PURPOSES : The aim of this study is to evaluate the stripping resistance of a bead coating via the Hamburg wheel tracking test and image analysis. METHODS : First, the stripping resistance of the bead coating was evaluated via the Hamburg wheel tracking test. A pneumatic wheel with a load of 175±2 N was used to simulate repeated skid cycles. Several bead coating mixtures with different numbers of coating layers, i.e., zero, one, two, three, and four layers, i.e., zero, one, two, three, and four layers,were conducted. Finally, an image analysis program was developed to analyze surface images captured from the Hamburg wheel tracking test. RESULTS : The results show that the samples with more coating layers exhibit higher stripping resistance. After 500 stripping cycles, the percentage of bead loss is 4% to 28%. At 80% bead loss, the mixture with one coating layer presents more skid cycles than the control sample without a coating layer. CONCLUSIONS : Incorporating a coating layer can improve the stripping resistance of glass beads under repeated skid cycles. Additionally, an image analysis program is established in this study to determine the percentage of bead loss caused by the stripping test.

PURPOSES : A mechanistic-empirical (ME) predictive design logic that can compute the reflective cracking life of hot-mix asphalt (HMA) overlaid on top of a composite pavement is proposed herein. METHODS : The overlay thickness design and analysis logic of the HMA were formulated based on the ME concept of reflection crack propagation. Climate data, traffic load data, the pavement material properties, and the thickness of each layer of the pavement are the main inputs for the ME-Reflective Cracking Rate (RCR) prediction algorithm. An Microsoft Excel Virtual Basic for Application (VBA) program was created to aid designers in assessing the expected performance of an HMA overlay design. Calibration was done using data from the Long-Term Pavement Performance (LTPP) sections. Sensitivity analysis was conducted to compare the results yielded by the program and data from a report by the Texas Transportation Institute. RESULTS : The predictive model performance effectively generates the dynamic and relaxation modulus curves. The correlation value of the calibration factors, R2, is 0.79. The calibration factors used for the Asphalt Overlay Thickness Design (AOTD) program and the sensitivity analysis, i.e., k1, k2,, and k3,, are set to 5, 5, and 150, respectively. The sensitivity of the AOTD program affords reasonable results. Additionally, the program yields results similar to the trends presented in a report by the Federal Highway Administration. CONCLUSIONS : The proposed ME design logic is successfully translated into an Excel VBA program, AOTD, which can perform routine assessments of laboratory tests for HMA overlays. The program can effectively perform numerous iterations and computations to predict an HMA overlay. The predictive model can generate reasonable dynamic modulus and relaxation modulus curves for the characterization of HMA overlays. Under the same asphalt binder grade and HMA type, doubling the HMA overlay thickness yields three times the expected reflective cracking service life.

A winter forage tetraploid rye (Secale cereale L.) cultivar, ‘Daegokgreen’, was developed at the Department of Central Area Crop Science, NICS, RDA in 2016. The mutant line ‘CG11003-8-B’, which was induced from rye cultivar ‘Gogu’ (diploid) by colchicine treatment, was selected for its excellent agronomic performance and was placed in preliminary yield trials for one year, 2013. The line was designated “Homil59” and was tested for regional yield trials at the four locations in Korea from 2014 to 2016. Finally, the new cultivar was named as the ‘Daegokgreen’ (grant number 8274). The leaf of cultivar ‘Daegokgreen’ is wide, long and dark-green color. The cultivar also has a big-size grain with light-brown color. The heading date of cultivar ‘Daegokgreen’ was April 17 which was 2 days later than that of check cultivar ‘Gogu’. The tolerance to cold and wet injury, and resistance to powdery mildew and leaf rust of the new cultivar were similar to those of the check cultivar but the resistance to the lodging of the new cultivar was stronger than that of the check. The average roughage fresh and dry matter yield of the new cultivar after 10 days from heading were 37.0 and 7.7 MT ha-1, respectively, which were similar to those (38.4 and 8.0 MT ha-1) of the check cultivar. The roughage quality of ‘Daegokgreen’ was higher in crude protein content (8.9%) than that of the check cultivar (7.9%), while was similar to the check in total digestible nutrients (56.9%). This cultivar is recommended for fall sowing forage crops at all of crop cultivation areas in Korea.

