• The Korean Journal of Pesticide Science
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• v.18 no.1
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• pp.26-32
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• 2014

This study was conducted to evaluate pest control efficacy of environment-friendly agricultural materials (EFAMs) according to their spray time and frequency against alfalfa weevil, Hypera postica Gyllenhal, at Chinese milk vetch field in Miryang, Korea. Larva, pupa and adult of H. postica occurred more in year 2010 than those in 2011, and the larval population peaked 5 days faster in year 2010 than on $10^{th}$ May in 2011. Control efficacies of EFAMS sprayed on various time and in several frequencies to H. postica during April in 2010 were 73.6%, 71.9% and 66.2% at single spray in early, middle and late April, respectively and ranged from 77.1% to 78.9% when sprayed twice. With three times spray the control efficacy averaged 87.2%. Control efficacies of EFAMs with a single application in early, middle and late April in 2011 were 57.9%, 66.8% and 65.2%, respectively and ranged from 73.7% to 76.8% when sprayed twice. Control efficacy averaged with 82.7% when EFAMs were sprayed for three times. Accordingly, control efficacy of EFAMs against was increased with increasing spray frequency. Among the tested, Ungsamee(R), Wangjoongwangeco(R) and Muchungjidae(R) with a single application showed relatively higher control efficacy with a 4 to 16% lower control rate than a chemical insecticide, etofenprox 20EC. Therefore, Ungsamee(R), Wangjoongwangeco(R) and Muchungjidae(R) can be effectively used for management of H. postica when sprayed at early April for high occurring population and middle April for low occurring population with a single spray.

• Korean journal of applied entomology
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• v.53 no.2
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• pp.157-169
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• 2014

Between 2010 and 2012, diseases and insect pests of sweet persimmon were surveyed at sweet persimmon export complexes and non-export orchards in Suncheon, Jeonnam Province; Jinju, Changwon (Dongeup and Bukmyeon), and Gimhae, Gyeongnam Province; and Ulzu, Ulsan. The following diseases were found in the sweet persimmon orchards: angular leaf spot (Cercospora kaki), anthracnose (Colletotrichum gloeosporioides and Colletotrichum acutatum), circular leaf spot (Mycosphaerella nawae), powdery mildew (Phyllactinia kakicola), and gray mold (Botrytis cinerea). Circular leaf spot was the most frequent and serious disease, and C. gloeosporioides and C. acutatum were found on fruits. Thirty-three insect pest species that belonged to 32 genera of 20 families in 5 orders were found in the sweet persimmon orchards; the two-spotted spider mite, Tetranychus urticae, was also found in the surveyed orchards. Apolygus spinolae, Pseudaulacaspis cockerelli, and Adoxophyes orana were widely found in the surveyed orchards; Spodoptera litura and Homona magnanima were also recorded. Damage by insect pests was low, and the quarantine insect pests peach pyralid moth (Dichocrocis punctiferalis) and persimmon fruit moth (Stathmopoda masinissa) were rarely or not found in the sweet persimmon export complexes. In addition, other quarantine insect pests, such as persimmon false spider mite (Tenuipalpus zhizhilashviliae) and Japanese mealybug (Planococcus kraunhiae), were not detected. These quarantine insect pests were also not found in the sorting places, storage houses, and fruits for export; however, scale insects and two-spotted spider mites were found at a low rate. Although anthracnose (C. acutatum) infested fruit was found in the storage houses, only one in Jinju and Gimhae.

• Journal of Bio-Environment Control
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• v.21 no.2
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• pp.114-119
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• 2012

We have conducted 4 experiments to develop the most environmental and effective use of the two-fluid fog system to prevent and exterminate whiteflies in tomato cultivation. In particular, these experiments used Vitamini tomatoes grown in stand-alone greenhouses at Buyeo Tomato Experiment Station as subjects. Each experiment utilized the fog system in a different way. The first experiment provided the control group, which was subject to the two-fluid fog system without additional humidity control. In the second experiment, the two-fluid fog system controlled the humidity level to be above 70%. The third and the fourth experiment utilized natural substances, which were 1.5 mg/L of Neem Oil and 2 mg/L of Oleic acid respectively, without additional humidity control. From the first experiment, we could observe that a simple use of the two-fluid fog system decreased the density of whiteflies in the greenhouses. This impact of the fog system on whiteflies was greater in the second experiment. By comparing the first and the second experiment, we concluded that whiteflies are more effectively prevented by maintaining a higher humidity level via the fog system's smaller water droplets that float in the air for longer time than the standard fog system in rather dry condition. In the third and the fourth experiments, the extermination level was 78% and 76.4% respectively, comparing only 53% in the first experiment without the humidity control. Therefore, using the natural substances in addition to the humidity control increases the extermination effectiveness. Considering the similar results from the 3rd and the 4th experiments, Oleic acid has a greater appeal for its lower price. Using the two-fluid fog system to both control the humidity on a daily basis and spray the substances for occasional extermination would reduce labor cost and increase production in an environmental way.

