• Korean journal of applied entomology
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• v.61 no.1
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• pp.255-266
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• 2022

This study was conducted to examine the effects of grass vegetation (W: manual weeding, NW: herbicide sprays) and pyrethroid spray (P: pyrethroid spray, NP: no pyrethroid spray) on the population dynamics of Panonychus citri and natural enemies in citrus orchards. Two essential hypothesis were made to test the population dynamics: 1) weed planting promotes natural enemies by offering habitat and alternative food sources, resulting in the reduction of P. citri populations, and 2) pyrethroid spray removes natural enemies by its non-selective toxicity, resulting in the increasement of P. citri populations. The observed natural enemy populations (mainly Phytoseiids and Agistemus sp.) were not different largely from the expected values in the hypothesis, which assumes more abundant natural enemies in weeds and no pyrethroid plots. Although some discrepancy was occurred in NW+NP and W+NP plots in 2011, the observed values were almost same with expected values in 2012. In overall, pesticide effect was strongly significant and pyrthroids removed largely natural enemies. Although habitat (weeds) effect showed a conflict result, natural enemy population increased in plots allowing weed growth, when considering the increased autumn population relatively compared to that of spring-summer population. The decreased abnormal P. citri populations in pyrethroid plots could be explained under the assumption of a strong repellent behavior of P. citri to the pyrethroids.

• Korean journal of applied entomology
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• v.52 no.4
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• pp.415-425
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• 2013

The yellow tea thrips, Scirtothrips dorsalis (Thysanoptera: Thripidae), has been regarded as a minor pest on citrus on Jeju Island. However, the damage of yellow tea thrips has gradually increased since 2007. This study was conducted to develop a forecasting model for generation peak time of S. dorsalis by using degree-days. Simple linear regression analysis was applied to determine the relationship between the generation number (x, dependent variable) and degree-days (y, independent variable). As a result, two regression models were established: citrus-based model (y = 310.9x + 69.0, $r^2$=0.99) and green tea-based model (y = 285.7x + 84.1, $r^2$=0.99). The models was fitted by independent data sets obtained from 2013 and evaluated using the technique of RSS (residual sum of square) and ${\chi}^2$-test. The green tea based-model showed a good fitting ability. The discrepancy between model outputs and actual data, and the practical application of models were discussed.

• Research in Plant Disease
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• v.11 no.2
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• pp.115-121
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• 2005

This studies were carried out to elucidate the control effect of copper fungicides against some citrus diseases, assess copper spray injury on leaf and fruit of citrus by spraying of copper fungicides according to growth stages and spray seasons and by tank mixing with paraffin oil in field experiments for 3 years (2003-2005 season). As results, the control value was approximately $75\%$ against scab disease in all tested copper fungicides, $85-88\%$ to canker and $75-86\%$ to melanose. In case of leaf, the copper injury was the severest in early stage of shooting, and the injury was gradually weakened according to growth of leaf. In fruit, the copper injury was more severe in midsummer (late of July and August) than early of summer and spring season (June and ealy of July). Among copper fungicides, the bordeaux mixture which made by level of farm induced more injury compared to other copper fungicides commercialized. Less copper spray injury was observed on treatments in which copper fungicide was sprayed as tank mixtures with paraffin oil when compared to treatment which sprayed with only copper fungicide.

• Korean Journal of Environmental Agriculture
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• v.17 no.2
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• pp.182-188
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• 1998

The effect of arbuscular mycorrhizae(AM) on the growth of trifoliate orange seeding were investigated in volcanic ash soil. Trifoliate orange is used as a root stock of citrus in Cheju island. Seedings innoculated with AM fungi were grown for 16 weeks in pots of various levels of fertilizer. Growth characteristics and mineral nutrient contents were measured and spores of AM fungi colonized were identified. Seventy % of the replicsted pots of seedings were colonized by AM in the treatment of high level fertilizer and additional phosphate (40g of 21-17-17 complex fertilizer and 50g of fused phosphate added to 50L of soil). In treatments of low levels fertilizer or without fused phosphate addition, the pots colonized were less than 20 %. Colonization of trifoliate seedings with AM fungi greatly increased the growth of seedings. Shoot length and weight of shoot and root positively regressed on AM colonization ratio. AM colonization caused higher concentrations of P, Cu and Mg in plant, and the relations were significant at 5 % level. Contents of N and Zn in plants also tended to increase, while that of Ca to decrease, with increasing colonization ratio. Four species of AM fungi - Glomus deserticola, G. rubiforme, G. vesiculiferum and Acaulospora sp, - were found in the soil where roots of trifoliate orange as an innoculation materials were collected. All of the 4 species were found in the inoculated pot soils after the seedling growth, indicating that these species can be colonized in trifoliate orange roots.

• The Journal of the Convergence on Culture Technology
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• v.8 no.4
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• pp.415-422
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• 2022

The heterogeneous Onju citrus genes (A=20.57, C=32.71, G=30.01, U=16.71%) and coffee genes (A=20.66, C=31.76, G=30.187, U=16.71%) have the same genetic ratio of 95% or more. It is known that gene compatibility is generally not possible with this group. However, it can be grafted if the conditions of Chargaff rule and Shannon Entropy are met with gene functional-similarity of more than 95%, and it becomes a new breed of Coffrange. We calculated the world's first BCJM matrix for DNA-RNA and published it in US patents and international journals. All animals and viruses are similar to human genes. Based on this, it was announced in June in the British matrix textbook by solving the genetic characteristics of COVID-19 and the human body. In plants, it is treated with BCJM-Transposon treatment, a technique that easily changes gene location. Simulation predicted that the matrix could be successful with Cut & Paste and Transpose.

