• Journal of The Korean Society of Grassland and Forage Science
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• v.32 no.3
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• pp.275-284
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• 2012

This study was carried out to determine the harvest management during autumn on the forage production, quality and regrowth of following year of Phragmites communis as native grass. Field experiments were conducted in Ansan and in Cheonan from 2010 to 2011. Forages were cut at 3 cm, 15 cm and 25 cm in height as compared to control (no harvest) in Ansan plots, and forages grown in Cheonan plots were cut at 10 cm and 20 cm in height with control (no harvest). The forages were harvested one time on Oct 7, 2011 in Ansan, and were harvested twice on July 7 and on October 7 in Cheonan. In Ansan, dry matter (DM) yield of control plot the following year were higher than those from harvested plots. In vitro digestible DM (IVDDM) yields, however, were the same: 1,236 kg/ha from control, 1,234 kg from 15 cm cut and 1,241 kg from 25 cm cut plots, except that lower IVDDM yield from 3 cm cut plot than these were observed. Forage quality of control plot was poorer than those of harvested ones. In vitro DM digestibility (IVDMD) and relative feed value (RFV) of control were 39.98% and 65.3, respectively as compared to harvested plots (42.36~46.40% IVDMD and 67.8~72.5 RFV). Yield and quality from Cheonan plots were similar to those from Ansan plots. Annual yield in DM and in CP from control plot were a little higher than those from harvested plots. However, there were no difference found in IVDDM yield between 20 cm cut (5,354 kg/ha) and control (5,178 kg). But IVDDM of 10 cm cut forages was less (4,531 kg). Forage quality scores were better from 20 cm cut, and 10 cm cut plot than control, in order (p<0.05). The quality grades were the 5th and 6th for forages from harvested plots and control plot, respectively. Regrown Phragmites communis from all Cheonan plots ranked the 4th in forage quality. More than 70% of annual yield was observed from the first grown forages. One time harvest per year was desirable for following regrowth and long time stable production of Phragmites communis. We recommended that Phragmites communis be harvested once for more forage yield with higher quality, and that optimum cutting height is 15~20 cm.

• Transactions on Electrical and Electronic Materials
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• v.16 no.5
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• pp.290-292
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• 2015

We have reported about bipolar resistive switching effect on Poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene]:Graphene oxide composite films, which are sandwiched between aluminum and indium tin oxide electrodes. In this case, I-V sweep curve showed a hysteretic behavior, which varied according to the polarity of the applied voltage bias. The device exhibited excellent switching characteristics, with the ON/OFF ratio being approximately two orders in magnitude. The device had good endurance (10⁵ cycles without degradation) and long retention time (5 × 10³ s) at room temperature. The bistable switching behavior varied according to the trapping and de-trapping of charges on GO sites; the carrier transport was described using the space-charge-limited current (SCLC) model.

• Journal of Biosystems Engineering
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• v.28 no.6
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• pp.497-504
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• 2003

The objectives of this study were to develop a harvesting gripper for perilla leaves and test its performance, which was a partial work of the automated perilla leaves harvesting system development. The results of this study could be summarized as the followings: The shear forces for harvesting the perilla were measured. The measured results showed that the average shear force required was 12.13N for cutting the petioles attached to the perilla stalks, and the maximum of 17.42N. The inner diameter of air cylinder used was 6mm and the air pressure was maintained as 0.7㎫ during the tests. The time required for cutting perilla leaves could be adjusted by the control program and cutting operation could be done within 1- 10 seconds. The performance tests were conducted to harvest the perilla leaves by the gripper developed. The average success rates of cutting were 72.2％ for the first test, 78.5％ for the second, and 74.2％ for the last. The perilla leaves were not damaged by the gripper The whole system operation could be finished within three seconds except the delay time for dropping harvested leaves.

• Journal of Drive and Control
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• v.20 no.3
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• pp.35-41
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• 2023

Radish and Chinese cabbage are the most produced and consumed vegetables in Korea. The mechanization of harvesting operations is necessary to minimize the need for manual labor. This study to develop and evaluate the performance of a multi-purpose driving platform that can apply modular Radish and Chinese cabbage harvesting devices. The multi-purpose driving platform consisted of driving, device control, engine, hydraulic, harvesting, conveying, and loading part. Radish and Chinese cabbage harvesting conducted using the multi-purpose driving platform each harvesting module. The performance of the multi-purpose driving platform was evaluated the field efficiency and loss rate. The total Radish harvesting operation time 34.3 min., including 28.8 min., of harvesting time, 1.9 min., of turning time, and 3.6 min., of replacement time of bulk bag. During Radish harvesting, the field efficiency and average loss rate of the multi-purpose driving platform were 2.0 hr/10a and 3.1 %. Chinese cabbage harvesting operation 49.3 min., including 26.6 min., of harvesting time, 4.6 min., of turning time, and 18.1 min., of replacement time of bulk bag. During Chinese cabbage harvesting, the field efficiency and average loss rate of the multi-purpose driving platform 2.1 hr/10a and 0.1 %. Performance evaluation of the multi-purpose driving platform that harvesting work was possible by installing Radish and Chinese cabbage harvest modules. Performance analysis through harvest performance evaluation in various Radish and Chinese cabbage cultivation environments is necessary.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.1
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• pp.34-41
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• 2008

