• Proceedings of the Plant Resources Society of Korea Conference
• /
• 2000.05a
• /
• pp.26-33
• /
• 2000

This study was conducted to investigate the relationships between yearly variations of elimatic elements and yearly variations of productivity in potato. In addition, correlation coefficients among yield and yield components were estimated. The data of yield and yield components were investigated for 9 years from 1987 to 1995. The meteorological data what gathered at the Goheung Weather Station for the same period of crop growing season were used to find out the relationships between climatic elements and crop productivity. Yearly variation of the daily minimum temperature in March and April were large with coefficients of variation (C.V.) of 126.0%, 368%, respectively, but the variation of the daily mean and maximum temperature in May and June were relative small. Stem length and number of stem show more C.V. of 9.3%, 14.3%, respectively, but the variation of the yield was relative small with 3.7%. Correlation coefficients between the amount of precipitation in April and yield, yield and daily mean temperature in June were negatively significant at the level of 5, 1 %, respectively. Correlation coefficients between the growth habits and yield are positively significant at the level of 5, 1 %, respectively. Simple linear regression equations by the least square method are estimated for stem length (Yl) and the precipitation in April(X) as Y,=82.47-0.11x (R2=0.3959), and for yield(Y2) and the precipitation in April(X) as Y,=2003.61-0.94X (R2=0.5418).

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.24 no.2
• /
• pp.35-41
• /
• 1979

To observe the effects of temperature and photoperiod on the growth and yield of winter wheat (Triticum aestivum, L) eight varieties including Chang Kwang were tested at various treatments like longday-high temperature (24hrs-20\circ), shortdayhigh temperature (12hrs-20\circ), longday-low temperature (24hrs-14\circ) and shortday-low temperature (12hrs-14\circ). Among the traits measured, days to heading, plant height, spike length, number of spikes per hill and grain yield per hill were generally decreased at high temperature and long day treatment and increased at low temperature and shortday condition. Number of grains per spike was decreased at low temperature and short day condition while increased at longday and high temperature conditions. Grain weight was decreased significantly at high temperature and shortday while increased at low temperature and longday treatment.

• Plant Resources
• /
• v.8 no.2
• /
• pp.91-95
• /
• 2005

In spring, to determine the optimal planting date and plant density of rapeseed in southern areas of Korea. $Taiwan^{\#1}$ variety for spring sowing, the highest yielding variety was grown under five different planting date and plant density. Yield components such as plant height, ear length, number of seedling stand per $m^2$, number of per ear and seed set percentage were highest at the plots with Mar. 5 of planting date and 50/20cm drilling of plant density. Yield of seed, oil, gas and 1,000 grains weight and erucic acid content were highest at the Mar. 5 of planting date and 50/20cm drilling of plant density. Judging from the results reported above, at optimum planting date and plant density of rapeseed seemed too be Mar. 5 of planting date and 50/20cm plant density in spring sowing.

• Korean Journal of Plant Resources
• /
• v.21 no.3
• /
• pp.192-195
• /
• 2008

This study was conducted to find out some important agronomic characteristics and qualities in response to different transplanting dates in Alisma plantago at southern parts of Korea. Yield components such as number of floral axis per plant, plant height and number of leaves were highest at the transplanting date of Aug. 15 and Aug. 25. Plants sown at Aug. 15 and Aug. 25 also showed highest yield. Considering from our results, optimum transplanting date were semed to be transplanting date of Aug. 15 and Aug. 25.

• Journal of Korean Institute of Industrial Engineers
• /
• v.21 no.3
• /
• pp.371-385
• /
• 1995

The yield of semiconductor chips is dependent not only on the average defect density but also on the distribution of defects over a wafer. The distribution of defects leads to consider a cluster index. This paper briefly reviews the existing yield prediction models ad proposes a new cluster index, which utilizes the information about the defect location on a wafer in terms of the coefficient of variation. An extensive simulation is performed under a variety of defect distributions and a yield prediction model is derived through the regression analysis to relate the yield with the proposed cluster index and the average number of defects per chip. The performance of the proposed simulation-based yield prediction model is compared with that of the well-known negative binomial model.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.25 no.2
• /
• pp.76-81
• /
• 1980

Root yield, number of missing and diseased plant in each line were investigated in various ginseng farms. Root yield per unit area was negatively correlated to missing percentage. Missing percentage showed significant positive correlation with diseased rate. Among lines yield was significantly different in most fields while missing rate was not, indicating that yield of each line is affected by present shading method but disease occurrence is not. Thus there are two ways of yield increase, shading improvement and disease control.

