• 한국작물학회지
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• 제59권4호
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• pp.406-412
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• 2014

The influence of rainfall during the ripening stage on pre-harvest sprouting, seed viability, and seed quality was investigated in two Korean rice cultivars, Shindongjin and Hopum. When the rainfall was artificially treated in a greenhouse, HP started to pre-harvest sprouting at three days of rainfall treatment (DRT), but Shindongjin did not show pre-harvest sprouting at 40 DAH treatment and just 0.3~0.8% at 50 DAH, which was much lower than 15.3~25.8% of Hopum in the same treatment. After harvest, the seed germination of Hopum decreased about 10~25% compared to non-treated seeds, but that of Shindongjin decreased much little rate than that of Hopum. The seed longevity tested by accelerated aging decreased with prolonged rainfall period in both cultivars, but the varietal difference was clear; Shindongjin could withstand longer accelerated aging than Hopum. Shindongjin maintained its germination (>50%) ability after 15 days of accelerated aging regardless of the rainfall treatment period and time, but Hopum dropped below 50% germination ability after only 5 days of accelerated aging. In conclusion, rainfall during the ripening stage induced not only pre-harvest sprouting, but also reduced seed quality and longevity during storage, which varied between two cultivars.

• Asian-Australasian Journal of Animal Sciences
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• 제32권2호
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• pp.224-232
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• 2019

Objective: Apart from various climatic differences, corn harvest stage and varieties are two major factors that can influence the yield and quality of corn silage in the tropics. A study was conducted to determine the optimum harvest stage of four corn varieties for silage production in Malaysia. Methods: Corn was harvested at four growth stages; silking, milk, dough, and dent stages from four varieties; Sweet Corn hybrid 926, Suwan, breeding test line (BTL) 1 and BTL 2. Using a split plot design, the treatments were then analysed based on the plant growth performance, yield, nutritive and feeding values followed by a financial feasibility study for potential commercialization. Results: Significant differences and interactions were detected across the parameters suggesting varying responses among the varieties towards the harvest stages. Sweet Corn was best harvested early in the dough stage due to high dry matter (DM) yield, digestible nutrient, and energy content with low fibre portion. Suwan was recommended to be harvested at the dent stage when it gave the highest DM yield with optimum digestible nutrient and energy content with low acid detergent fibre. BTL 1 and BTL 2 varieties can either be harvested at dough or dent stages as the crude protein, crude fibre, DM yield, DM content, digestible nutrient and energy were not significantly different at either stage. Further financial analysis showed that only Sweet Corn production was not financially feasible while Suwan had the best financial appraisal values among the grain varieties. Conclusion: In conclusion, only the grain varieties tested had the potential for silage making according to their optimum harvest stage but Suwan is highly recommended for commercialization as it was the most profitable.

• East Asian mathematical journal
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• 제34권5호
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• pp.683-691
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• 2018

We consider an optimal control problem for an impulsive stage-structured model involving ordinary differential equations with impulsive values of initial conditions in the next year. The main goal is to maximize a profit of the catch of Pacific cod in the South Korea through optimal harvest strategy as a control of adult cod. We established necessary conditions for the optimal harvest control using idea of Pontryagin's maximum principle. The optimal harvest strategy is to numerically solve the equation by using an iterative method with the Runge-Kutta method. Finally, we compare a monthly average of fishing mortality of Pacific cod from 2013 to 2017 with monthly fishing mortality for result obtained optimal harvest strategy.

• 한국초지조사료학회지
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• 제15권2호
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• pp.112-117
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• 1995

A field experiment was canied out to determine the effects of harvest time (grazing, soiling and hay stage) on the grass growth, dry matter (DM) yield, nutritive value, and weed development in reed canarygrass (Phalaris arundinacea L.) pasture. The cultivars of reed canarygrass used in this study were Palaton, Venture, Castor, and Frontier (control). The grass was harvested 3 times at hay stage, 4 times at soiling stage, and 6 times at grazing stage in 1992. The average plant height was 31-41cm at grazing, 47-59cm at soiling, and 76-86cm at hay stage. Similar DM yield was observed in Palaton(12,567 kglha), Venture(l2,435kg), and Frontier(12,762kg), and the yields of 3 cultivars were significantly higher than that of Castor(ll,025kg) (P<0.05). Total yields affected by harvest time were lO,O6 1, 1 1,832, and 14,699 kg/ha at grazing, soiling, and hay stage, respectively(P<0.05). The content of crude protein (CP) was not significantly different among cultivars. CP contents by harvest time were 21.6% at grazing, 19.3% at soiling, and 18.8% at hay stage, regardless of cultivm(P<0.05). The contents of neutral detergent fiber (NDF) and acid detergent fiber (ADF) were similar among cultivars and harvest time. However, slightly higher NDF and ADF contents were found in Frontier. The contents of Ca, P, K, and Mg were not affected by cultivars and harvest time. The appearance of weeds was high in Castor, and low in Frontier. The weeds at grazing stage(33.3-60.0%) were remarkably higher than those at soiling and hay astage (ca 10%). In conclusion, it is suggested that 3-4 times (soiling and hay stage) of harvest was recommended for grass production, nutritive value, and weed control in reed canarygrass pasture, regradless of cultivars of Palation, Venture and Frontier, except Castor.

