• 한국초지조사료학회지
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• 제15권2호
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• pp.124-131
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• 1995

In order to find out optimum seed production date according to different defoliation and flooding period of Italian ryegrass, this studies with Tetrone were canied out on the experimental field of Honam Crop Experiment Station from 1986 to 1988. Treatments included cutting date of Nov. 20 and Apr. 10 and flooding period of 5-25 days. In soil after experiment, organic matter, phosphate and silicate content increased, but potassium content decreased 0.16% than that before experiment. Heading and maturing date of Nov. 20 cutting were same with those of non cutting, those of Apr. 10 cutting lates 6 days to heading date and 2 days to maturing date. Plant height and culm length of Nov. 20 cutting were sirniller to those of non cutting, those of Apr. 10 cutting were shorter and panicle length have no difference between non cutting and cutting. Lodging of cutting treatment was reduced than that of non cutting. Lodgin was increased as flooding period was long, also loding of all treatment occured at 30 days after heading. Two cutting times of Nov. 20 and Apr. 10 have the most fresh yield, while non cutting have the most dry matter yield. Optimun seed productin date was considered to suitable when 35 days after heading (Jun. 14), at this time, seed production was 1,640 to 2,640 kg/ha. Also if flooding j u r y have, seed production was good between 10 days and 15 days after flooding.

• 한국작물학회지
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• 제63권3호
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• pp.186-195
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• 2018

중부 평야지에서 사료용 벼 기계이앙과 담수산파 재배의 건물 생산 특성을 비교 분석하기 위하여 국립식량과학원 중부작물부 수원 벼 재배 시험 포장에서 최근 육성 등록된 목우와 녹우 품종을 이용하여 5월 20일에 이앙 및 직파하여 3년간 검토한 연구 결과는 다음과 같다. 1. 담수산파 재배의 $m^2$당 입모수는 125~192개였으며, 출수기는 9월 11일~18일로 기계이앙보다 11~17일 지연되었다. 2. 기계이앙보다 담수산파 재배에서 수확기의 3년 평균 볏짚 건물중은 증가하였고 이삭 건물중은 감소하였는데, 볏짚 건물중 증가량이 이삭 건물중 감소량의 3.3배로 많아 전체 건물 수량은 증대되었다. 3. 건물 수량은 볏짚 건물중과 밀접한 정의 상관 관계를 보였고 이삭 건물중과는 일정한 관계가 없었으며, 출수 후 수확기까지의 볏짚 건물중 감소 정도와 이삭 건물중 증가 정도는 유의한 관계가 인정되지 않았다. 4. 건물 수량과 밀접하게 관련된 볏짚 건물중은 초장과는 상관을 보이지 않았던 반면 $m^2$당 수수가 많아짐에 따라 유의하게 증가하였으며, 기계이앙 대비 담수산파의 전체 건물중 비율은 이삭 건물중 비율과는 관계가 없었고 볏짚 건물중 비율과는 정의 상관을 보였다. 5. 기계이앙 대비 담수산파에서 $m^2$당 수수는 9% 증가하여 하나의 이삭이 차지하는 평균 면적이 감소하였음에도 이삭줄기당 건물중 비율이 비슷하게 유지되었다. 6. 따라서 담수산파 재배를 통하여 생산성을 높이는 동시에 노동력과 생산비를 절감할 수 있는 것으로 평가되며, 담수산파에서 이삭 생산량을 높이기 위한 품종 재배적 보완 연구가 필요할 것으로 생각된다.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.46-46
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• 2017

We developed a rice simulation model for remote-sensing (SIMRIW-RS, Homma et al., 2007) to evaluate rice production and management on a regional scale. Here, we reports its application trial to estimate rice production in farmers' fields in Sendai, Japan. The remote-sensing data for the application was periodically obtained by multispectral camera (RGB + NIR and RedEdge) attached with unmanned air vehicle (UAV). The airborne images was 8 cm in resolution which was attained by the flight at an altitude of 115 m. The remote-sensing data was relatively corresponded with leaf area index (LAI) of rice and its spatial and temporal variation, although the correspondences had some errors due to locational inaccuracy. Calibration of the simulation model depended on the first two remote-sensing data (obtained around one month after transplanting and panicle initiation) well predicted rice growth evaluated by the third remote-sensing data. The parameters obtained through the calibration may reflect soil fertility, and will be utilized for nutritional management. Although estimation accuracy has still needed to be improved, the rice yield was also well estimated. These results recommended further data accumulation and more accurate locational identification to improve the estimation accuracy.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 추계학술대회
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• pp.80-80
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• 2022