This study was conducted to clarify the effect of high temperature during winter period(autumn sowing) and spring sowing on yield, quality and growth and development in barley. The varieties used for the experiments were heenchalssalbori and keunalbori 1 having a strong spring habit characteristics. In spring sowing treatment, spikelet differentiation was proceeded rapidly and tillering was proceeded slowly compared to the development stage, because the barley sowed at spring is cultivated in high temperature and long day conditions from sowing to spikelet differentiation stage compared with autumn sowing(control). And in high temperature treatment during winter period, like spring sowing, tillering was inhibited compared to the development stage. The number of grain per panicle and the period required to heading stage from spikelet differentiation were reduced largely at spring sowing, because spring sowing treatment was conducted in high temperature and long day condition compared with autumn sowing and high temperature treatment during the period from spikelet differentiation to heading stage. Meanwhile in spring sowing treatment, average temperature during ripening stage was higher than the autumn sowing and high temperature during winter, because heading stage was so late. After all, starch, amylose content and grain weight were reduced while protein content was relatively increased in spring sowing treatment due to difference of average temperature of ripening stage. These changes affected the decrease of viscosity of peak, trough, breakdown and the increase of setback viscosity

‘Palbangmi’ is a super high-yield rice cultivar bred by interspecies cross between Tongil type and Africa rice. But, ‘Palbangmi’ has a problem in grain maturation which results in rice yield decreases. Because ‘Palbangmi’ is Tongil and Africa rice interspecies-crossed cultivar, it would be predicted to require higher temperature for grain maturation than japonica rice. Therefore, ‘Palbangmi’ would be required to determine Late Marginal Heading Date (LMHD) for normal maturation. In this study, experiment of transplanting date was carried out to determine LMHD of ‘Palbangmi’ in Suwon and Iksan for 3 years. When daily mean temperature was below 23oC, grain filling ratio (%) increased about 8% for each 1oC. On the other hands, grain filling ratio (%) didn't increase when the daily mean temperature was above 23oC. Therefore, it is determined that 23oC is adequate for minimum threshold temperature for grain maturation. The LMHD of ‘Palbangmi’ was determined from calculated heading dates for each year which could satisfy threshold temperature for 40 days after heading during last 15 years. As a results, LMHD was earlier than August 1 in 16 regions where it is inadequate for ‘Palbangmi’. Continually, LMHD was August 1 ~ August 5 in 13 regions, August 6 ~ August 10 in 14 regions and August 11 ~ August 15 in 21 regions. Finally, LMHD was later than August 15 in 14 regions. Considering that heading date of ‘Palbangmi’ is August 13 as mid maturing ecotype, it is suggested that earlier transplanting required for normal maturing in almost areas except south plain area and some areas of central plain area.

This experiment was conducted to clarify the effect of the high temperature on physicochemical properties of barley kernels during ripening stage. High temperature treatment was lasted from each 10, 17 and 24 days after heading(DAH) until the harvest time at 21oC, 24oC, 27oC in artificial climate room. The results showed that ripening period from heading to maturity was tend to be shorter at higher temperature treatment condition and at longer duration treatment condition. and 1000-grain weight was decreased as the ripening period shortened. Furthermore, gelatinization properties was changed by high temperature due to the reduction of starch and amylose contents. As the shortening of grain filling period by a high temperature treatment, the protein content was increased. In the 10 DAH at 27oC treatment, the grain filling period was shortened by 9 days. The starch contents was reduced by 5.7 %, and the protein content was increased by 5.6 % in a such condition. Protein contents was showed negative correlations with amylose, starch contents and gelatinization properties, respectively. Starch contents, however, showed positive correlations with amlyose content and gelatinization properties.

청보리 신품종 ‘유한’은 삼차망으로 가축 기호성이 좋고 보리호위축병에 강하면서 탈립이 적은 양질 다수성 품종이다. ‘유한’은 직립 초형으로 파성은 III이고. 엽색은 담녹색, 넓이는 중 정도이다. 초장은 107 cm로 장간이고, 경수는 m2당 641개로 다얼성이다. 출수기는 전작에서 5월 2일로 대비품종인 ‘유연’ 보다 1일 늦었으며, 답리작에서는 4월 28일로 2일 빨랐다. 황숙기는 전작에서 6월 4일, 답리작에서는 5월 31일로 ‘유연’과 같았다. 도복은 3 정도로 중강이고, 내한성은 ‘유연’ 보다 강하였으며, 보리호위축병은 익산(Ⅲ형), 나주(Ⅰ형), 진주(Ⅳ)에서 모두 저항성을 보였다. 건물수량은 전작 1개소 및 답리작 5개소 평균 12.6톤/ha으로 ‘유연’ 보다 6% 증수하였으며, 답리작에서는 12톤/ha로 5% 증수하였다. 조사료 품질은 조단백질 함량 7.3%, ADF 26.8%, NDF 47.8%, TDN 67.7%로 ‘유연’과 비슷하였고, 사일리지 품질은 2등급으로 양호하였다. 적응지역은 1월 최저평균기온 －8℃ 이상으로 북부 산간내륙지방을 제외한 전국이다.

