• Korean Journal of Medicinal Crop Science
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• v.23 no.4
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• pp.311-318
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• 2015

This study had been conducted to investigate the effect of some plant growth regulators inducing fruit enlargement and optimal harvest time in Sageretia thea. Two hundred fifty $mg/{\ell}$ mepiquat chloride treatment, $1mg/{\ell}$ thidiazuron treatment on full bloom, and $200mg/{\ell}$ gibberellic acid treatment on 7 days before full bloom resulted in the increase of 21.7% in weight, and $200mg/{\ell}$ gibberellic acid treatment 7 days before full bloom, 10$mg/{\ell}$ forchlorfenuron treatment 14 days after full bloom, and $1mg/{\ell}$ thidiazuron treatment on full bloom also brought about positive effects on the enlargement of the fruit, increasing 6.3%, 6.3% and 8.1% in its transverse diameter, respectively. Furthermore, the effects of the plant growth regulator treatments on the harvest time of Sageretia thea were determined as follows: the increase in the optimal harvest time of 57.2 - 75.4%, shorter maturation period, by the treatments with $500mg/{\ell}$ mepiquat chloride 7 days after full bloom, $100mg/{\ell}$ gibberellic acid treatment on full bloom, $2.5mg/{\ell}$ forchlorofenuron 7 days after full bloom and $2mg/{\ell}$ thidiazuron treatment 7 days before full bloom; and the greater effects of plant growth regulator treatments on the fruit maturation in the following order, gibberellic acid > thidiazuron > forchlorofenuron > mepiquat chloride. The results of this study are expected to be used as a reference data to develop Sageretia thea as a new local specific crop for Jeju island.

• Journal of Forest and Environmental Science
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• v.38 no.4
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• pp.256-262
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• 2022

The timing of seed harvesting is an important decision in the management of seed orchards because it affects seed quality and yield. To investigate the effect of cone harvest time on seed quality and determine the optimal harvesting time, cones were regularly collected in seven times and germination tests were performed at each harvest time in two clonal seed orchards of Chamaecyparis obtusa. As cones developed, the percentage of seed germination increased before cone moisture content began to decrease significantly. The moisture contents of cones were highest at the first collection as 68.3% and 67.3% in Jeju and Gochang seed orchards respectively. At this time, germination speed was slowest, indicating poor seed vigour. The highest germination was found at the second stage in Jeju (36.5%) and at the seventh stage in Gochang (28.6%) seed orchard. The germination speed increased as cone moisture content decreased. Additionally, changes of seed vigour differed among the developmental stages in both seed orchards. Consequently, the optimal cone harvest time of C. obtusa seed orchards in Jeju was early September when high germination percentage was obtained. In Gochang seed orchards, late October was optimal cone harvest time when the germination speed was fast and the cone moisture content decreased.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2023.04a
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• pp.25-25
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• 2023

As the demand for processing potatoes increases, imports of raw potatoes and potato products are increasing, so it is necessary to expand potato production as raw materials for processing in Korea. Potato varieties for processing that can be grown in fall have been developed, but research on cultivation technology and processing quality management technology to improve chip processing quality is very insufficient. Therefore, this study was conducted to investigate the optimal harvest time by investigating the quantity and chipping characteristics of potato chips during autumn cultivation. As the test varieties, the chip processing varieties "Saebong", "Eunsun", and "Geumnaru" were used, and the potato cultivation site was the Seocheon-gun Test field (214 Gaeya-ri) of the Chungcheongnam-do. The test treatment was at harvest time after spring cultivation, and the potatoes were harvested at 70, 80, 90, and 100 days after sowing based on the sowing time. The investigation items were potato productivity (total yield, yield of standard processing, and number of tubers) and chip-processing characteristics (chip color, dry matter content, glucose content, etc.). As a result of examining the yield characteristics according to the harvest time, statistical significance was not found according to the treatment. The total yield (ton/ha) was 27.5 to 30.5, and there was no significant difference depending on the time of 70 to 100 days after harvest. The standard quantity for processing (yield of 81-250g potatoes per unit) also showed a similar trend. In chipping characteristics according to harvest time, statistical significance was high in specific gravity and glucose content. The specific gravity was highest at 1.077 at 70 days after harvest, and the glucose (mg/dL) content was the lowest at 37.5 at 80 days after harvest. Statistical significance was not recognized, but chip color (L value) was the highest at 64.4 at 70 days after harvest. Therefore, it is judged that the optimal harvesting time for chip processing is 70 to 80 days after sowing.

