• Horticultural Science & Technology
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• v.17 no.4
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• pp.476-480
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• 1999

This study was carried out to determine the optimum storage temperatures of six fruit nurseries ('Fuji' apple, 'Niitaka' pear, 'Sheridan' grape, 'Yumyoung' peach, 'Fuyu' persimmon, and 'Hayward' kiwifruit) from 1995 to 1997. Nursery plants were planted in field after storage at -5, 0, and $5^{\circ}C$ for one year. Nurseries stored at $0^{\circ}C$ showed highest survival rate and growth after planting. The survival rate of 'Sheridan' grape and 'Hayward' kiwifruit nursery plants stored at $-5^{\circ}C$ was 0%. Cold resistance of the two fruit nursery plants appeared weaker than others. Also, 'Niitaka' pear nursery plants stored at $5^{\circ}C$ showed significantly high survival rate and growth after planting. The higher storage temperature, the lower mineral and carbohydrate contents of nursery plants. Therefore, $0{\sim}5^{\circ}C$ in 'Niitaka' pear and near $0^{\circ}C$ in other five fruit nursery stocks were found to be the optimum storage temperatures.

• Journal of the Korean Society for Nondestructive Testing
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• v.22 no.4
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• pp.361-368
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• 2002

The aim of this study was to investigate the effect of preprocessing the transmitted energy spectrum data on development of a robust model to predict the sugar content in intact apples. The spectrum data were measured from 120 Fuji apple samples conveying at the speed of 2 apples per second. Computer algorithms of preprocessing methods such as MSC, SNV, first derivative, OSC and their combinations were developed and applied to the raw spectrum data set. The results indicated that correlation coefficients between the transmitted energy values at each wavelength and sugar contents of apples were significantly improved by the preprocessing of MSC and SNV in particular as compared with those of no-preprocessing. SEPs of the prediction models showed great difference depending on the preprocessing method of the raw spectrum data, the largest of 1.265%brix and the smallest of 0.507% brix. Such a result means that an appropriate preprocessing method corresponding to the characteristics of the spectrum data set should be found or developed for minimizing the prediction errors. It was observed that MSC and SNV are closely related to prediction accuracy, OSC is to number of PLS factors and the first derivative resulted in decrease of the prediction accuracy. A robust calibration model could be d3eveloped by the combined preprocessing of MSC and OSC, which showed that SEP=0.507%brix, bias=0.0327 and R2=0.8823.

• Research in Plant Disease
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• v.28 no.4
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• pp.221-230
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• 2022

The fire blight caused by Erwinia amylovora (Ea) was first reported in 2015 in Korea, and the disease has rapidly spread to 22 regions until 2021. In Korea, all host plants in the apple and pear orchards where fire blight occurred should be eliminated and buried by the Plant Protection Act. To prevent the spread of the disease, all burial sites were prohibited from planting the new host plants for the next three years. To confirm the eradication efficiency of Ea and the reoccurrence of fire blight, the surveillance facilities were established on three burial sites from 2019 to 2020 in Anseong-si, Gyeonggi-do, and Chungju-si, Chungcheongbuk-do. As host plants, five apple trees of fire blight-susceptible cultivar 'Fuji', were planted in each facility. All facilities were enclosed with fences and nets and equipped with two CCTVs, motion sensors, and several other sensors for recording weather conditions to monitor the environment of the sentinel plants in real-time. The sentinel plants were checked for the reoccurrence of fire blight routinely. Suspicious plant parts were collected and analyzed for Ea detection by loop-mediated isothermal amplification polymerase chain reaction and conventional polymerase chain reaction. Until November 2022, Ea has not been detected in all sentinel plants. These results might support that the burial control of infected plants in soil works efficiently to remove Ea and support the possibility to shorten the prohibition period of host plant establishment in the burial sites.