• International Journal of Industrial Entomology and Biomaterials
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• 제10권1호
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• pp.65-68
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• 2005

Growth and development of a plant over a growing season is closely related to the daily accumulation of heat. Heat unit measured by accumulated growing degree days (GDD) is becoming increasingly popular to estimate the growth of a plant or even in insect. GDD or heat accumulation per day is measured by calculating average daily temperature and then subtracting the base temperature below which growth does not occur. Heat accumulation per day is added for the desired period and accumulated GDD is determined. The present study was conducted in five seasons in an established garden with K-2, S-36 and V-1 mulberry varieties belonging to Morus indica L. grown under completely irrigated condition at the farm of CSRTI, Mysore during 2001 - 2002. Plants were pruned in each season and the growth of the plant measured by total shoot length and fresh leaf yield was recorded at an interval of 5 days starting from 30 days of pruning (DAP) to 70 days when all the plants were pruned. The accumulated GDD for the corresponding days were recorded and used for analysis. Accumulated growing degree days (GDD) have been found to be perfectly correlated with both growth and yield in all the seasons in all the varieties studied. The high $R^2$ values indicated a strong relationship between the accumulated GDD and, growth and yield of mulberry.

• 대한원격탐사학회지
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• 제29권5호
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• pp.461-476
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• 2013

CASA 모델은 작물의 순 일차생산량(NPP)을 추정하는 가장 빠르고 정확한 모델 중 하나이다. 본 연구의 목적은 (1) 2002년 ~ 2012년 동안 한국의 논지역을 대상으로 작물 NPP의 시공간적 변화 패턴을 분석하고, (2) 연간 NPP와 쌀 생산성 간의 관계를 파악하여, (3) MODIS Product와 태양 복사량을 CASA 모형에 적용하여 2012년 한국의 쌀 수량을 추정하는 것이다. 또한, (4) 통계청이 발표한 최종 수량과 비교를 통해 적용을 검토하였다. 이를 위해, 월별 또는 누적 NPP와 수량과의 상관분석을 실시하였다. 그 결과, 총 누적 NPP와 9월의 NPP가 쌀 수량과 높은 상관성을 나타내었으며, 이를 이용하여 추정한 2012년 예측 수량은 누적 NPP 적용시 526.93 kg/10a, 9월의 NPP 적용시 520.32 kg/10a로 추정되었다. 통계청의 최종 수량과의 RMSE는 각각 9.46 kg/10a, 12.93 kg/10a를 나타내었으나, 전반적으로 두 모형 모두 1:1선에 근접한 결과를 보이고 있어 NPP를 이용한 벼 수량 추정 모형이 논벼 수량의 변화특성을 잘 반영하고 있는 것으로 판단된다.

• 한국작물학회지
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• 제46권6호
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• pp.468-472
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• 2001

출수 조.만에 따른 보리의 생육 및 수량변화를 알고자 최근 맥류 작황 24년('76~'99)자료와 그 중 출수기가 빨랐던 해와 늦었던 해를 추출하여 생육 및 수량과의 관계를 분석하였다. 1. 출수 조.만 그룹사이의 차이는 2월과 3월의 적산온도에 기인하며 특히 2월의 적산온도 차이에 고도의 유의성이 있었다. 2. 10월부터 12월까지의 적산온도가 $650^{\circ}C$ 정도되면 평년정도로 출수하고 62$0^{\circ}C$이하이면 출수 지연, 67$0^{\circ}C$이상이면 조기출수할 것이며 2월까지는 72$0^{\circ}C$되면 평년정도의 출구기일 것이고, $650^{\circ}C$이하이면 출수지연, 78$0^{\circ}C$이상이면 조기출수할 것으로 분석되었다. 3. 출수가 빨라지는 해의 온도유형을 분류하면 월동전 고온형, 월동기~재생기 고온형, 전생육기 고온형으로 나타났다. 4. 출수가 늦어지는 해는 월동~재생기 저온형과 3월 저온형으로 나뉘어졌다. 5. 출수기가 빠른 경우는 구분이 어려웠지만 출수기가 늦은 해는 월동기의 생육기간이 긴 형과 분얼기에 생육기간이 긴형, 전체 생육기간이 긴 형으로 나누어졌다. 6. 출수가 빠른 해의 수량이 출수가 늦은 해보다 많았는데 이는 수수의 증가에 기인한 것으로 나타났다.

