• Korean journal of applied entomology
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• v.47 no.3
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• pp.303-308
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• 2008

An unidentified moth was captured in sex pheromone traps of the oriental fruit moth, Grapholita molesta, especially at spring season in apple orchards and their vicinity. Though the captured males were similar in appearance to G. molesta males, they were easily distinguished by a matted difference in body size. Their occurrence pattern was also similar to that of overwintering G. molesta population from April to May, at which more males were captured in the pheromone traps installed in the vicinity of apple orchards than within apple orchards. After May, they were no longer captured in the pheromone traps. To investigate any larval damage due to this unidentified moth, molecular markers needed to be developed. Four PCR-RFLP markers originated from cytochrome b region of mitochondrial DNA could distinguish this unidentified moth from G. molesta.

• Journal of Biosystems Engineering
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• v.36 no.6
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• pp.407-415
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• 2011

Damage to agricultural production caused by insects and diseases affects farming yields. The orchard sprayer is mainly used in the country to protect the fruit in a large area, with less effort and at minimum cost. The excellent performance of the air blast spray increases the fruit protection. Chemical application in orchards has been accomplished by the orchard sprayers with air assist nozzles and a axial fan in Korea. However, the orchard sprayers without ROPS resulted in severe injury or death when operators drive the sprayers improperly on hilly orchard or farming road. This study was to develop a ROPS for the orchard sprayers improving farmer's safety. In this study, the accident case was used in analysing the design and building TOP structure of the orchard sprayer. The maximum impact, body torsion frame structures including the driver's protection are also analysed for adherence to safety regulations. The ROPS safety regulations according to the strength test results were established.

• The Korean Journal of Food And Nutrition
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• v.33 no.4
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• pp.363-371
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• 2020

This study was designed to evaluate the improvement in exercise endurance by Hovenia dulcis fruit hot water extract (HDWE) for the potential application as a functional food material. The effect was based on the evaluation of the forced-swimming capacity and changes in biochemical parameters in mice. Six-week-old mice were classified into four groups based on a randomized block design: the negative control group, the HDWE 50 mg/kg body weight group, the HDWE 200 mg/kg body weight group, and the 1-octacosanol 50 mg/kg body weight group (n=8 mice per group). The swimming exercise time in the HDWE-50 group was increased at 545±43 sec compared to the control group at 263±28 sec. The HDWE-200 fatigue indicators, lactate acid and ammonia content, decreased to 4.99±0.33 mg/mL and 0.63±0.05 mg/mL, respectively. In addition, the content of glycogen in the liver and muscle tended to increase in the group administered HDWE but was not significant. Likewise, the LDH and glucose contents were increased compared to the control group. The muscle damage indicators ALT (52.7±2.6 U/L) and AST (42.5±5.2 U/L) tended to decrease compared to the control group (76.4±10.2 U/L).

• Korean Journal of Agricultural and Forest Meteorology
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• v.7 no.3
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• pp.185-191
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• 2005

An accurate prediction of dormancy release and bud burst in temperate zone fruit trees is indispensable for farmers to plan heating time under partially controlled environments as well as to reduce the risk of frost damage in open fields. A thermal time-based two-step phenological model that originated in Italy was applied to two important grapevine cultivars in Korea for predicting bud-burst dates. The model consists of two sequential periods: a rest period described by chilling requirement and a forcing period described by heating requirement. It requires daily maximum and minimum temperature as an input and calculates daily chill units (chill days in negative sign) until a pre-determined chilling requirement for rest release is met. After the projected rest release date, it adds daily heat units (anti-chill days in positive sign) to the chilling requirement. The date when the sum reaches zero isregarded as the bud-burst in the model. Controlled environment experiments using field sampled twigs of 'Campbell Early' and 'Kyoho' cultivars were carried out in the vineyard at the National Horticultural Research Institute (NHRI) in Suwon during 2004-2005 to derive the model parameters: threshold temperature for chilling and chilling requirement for breaking dormancy. The model adjusted with the selected parameters was applied to the 1994-2004 daily temperature data obtained from the automated weather station in the NHRI vineyard to estimate bud burst dates of two cultivars and the results were compared with the observed data. The model showed a consistently good performance in predicting the bud burst of 'Campbell Early' and 'Kyoho' cultivars with 2.6 and 2.5 days of root mean squared error, respectively.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.13 no.1
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• pp.19-23
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• 2007

Shock and vibration inputs are transmitted from the transporting vehicle through the packaging to the fruit. The vibration causes sustained bouncing of fruits against each other and the container wall. The steady state vibration input may cause serous fruit injury, and the damage is particularly severe if the fruits are bounced at its resonance frequency. The determination of the resonance frequencies of the fruits and vegetables may help the packaging designer to determine the proper packaging system providing adequate protection for the fruits, and to understand the complex interaction between the components of the fruits when they relate to expected transportation vibration inputs. To analyze the vibration properties of the apples for optimum packaging design during transportation, random vibration tests were carried out. In the random vibration test, the resonance frequency and PSD of the packaged freight of apples in the test were in the range of 82 to 97 Hz and 0.0013 to $0.0021G^2/Hz$ respectively and the resonance frequency and PSD of the packaged apples in the test were in the range of 13 to 71 Hz and 0.0143 to $0.0923G^2/Hz$.

