• Korean Journal of Environmental Agriculture
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• v.42 no.3
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• pp.239-252
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• 2023

Most apple trees in South Korea are grafted on M.9 and M.26 rootstocks; however, these rootstocks are susceptible to fire blight. Although M.7 rootstocks are moderately resistant to fire blight, they tend to exhibit excessive vigor, which is unsuitable for high-density planting, unless weak cultivars are used. This study investigated the vegetative growth, yield, and fruit quality of apple trees grafted onto M.7, M.9, or M.26 rootstocks to assess the feasibility of establishing high-density apple orchards domestically using the M.7 rootstock a period of seven years (1-7 years after planting). Rootstocks were tested using three cultivars with contrasting induced vigor and harvesting times: vigorous and late-maturing 'Fuji,' moderate vigor and middle-maturing 'Hongro,' and low vigor and early-maturing 'Sansa.' The planting density was maintained constant, with 190 trees per 10 a. Primary thinning (leaving only the king fruit on clusters) was performed, whereas secondary thinning (controlling crop load) was not. Vegetative growth, accumulated yield per 10 a, and yield efficiency varied depending on cultivars and rootstocks; however, the cultivars had a more notable effect on fruit quality than the rootstocks. Biennial bearing often occurred in the M.26 rootstock. 'Fuji'/M.7 was overly vigorous for high-density planting. The fruit quality and accumulated yield per 10 a of M.7 were similar to those of M.9 with the 'Hongro' and 'Sansa' cultivars. In particular, 'Hongro'/M.7 did not show tree vigor reduction due to heavy crop load, and the degree of biennial bearing in 'Sansa'/M.7 was not particularly high. These results indicated that high-density apple planting using the M.7 rootstock was achievable using the 'Hongro' and 'Sansa' cultivars.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2005.05a
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• pp.89-94
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• 2005

• Journal of Biosystems Engineering
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• v.24 no.3
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• pp.243-252
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• 1999

The damage caused in the processes and distributions after harvesting the fruits and vegetables is attributed to the mechanical factors such as compressive and impact forces. Compression tests of biological materials provide an objective method for determining the apparent modulus of elasticity and mechanical properties which are significant in quality evaluation and control, and them maximum allowable compressive forces for minimizing mechanical damage. This study was performed to determine the mechanical properties of apple and pear, and to investigate effect of specimen shapes on the mechanical properties of them. A computer program was developed for measuring the mechanical properties and analyzing the data obtained from the measurement. Compression tests on the sample were performed with then replications at each treatment and at 25 mm/min loading rate. Mechanical properties of the apple was generally shown the higher value than those of the pear, and it was though that data obtained form the cylindrical specimen removed from the sample was more reliable than from the specimen cut in half.

• Mycobiology
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• v.35 no.4
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• pp.238-240
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• 2007

Anthracnose symptoms often occurred on fruits of Asian pear trees grown in Anseong, Naju, Seonghwan and Pyeongtaek in Korea during the harvesting period from 2000 to 2005. A total of 28 isolates of Colletotrichum sp. were obtained from the anthracnose symptoms. All the isolates were identified as Colletotrichum acutatum based on their morphological and cultural characteristics. Four isolates of the fungus were tested for pathogenicity to fruits of Asian pear tree by artificial inoculation. All the isolates induced anthracnose symptoms on the fruits by wound inoculation but not by unwound inoculation. The anthracnose symptoms induced by artificial inoculation were similar to those observed in the orchard. This is the first report of anthracnose of Asian pear tree caused by Colletotrichum acutatum.