• Journal of Distribution Science
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• v.13 no.10
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• pp.115-122
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• 2015

Purpose - This study was conducted to develop a beekeeping farm management standard checklist. This is essential to increase the competitive power of beekeeping farmers. Checklists in relation to crops and livestock were established by the Rural Development Administration in the 2000s. To date, 60 checklists have been created by crop and livestock experts. However, other farmers outside the 60 checklists are increasing. Therefore, extra development is required for these farmers. This study was conducted to meet farmers' requirements. The special farming dealt with in this study is beekeeping. Such checklists were not developed due to the small number of beekeeping farmers. However, these days, a number of such farmers are emerging. Research design, data, and methodology - Many related experts participated in this study. This study was conducted in four stages. First, a basic outline of beekeeping was created by surveying many kinds of beekeeping experts. The draft of the beekeeping checklist was created by a secondary advisory council. This draft was then sent to 14 beekeeping experts to confirm whether or not it was suitable as a management checklist. For collecting the experts' opinions, a direct visit survey was done through an arranged questionnaire. Additionally, a basic management checklist blueprint was reviewed by many experts. In the third stage, a Delphi survey method was utilized with a special Delphi questionnaire. In this stage, experts who participated in the first and second stages were excluded. As there were uncertain answers among them, a second Delphi survey was done. As a result of this survey, all answers were agreed among them. Results - From the results of this survey, four subjects in the management accomplishment index were determined. These are farming scale, average product per beehive, the sale price of honey (1kg), and the number of bee plates in the beehive. In the case of the management checklist content, five items were determined. These are beekeeping farming facilities, the environment around the farm land and general management, the product management of the beekeeping harvest, the management of the disease and pest, and farming management. This checklist will be utilized for beekeeping farmers to implement in a management situation. Conclusions - These days, the number of beekeeping farmers is increasing. The management checklist for beekeeping farmers will be used to improve their farming situation and marketing. Beekeeping farmers can understand their management by reviewing their checklist. After checking, the situation of management can be analyzed. Farmers can supplement weaknesses with expert advice. This checklist will be used by agricultural technique extension workers for farming management consulting. This checklist has to be complemented by a change in the management of the environment. This checklist will be delivered to beekeeping farmers after a verification survey is done. The result of the checklist score will be utilized for a benchmarking service to be implemented for beekeeping farmers to utilize.

• Journal of the Korean association of regional geographers
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• v.2 no.1
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• pp.51-67
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• 1996

There are three main rice-growing regions in the United States: the prairie region along the Mississippi River Valley in eastern Arkansas; the Gulf Coast prairie region in southwestern Louisiana and southeastern Texas; and the Central Valley of California. The Central Valley of California is producing about 23% of the US rice(Fig. 1). In California. most of the crop has been produced in the Colusa, Sutter, Butte, Glenn Counties of the Sacramento Valley since 1912, when rice was commercially grown for the first time in the state(Fig. 2). Roughly speaking, the average annual area sown to rice in California is about 300,000 acres to 400,000 acres during the last forty years(Fig. 3). California rice is grown under a Mediterranean climate characterized by warm, dry, clear days, and a long growing season favorable to high photosynthetic rates and high rice yields. The average rice yield per acre is probably higher in California than in any other rice-growing regions of the world(Fig. 4). A dependable supply of irrigation water must be available for a successful rice culture. Most of the irrigation water for California rice comes from the winter rain and snow-fed reservoir of the Sierra Nevada mountain ranges. Less than 10 percent of rice irrigation water is pumped from wells in areas where surface water is not sufficient. It is also essential to have good surface drainage if maximum yields are to be produced. Rice production in California is highly mechanized, requiring only about four hours of labor per acre. Mechanization of rice culture in California includes laser-leveler technology, large tractors, self-propelled combines for harvesting, and aircraft for seeding, pest control, and some fertilization. The principal varieties grown in California are medium-grain japonica types with origins from the cooler rice climates of the northern latitudes (Table 1). Long-grain varieties grown in the American South are not well adapted to California's cooler environment. Nearly all the rice grown recently in California are improved into semidwarf varieties. Choice of variety depends on environment, planting date, quality desired, marketing, and harvesting scheduling. The Rice Experiment Station at Biggs is owned, financed, and administered by the rice industry. The station was established in 1912, as a direct result of the foresight and effort of Charles Edward Chambliss of the United States Department of Agriculture. Now, The station's major effort is the development of improved rice varieties for California.