This study was conducted to investigate antioxidant component content during maturity for judgement of optimum harvest time in black soybean. For high-functional black soybean production, accumulation pattern of isoflavone and saponin contents and anti oxidative activity according to maturity stage were investigated. Varieties used in this experiment were Ilpumgemojeongkong and heukcheongkong, which are the recommended black soybean in Korea. Isoflavone and saponin contents during maturity period in black soybean was the highest at $6{\sim}7$ days earlier than general harvesting time. It was indicated that optimum harvesting time for high quality soybean were $3{\sim}7$ days earlier than harvesting time for higher yield. As a result of investigation about accumulation pattern of antioxidant components by maturity stages in seed, total isoflavone content was the highest at 61 DAF in Ilpumgeomjeongkong and at 77 DAF in Heukcheongkong. Contents of total saponin were the highest at 61 DAF and at 71 DAF, respectively. In case of leaf, total isoflavone content was the highest at 55 DAF in Ilpumgeomjeongkong and Heukcheongkong. Contents of total saponin were the highest at 18 DAF and at $55{\sim}71$ DAF, respectively. It showed that black soybean's leaf could be developed as a new health food material, owing to high contents of antioxidant components and biological activity and it's suitable harvest time was at $R_7$.

• Journal of The Korean Society of Grassland and Forage Science
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• v.28 no.1
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• pp.29-34
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• 2008

This experiment was conducted to study the effects of growth stage and variety on the quality of whole crop rice(WCR) silage at National Institute of Animal Science, RDA from 2004 to 2005. Two types of rice("Chucheong" for food and "Hamasari" for whole crop) were harvested at six different growth stages (heading, flowering, milk, dough, yellow ripen and fully ripen stage) and ensiled each harvest stages. Crude protein(CP) content of all whole crop rice silage was also decreased with progressed maturity at harvest and TDN(total digestible nutrient) content of WCR was increased. The average CP content of whole crop rice was higher than that of food rice. The contents of ADF(acid detergent fiber) and NDF(neutral detergent fiber) decreased with delayed harvest maturity. The content of TDN estimated from ADF content was increased with progressed maturity, but there was not found significant difference between rice varieties(p<0.05). The average pH value was 4.69 and it was increased with delayed harvest maturity. Acetic and butyric acid content were decreased, but lactic acid content was increased with progressed maturity. The experiments presented here show that all rice varieties may give a good quality silage. But some wrong practical method(grain loss, productivity, nutrient value, etc.) will make poor quality of rice silage. Therefore, dough stage of harvest maturity will be recommendable as proper harvest time for making high quality of whole crop rice silage in Korea.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.66 no.2
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• pp.155-170
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• 2021

Oats (Avena sativa L.) represent a good forage crop for cultivation in regions with short growing periods and/or cool weather, such as the mountainous areas of southern Korea. In this study, using the Korean elite summer oat varieties 'High speed' and 'Dark horse', we aimed to determine the optimal time to plant and harvest forage oats seeded in spring and summer in a mountainous area. Seeds were planted three times from late February and early August at 9- or 10-days intervals, respectively, and plants were harvested three times from late May to October at 10-day intervals. The experiment was carried out in an upland field (Jangsu-gun Jeonbuk) in 2015 and 2016. We investigated the changes in forage yield (FY) and quality [crude protein (CP) and total digestible nutrient (TDN) contents] based on the time of planting and harvest. Neither the forage quality nor yield of either spring and summer oats was significantly influenced by the time of planting. The CP of spring oats harvested three times at 10-day intervals from late May was 12.0%, 8.2%, and 6.5%, thereby indicating a reduction with a delay in the time of harvest. In summer oats, CP ranged from 8.4% to 8.7%, although unlike CP in spring oats, was not significantly influenced by the time of harvest. For both forage types, harvest time had no significant effect on TDN. The FY of spring oats harvested in late May and early and mid-June was 10.2, 18.7, and 19.5 ton ha^-1, respectively, with that of oats harvested on the latter two dates being significantly increased by 83% and 91%, respectively, compared with that in late May. Similarly, the FY of spring oats harvested in late October and early and mid-November was 7.1, 12.5, and 12.1 ton ha^-1, respectively, with that of oats harvested on the latter two dates being significantly increased by 75% and 71%, respectively, compared with that in late October. Taking into consideration forage yield and quality (not less than 8% CP), it would be profitable to plant spring oats in the mountainous areas of southern Korea until March 15 and harvest around June 10, whereas summer oats could be beneficially planted until August 25 and harvested from early November.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.6
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• pp.721-729
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• 2017