• Journal of Biosystems Engineering
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• v.25 no.2
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• pp.141-150
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• 2000

This study was carried out to de develop a control strategy of a fruit harvesting redundant robot. The method of generating a safe trajectory, which avoids collisions with obstracles such as branches or immature fruits, in the 3D(3-dimension) space using artificial potential field technique and virtual plane concept was proposed. Also, the method of setting reference velocity vectors to follow the trajectory and to avoid obstacles in the 3D space was proposed. Developed methods were verified with computer simulations and with actual robot tests. Fro the actual robot tests, a machine vision system was used for detecting fruits and obstacles, Results showed that developed control method could reduce the occurrences of the robot manipulator located in the possible collision distance. with 10 virtual obstacles generated randomly in the 3 D space, maximum rates of the occurrences of the robot manipulator located in the possible collision distance, 0.03 m, from the obstacles were 8 % with 5 degree of freedom (DOF), 8 % with 6-DOF, and 4% with 7-DOF, respectively.

• Food Science and Preservation
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• v.7 no.1
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• pp.51-56
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• 2000

Quality characteristics of Satsuma mandarin (Citrus unshiu Marc.var.miyagawa) harvest on early December according to production areas and sea level altitude of Cheju were investigated. Soluble solids and flesh ratio were distributed 9.32∼12.50, 75.95%-81.3 in citrus fruits harvested in orchards located below 10m sea level altitude (lower area), and was 10.23-12.17 , 77.35%-80.29% on those over 150m sea level altitude )higher area), respectively. Acid content of citrus juice was 0.95%-1.26% in fruits harvested inlower area, and was 1.02%-1.39% in higher area. In proportion to late harvesting , Brix/acid ratio and fruits quality was improved. Soluble solids of fruits harvested in higher area were higher than those of fruits from higher area, but acid contents were on the contrary . In sensory evaluation on fruit appearance, the differences between two altitudes were not clear.

• Korean Journal of Plant Resources
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• v.7 no.1
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• pp.23-27
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• 1994

The growing condition and the point at issue were investigated for utilization as a fundamental data of the Boxthorn research in the growing farm household, which was chief producing district of Box-thorn in Chongyang, Chungmam province. The results were summarized as follow'; Lycium fruit wasproduced 445M/. in the 170.4ha. In practical cultivation, major numbers of decapitation were threetimes,, and planting distance was dense planting, and also amount of applied fertilizer was beyondbasic-fertilizer level and number of split application was abundant.Numbers of harvesting were six-ten times, and many labor was requiremented.The issues in cultivation were development of processing technique, supplement of varieties whichhave disease tolerance, superior quality and high yielding, improving of cultivation methods for laborsaving and magnification of demand.

• Korean Journal of Medicinal Crop Science
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• v.17 no.2
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• pp.115-120
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• 2009

To obtain the information on antioxidant activity by harvesting parts and time in Cudrania tricuspidata Bureau, total phenolic contents, flavonoid contents, superoxide dismutase (SOD) like activity and 2,2-diphenyl-1-picrylhydrazyl(DPPH) radical scavenging activity of methanol extracts from Cudrania tricuspidata were investigated. Total phenolic contents was the highest in leaf [$30.2{\sim}38.8\;mg/g$ dry weight (DW)] and followed by root bark, stem bark, fruit, root except bark and stem except bark. Among harvesting time, total phenolic contents of leaf was the highest as $38.1{\sim}38.8\;mg/g$ DW in May and June, and then decreased to October. Root bark harvested in April and May contained $26.6{\sim}27.8\;mg/g$ DW total phenolic compounds and total phenolic content fell to a very low values at 1.8 mg/g DW in February. Flavonoid contents was very high in leaf and root bark. Especially, root bark harvested in April had the highest of flavonoid contents as 23.2 mg/g DW. As a result of simple linear regression analysis of total phenolic contents on flavonoid contents according to harvesting parts, it showed a high correlation (p < 0.001) with $0.57{\sim}0.97\;R^2$ (coefficient of determination). As $RC_{50}$ value, that was, the concentration of sample required for 50% reduction of DPPH absorbance, was $13.7{\sim}20.5\;{\mu}g/mL$ in leaf so DPPH radical scavenging activity was very high. But SOD like activity of $1,000\;{\mu}g$ extract/mL MeOH was a low value of $0.3{\sim}9.2%$ in all samples.

