• Korean Journal Plant Pathology
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• v.1 no.2
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• pp.109-114
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• 1985

The experiments were conducted to clarify the influence of transplanting date on the occurrence of rice virus in field condition of 1984. The rate of RBSDV (rice black-slreaked dwarf virus) viruliferous vector, smaller brown planthopper (Laodelphax striatellus Fallen), was shown to be $13.6\%$ at the 2nd adult and that of rice stripe virus (RSV) viruliferous was $6.7\%$ at the 2nd adult. The vector in the field was begun to come from May 29, the maximum densities were 19.6 insects per hill on June 13 in cultivar Chucheongbyeo, 19.3 in Nagdongbyeo, 7.4 in Cheongcheongbyeo and 4.9 in Samgangoyes. The number of vectors per hill was inclined to increase by early transplanting. Although the infection of rice virus in nursery bed was not recognized until May 30 transplanting, the nursery infection could be seen from June 10 transplanting. The highest rate of nursery infection with RSV was $4.1\%$ at June 10 transplanting plot, and that of RBSDV was $14.2\%$at June 20 trans planting plot. The infection of rice virus in paddy field was the highest at May 20 transplanting plot, the lowest at July 10 plot. The earlier transplanting, the more severe occurrence of rice viruses. Occurrence of infected plants with RBSDV was shown to increase more rapidly at May 20 and May 30 planting plot than May 10 plots. However, the occurrence of infected plant with RSV was more rapid at May 10 transplanting plot than May 20 and 30.

• Korean Journal of Weed Science
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• v.13 no.2
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• pp.122-131
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• 1993

Differences in competitive characteristics for mineral nutrition were compared with rice and weeds according to rice planting types like the traditional hand transplanting, machine transplanting of young(10days old) and mature(30days old) seedling, flood direct seeding of germinated seeds and dry direct seeding of dry seeds. There was a slight competition for such nutrients as N, P, K, Ca, and Mg by E. crus-galli and E. kuroguwai in transplanting cultivations. However, nutrient uptake by rice in direct-seedings was severely inhibited throughout the whole growth period by the two weeds including annual weeds such as S. Juncoides and C. difformis. The competition for nutrients at different cultivation types was mainly governed by the dominant weeds.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.64 no.2
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• pp.63-69
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• 2019

Black-colored rice contains anthocyanin, which has an antioxidant function on the seed coat. Anthocyanin content is greatly affected by the cultivation environment, especially the average temperature during the ripening stage. Generally, low temperatures during the ripening stage increase anthocyanin content. To control the average temperature during ripening stage in the field, transplanting time has to be regulated. In this study, anthocyanin content variation was examined in relation to the transplanting time and the average temperature during the ripening stage. For the study, fourteen black-colored rice cultivars with different maturity types (four of early-maturing, five of medium-maturing, and five of medium-late maturing) were selected. The transplanting times used were May 20, June 5, June 20, and June 30. The field experiment was conducted in the Miryang, Kyoungsangnamdo province, Korea from 2014 to 2017. The anthocyanin content in all cultivars was higher when the transplanting time was delayed, and the highest anthocyanin content was observed in the transplanting on June 30. Variation in anthocyanin content according to the change in transplanting time is the greatest in the early maturing cultivars. The least change was observed in medium maturing cultivars. Regression analysis showed a significant correlation between temperature and anthocyanin content, but the degree of correlation was very low in the medium maturing cultivar. As a result, the optimal average temperature during the grain filling stage for increasing the anthocyanin content of black colored rice was $22{\sim}23^{\circ}C$. The rice yield increased in plants transplanted until June 20 and decreased thereafter owing to low temperature during the grain filling stage. The anthocyanin content increased with delaying the transplanting time up to June 30 but the rice yield decreased after June 20. Nevertheless, the rate of increase in anthocyanin content was higher than the rate of decrease in rice yield. As a result, the optimum transplanting time and an average temperature of grain filling stage for black-colored rice variety were June 30 and $23{\sim}24^{\circ}C$ considering both anthocyanin content and rice yield.

• Korean Journal of Organic Agriculture
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• v.7 no.2
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• pp.169-177
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• 1999

This experiment were performed on rice dignity during 1998 at paddy field of Dong-a Univ., Pusan, Korea. Depression effect of weed occurrence by pasture of 2kg of the Ampullarius insularus per 10a was 80.4% at the 7th day after transplanting, 69.7% at the 14th day after transplanting pasture plot and 51.8% at the 21th day after transplanting. Deperssion effect of weed occurrence by pasture of 5kg of the Ampullarius insularus per 10a was 97.9% at the 7th day after transplanting, 79.2% at the 14th day after transplanting pasture plot and 64.1% at the 21th day after transplanting. Depression effect of weed occurrence by pasture of 8kg of the Ampullarius insularus per 10a was 97.9% at the 7the day after transplanting, 87.1% at the 14th day after transplanting pasture plot and 71.4% at the 21th day after transplanting. Weeds ingestied by the Ampullarius insularus were in the order of perennial weed, annual weed.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2017.10a
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• pp.119-119
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• 2017