• 한국초지조사료학회지
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• 제8권3호
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• pp.141-146
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• 1988

This field experiment was carried out to determine the effects of fertilizer application time in spring on the growth, crude protein (CP) content and dry matter (DM) yield of gasses for grazing Application times of fertilizer were on March 10, March 20, March 30, April 9 and April 19, and control (non-fertilized) plot was involved. All fertilized plots were also treated with single and compound fertilizer. The first harvesting date for grazing was on April 30, and the regrowth soiling yield was investigated on June 9, 1988. In all fertilized plots, the growth, DM yield, CP, CP yield and nigrogen recovery of grasses were significantly increased compared with control, especially on the plot of March 30. The regrowth yield on March 30, April 9 and April 19 were shghtly hig!!a than those of the others. And there were not significant differences of grass growth, CP content, and DM yield between single-and compound fertilizer treatment. On March 30 which was the best time of fertilizer application in spring, the accumulated temperature was 116.6^{\circ}C.$ and the subsoil temperature at 10 cm depth was 8.1 - 8.6^{\circ}C.$. Considering the average meteorological condition in Suwon area, the optimum application time of spring fertilizer for grazing may be recommended on March 30-April 3 (accumulated temp.; 100-125^{\circ}C.$, subsoil temp.; 8-9^{\circ}C.$).

• 한국환경농학회지
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• 제42권2호
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• pp.104-111
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• 2023

As apple trees mature, it is important to maintain good light distribution within the canopy to produce marketable fruits. Tree thinning is the selective removal of a proportion of trees growing in the orchard to provide more growing space and a good light environment for the remaining trees. This study was conducted over 3 years (14-16 years after planting) to investigate the influence of tree thinning on vegetative growth, yield, fruit quality, and blooming in the 14 years old slender spindle 'Fuji'/M.9 apple trees planted with the tree space of 3.2×1.2 m. The trees were placed in a control group (no thinning; 260 trees per 10 a) or a tree thinning group (thinned 50% of the control; 130 trees per 10 a). The tree thinning successfully improved light penetration, yield per tree, fruit red color, and yield efficiency for 3 years, and the tree thinning controlled the occurrence of biennial bearing. However, tree thinning significantly decreased accumulated yield per 10 a compared with the control. The vegetative growth, yield per tree, soluble solid contents, and blooming were not clear by the occurrence of biennial bearing in the control. These results indicated that tree thinning was a good method for improving light penetration and preventing biennial bearing in the old 'Fuji'/M.9 high-density apple orchards.

• 한국환경농학회지
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• 제42권4호
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• pp.297-310
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• 2023

M.7 rootstock is moderately resistant to fire blight. However, M.7 is generally too vigorous for high-density apple systems, but it can be grafted onto cultivars that exhibit weak tree growth, such as 'Sansa'. This study investigated the vegetative growth, yield, and fruit quality of 'Sansa' apple trees grafted on M.7 or M.9 rootstocks to assess the feasibility of establishing domestic high-density apple systems using M.7 and to determine the optimum exposure length for rootstocks. Trees were planted with exposed rootstock lengths of 5, 10, and 15 cm. The vegetative growth of apple trees grafted onto M.7 was greater than that of M.9 and vegetative growth tended to decrease as the exposed length of rootstock increased. However, the differences in yield per tree, average weights, soluble solids contents, and titratable acidity due to the rootstock and its exposure length varied. The accumulated yield over a 10 year period and the yield efficiency of M.7 were lower than that of M.9 and the yield efficiency tended to decrease as the exposed length of rootstock increased. When apple trees were grafted onto M.9, biennial bearing and tree vigor weakening occurred if the exposed length of the rootstock was over 10 cm. Conversely, when apple trees were grafted onto M.7, vegetative growth was excessive if the exposed length of rootstock was below 10 cm. Based on the results from this study, the optimum M.7 and M.9 exposure lengths for 'Sansa' were 15 cm and 5 cm, respectively.