• Horticultural Science & Technology
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• v.31 no.4
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• pp.437-446
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• 2013

This study was conducted for three years (2007, 2009, and 2010) to investigate the changes in fruit quality during maturation, and the quality and storage ability of fruits harvested at different times of 'Fuji' apple in Daegu region with a high air temperature during the fall season. Changes in apple fruit quality during the maturation period were investigated from 120-135 days to 183-198 days after full bloom. In comparing quality and storage ability of fruits harvested at different times, fruits harvested more than 180 days after full bloom were used. During the maturation period, poor coloring was the problem for 'Fuji' apple in Daegu region by the high air temperature about $20^{\circ}C$. In comparing quality of fruits harvested at different times, the soluble solid contents and hunter a value were increased by the extended harvest time. Fruit weight during harvest was not affected by different harvest time, while the fruit firmness and titratable acidity during harvest were decreased critically when the freezing damage happened. Ethylene production, fruit firmness, and titratable acidity during cold storage for twenty weeks did not differ according to the different harvest time. Soluble solid contents of fruits harvested at 216 days after full bloom in 2009 were similar at the time of harvest and cold storage. For fruits harvested at 201 days after full bloom, soluble solid content during cold storage was higher than during harvest time. However fruit firmness, soluble solid content, and titratable acidity after cold storage of fruit harvested after freezing damage was lower than those of the fruit harvested before freezing damage. The results show that the extended harvest time of 'Fuji' apples about 2-4 weeks from 180-200 days after full bloom in area with above-air temperature during fall season was seemed to be beneficial to enhancing soluble solid contents and fruit red color, but harvesting after the middle of November was dangerous because minimum air temperature began to fall under $-3.0^{\circ}C$.

• Journal of Bio-Environment Control
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• v.14 no.2
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• pp.89-94
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• 2005

This study was conducted to investigate the effect of nonwoven fabrics weight(Ounce) on growth, quality and yield of oriental melon (Cucumis melo L. var. makwa Mak.). Seedling of 'Gumssaragi-Eunchun' was grafted on 'Shinthozoa' root stock. In this study, The minimum air temperature in 6 ounce at night was $4.8^{\circ}C,\;6.9^{\circ}C$ in 9 ounce, $7.9^{\circ}C$ in 12 ounce and $8.0^{\circ}C$ in 15 ounce, respectively. Leaf length, stem diameter, leaf numbers, leaf area, fresh weight and dry weight for 30 days after planting were better in high minimum air temperature at night than in low minimum air temperature, particularly leaf areas of the plant in 9 ounce was $370cm^2$ at 30 days after planting, $116\%$ in 12 ounce, $129\%$ in 15 ounce. The xylem exudates amount in 9 ounce for 24 hours just after basal stem abscission was 10.1mg. It was 1.2 times much in 12 ounce and 1.9times much in 15 ounce than in 9 ounce at 30 days after planting. The blooming of female was faster by 6 days in 15 and 12 ounce but was delayed by 3 days in 6 ounce than 9 ounce, and the days of blooming to harvesting were shorter by 3 days in 15 ounce and 4 days in 12 ounce but was delayed by 3 days in 6 ounce than in 9 ounce. Fruit weight, fruit length, fruit diameter, flesh thickness, soluble solids, and total yield was the highest in 15 ounce followed by 12 ounce,9 ounce and 6 ounce. Fermented fruit rate was the highest in 6 ounce followed by 9 ounce, 12 ounce and 15 ounce, and marketable fruit rates were 15, 12, 9 and 6 ounce in order. Compared to 1,781kg yield per 10a of 9 ounce, $19\%\;and\;49\%$ was increased under 12 ounce and 15 ounce but $47\%$ were decreased 6 ounce.