as bottlenecks in the spread of pathogen which can link the core areas. Especially, the cities in the coastal areas of West Sea that have the high density of rice crops, represented a low spread resistance to pathogen infection. These results may suggest insights into planning the integrated pest management possibly through regional collaboration.

• The Korean Journal of Pesticide Science
• /
• v.12 no.2
• /
• pp.177-183
• /
• 2008

For the development of integrated pest management system by harmonizing biological and chemical control, some experiments were carried out to select low toxic pesticides against natural enemies. Leaf dipping method, body dipping method, and diet treatment method were used for the toxicity evaluation against Microplites mediator adults. We tested 49 different pesticides (34 insecticides, 11 fungicides, 4 herbicides) at recommending concentration commonly used to control insect pests, disease and up-land weeds in chinese cabbage field. 16 insecticides, 11 fungicides, and 4 herbicides were shown to be low toxic to Microplites mediator adults in the treatment of body dipping.

• Weed & Turfgrass Science
• /
• v.2 no.1
• /
• pp.95-99
• /
• 2013

To investigate the actual condition of production and management of sod, a questionnaire was ask to 57 farmers in major cultivated areas of turf sod in Korea in 2010 and 2011. The results of the turfgrass management situation analysis showed a mixed farming where the ratio of the principal work and the side work progress similarly, and for the landholding type depending on the management scale, the rental ratio was high for a scale over 0.5 ha. Sod production farmers has high-profile in new varieties of turfgrass, integrated management of the fertilization and soil or disease and insect pest however the future of the turfgrass industry does not seem optimistic due to the problems such as market stability or scarcity of worker. Obtaining of information on culture methods depended neighbor's experience (81.8%). Concerning the varieties preference analysis, the 32.1% of farmer answered that the reproductive rate was a key factor for the new variety. Sod production farmers want to receive financial support (28.1%), improvement of distribution structure of sod (26.6%), and spread of good variety turfgrass (23.4%).

• Korean Journal of Organic Agriculture
• /
• v.21 no.4
• /
• pp.601-615
• /
• 2013

This study was conducted to compare the community structure and biodiversity of arthropods between conventional and organic red pepper fields. A total of 36 species of 24 families belonging to 10 orders from collected 28,718 arthropods; 6,901 individuals from conventional field and 21,871 individuals from organic field. A number of species comprising arthropod community was same in both fields as 32 species. Species richness of Diptera was the highest in conventional field and that of Hymenoptera and Colembolla was the highest in organic field. Abundance of Frankliniella intonsa was the highest regardless of farming method. Helicoverpa assulta was dominant in conventional field, and Homidia mediaseta, Diptera sp. 4 and Pardosa astrigera were dominant in organic field. Diversity of community on the ground was higher in organic field and statistically different. Similarity of arthropod community showed difference with 34.07% on the ground and 26.95% in the plant above ground. In the ecologically functional guild: species richness of general, pest and parasitoid of natural enemy groups in the plant above ground were statistically different and pest and parasitoid groups were higher in organic field, abundance of predator group of natural enemy on the ground was 2 times higher in organic field and statistically different and diversity of general and parasitoid groups in the plant above ground were statistically different. In the relative occupancy rate, pest group was the highest in conventional field and decomposer group was the highest in organic field. The results of present study is considered to provide useful information of arthropod community for developing efficient insect pest management in organic farming.