• Proceedings of the Korean Society of Crop Science Conference
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• 2023.04a
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• pp.75-75
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• 2023

• Korean journal of applied entomology
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• v.33 no.4
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• pp.270-280
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• 1994

This study was conducted to establish a nce insect pest control system, ~ es.ys tematic application of insecticides using carbohran and buproiezin, in Korea. The effects oi various dates of application and rates of buprofezin (25% WP) after carbofuran (3G) soil incorpombon in late May on the pop~~lation densities of the brown planthoppa (BPH) immigrating in July were investigated Appropriate application tune of buprofezin for the BPH that had evaded insecticidal effect of 5011 incorporated carbofuran was late July-early August. Application rate of buprofezln at 7.0g a.i/lOa was enough to suppress the BPH density. Buprofezin treatment after carbofumn soil incorporation could also suppress the whlte backed planthopper population but did not affect the densities oi the paddy rice spiders. Considering the charactenstics of occurring patterns of the nce insect pests in Korea. buprofezin treatment m late July or early August after carbofuran soil incorporation in late May can be a useful application system of ir~sectic~deins controlling early season Insect pests and migmtoly planthoppers on rice.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.29 no.4
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• pp.394-400
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• 1984

In order to find out the possibility of increasing the number of spikelets by changing transplanting date, this study was conducted at Suwon, Yuseong and Jinju in 1979 and 1980. Climatic consumption effect was different depending on location, year, and variety. Number of spikelets can be increased by changing transplanting date due to the decrease of climatic consumption index (C C I) during the reproductive stage. Transplanting date for higher yield and number of spikelets of Tongil was May 25 at Suwon, from May 25 to June 5 at Yuseong and June 5 at Jinju, and in the japonica, it was slightly earlier than that of Tongil in each location. Increasing the number of spikelets and grain yield by the effect of decrease in C C C during the reproductive stage should be considered the percentage of ripened grains.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.396-396
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• 2018

우리나라의 가뭄은 통계적으로 5~6년 주기로 발생해 왔으나 최근에는 가뭄의 발생 빈도가 점점 증가하고 주기 또한 짧아지는 경향을 보이고 있다. 가뭄의 패턴 또한 지속적이고 국지적으로 강하게 나타내는 경향이 있어 피해가 심각해지고 있다. 2017년도에는 모내기가 시작되어야 할 시기에 극심한 물 부족으로 이앙시기가 지연되고 밭작물이 마르는 피해를 겪었다. 국가가뭄정보센터의 2017년 가뭄예경보 자료에 따르면, 1~7월에는 안성, 서산, 홍성 지역을 중심으로, 7~9월에는 남해안지역을 중심으로, 10월~12월에는 울주, 경주, 밀양 지역을 중심으로 가뭄이 나타났음을 확인 할 수 있다. 가뭄 파악을 위한 방법 중 하나로 인공위성영상을 활용한 원격탐사 기법이 있으며, 국내에서는 관측주기가 짧고 관측폭이 넓은 Terra MODIS 영상을 활용하는 연구 사례를 다수 찾아볼 수 있다. 최근에는 드론에 NIR, 열화상, 초분광 카메라 등을 탑재하여 탐지범위가 국소적이지만 가뭄에 따른 작물의 상태를 보다 상세하게 파악하기 위한 연구가 시도되고 있다. 본 연구에서는 드론을 이용한 가뭄지역의 영상특성을 분석하는 기초자료를 구축하기 위하여 2017년 극심한 가뭄이 발생하였던 안성지역을 대상으로 Terra MODIS NDVI를 이용한 식생상태지수(VCI), 정규식생지수(SVI)를 분석하여 가뭄으로 추정되는 드론촬영 대상지역을 파악하였으며, 선정된 지역을 대상으로 R-G-NIR 카메라를 탑재한 드론 촬영을 실시하였다. 드론영상의 전처리를 통하여 고해상도 NDVI영상을 작성하고 지상의 작물 및 토지이용 상태에 따른 NDVI 분포특성과 Terra MODIS NDVI와의 차이점을 분석하였다.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.4
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• pp.459-465
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• 1997

This experiment was conducted to compare the change of growth and canopy photosynthesis between transplanting and direct seeding on paddy surface in rice. Total tiller number by the early vegetative growth stage was significantly higher in the direct seeding flooded paddy surface, while it was reversed from later vegetative growth stage in terms of tillering ability per unit period. But total panicle number was higher in direct seeding on paddy surface. Leaf area index, nitrogen content in leaf blade and canopy photosynthetic ability at later vegetative growth stage were lower in direct seeding on flooded paddy surface than transplanting. Biological yield at harvest stge, leaf area index and conopy photosynthetic activity at heading stage were gradually increasing according to nitrogen level increased both transplanting and direct seeding on paddy surface. Leaf area index, canopy photosynthetic activity, however, were lower in direct seeding on paddy surface than transplanting in the same nitrogen level. Nitrogen content per unit leaf area was high in transplanting.