• Korean journal of food and cookery science
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• v.10 no.2
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• pp.142-145
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• 1994

Effects of different harvest time were studied on chemical composition, yield, and hardeness of milled rice. There was no difference between harvest time after 33 days. Yield of milled rice was increased as harvest time increased and only rice flour prepared in harvest time after 45 days had a good appearance. Results of different enzyme solution treatment showed that a-amylase solution had the best result and optimal condition of soaking time was 4 hour.

• Journal of Communications and Networks
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• v.16 no.3
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• pp.293-300
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• 2014

As energy harvesting communication systems emerge, there is a need for transmission schemes that dynamically adapt to the energy harvesting process. In this paper, after exhibiting a finite-horizon online throughput-maximizing scheduling problem formulation and the structure of its optimal solution within a dynamic programming formulation, a low complexity online scheduling policy is proposed. The policy exploits the existence of thresholds for choosing rate and power levels as a function of stored energy, harvest state and time until the end of the horizon. The policy, which is based on computing an expected threshold, performs close to optimal on a wide range of example energy harvest patterns. Moreover, it achieves higher throughput values for a given delay, than throughput-optimal online policies developed based on infinite-horizon formulations in recent literature. The solution is extended to include ergodic time-varying (fading) channels, and a corresponding low complexity policy is proposed and evaluated for this case as well.

• Horticultural Science & Technology
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• v.31 no.6
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• pp.687-699
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• 2013

This study was conducted to examine the effect of grafted peppers (Capsicum annuum) on different rootstocks on fruit quality. Three pepper cultivars, 'Nokkwang', 'Saengsaeng Matkkwari', and 'Shinhong' were grafted onto five commercial rootstocks that are known to be resistant to Phytophtora blight. Non-grafted or auto-grafted peppers were used as controls. Grafted plants were grown during two consecutive harvest periods by semi-forcing culture (April to August) and retarding culture (September to March the subsequent year). Full size green fruits were harvested and weighed weekly from June to August (Semi-forcing culture) and from December to March of the subsequent year (Retarding culture). The fruit size, weight, flesh thickness, and firmness were measured every month. Total marketable yield was not significantly influenced by either auto-graft of 'Nokkwang', 'Saengsaeng Matkkwari', and 'Shinhong' of pepper or grafted with the five commercial rootsctocks. By contrast, grafting influenced the apparent fruit quality of peppers. Fruit characteristics differed depending on the rootstock cultivars. However, the fruit characteristics of rootstock did not affect the fruit characteristics of scion grafted onto that rootstock. Fruit characteristics in each treatment differed among harvest time (first, second, and third harvest). Fruit quality parameters were also different as affected by the harvest period. In conclusion, apparent quality and textural property of pepper fruits were influenced by not only grafting with different rootstocks but also by the harvest period and harvest time. Accordingly, rootstock/scion combination, the scion variety and the harvest period must be carefully chosen to get the desired optimal fruit quality.

• Journal of Biosystems Engineering
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• v.38 no.1
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• pp.18-24
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• 2013

Purpose: This study was conducted to develop an optimal combine scheduling program using Max-Coverage algorithm which derives the maximum efficiency for a specific location in harvest seasons. Methods: The combine scheduling program was operated with information about combine specification and farmland. Four operating types (Max-Coverage algorithm type, Boustrophedon path type, max quality value type, and max area type) were selected to compare quality and working capacity. Result: The working time of Max-Coverage algorithm type was shorter than others, and the total quality value of Max-Coverage algorithm and max quality value type were higher than others. Conclusion: The developed combine scheduling program using Max-Coverage algorithm will provide optimal operation and maximum quality in a limited area and time.