• Current Research on Agriculture and Life Sciences
• /
• v.3
• /
• pp.129-150
• /
• 1985

The present investigation was conducted to provide a systematic approach necessary to establish an integrated insect pest management program of barley in Korea. Some ecological surveys on insect pests of barley have been undertaken at the field of Experimental Station, Ky$\check{o}$ngbuk Provincial Office of Rural Development as a fixed point survey area, and at 23 localities for round survey throughout southern and central Korea from 1983 to 1984. Previously known insects injurious to barley in Korea were revised and the population dynamics of 10 dominant harmful species were analyzed according to either 24 localities or 25 cultivars respectively by using several sampling methods of net sweeping, black light traps, yellow water pan traps and visual counting. As the results, a total of 94 species belonging to 77 genera under 32 families are known to be injurious to barley, among them 20 species are newly added here. In the population density level, the dominant species were disclosed as Laodelphax striatellus (43.1 %), Macrosiphum avenae(27.0 %), Rhopalosiphum padi(6.5 %), R. maidis(5.4 %), Psammolettix strialus(2.7 %), Chlorops oryzae(2.2 %), Agromyza albipennis(2.1 %) Phyllotreta nemorum(1.4 %), Chaetoenema cylindrica(1.0 %), Dolycoris baccarum(1.0 %) in order. For the general abundance of major insect pests, it was highest in the cultivar P'aldal whereas lowest in Milyang #22. There were tendencies that Psammotettix striatus, Dolycoris baccarum, Phyllotreta nemorum and Chaetocnema cylindrica represented a maximum increase in the beginning of June, while Chlorops oryzae and Agromyza albipennis showed in the middle of May but aphids were in the end of May. In the dominance of natural enemies, Nabis stenoferus occupied 21.4 % and Propylaea japonica 9.6 %.

• Journal of Korean Society of Forest Science
• /
• v.105 no.1
• /
• pp.42-47
• /
• 2016

To examine the natural regeneration in the natural mixed-broadleaved forest, flowering, fruiting, seed-fall, and seed viabilities of Acer pseudosieboldianum (Ap) were investigated in Mt. Jungwang, Gangwon-do, from 2009 to 2015. The flower of Ap consisted many male and bisexual flowers on the corymb. Flowering dates are differed between sex morph in the same inflorescence. Stamens are stop growing and disappeared after pollinated pistil begin to grow in bisexual flowers, and male flowers have vestial pistil. The flowers of Ap might be pollinated by Apis mellifera, Andrenidae spp. and Syrphinae spp. Ap had some mechanism to prevent from self pollination with heterodichogamy. Mean annual seedfall of Ap was 70,780 ea/ha (ranged 310~234,840 ea/ha). Annual seedfall of Ap varied severely, and the maximum was about 760 times the minimum. Annual seed production of Ap might be to a normal distribution. Rates of damaged or decayed seeds are highest 59.3%, and those of sound seeds are 23.9%, Those of undeveloped and empty seeds are 9.2% and 7.6%, respectively. The most important factors influencing sound seed production might be the density and activities of insect pollinators and sucking pest in the flowerwing period, middle-late May. Successful regeneration of Ap might be in masting year and on the gap sites with proper conditions to germinate and grow. To understand the natural regeneration of deciduous hardwoods, further study on the characteristics of flowering and fruiting, pre- and post-dispersal seed predation, and annual variation on these factor should be needed.

• Korean journal of applied entomology
• /
• v.17 no.2 s.35
• /
• pp.115-123
• /
• 1978

Present status on the pesticides production, supply, manufacture and pests control in Korea are summarized. The data in the past several years (1971-76) are analyzed to find out the problems and solutions for the further development of plant protection and pesticide industry in Korea. Since the acreages of crop plantation and the quantities of pesticides uses are already near to the stage of plateau, pesticide formulation with imported technical grade should be modified by local synthesis with imported quality. The government pesticides management act and regulations must be modernized urgently in connection with the synthesis. formulation, tests, registration, quality control. price and supply system as well as the safety use of pesticides. Recommendation concerning acceptable daily intakes(ADI) and residue limits must be established for the strengthning pesticide safety use and plant protection activities as soon as possible. The use of fungicide-insectide mixture in dust formulation must be authorized and practiced immediately for the labor saving and one-hit cooperative mass control of rice disease and insect pests, especially. At present, serious considerations on pesticide safety use and integrated pest control are strongly urged to help the farmers, to save the industries and to keep the nature as it is required.