Estimation of heading date of paddy rice is laborious and time consuming. Therefore, automatic estimation of heading date of paddy rice is highly essential. In this experiment, deep learning classification models were used to classify two difference categories of rice (vegetative and reproductive stage) based on the panicle initiation of paddy field. Specifically, the dataset includes 444 slanted view images belonging to two categories and was then expanded to include 1,497 images via IMGAUG data augmentation technique. We adopt two transfer learning strategies: (First, used transferring model weights already trained on ImageNet to six classification network models: VGGNet, ResNet, DenseNet, InceptionV3, Xception and MobileNet, Second, fine-tuned some layers of the network according to our dataset). After training the CNN model, we used several evaluation metrics commonly used for classification tasks, including Accuracy, Precision, Recall, and F1-score. In addition, GradCAM was used to generate visual explanations for each image patch. Experimental results showed that the InceptionV3 is the best performing model in terms of the accuracy, average recall, precision, and F1-score. The fine-tuned InceptionV3 model achieved an overall classification accuracy of 0.95 with a high F1-score of 0.95. Our CNN model also represented the change of rice heading date under different date of transplanting. This study demonstrated that image based deep learning model can reliably be used as an automatic monitoring system to detect the heading date of rice crops using CCTV camera.

• 한국작물학회지
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• 제51권2호
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• pp.130-136
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• 2006

Growth and quality of rice are affected by various factors including the location of cultivation. This study was conducted to investigate the effects of altitudinal locations on the growth and yield-related components of rice. Nineteen Japonica type varieties were grown at Iksan (altitude, 10 m), Imsil (altitude, 150 m), Jinan (altitude, 275 m) and Jangsu (altitude, 430 m) at a similar latitude in Jeonbuk province in the south western Korea. Minimum air temperature showed a strong negative correlation with altitude. The morphological traits and yield-and quality-related components were analyzed. Longer days to heading was required at higher altitudes. However, culm length, panicle length, panicle number, grain number and rice yield were reduced at higher altitudes. Protein content of brown rice increased but fatty acid content decreased at higher altitudes. Amylose content was affected by neither the altitude nor the ecotype. Palatability of polished rice tends to be improved at higher altitudes and in early-maturing ecotypes but its relationships with altitude and ecotype were not significant. Head rice ratio was lower at higher altitudes but broken rice ratio vise versa. These results indicate that growth and quality of rice are affected significantly by changes in temperatures at the locations of different altitude. Also, the characters related to yield and quality of rice often respond incompatibly to the changes in altitudes. These results could provide valuable information for the strategic planning of rice production in geographically diverse areas.

• 한국작물학회지
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• 제32권1호
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• pp.48-54
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• 1987

수도 기계이앙 재배에 있어 관행 시비법과 추비시기 및 비율를 달리하여 적정 분시방법을 밟히고자 '85년 호남작물시험장(이리)에서 동률벼를 공시하여 시험을 실행한 결과를 요약하면 다음과 같다. 1. 엽신질소함량은 기비중점시비(T$_1$, T$_2$)에서는 최고분얼기에 수비중점 (T$_4$, T$_{5}$) 및 5회분시(T$_{7}$)에서는 감수분열기에서 높았다. 2. 출수이후의 CGR, RGR, NAR은 5회분시구(T$_{7}$)가 가장 컸다. 3. 각 생육시기별 CGR과 NAR, NAR과 RGR, CGR과 RGR 간에는 유의적인 정의 상관이 있었으며 생육시기가 진전됨에 따라 상관계수가 커지는 경향이었다. 4. 수량에 대한 각 생육시기별 CGR의 상여도는 출수후의 CGR이 가장 컸다. 5. 수량은 기비중점(T$_1$, T$_2$) 보다 수비중점(T$_4$)및 기비 30%후 4회 분시구(T$_{7}$)에서 높았다.

• 한국작물학회지
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• 제44권2호
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• pp.122-128
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• 1999

Three rice cultivars, Namweonbyeo (early maturing), Hwaseongbyeo (medium maturing) and Dongjinbyeo (medium-late maturing) were trans-planted with 3 different seedling ages to investigate their growth habits and to improve the cultural method in paddy fields in the southern plain area of the Honam region in 1993. The 10-day old seedlings had more vigorous elongation of plant height and higher tillering ability but lower effective tiller rate, when compared with 35-day or 40-day old seedlings. Leaf area index and top dry weight were lower in 10-day old seedlings up to 40 days after transplanting but thereafter, were not different among seedlings ages. CGR was later in 10-day old seedlings, up to 30 days after transplanting, but in 30 to 40 days after transplanting, it was reversed. RGR was the highest in infant seedlings to 40 days after trans-planting, while in 50 days after transplanting, it was reversed. Panicle number and spikelet number per square meter were the highest in 40-day old seedlings, next highest in 35-day old seedlings and the lowest and in adult seedlings up to 40 days after transplanting, while spikelet number per panicle was vice versa. Milled rice yield did not vary significantly by seedling ages, but among the varieties, it was less in Hwaseongbyeo compared with Naweonbyeo and Dongjnbyeo.