• 한국초지조사료학회지
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• 제30권1호
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• pp.25-34
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• 2010

최근에 청보리 사일리지는 국내에서 가장 많이 이용하는 조사료이지만 유기축산을 위한 유기조사료의 생산과 품질에 관한 연구는 미흡한 실정이다. 따라서 본 시험은 유기 청보리 사일리지의 적정 수확시기를 구명하고, 사일리지 품질 향상을 위하여 예건과 싸라기를 첨가하여 사일리지를 평가하였다. 시험구 배치는 12처리 3반복의 분할구 배치법으로 주구는 수확시기로 출수기, 유숙기 및 황숙기를 두었으며, 세구는 무처리, 예건, 싸라기 10%, 싸라기 15%를 두었다. 수확시 건물함량은 출수기, 유숙기 및 황숙기가 각각 12.8%, 21.9% 및 29.8%로 증가하였다. 청보리의 건물수량은 출수기, 유숙기 및 황숙기가 각각 10,346, 15,819 및 18,336 kg/ha였으며, TDN 수량은 6,288, 9,550 및 10,178 kg/ha였다. 유기 사일리지의 pH는 출수기, 유숙기 및 황숙기가 각각 4.70, 4.03 및 5.37로 유숙기가 가장 낮았다. 청보리의 수확시기가 늦어짐에 따라 조단백질, 조지방, NFC 및 TDN 함량은 감소하였으나, NDF 및 ADF 함량은 증가하였다. 그러나 조회분 함량은 유숙기가 가장 낮았다. 사일리지의 예건과 싸라기의 첨가는 조회분, NDF 및 ADF 함량을 감소시키고, NFC와 TDN 함량은 증가시켰다. 사일리지의 건물소화율은 수확시기가 늦어짐에 따라 감소하였으며, 예건과 싸라기 첨가에 의하여 건물소화율이 증가하였다. 유숙기가 다른 수확시기보다 젖산과 총유기산 함량은 높고 낙산 함량이 낮아 총유기산 중 젖산함량이 가장 높았다. 예건과 싸라기 첨가에 의한 젖산 함량 증가 효과는 출수기가 다른 수확기보다 효과가 있었다. 이상의 결과를 종합해 볼 때 유기 청보리 사일리지 제조를 위한 수확적기는 유숙기 이었으며, 예건과 싸라기 첨가에 의하여 청보리 사일리지의 품질을 향상시킬 수 있었다.

• Asian-Australasian Journal of Animal Sciences
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• 제14권12호
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• pp.1705-1711
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• 2001

Silage corn (Zea mays L) is grown extensively in livestock operations, and many managements focus on forage yield. This experiment was conducted at Seoul National University (SNU) Experimental Livestock Farm, Suwon in 1998. We determined the effect of planting date and harvest stage on forage yield and quality responses of corn hybrids (five relative maturity groups). The five maturity groups (100 d, 106 d, 111 d, 119 d and 125 d) were planted on 15 April and 15 May, and harvested at maturity stages (1/3, 1/2 and 2/3 kernel milkline). Whole plant dry matter (DM) and ear percentages had significant differences among corn hybrids. Ear percentages of early maturing corns (100 d and 106 d) were higher than for other hybrids. Ear percentage at the early planting date was higher than that at the late planting date for all corn hybrids. The DM and total digestible nutrients (TDN) yields of the 106 d and 111 d corn hybrids were higher than other hybrids, and the DM and TDN yields at the early planting date were higher than that at the late planting date. The acid detergent fiber (ADF) and neutral detergent fiber (NDF) percentages were greater for the late maturity corn hybrids. For plants of the early planting date, the ADF and NDF percentages were lower than for those of late planting date for hybrids. From the comparison among harvest stages, ADF and NDF percentages were decreased as harvest stage progressed. The TDN, net energy for lactation (NEL), and cellulase digestible organic matter of dry matter (CDOMD) were decreased as maturity of corn hybrid delayed. The TDN, NEL, and CDOMD values at the early planting date were higher than those at the late planting date among for corn hybrids. From the comparison among harvest dates, TDN, NEL, and CDOMD values were increased as harvest stage progressed. The correlation coefficient for DM percentage of grain at harvest with DM and TDN yields were 0.68*** and 0.76***, respectively. And the correlation coefficient for ear percentage with ADF, NDF, and CDOMD were -0.81***, -0.82*** and 0.73***, respectively. Our study showed differences of silage corn in forage production and quality resulting from hybrid maturity, planting date, and harvest stage. We believe that for the best silage corn, selection of the hybrid and best management practices are very important.

