• Journal of Korean Society of Forest Science
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• v.102 no.1
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• pp.107-112
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• 2013

The purpose of the study is to give ROI information about management status and investment returns to someone who will newly cultivate Rhus verniciflura and expand area of Rhus verniciflura cultivation. In this study, IRR (Internal Rate of Returns), B/C Ratio and NPV are applied for ROI analysis. We basically surveyed thirty household among Rhus verniciflura cultivation farmhouses in chief producing districts Won-ju in Gang- Won, Ok-Cheon in Chung-Buk, Ham-Yang in Gyeong-Nam in Korea from May until October in 2011. Hence, the research surveyed these farmers about production cost, management cost, input labors and materials, land price and etc. by working process to calculate production and operation cost. As the result of farm survey, the result of the analysis shows income rate 27.76%, B/C Ratio 2.5, and NPV 121,830,831 won in $16,500m^2$ with 10 years period when local price of Rhus verniciflura is 2,200,000 won/3.75 kg at locals with 3% discount rate is applied. Therefore, starting open field cultivation of Rhus verniciflura, which requires intensive labor or expanding the cultivation area needs more labor force.

• Journal of Sericultural and Entomological Science
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• v.14 no.2
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• pp.95-103
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• 1972

The major purpose of this study is to collect the information related on the aspects of economic efficiency for solving the problems which are faced by farmers and areas, and providing scientific facts to farmers and related institutions for further development of sericultural sector in Korea. In order for obtaining the related information 12 sample areas among 23 major sericultural farming areas and 30 farm units in each area are selected and analyzed in this study. The fold suevey is made by member of this study team and graduate students in the Department of Sericultural Science with a prepared questionnaires. Cross-section and regression analysis methods are employed for processing the data in this study. The major findings obtained are as followings. 1. Sericultural earnings per Tanbo is, on the average, 22, 752 won in new cultivated areas and 29, 403 won in ordinary ones. There are big difference in the size of earnings by areas, especially, 46, 968 won in Kumo mountain area, compared with 16, 798 won in Yeoju and Yichun areas. General trend is finded that small scale farming units are made higher earnings and operating their farms efficiently. 2. Cocoon production expences per Tanbo is 16, 737 won in new cultivated areas and 19, 802 won in ordinary areas. There are also big difference in farming expences, especially, 27, 389 won in Sudang area, compared with 11, 689 won in Emjin area. 3. Sericultural income per Tanto is 10, 664 won in ordinary areas and 6, 898 won in new cultivated areas. Farmers in Kumo mountain area make the highest income of 21, 164 won and lowest income of 1, 296 won in Sudang area. It can be generized that about 30-50 a sized farmers make higher income. 4. Land, labor and capital productivities estimated by fitting Cobb-Douglas functions in ordinary areas are higher than in new cultivated areas, especially, labor productivity is higher in ordinary areas. 5. Changsung, Kwangna, Yunsun and Kumo mountain areas are technically and economically efficient. Sudang and Mujinchang areas are technically successful but economically inefficient and Emjin and Honam areas are technically inefficient but economically efficient. YeojuYichun, Chunwon and West Kyongnam are technically and economically inefficient. Technical and economic improvement program should be implemented for these areas. 6. Estimated Internal Rate of Return (IRR) on capital investment in Chongwon are is 23.5 percent. It is economically feasible, if we consider 20 percent of opportunity cost of capital in our economy.

• Journal of Veterinary Clinics
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• v.26 no.5
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• pp.450-456
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• 2009

This study evaluated the efficacy of topical eprinomectin (0.5% pour-on solution, $Eprinex^{(R)}$, Merial) against Chorioptes texanus (C texanus) infestation in dairy cows reared in Korea. Dairy cows naturally infected with C texanus showed skin lesions as alopecia, erythema, excoriations and crusts on the tail head, the caudal folds, the back of udder and the rump area. Fourteen adult Holstein dairy cows with chorioptic mange at National Institute of Animal Science were selected on the basis of gross lesion and microscopic examination. Experimental dairy cows infected with chorioptic mange were treated with eprinomectin ($Eprinex^{(R)}$, Merial, France) at the rate of 1 ml /10 kg/BW. Evaluation of therapeutic effect is based on mite counts and gross lesion at weekly interval for 6 weeks. Milk yields were measured every day and calculate at the mean of milk yield at weekly interval. Mange mites absolutely removed after 1 week of topical eprinomectin against C. texanus infestation on dairy cows. The skin lesion of dairy cows infested with C. texanus recovered normal status after 6 weeks of eprinomectin treatment. After eprinomectin treatment, return to the normal level of milk yields in diary cows infested with C. texanus has indirectly indicated that C. texanus infestation have negative effect on productivity of dairy farm. However, it would be suggested that the investigation of actual condition and the effective control method of C. texanus infestation of dairy farms in Korea should be studied in the future.