• Korean journal of applied entomology
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• v.59 no.2
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• pp.153-163
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• 2020

This study was conducted to evaluate the fitness of Tetranychus kanzawai Kishida on different host plants: young and old leaves of the mandarin orange 'shiranuhi' ((Citrus unshiu × C. sinensis) × C. reticulata), Japanese violet (Viola japonica Langsd.) and kidney bean (Phaseolus vulgaris L.). The development and oviposition experiments were conducted at constant temperatures (20, 25 and 30℃) and a life table parameters were estimated. T. kanzawai could complete it's development on 'shiranuhi' young leaves, japanese violet and kidney bean, while all died during the immature period on 'shiranuhi' old leaves. The total developmental period of T. kanzawai feeding on 'shiranuhi' young leaves was 17.4, 13.4 and 10.2 days at each temperature, respectively, which was longer than 16.1, 9.5 and 7.0 days of kidney bean. The female longevity of T. kanzawai on young leaves of 'shiranuhi' were 19.1, 15.0 and 12.3 days at each temperature, respectively, and there was no significant difference from 22.1, 14.1 and 10.9 days investigated from kidney bean. The fecundity was 18.1, 23.9 and 17.8 eggs per female, which was less than them of japanese violet and kidney bean at each temperature, respectively. As a result of estimating the life table parameters based on the experimental data, intrinsic rate of increase (r_m) were significantly different from each other, and appeared in the following order: kidney (0.1542, 0.2563 and 0.3251), japanese violet (0.1087, 0.2007 and 0.2673) and 'shiranuhi' young leaves (0.0868, 0.1002 and 0.1217) at each temperature, respectively. Finally, the management strategy against T. kanzawai in citrus orchards was discussed based on the results.

• Feed Journal
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• v.4 no.3 s.31
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• pp.102-109
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• 2006

세계적으로 환경문제의 중요성이 심각하게 대두되고 있고, 그에 따른 관련법규도 강화되어 환경비용이 급속하게 증가하고 있으므로, 식품가공부산물 중에서 비교적 발생량이 많으면서 방치할 경우 환경문제를 야기할 가능성이 높은 맥주박, 비지, 주정박, 전분박 및 감귤박 등에 대한 사료가치 증진방안과 이 들을 원료로 한 한 · 육우에 대한 TMR 제조 및 이용기술을 제시함으로서 생산비절감을 기본으로 한 고급육 생산방안을 제시하고자 한다.

• Korean journal of applied entomology
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• v.47 no.4
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• pp.467-472
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• 2008

During the survey of plant parasitic nematode of Citrus orchard in Korea, Paratrichodorus minor (Colbran, 1956) Siddiqi is founded from the soil of Citrus unshiu Markovich for the first time in Korea. The body length of females is $428.34{\sim}506.22{\mu}m$ long: a = $12.08{\sim}22.79$, b = $4.02{\sim}5.02$, V(%) = $38.46{\sim}60.68$. The excretory pore is located near the base of esophagus. Additionally, the morphological characteristics on P. porosus (Allen, 1957) Siddiqi, 1974 recorded in 1976 on Korea is redescribed in detail.

• Journal of Agricultural Extension & Community Development
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• v.28 no.3
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• pp.153-165
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• 2021

This study aims to analyze the difference in production elasticity based on the types of agricultural labor input regarding its qualitative difference in Jeju mandarin production. To estimate the production function of qualityadjusted labor, we have set up a Quality-Adjusted Index based on the market wage of the agricultural field. We have conducted a multiple regression analysis of the newly estimated labor inputs using the Ordinary Least Squares regression. Results show that the production efficiency of aggregate total labor hours (quality-unadjusted labor input) is overestimated compared to quality-adjusted labor with qualitative labor homogeneity. Moreover, by analyzing household labor and employment labor, we have observed that the marginal productivity of household labor exceeds that of employment labor. In conclusion, this study verifies that securing labor input homogeneity is crucial for analyzing agricultural labor hours' economic efficiency accurately.

• Journal of Life Science
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• v.27 no.2
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• pp.123-130
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• 2017

This study was conducted to investigate the physicochemical quality characteristics of pork patty added with four different amount (T0:0%, T1:0.3%, T2:0.7%, T3:1.0%) of tangerine (Citrus unshiu) peel. There was no significant difference in chemical composition, cooking yield, water holding capacity, moisture retention, fat retention, hardness, springiness, cohesiveness, gumminess, chewiness, VBN content, L-value. In taste, texture, juiciness and palatability, the addition of 0.3%~1.0% tangerine peel in pork patty showed no significant difference on sensory properties compared to the pork patty without tangerine peel. Total polyphenol content was highest in T3, and DPPH radical scavenging activity was highest in T2 and T3 (p<0.001). The TBARS contents decreased as tangerine peel become added (p<0.001). The pH was highest in T0, and was lowest in T3 (p<0.001). The external a-value of T2 and T3 were significantly higher than that of T0 (p<0.01). The external and internal b-value of T2 and T3 were higher than those of T0 (p<0.01). Flavor of T2 and T3 were higher than those of T0 and T1 (p<0.01). In conclusion, the results of this study indicate that an addition of tangerine peel could be utilized as an ingredient in pork patty in promotion of function of tangerine by-products.