• Journal of Crop Science and Biotechnology
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• 제10권1호
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• pp.33-38
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• 2007

Nitrogen management at the panicle initiation stage(PI) should be fine-tuned for securing a concurrent high yield and high quality rice production. For calibration and testing of the recommendation models of N topdressing rates at PI for target grain yield and protein content of rice, three split-split-plot design experiments including five rice cultivars and various N rates were conducted at the experimental farm of Seoul National University, Korea from 2003 to 2005. Data from the first two years of experiments were used to calibrate models to predict grain yield and milled-rice protein content using shoot fresh weight(FW), chlorophyll meter value(SPAD), and the N topdressing rate(Npi) at PI by stepwise multiple regression. The calibrated models explained 85 and 87% of the variation in grain yield and protein content, respectively. The calibrated models were used to recommend Npi for the target protein content of 6.8%, with FW and SPAD measured for each plot in 2005. The recommended N rate treatment was characterized by an average protein content of 6.74%(similar to the target protein content), reduced the coefficient of variation in protein content to 2.5%(compared to 4.6% of the fixed rate treatment), and increased grain yield. In the recommended N rate treatments for the target protein content of 6.8%, grain yield was highly dependent on FW and SPAD at PI. In conclusion, the models for N topdressing rate recommendation at PI were successful under present experimental conditions. However, additional testing under more variable environmental conditions should be performed before universal application of such models.

• 한국토양비료학회지
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• 제49권2호
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• pp.157-167
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• 2016

The interspecific estimation for tolerance capacities of upland crop species to excessive soil water stress in paddy field is significant in agricultural practices. Most of upland crops can be damaged by either excessive soil water or capillary rise of the water table during rainy season in paddy fields. The major objective of this study was to evaluate water stress of upland crops under different drainage classes in converted paddy field. This experiment was carried out in poorly drained soil (PDS) and imperfectly drained soil (IDS) of alluvial sloping area located at Toero-ri, Bubuk-myeon, Miryang-si, Gyeongsangnam-do. The soil was Gagog series, which was a member of the fine silty, mixed, nonacid, mesic family of Aeric Endoaquepts (Low Humic-Gley soils). Two drainage methods, namely under Open ditch drainage methods (ODM) and, Closed pipe drainage methods (PDM) were installed within 1-m position at the lower edge of the upper paddy fields. The results showed that sum of excess water days ($SWD_{30}$), which was used to represent the moisture stress index, was 42 days (the lowest) in the PDM compared with 110 days in the ODM. Most of upland crops were more susceptible to excessive soil water during panicle initial stage on more PDS than on IDS. Yield of upland crops in the PDM was continuously increased by the rate of 15.1% on sorghum, 15.4% foxtail millet, 53.6% proso millet, 49.6% soybean and 47.9% adzuki bean as compared in the ODM. The capacity for tolerance by excessive soil water based on yield of each upland crop in the poorly drained sloping paddy fields was the order of sorghum, soybean, foxtail millet, proso millet and adzuki bean. Therefore, Sorghum is relatively tolerant to excessive soil water conditions and, may be grown successfully in converted paddy field.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 추계학술대회
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• pp.133-133
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• 2022

Temperature is a crucial environmental factor for rice cultivation due to the climate change and can influence the rice growth and development. Therefore, the effect of temperature on plant growth characters was examined during the vegetative stage. Plants were grown under three different temperatures: 23℃/13℃ for 18℃, 26℃/16℃ for 21℃ and 29℃/19℃ for 24℃ in the phytotron. The temperature was treated after transplanting and ended in early panicle initiation stage. Heading date of the two varieties were strongly affected by the temperature and were delayed in the 18℃. The plant height in the 18℃ was 21 % shorter than the 21℃ and 24℃ and the tiller and leaf number were increased in the 18℃. All the growth rates of the characters were the slowest in 18℃. The stem dry weight was significantly increased in 18℃. Nitrogen content was increased in the leaves of 18℃ whereas available phosphate and potassium content was found to be increased in the stems of 21℃ and 24℃. OsNRT 2.1 was overexpressed in the leaves and stems of 18℃ and OsNRT2.3a could be expressed in 18℃ and 21℃ temperatures whereas more expressed in 21℃. OsPT1 and OsPT6 could be expressed in the leaf of 18℃ and 24℃ but could be expressed in the stem of 18℃. OsHAK1 and OsHAK5 could be overexpressed in the leaves and stems of 18℃. For hormone, OsCKX2 gene was found to be up regulated in the leaves of 18℃ and OsIAA1 gene could be expressed more in the stem of 24℃.