청보리 신품종 ‘녹양’은 총체생산성이 높고 생육후기 녹체성이 우수하며, 도복에 강하고 보리호위축병에 저항성 인 품종이다. 이 품종은 2001년 ‘낙영’을 모본, 육성계통인 ‘SB77368-B-145’를 부본으로 교배하여 선발된 ‘SB01T2017- B-B-1-2’ 계통을 2007년～2012년까지 관찰시험, 생산력검정 시험과 지역적응시험을 거쳐 2012년에 육성되었다. ‘녹양’ 은 반포복 초형으로 파성이 Ⅲ 정도이며, 잎은 담녹색이면 서 넓고, 줄기 굵기는 중간 정도이며, 이삭은 길고 까락은 일반망이다. ‘녹양’은 잎과 줄기의 후기녹체성이 ‘영양’에 비해 오래 지속되었다. ‘녹양’의 초장은 104 cm로 대비품종 인 ‘영양’에 비해 장간형이고, 평균 출수기와 성숙기는 각 각 5월 6일과 6월 4일로 ‘영양’보다 늦었다. ‘녹양’은 ‘영 양’보다 추위와 도복에 강하였고, 보리호위축병에 대하여 익산(Ⅲ형), 나주(Ⅰ형), 진주(Ⅳ) 등 모든 지역에서 저항성 을 보였다. ‘녹양’의 평균 건물수량은 전작에서 12.8톤/ha, 답리작에서 11.5톤/ha으로 영양’에 비하여 각각 7%, 2% 증수하였다. ‘녹양’과 ‘영양’ 모두 황숙기에 곡실의 탈립 정 도가 매우 낮았고, 조사료 품질은 조단백질 함량 7.2%, ADF 25.9%, TDN 68.5%로 ‘영양’과 대등하였고, 젖산함량 도 3.36%로 3.04%인 ‘영양’과 비슷하였으며, 사일리지 등 급은 2등급으로 양호하였다.

This experiment was conducted to evaluate the effects of high temperature on the stem, leaf and grain of barley during the ripening period and to provide information for the development of high-temperature cultivation techniques and adaptive varieties. We used an artificial climate control facility, to provide a temperature 3℃ higher than the normal average temperature during the ripening stage. Although the maximum rate of starch synthesis was increased at high temperature by approximately 11%, the starch content was decreased, because the period of starch synthesis ended 4 days earlier. As in the case of starch synthesis, the expression of genes related to starch synthesis was increased at the early ripening stage in the high temperature treatment, however, the duration of expression tended to decrease rapidly. Furthermore, the partitioning rate of assimilation products in the panicle increased to a greater extent in the high temperature treatment than in the control. In contrast, for the stem and leaf, the partitioning rate of assimilation products decreased more rapidly in the high temperature treatment than in the control. On the basis of these results, it can be considered that the translocation rate of assimilation products increased to a greater extent in the high temperature treatment than in the control at the early ripening stage. These results indicate that the decrease in grain weight at high temperature during the ripening stage is attributable to an increase in the speed of starch synthesis at high temperature, but the increase in ripening speed does not compensate for the shortening of the ripening period. Finally to develop varieties and cultivation techniques suited to high temperature, we need to focus on physiological characteristics related to the duration of starch synthesis.

Even though phosphorus (P) is essential element for plant growth and development, it is not enough for crop production in soil. To breed more P deficient tolerance rice, screening and selection in rice population is needed. We tried to develop more simple and rough screening method for breeding of P deficient tolerance rice. In P deficient condition, tiller number was dramatically decreased among yield components in rice. Though this result, we confirmed tiller number could be the best marker in screening of P deficient tolerance rice. 480 rice genetic resources were cultivated in rice bed tray filled with P deficient soil for four weeks and each dry weight was measured. Among them, the 55 kinds of genetic resource were selected then cultivated in paddy field with 3 fertilizer conditions. Plant dry weight and tiller number in ripening stage were shown significant difference according to P condition. Plant dry weight and tiller number in ripening stage was highly correlated especially in P deficient condition. Furthermore, the tiller number in ripening stage and plant dry weight in rough screening were shown high degree correlation. Though these results, we might expect measuring of plant dry weight after cultivation in rice bed tray filled with P deficient soil could be a simple and effective screening method in selection of P deficient tolerance rice.