• Journal of Bio-Environment Control
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• v.31 no.4
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• pp.384-392
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• 2022

The objective of this study was to estimated nitrogen content and chlorophyll using RGB, Hyperspectral sensors to diagnose of nitrogen nutrition in apple tree leaves. Spectral data were acquired through image processing after shooting with high resolution RGB and hyperspectral sensor for two-year-old 'Hongro/M.9' apple. Growth data measured chlorophyll and leaf nitrogen content (LNC) immediately after shooting. The growth model was developed by using regression analysis (simple, multi, partial least squared) with growth data (chlorophyll, LNC) and spectral data (SPAD meter, color vegetation index, wavelength). As a result, chlorophyll and LNC showed a statistically significant difference according to nitrogen fertilizer level regardless of date. Leaf color became pale as the nutrients in the leaf were transferred to the fruit as over time. RGB sensor showed a statistically significant difference at the red wavelength regardless of the date. Also hyperspectral sensor showed a spectral difference depend on nitrogen fertilizer level for non-visible wavelength than visible wavelength at June 10th and July 14th. The estimation model performance of chlorophyll, LNC showed Partial least squared regression using hyperspectral data better than Simple and multiple linear regression using RGB data (Chlorophyll R²: 81%, LNC: 81%). The reason is that hyperspectral sensor has a narrow Full Half at Width Maximum (FWHM) and broad wavelength range (400-1,000 nm), so it is thought that the spectral analysis of crop was possible due to stress cause by nitrogen deficiency. In future study, it is thought that it will contribute to development of high quality and stable fruit production technology by diagnosis model of physiology and pest for all growth stage of tree using hyperspectral imagery.

• Korean journal of applied entomology
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• v.62 no.4
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• pp.227-243
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• 2023

The Asiatic pink stem borer, Sesamia inferens (Walker, 1856) (Lepidoptera: Noctuidae) is a pest that attacks rice stems. In this study, we estimated the annual generation of insect in several regions of the Republic of Korea. Adult trapping using a sex pheromone trap detected the occurrence of S. inferens adults in the three northernmost areas around 38° latitude and showed that the insect inhabits all of Korea. In most areas investigated, the seasons of the adult generations estimated using the single-sine degree-day model did not deviate from the corresponding observed seasons of adult occurrence. We estimated that the overwintering larvae hypothetically-estimated using the model could be originated from the last generation of adults. When larvae collected in paddy fields during the autumn season in a few middle and southern areas were reared at 25℃, ca. 70% of pupae did not show additional larval molting before their pupation. All larvae collected in early March in a southern area (Goseong, Gyeongsangnam-do) pupated without additional larval molting when reared at 25℃. Based on these results, we presumed that S. inferens could overwinter as mainly the last instar larval stage in the area. Taken together, we conclude that S. inferens primarily has two generations per year in areas around 38° latitude, and three generations in the areas between 35.3° and 37.3° latitude. In addition, approximately 35% of insects captured by the sex pheromone trap were species other than S. inferens, as determined by analyzing the nucleotide sequences of the cytochrome c oxidase 1 gene. These species were not morphologically misidentified as S. inferens.