This study aimed to improve customer perception of Prunus mume through analysis of amygdalin contents according to changes in variety, harvest time, and fermentation conditions. Five Prunus mume domestic cultivars were harvested at five harvest times. We compared cyanogenic glucosides in four types of fruits on the market. For amygdalin contents in seeds and flesh of Prunus mume by variety and harvest time, seeds contained higher amygdalin contents than flesh with time. As Prunus mume ripened, both amygdalin contents in seed and flesh increased. However, the rate of increase gradually decreased. For prunasin contents in Prunus mume, we determined that the dramatic increase in amygdalin from May 3 to 19 was due to amygdalin synthesis from prunasin. Moreover, in the case of fermented Prunus mume, we observed lower amygdalin content as the sugar ratio and fermentation time increased until around 90 days, followed by a decrease. Furthermore, we analyzed alteration of organic acids in Prunus mume and fermented solution based on analysis of amygdalin content in four other market fruits. Amygdalin was detected at $252.37{\pm}2.3$, $22.01{\pm}0.31$, and $8.75{\pm}0.14mg$ per 100 g in plums, peaches, and grape seeds, respectively. In flesh of plums and peaches, amygdalin contents were detected at $84.14{\pm}0.26$ and $7.54{\pm}0.06mg$ per 100 g, respectively. These results suggest scientific improvements for consumption and breeding lines.

• Journal of Radiation Protection and Research
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• v.22 no.3
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• pp.171-181
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• 1997

A mixed solution of $^{54}Mn$, $^{60}Co$, $^{85}Sr$ and $^{137}Cs$ was applied to the soil of culture boxes in a greenhouse 2 days before transplanting red pepper and at 3 different times during its growth for investigating transfer factors ($m^2/kg-dry$) for its green and red fruits. Transfer factors varied with radionuclide, application time and harvest time by factors of about $20{\sim}100$. They decreased mostly in the order of $^{85}Sr>^{54}Min>^{60}Co>^{137}Cs$ while $^{54}Mn$ and $^{60}Co$ was higher than $^{85}Sr$ when time lapse between application and harvest was short. Transfer factors of $^{85}Sr$ and $^{137}Cs$ at the last application were lower than those at the previous one by factors of $3{\sim}20$ depending on harvest time. Variations in $^{54}Mn$ and $^{60}Co$ transfer factors with application time after transplanting were comparatively low. Transfer factors of $^{54}Mn$, $^{60}Co$ and $^{85}Sr$ mixed with topsoil before transplanting were up to $3{\sim}9$ times higher than those for the application onto soil surface 2 days after transplanting while there was no difference in $^{137}Cs$. The present results can be referred to in estimating root-uptake concentrations of the radionuclides in red pepper fruit and taking proper measures for its harvest and consumption at the event of an accidental release during the growing season of red pepper.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.4
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• pp.343-349
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• 1993

This study was conducted 1)to determine the factors responsible for the gradually increased rice yield by examining any improvements in yield-related characters and physiological characters among the historically recommended varieties of rice in Korea, and 2)to reveal the way of achieving further yield improvement by breeding in the future. Eight recommended varieties from 1911 to 1988 were selected and grown at the same conditions. The yield-related characters were observed at the harvest time, and the physiological characters such as RGR, NAR, LAR, SLA and L WR were estimated by the classical method of growth analysis. The newer varieties are shorter and those released after 1970's are greater in percent of filled spikelets and harvest index than the older varieties. There are no definite changing trends in the variations of number of panicles per hill, number of spikelets per panicle and 1000 grain weight according to the course of evolution in the recommended varieties. There is little evidence of improvement in the physiological characters such as NAR, LAR, SLA and LWR among the recently developed varieties compared with those of the older varieties. The increase in grain yield due to variety improvement, if any, is largely associated with the greater harvest index and percent of filled spikelets by breeding blight resistant and / or lodging resistant genotypes with short culm. It is suggested that increase in NAR should be carried out simultaneously with increase in harvest index to breed high yielding genotypes. I t appears to be important to breed genotypes with long culm in order to enhance light penetration into the canopy as long as they are lodging resistant. Since NAR is negatively correlated with LAR, it is unlikely to succeed to improve both characters simultaneously. The direct effect of NAR on RGR by path analysis is much larger than that of LAR, and hence it is suggested that breeding genotype with large NAR is more effective on enhancing RGR. It is also suggested that improving LAR through LWR is likely effective on increasing RGR.