콩의 수량은 건물생산성에 비해 고온에 민감하게 반응하는 하는 형질로 알려져 있다. 따라서 본 연구는 등숙기 고온이 종실의 발달, 품질특성 및 수분흡수특성에 미치는 영향을 검토하기 위해 수행하였으며 그 결과를 요약하면 다음과같다.1. 등숙온도가 높을수록 백립중은 감소되었는데, 황금콩은 선유콩에 비해 감소폭이 컸고, 등숙기 지속적인 고온은 종실비대를 억제시켜 소립종의 비율이 증가될 뿐만 아니라 종피율을 감소시키는 것으로 나타났다.2. 등숙온도가 높을수록 지방 함량 및 C/N율이 감소되고,단백질 및 총당 함량이 증가되었으나 당의 조성으로볼 때 단당류와 이당류는 증가되고 올리고당류는 오히려 감소되는 것으로 나타나 고온은 동화물질의 축적을억제시키는 것으로 판단되었다.3. 고온에서 등숙된 콩은 침지초기에 부피 및 무게의 증가가 비교적 빠르게 이루어졌으나 침지시간이 경과됨에 따라 대조구에 비해 부피 및 무게증가율이 모두 낮게 나타났고, 황금콩은 선유콩에 비해 침지에 따른 부피증가율 및 무게증가율이 상대적으로 낮았다.4. 콩의 백립중과 종피율은 침지에 따른 종실의 부피 및무게증가율뿐만 아니라 용출액의 TDS와 EC에 영향을 미치는 주요 형질로 판단되었고, 단백질 함량과C/N율은 TDS 및 EC와 유의한 상관을 보였으나, 당함량은 부피증가율과 무게증가율뿐만 아니라 TDS 및EC와 상관이 인정되지 않았다.5. 따라서 등숙온도가 높을수록 종실에 동화물질의 축적이 불완전하게 이루어져 침지에 따른 가용성 고형물의용출량이 많아지고, 결과적으로 TDS 및 EC가 높아지는 것으로 판단되었다.

헤어리베치의 꽃색 중 보라색, 분홍색, 백색의 유전 양상을 구명하기 위하여 보라색 꽃 품종(청풍보라), 분홍색 꽃 품종(Mamecho) 그리고 백색 꽃 품종(HV-Kw1) 상호 간에 교잡하여 잡종 2세대(F2)에서 꽃색 분리 비율을 조사하고, 또한 분홍색과 연분홍색 사이의 유전 양상을 조사하기 위하여 연분홍색 꽃 품종(HV-Mp1)과 분홍색 꽃 품종(Mamecho)을 교잡하여 F2에서 꽃색 분리 비율을 조사한 결과 백색/보라색 조합과, 보라색/분홍색 조합에서 보라색은 백색과 분홍색에 대해 3 : 1의 비율로 분리하였고, 연분홍색/분홍색 조합에서 분홍색 3, 연분홍색 1의 비율로 분리하였으나, 백색/분홍색 조합의 F2 집단에서는 보라색 9, 분홍색 3, 백색 4의 비율로 분리하였다. 이러한 헤어리베치 꽃색 유전분리 결과로 볼 때 본 연구에서 사용된 품종들의 보라색, 분홍색, 그리고 백색 꽃은 서로 다른 두 쌍의 유전자 열성상위 작용에 의해 발현되며, 연분홍색은 분홍색에 대하여 단일 열성관계인 것으로 나타났다. 본 연구결과는 헤어리베치 품종 육성의 기초 자료로 유용하게 활용될 수 있을 것으로 기대된다.

‘Youhan’ (Hordeum vulgare L.), a new whole crop barley cultivar, was developed by the breeding team at the Department of Rice and Winter Cereal Crop, National Institute of Crop Science, RDA in 2012. ‘Youhan’ has the growth habit of III, light green and middle size leaf, hooded and lax-type spikes. The cultivar showed 107 cm of culm length, 641 spikes per m2. Heading date of ‘Youhan’ was May 1, one day later than that of check cultivar ‘Yuyeon’ in upland, and 2 days earlier than that of check in paddy field. Maturing time was similar to check cultivar ‘Yuyeon’ as June 4 in upland and May 31 in paddy field. ‘Youhan’ also showed better winter hardiness, the resistance to lodging and disease than those of check cultivar. The average forage dry matter yield in the regional yield trial was about 12.6 and 12.0 ton ha-1 in upland and paddy field, respectively, which were 6%, 5% higher than that of the check. It also showed 7.3% of crude protein, 26.8% of ADF(Acid Detergent Fiber), 47.8% of NDF(Neutral Detergent Fiber), and 67.7% of TDN(Total Digestible Nutrients), including higher grade of silage quality for whole crop barley. Fall sowing cropping of ‘Youhan’ is recommended only in areas where average daily minimum mean temperatures in January are higher than －8°C, and it should not be cultivated in mountain areas of Korea.