• Weed & Turfgrass Science
• /
• v.6 no.3
• /
• pp.189-195
• /
• 2017

This study was conducted to evaluate weed control effect in organic soybean upland field as affected by cover crops including rye, hairyvetch, and its mixture. The experiment was conducted during two years (2015 and 2016) at the NAS (National Institute of Agricultural Sciences) organic farming experimental field. The cover crops were seeded after tillage at fall crop season in 2014, and then, the soybean field was managed with no tillage system from 2015. The weed suppression rates of cover crops application for rye and mixture (rye+hairyvetch) treatment during 60 days after transplanting were 80% and 30%, respectively. However, weed suppression rate of hairyvetch treatment was not significantly different as compared to control. Weed flora in experimental field were less than general soybean field. The average organic soybean yield was generally low compare to normal year, nevertheless, the soybean yield for rye and mixture treatment in 2016 were significantly higher than PE mulching treatment.

• Weed & Turfgrass Science
• /
• v.6 no.3
• /
• pp.165-178
• /
• 2017

This study was carried out to investigate the characteristics of weeds occurring in paeony field in June and July, 2015 in Uiseong, Cheongsong of Kyungbuk province, and Hwasun, Jangheung, Gangjin of Jeonnam province. In total paeony field, there were 35 families and 105 species, including 30 species of Asteraceae, nine species of Poaceae, eight species of Polygonaceae, and each five species of Fabaceae and Convolvulaceae, By life style, there were 49 species of annuals, 27 species of winter annuals and 24 species of perennials. In Kyeongbuk province, 30 families and 75 species were found including 20 species of Asteraceae, seven species of Poaceae, six species of Polygonaceae, each four species of Brassicaceae, Fabaceae and Convolvulaceae, three species of Euphorbiaceae. By life style, there were 35 species of annuals, 21 species of winter annuals and 19 species of perennials. In Jeonnam province, 34 families and 88 species were found including 23 species of Asteraceae, seven species of Poaceae, eight species of Polygonaceae, six species of Fabaceae and four species of Scrophulariaceae. By life style, there were 43 species of annuals, 15 species of winter annuals and 25 species of perennials. Therefore, there are various occurrences of annual, annual, and perennial weeds in peony fields, and weed control system should be set up accordingly.

• Journal of Korean Society for Geospatial Information Science
• /
• v.18 no.2
• /
• pp.29-33
• /
• 2010

The purpose of LiDAR ground classification is to archive both goals which are acquiring confident ground points with high precision and describing ground shape in detail. In spite of many studies about developing optimized algorithms to kick out this, it is very difficult to classify ground points and describing ground shape by airborne LiDAR data. Especially it is more difficult in a dense forested area like Korea. Principle misclassification was mainly caused by complex forest canopy hierarchy in Korea and relatively coarse LiDAR points density for ground classification. Unfortunately, a lot of LiDAR surveying performed in summer in South Korea. And by that reason, schematic LiDAR points distribution is very different from those of Europe. So, this study propose enhanced ground classification method considering Korean land cover characteristics. Firstly, this study designate highly confident candidated LiDAR points as a first ground points which is acquired by using big roller classification algorithm. Secondly, this study applied weighted gradient kernel(WGK) algorithm to find and include highly expected ground points from the remained candidate points. This study methods is very useful for reconstruct deformed terrain due to misclassification results by detecting and include important terrain model key points for describing ground shape at site. Especially in the case of deformed bank side of river area, this study showed highly enhanced classification and reconstruction results by using WGK algorithm.

• Korean Journal of Weed Science
• /
• v.15 no.3
• /
• pp.224-231
• /
• 1995

Paraquat, the representative bipyridilium herbicide, has high phytotoxic activity through generating toxic oxygen species such as superoxide, hydrogen peroxide and hydroxy radical. The response patterns of plants to paraquat were various. It was assumed that the different response was derived from different antioxidative mechanisms including antioxidative enzymes and antioxidant. Paraquat treatment increased reducing sugar content and malondialdehyde formation at 35 days after treatment in a dose-dependent manner but chlorophyll content decreased. Glutathione content increased by paraquat treatment and tolerant species showed more glutathione content than susceptible species. Superoxide dismutase activity increased with the increase in paraquat concentration and that was higher in tolerant species than susceptible species. Photosynthetic activity(PSII activity) was affected by paraquat, so the susceptible species showed more reduced oxygen evolving capacity than tolerant species. Catalse, NADPH-cytochrome C reductase, and malate dehydrogenase, the enzymes tested in this study, showed that the activities decreased by paraquat treatment. Further studies are necessary to determine whether antioxidative system cause the tolerance to paraquat.

• Korean Journal of Weed Science
• /
• v.15 no.3
• /
• pp.183-187
• /
• 1995

The germination characteristics of Diplachne fusca (L.) P. Beauv. seeds were investigated under different seed storage conditions to find out reliable system for maintaining the seeds with high and uniform germination rate and thus for possible use of the seeds in herbicide screening with a continuous seed supply. When the seeds were stored under wet-low temperature($4^{\circ}C$) condition, the germination rate was 88% after 4-week-storage. The germination rate slightly declined after the storage for longer than 3 months. Dry seeds stored at room temperature exhibited very low germination rate. The wet-low temperature treatment was effective for inducing the germination of the seeds which had been stored under dry-room temperature condition for 4 months. The germination rate was 70% after 2-week- storage under the wet-low temperature condition. The germination rate was much higher under an alternate temperature condition than under a continuous temperature condition. The optimum temperature was 35/$25^{\circ}C$(14/10hrs). The seeds had a capability to germinate under NaCl-treated condition even at a concentration of 1.0%, whereas the germination of Echinochloa crus-galli seeds was completely inhibited by 0.5% NaCl. This result indicates that D. fusca has an advantage over E. crus-galli to survive in reclaimed 1and from the sea.