• Korean Journal of Environmental Agriculture
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• v.33 no.4
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• pp.395-402
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• 2014

BACKGROUND: Azadirachta indica Extract(AIE) containing azadirachtin as active ingredient have been used worldwide as environment-friendly organic material having pest control properties. However, the extracts prepared with different solvent and from different plant site is very diverse and have different toxicity. METHODS AND RESULTS: In this study, the four week repeated oral dose toxicity test of aqueous AIE in Sprague-Dawley rats was carried out to investigate the toxic effect of liver, main toxicity target organ of AIE. The male and female rats were divided into 4 groups, respectively; control(0 g/Kg bw), low-dose group(0.5 g/Kg bw), middle-dose(1.0 g/Kg bw) and high-dose group(2.0 g/Kg bw). As a results, relative liver weight increased with dose-dependent of AIE(p<0.05). Serum LDH in all AIE-treated groups were significantly lower than the control in male rats(p<0.05). However, serum GOT and GPT were significantly increased in all male AIE-treated groups in male rats(p<0.05) and, in particular, increase of serum GPT in dose-dependent manner raise the possibility of liver damage. Even through serum GLU was increased significantly in high-dose group in male rats compared to control, there were no significant differences of urinary GLU among all groups(p<0.05). In addition, histopathological examination of the liver did not reveal any lesions in all AIE-treated groups. CONCLUSION: In conclusion, 4 weeks of the repeated oral administration of AIE 2.0 g/Kg to rats has resulted no toxic response in liver. Therefore, AIE was no indicated to have any toxic effect in the SD rats, when it was orally administrated below the dosage 2.0 g/Kg/day for 4weeks.

• Journal of Forest and Environmental Science
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• v.19 no.1
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• pp.85-98
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• 2003

The articles, published in the Journal of Korean Forestry from Number 1(1962) to Number 6, Volume 91(2002), were surveyed and investigated for the research trend analysis about resource-plants for special use or purpose, i. e., edible plants, medicinal plants, feed resource, landscape plants, fiber plants, industrial usuage, and bee plants. If the purpose or subject matter of the research was construction or furniture timber production, mushrooms and/or pulp and paper, such research was not included in this study. These articles were classified again depending on the content of research into 14 categories: habitat environment, ecology, physiology, propagation, silviculture (tending and culture), genetics and breeding, identification, insect and disease control, animal-related research, component analysis, vegetation survey, biotechnology, management, and review. Among the total 1.434 articles published, 396 ones (27.6%) were related with plants for special use or purpose. Vegetation survey was 60 (15.2%): physiology 56(14.1%) : genetics and breeding 56(14.1%): propagation 53(13.4%): and ecology 37(9.3%). Siviculture research field included 11 articles (2.8%), which indicates that the management of resource-plants is so far from economic income as seen in the low number of management research filed articles, i. e., only 6 reports (1.5%) Korean white pine was most popular for research and included 42 articles: Robinia pseudoacacia 23: Castanea crenata 14: and ginkgo tree 14. Research related with these species had focused mainly on propagation, physiology, genetics and breeding, ecology and pest control. Based on this survey and analysis, the followings are suggested: 1. More research is required on forest herbaceous plants. 2. Cooperative research work with other industrial and/or scientific area is recommendable for commercialization including medicine, cosmetics, and food etc. 3. Research on resource-plant conservation, which includes biology, social education and policy, should be supported for next generation. 4. Mutual correspondence and information exchange about the research results between researchers and institutes is more necessary than now.

• Horticultural Science & Technology
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• v.32 no.4
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• pp.517-524
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• 2014

As an assessment of substantial equivalence and environmental risks of branchless chrysanthemum GM lines (LeLS69, LeLS76, LeLS80) developed in Korea, we investigated their degree of branchlessness and developmental characteristics including growth and flowering, as well as the stability of populations of insect pests and soil microbes. The GM lines were compared with a control variety, 'Jinba'. LeLS80 showed the highest level of branchlessness among the three GM lines, whereas abnormal axillary buds developed in lines LeLS76 and LeLS69. There were no significant differences between the growth characteristics of 'Jinba' and the GM lines. The branchlessness LeLS80 was increased during the summer season, suggesting that it is a useful germplasm for developing elite branchless cultivars. These GM lines showed no significant differences in the occurrence of five insect pests including aphids, mites, leaf miners, thrips, and whiteflies. Similarly, for soil microbes including bacteria and actinomycetes, there were no significant differences between 'Jinba' and the GM lines. However, there was a higher occurrence of fungi in the GM lines compared to 'Jinba'. Our findings suggest that 'Jinba' and the GM lines are substantially equivalent, although further monitoring studies are needed to confirm this.