• Korean journal of applied entomology
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• v.34 no.1
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• pp.75-81
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• 1995

To reduce crop damage from root-knot nematode, Meloidogyne spp. chemical, cultural, physical control methods were compared in commercial greenhouse for 3 years from 1992 to 1994. Timing of sol exchange for economic losses due to the nematodes is important: every 3 years for coarse sand (Masatto) and every 4 years for red-yellow soil. Control effects on Meloidogyne spp. in cucumber were 78.2% in Dazomet DP, 72.1% Carbo G+Soil reverse+submergence, and 66.3% in Carbo G+submergence. Pesticide effects were temporally different after treatment: 77.7~80.6% in 20 days and 33.7~49.5% in 60 days. Cropping system in oriental melon gave an excellent control effect of 81.1% at oriental melon/rice culture. All methods controled root-knot nematodes at the time of the treatment but the number of the nematodes increased at the end of the season. However, soil exchange was effective for 3 years. The most economic control practice is rotation with rice for every three years.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.12 no.2
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• pp.97-102
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• 2006

Shock and vibration inputs are transmitted from the transporting vehicle through the packaging to the fruit. The vibration causes sustained bouncing of fruits against each other and the container wall. The steady state vibration input may cause serous fruit injury, and the damage is particularly severe if the fruits are bounced at its resonance frequency. The determination of the resonance frequencies of the fruits and vegetables may help the packaging designer to determine the proper packaging system providing adequate protection for the fruits, and to understand the complex interaction between the components of the fruits when they relate to expected transportation vibration inputs. To analyze the vibration properties of the watermelon for optimum packaging design during transportation, sinusoidal sweep vibration tests were carried out. The resonance frequency of the watermelon ranged from 19 to 32 Hz and the amplitude at resonance was between 1.6 and 2.9 G. The resonance frequency and amplitude at resonance frequency band of the watermelon decreased with the increase of the sample mass. The multiple nonlinear regression equation for predicting the resonance frequency of the watermelon were developed using the independent variables such as mass, input acceleration and sphericity.

• Horticultural Science & Technology
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• v.18 no.3
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• pp.387-390
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• 2000

The experiment was conducted to investigate the effects of vine management and yield on fruit quality and bud burst of 'Campbell Early' grapevines in Hwaseong and Suwon area. The extreme value of minimum temperature of Hwaseong area, frequently causing cold damage, was lower than that of Suwon area in winter. Narrow spacing, overbearing, and poor vine management were observed in Hwaseong area, where the harvest time was delayed by 7 days compared with that of Suwon area. Total carbohydrate content of bearing mother branches was lower with 1.2~1.7%, and the percentage of bud burst was extremely lower at $-15^{\circ}C$. In Suwon area, there were no differences in cluster and berry size, but soluble solids content was lower and skin coloration was poorer when yield was high. Total carbohydrate content was lower when yield was high. The percentage of bud burst was lower at cold treatments below $-20^{\circ}C$. The results suggest that appropriate yield based on fruit quality is 2.3~2.6 MT/10a.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.04a
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• pp.52-52
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• 2018

Apple (Malus domestica) is one of the most economically important fruits in Korea. But virus infection has decreased sustainable production of apple and caused the serious problems such as yield loss and poor fruit quality. Virus or viroid infection including Apple chlorotic leaf spot virus (ACLSV), Apple stem pitting virus (ASPV), Apple stem grooving virus (ASGV), Apple mosaic virus (ApMV) and Apple scar skin viroid (ASSVd) has been also reported in Korea, furthermore, its damages and economic losses have increased constantly. In our research, we tried to survey virus infection for commercial nursery trees of major apple cultivars, especially dwarfing rootstocks 'M.9' and 'M.26' as well as scions. Trees were collected from 11 locations which have produced a great amount of apple nursery stocks in Korea. Infection degree was investigated in apple cultivars, 'Hongro' and 'Fuji' using RT-PCR method. In the scion of cultivar 'Hongro', infection ratio of ACLSV, ASPV and ASGV were 100%, 81.8% and 100% respectively. In the rootstock of cultivar 'Hongro', infection ratio of ACLSV, ASPV, ASGV and ApMV were 90.9%, 81.8%, 100% and 9.1% respectively. In the scion of cultivar 'Fuji', infection ratio of ACLSV, ASPV and ASGV were 81.8%, 90.9% and 100% respectively. In the rootstock of cultivar 'Fuji', infection ratio of ACLSV, ASPV, ASGV and ApMV were 81.8%, 90.9%, 100% and 9.1% respectively. Infection of ASSVd was not detected in both cultivars. From our results, it was found that most of apple rootstocks and scions had multiple infections by apple viruses which have caused economic damage in fruit production.

• Korean journal of applied entomology
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• v.45 no.2 s.143
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• pp.235-240
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• 2006

Efficacies of two commercial mating distruptor (SPLAT$^{(R)}$ and Isomate$^{(R)}$-ROSSO) were evaluated on field overwintering populations of Oriental fruit moth, Grapholita molesta (Busck), in four apple orchards. Based on the monitoring with sex pheromone traps, all the orchards (Youngchun, Kyungsan, Chungsong, and Youngju in Korea) exhibited significant overwintering populations from late April to late May. Both mating disruptors that were applied 10 days before the monitoring period significantly inhibited the male orientation to the monitoring lures, in which SPLAT type was more effective than Isomate type in the disrupting efficacy. The disruption of male orientation was highly correlated with the reduction in the early leaf damage caused mostly by G. molesta.