• Weed & Turfgrass Science
• /
• v.4 no.4
• /
• pp.308-314
• /
• 2015

This study was conducted to establish a fluorescence assay system for high efficient mass screening of the herbicides causing rapid membrane peroxidation, based on the fact that peroxide in cellular leakage could be fluorometrically determined through the fuorescent compounds formed after reacting with homovanillic acid (HVA) and peroxidase (HRP). The assay procesure established in this study was as follows. Only single disc (4 mm diameter) excised from cucumber cotyledon is placed on the well containing test solution ($200{\mu}L$) with 96-well microplate. The plate is shaking-incubated for 8 h under light condition. Then after removing the cucumber disc, HVA and HRP are supplied in the medium buffer and incubated for 5 min at room temperature. Fluorescence values are determined at Ex 320 nm/Ex 425 nm. The higher fluorescence values are obtained in the treatment of chemical having higher herbicidal activity. Using this assay with 96-well microplates, a large number of herbicides inducing rapid membrane peroxidation seemed to be screened more efficiently than spectrophotometric microtiter assay reported previously.

• Weed & Turfgrass Science
• /
• v.4 no.4
• /
• pp.405-412
• /
• 2015

Forty schools having natural turf playgrounds were investigated by on-spot investigation and oral interviews with relevant school officials to find out basic information on turfgrass management practices of school playgrounds in Gyeonggi province. Average area of playground was $3,890m^2$ per school and $12m^2$ per student. Ninety five percent of turf playgrounds were managed by school staff and ninety percent of schools spent less than 5 million won per year for turf management. The difficulties in turfgrass management were considered as a major challenge for the schools, followed by turfgrass management cost. Among the management practices, school officials pointed out weed management as the most difficult work, followed by irrigation. The average number of fertilization and mowing was 2 and 6 times per year, respectively. About the half of playgrounds were irrigated only when there was wilting symptom. Zoysiagrass was the most popular choice for the school playgrounds and only three school playgrounds were established with pop-up irrigation system. Fourteen school playgrounds had good turf quality but the rest of school playgrounds had inadequate turf quality requiring minor or full renovation.

• Weed & Turfgrass Science
• /
• v.4 no.4
• /
• pp.368-375
• /
• 2015

Earthworm cast occurred in surface of turfgrass in golf courses which affect turfgrass maintenance and golf play. In this study several survey of seasonal fluctuation of earthworm cast in different golf courses (Anseong, Gapyeong, Gunpo and Yongin in Gyeonggi province, and Geumjeong in Busan) was done. A number of earthworm, soil temperature and moisture of detection site of earthworm cast in each golf course were also done. Cast occurred in different golf courses are found mostly from April to November on turf surface and the cast number varied in different month as well as in golf courses. In the same golf courses, a number of detected cast was difference from individual sites. A number of cast and earthworm was correlated. Also, in higher soil moisture showed the higher cast density in different golf courses. Soil temperature and moisture of detecting cast ranging from $2.1^{\circ}C$ to $33.1^{\circ}C$ and 4.9 to 44.1%, respectively. In case of cast, soil temperature level lies in between $10-15^{\circ}C$ where the highest soil moisture was 25%.

• Korean Journal of Weed Science
• /
• v.30 no.2
• /
• pp.153-163
• /
• 2010

This study was carried out to establish an improved bioassay system, whole-plant bioassay which is more effective in developing natural herbicides for foliar treatment such as herbicidal essential oils. Two bioassay systems using four weed species (Echinochloa crus-galli, Digitaria sanguinalis, Aeschynomene indica, and Abutilon theophrasti), spraying method and spotting method, were established. Spraying method is applicable if the amount of test compounds is enough, while spotting method is useful for the small amount of test compounds. The initial application rate was desirable at $2,500{\sim}5,000\;{\mu}g\;mL^{-1}$. Herbicidal activities were higher in the NOP treatment when compared to the Tween 20 treatment. To efficiently evaluate volatile compounds such as essential oils, if the compound-treated pots were incubated in dew chamber for about 10hrs, better results were obtained in the degree and stability of herbicidal responses. When the efficiency of bioassay systems established in this study was compared, the spraying method was minimized four times to the conventional method that has beed used for screening of synthetic compounds in KRICT. On the other hand, in the spotting method, screening for development of a natural herbicides was possible even in level of 1/100 test volume and 1/200 amounts of test compound compared to the spraying method.

• Proceedings of the Korea Contents Association Conference
• /
• 2016.05a
• /
• pp.21-22
• /
• 2016

본 논문에서는 대용량 과학데이터 아카이브 시스템 설계를 위해 기존 리포지터리 시스템을 분석한다. 대용량 과학데이터를 효율적으로 수집하고 저장하기 위한 아카이브 시스템 아키텍쳐 설계를 위하여 현재 서비스되고 있는 다양한 과학데이터 리포지터리 시스템을 분석한다. 분석한 내용을 바탕으로 대용량 과학데이터 아카이브 시스템 아키텍쳐를 설계하기 위한 기술적인 요구사항을 도출한다.