• Korean Journal of Medicinal Crop Science
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• v.27 no.5
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• pp.315-321
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• 2019

Background: There have been no studies to date on rhizome development and optimal harvest timing for Rehmannia glutinosa. We therefore, undertook this investigation. Methods and Results: R. glutinosa 'Jihwang 1' was sown in early May and harvested in early November. Growth investigations were carried out at intervals of 10 days between 90 and 180 days after sowing (DAS). Leaf length, leaf width, and number of leaves increased until 150 DAS but decreased after 160 DAS. Rhizome length increased until 120 DAS subsequently, rhizome diameter increased rapidly between 130 and 150 DAS. Thus, the key period for rhizome enlargement in R. glutinosa is thought to be 130 to 150 DAS. Fresh root yield increased sharply from 916 kg/10a to 1,914 kg/10a between 4 and 5 months after sowing (MAS). Dry matter ratio increased gradually from 19.2% at 4 MAS to 24.4% at 6 MAS. Finally, the level of catalpol, a key active ingredient, increased sharply from 0.41% to 4.21% between 5 and 6 MAS. Given the dry matter ratio, catalpol content and yield measured, we suggest that optimal R. glutinosa harvest time is 6 MAS. Conclusions: Based on our results, the key period for rhizome enlargement is 130 to 150 DAS and optimal harvest timing is 6 MAS. We anticipate that these and other results of this study can be used to inform cultivation of R. glutinosa.

• Journal of Korean Society of Forest Science
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• v.103 no.3
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• pp.353-358
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• 2014

In order to obtain the basic data that could be used to evaluate the harvest time of new hardy kiwifruit cultivars (Actinidia arguta 'Saehan', 'Daesung' and 'Chilbo'), the seasonal fruit quality and ripening characteristics of hardy kiwifruit were investigated. Fruit sizes of 'Saehan', 'Daesung' and 'Chilbo' were increased from full bloom to 66 days, 85 days and 78 days, respectively. The growth curve of developing fruit of three cultivars showed double sigmoid. As a result of correlation analysis, the seed number per fruit showed a significant positive correlation with fruit weight (r = 0.94~0.97, p<0.01). Fruit length, width, thickness, weight, soluble solid content and titratable acidity were significantly different among the cultivars. Titratable acidity was increased from full bloom to harvest time and the titratable acidity of 'Saehan', 'Daesung' and 'Chilbo' were 1.77%, 1.22% and 1.37% on havest time, respectively. Optimal harvest time of 'Saehan' was 108 days (23 Sep.) after full bloom, those of 'Daesung' and 'Chilbo' were 92 (9 Sep.) days after full bloom.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.63 no.4
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• pp.294-303
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• 2018

To set an optimal harvest time for five main whole-crop silage (WCS) rice cultivars, Nokyang (Ny), Mogwoo (Mw), Mogyang (My), Nokwoo (Nw) and Yeongwoo(Yw), based on feed value and dry matter yield, we analyzed water content (WC), feed values such as percent crude protein (CP), crude fat (CF), crude ash (CA), neutral detergent fiber (NDF), acid detergent fiber (ADF), estimated total digestible nutrients (TDN), and calculated their dry matter yield (DMY). These parameters were estimated at the booting stage and every 10 days from start of heading to 45 days after heading (DAH) to identify the optimal harvest time for these rice varieties. In all varieties, except Ny, the WC was about 65% on the $30^{th}$ DAH. In terms of WC, it is judged that there would be no major problem in preparing high quality silage when harvested between 20~30 DAH for Ny and about 30 days for the other cultivars. The CP and CA decreased significantly as the harvest time was delayed in all varieties (p<0.05). However, the CF in the tested varieties generally declined as DAH increased, and then increased again(p<0.05). The decrease in ADF and NDF was significantly different from the booting stage to 45 DAH in all varieties (p<0.05) and the estimated TDN increased gradually in all varieties as the harvest time was delayed. The TDN of all varieties, except Nw, was over 70% around 30 DAH. As harvest time was delayed, the DMY for all WCS rice increased significantly (p<0.05). The maximum DMY for each cultivar was observed at 45 DAH, however, no significant difference (p<0.05) was seen after 40 DAH for Ny and Yw, 30 DAH for Mw and Nw, and 20 DAH for My. Considering these results and others factors such as lodging, shattering, digestibility of grains, conversion of eating rice, etc., the optimal harvest time for silage use of all WCS rice tested was generally the yellow ripening stage, at about 30 DAH (30~40 DAH for Ny and Mw, and 30 DAH for My, Nw and Yw).