• 농업과학연구
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• 제45권1호
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• pp.43-49
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• 2018

The species of forage crops used in this study were Italian ryegrass (cv. Kowenery), sorghum (cv. SX17), proso millet (cv. domestic) and Japanese millet (cv. Jeju). The plant height of the summer crops was the highest at the dough stage. The dry matter yield of Italian ryegrass was 902.7 kg per 10 a. The dry matter yield of the winter crop and sorghum was 11,985 kg when harvested at the dough stage rather than at the first and second harvests. The proso and Japanese millet also had higher yields for dry matter during the dough stage rather than during heading and regeneration. The acid detergent fiber (ADF) content of Sorghum was lower than that of the first and second harvest; however, the proso and Japanese millet had a higher ADF content at the dough stage. The neutral detergent fiber (NDF) content was higher at the dough stage than at the first and second harvest, and the crude protein content was also lower at the dough stage than at the first and second harvest. The crude protein production for the dry matter yield was about 84 kg in Sorghum when harvested at the dough stage. Proso millet showed no difference for the crude protein production at the heading and dough stage while the Japanese millet had a higher crude protein production. There were no differences in the total digestible nutrients (TDN) content for the three crops according to the harvesting time. Therefore, if Sorghum and Proso and Japanese millet are to be combined with Italian ryegrass, it is better to harvest them at the dough stage.

• 한국초지조사료학회지
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• 제31권1호
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• pp.65-74
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• 2011

본 시험은 수확시기가 옥수수 원형 곤포사일리지의 품질에 미치는 영향을 구명하기 위하여 2009년부터 2010년까지 국립축산과학원에서 수행되었다. 옥수수 사일리지 전용 품종인 광평옥을 이용하여 숙기별 3회(유숙기, 황숙기 및 완숙기)에 걸쳐 수확을 하여 사일리지로 조제하였다. 숙기가 진행됨에 따라 옥수수 원형 곤포사일리지의 조단백질과 TDN 함량은 감소하는 경향을 보였으나 섬유소인 NDF 및 ADF 함량은 증가하였다. 그리고 숙기별 in vitro 건물 소화율은 비슷하였다. 숙기별 사일리지의 pH는 3.8~4.0을 유지하였으며, 숙기별 차이는 크지 않았다. 또한 생육이 진행됨에 따라 초산 함량은 감소되었으나 젖산 함량은 증가되었다. 그리고 품질등급은 완숙기> 황숙기> 유숙기 순으로 나타났다. 이상의 결과를 종합하여 볼 때 양질의 옥수수 원형 곤포사일리지 제조를 위해서는 황숙기에 수확하여 사일리지를 만드는 것이 옥수수 사일리지 발효를 향상시킬 수 있다.

• 한국연초학회지
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• 제7권1호
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• pp.39-47
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• 1985

Normally cultured aromatic tobaccos, KA 101 and KA 103, were primed progressively in three-leaf segments, either 7 days before bud, bud, or early flower stage with 7 days interval, respectively, The cured leaves were weighed for yield, graded, analyzed for quality-related constituents including volatile aroma components. Also the cured leaves were manufactured and smoked by panelists. Yield and quality by price decreased with advancing ripeness. Reducing sugar, total nitrogen, protein nitrogen decreased with successive ripeness, but reverse in this trends with nicotine, petroleum ether extracts and volatile acids components. Among volatile neutral components, furfural, furfuryl alcohol, benzyl alcohol, penethyl alcohol and p-cresol decreased, but solanone increased with delayed harvest. Neophytadiene, oxysolanone, furfuryl aceton was highest at mid harvest, which was judged to be best by panelists. Mid harvest, first primed at bud stage when leaf color comes to pale green to yellow green, seems to be highly recommendable.

• 한국초지조사료학회지
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• 제32권4호
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• pp.405-410
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• 2012

본 연구에서는 관상용으로써 가치가 없어지면 잡초로 변해 버린 유채를 조사료원으로써 이용하기 위한 방법을 모색하기 위해서 천안에 위치한 국립축산과학원 자원개발부 초지사료포장에서 수행되었다. 유채는 생육시기별 3회(개화기, 유숙기, 호숙기)에 걸쳐 수확을 하여 사일리지를 제조한 후 사료가치 및 품질을 조사하였다. 수확시기가 늦어짐에 따라 수분함량은 감소하는 경향을 보였으며 예건에 의해서 사일리지 제조 적기 수분함량을 유지하였다. 그리고 호숙기는 거의 헤일리지 수준의 수분함량을 나타냈다. 유채의 원형곤포 사일리지는 수확시기가 늦어짐에 따라 조단백질 함량은 감소하는 경향을 보였으나(p<0.05) 섬유소인 ADF 및 NDF 함량은 증가하는 경향을 보였다(p<0.05). 그리고 유채 사일리지의 TDN 함량도 수확시기가 늦어짐에 따라 감소되었다(p<0.05). 수확시기에 따른 사일리지의 pH는 3.8~4.4을 유지하였으며, 호숙기의 pH는 개화기나 유숙기 보다 높았다(p<0.05) 그리고 수확시기가 늦어짐에 따라 젖산 함량은 증가하였으나(p<0.05) 초산 함량은 감소하였다(p<0.05). Flieg법에 의한 유채의 원형곤포 사일리지의 품질등급은 개화기(100), 유숙기(100) 및 호숙기(88) 모두 우수등급을 나타났다.