• Advances in Energy Research
• /
• v.8 no.4
• /
• pp.233-241
• /
• 2022

Biodiesel is a non-polluting and non-toxic energy source that can replace conventional diesel. However, the higher production cost and raw material scarcity became challenges that obstruct the commercialization of biodiesel production. In the current investigation, fried cooking oil is used for biodiesel production in a hydrodynamic cavitation reactor, thus enhancing raw material availability and helping better waste oil disposal. However, due to the cavitation effect inside the reactor, the hydrodynamic cavitation reactor can give biodiesel yield above 98%. Thus, the use of orifice plates (having a different number of holes for cavitation) in the reactor shows more than 90% biodiesel yield within 10 mins of a time interval. The effects of rising temperature at different molar ratios are also investigated. The five-hole plate achieves the highest yield for a 4.5:1 molar ratio at 65℃. And the similar result is predicted by the response surface methodology model; however, the optimized yield is obtained at 60℃. The investigation will help understand the effect of hydrodynamic cavitation on biodiesel yield at different molar ratios and elevated temperatures.

• Asian-Australasian Journal of Animal Sciences
• /
• v.5 no.4
• /
• pp.717-722
• /
• 1992

An experiment was conducted to examine the feasibility of producing multiple calves using embryo transfer in Japanese Black cattle. Milk yield of cows and forage intake of calves were measured for 11 cows with single calves, 14 cows with twins and one cow with triplets. The means of 26 weeks cumulative milk yield were 854, 1028 and 1271 kg for cows having singles, twins and triplets, respectively. Male birth weights for single calves, twins and triplet were 34.9, 26.6 and 19.9 kg, and female ones were 31.7, 24.1 and 22.1 kg, respectively. Weight and daily gain of calves were affected by weeks (W), sex (S), the number of calves (N), parity, birth season, $W{\times}N$, $S{\times}N$ and regression on milk yield. Growth rate was higher for single calves than for twins until about 9 weeks of age, then weights increased at a similar rate. Male calf weaning weights for singles, twins and triplets were 207.0, 177.1 and 162.2 kg, and those for females were 185.4, 151.6 and 180.4 kg, respectively. Average regression coefficients of calf growth on milk yield were significant, and single calf was affected more than twin calves by increment of milk yield. As the number of calves per cow increased, hay intake of calves decreased and concentrate intake tended to increase between 6 and 13 weeks of age.

• Korean Journal of Agricultural Science
• /
• v.46 no.4
• /
• pp.791-798
• /
• 2019

This experiment was conducted to find out the difference between roughage productivity and feed value by using two domestic forage rice cultivars in a mid-west reclaimed rice field in Korea. During the growing period, Na⁺ content in soil showed no significant difference between the two cultivars; however, the K⁺ content in the soil was significantly lower than that in which the Mogwo was grown. The tiller number was 45.5 to 58.8, which was higher than that of Mogyeong, and the leaf number was higher than that of Mogyeong. The dry matter yield per 10 a was 1,338 kg for Moggyang and 1,532 kg for Mogwoo. At the harvest time, the crude protein yield per 10 a produced 108 kg of Mogyang and 170 kg of Mogwoo, and the total digestion nutrient (TDN) yield per 10 a also produced about 617 kg of Mogyang and 880 kg of Mogwoo. To sum up the above results, Mogwo, which has many tiller numbers and leaf numbers, has a high dry matter production, a relatively low neutral detergent fiber (NDF) and acidic detergent fiber (ADF), and a high crude protein yield and TDN yield, and it was better when cultivating the forage rice cultivars in reclaimed land.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.30 no.1
• /
• pp.84-92
• /
• 1985

This experiment was carried out to study the morphological traits, yield and yield components of barley cultivars - Kangbori, Olbori and Suwon 18 - on different seeding dates. It appeared generally rapid development of young spike from late stage of floret differentiation (X stage) to complete it at heading stage. Young spike appeared more influencials by the different seeding dates rather than years and cultivars. Stem started the development from late stage of spikelet differentiation (VII stage) to early stage of floret differentiation (IX stage), indicating the continuing development from basal to upper internodes. Number of spikes per unit area showed more effect in seeding date rather than cultivar and year. However, number of kernels per spike and 1,000 kernel weight affected more due to years rather than cultivar and seeding date. It was significantly difference in grain yield according to different seeding dates.