• 한국환경농학회지
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• 제42권3호
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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.

• 소성∙가공
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• 제9권4호
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• pp.372-378
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• 2000

A process model including the effects of both the texture development and ductile damage evolution In plane strain rolling is presented. In this process model, anisotropy from deformation texture and deterioration of mechanical properties due to growth of micro voids are directly coupled Into the virtual work expressions for the momentum and mass balances. Special treatments in obtaining the initial values of field variables in the nonlinear simultaneous equations for the anisotropic, dilatant viscoplastic deformation are also given. Mutual effects of the texture development and damage evolution during plate rolling are carefully examined in terms of the distribution of strain components, accumulated damage, R-value as well as yield surfaces.

• 한국작물학회지
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• 제45권6호
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• pp.366-369
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• 2000

춘파재배시 파종기에 따른 생육단계별 적산온도, 소요일수, 엽 전개 및 수량에 미치는 영향을 검토하기 위하여, 파성 I인 사천6호와 파성 IV인 새찰쌀보리를 공시하여 2월23일부터 10 및 간격으로 4시기에 파종하여 시험한 결과는 다음과 같았다. 1.사천6호를 2월 23일 파종하면 6월 16일에 성숙하여 생육일수가 111일 소요되었고, 3월 24일 파종하면 6월 21일에 성숙하여 생육일수는 87일 소요되었다. 파종이 늦어지면 생육일수가 단축되어 성숙기는 비슷하여지는데 이는 주로 파종에서 출수까지 일수가 단축되기 때문이었다. 2. 품종에 따라 적산온도는 출현까치는 111-142$^{\circ}C$, 출수까지는 683-756$^{\circ}C$, 성숙까지는 1274-1326$^{\circ}C$ 소요되었다 추파성인 새찰쌀보리는 만파하면 파성이 완전히 소거되지 않아 성숙까지의 적산온도는 다른 시기에 비하여 많았다. 3. 2월 23일 파종한 사천6호는 엽이 하루에 0.1938개 전개되었으나 3월 24일 파종은 0.2156개 전개되어 파종이 늦을수록 엽전개는 빨라졌다 새찰쌀보리도 3월 24일 파종을 제외하고 같은 경향이었다. 4. 파종이 늦을수록 천립중이 감소하고 설립이 증가하여 수량이 감소하였는데, 사천6호의 2월 23일 파종은 수량이 10a당 299kg에 비하여 3월 24일 파종은 125kg으로 수량이 크게 감소하였다. 5. 춘파보리는 파성이 낮고 대립종인 사천6호가 좋았고, 가능한 일찍 파종하는 것이 좋고, 수원지방에서 늦어도 3월 10일 이전에 파종하여야 수량감소를 최소화할 수 있었다.

• 한국농공학회논문집
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• 제54권3호
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• pp.141-148
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• 2012

Food policy is considered as the most basic and central issue for all countries, while making efforts to keep each country's food sovereignty and enhance food self-sufficiency. In the case of Korea where the staple food is rice, the rice yield prediction is regarded as a very important task to cope with unstable food supply at a national level. In this study, Korean paddy Rice yield Prediction Model (KRPM) developed to predict the paddy rice yield using meteorological element and MODIS NDVI. A multiple linear regression analysis was carried out by using the NDVI extracted from satellite image. Six meteorological elements include average temperature; maximum temperature; minimum temperature; rainfall; accumulated rainfall and duration of sunshine. Concerning the evaluation for the applicability of the KRPM, the accuracy assessment was carried out through correlation analysis between predicted and provided data by the National Statistical Office of paddy rice yield in 2011. The 2011 predicted yield of paddy rice by KRPM was 505 kg/10a at whole country level and 487 kg/10a by agroclimatic zones using stepwise regression while the predicted value by KOrea Statistical Information Service was 532 kg/10a. The characteristics of changes in paddy rice yield according to NDVI and other meteorological elements were well reflected by the KRPM.