• Korean Journal of Weed Science
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• v.31 no.2
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• pp.167-174
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• 2011

Weed control using cover crops has advantages of agricultural and environmental aspects which prevent soil erosion, nitrogen supply, improving soil physical properties, reduction of nitrate leaching, organic supply and control of weed occurrence. In this study, we evaluated the inhibitory effects of cover crops on the weed occurrence, growth and yield of soybean in cover crop-soybean cropping system. The treatments were consisted of 4 different mulching system such as crimson clover (Trifolium incarnatum) residue, hairy vetch (Vicia villosa) residue, rye (Secale cereale) residue and Polyethylene plastic(P.E.) mulch with no mulch treatment (control). Three cover crops were grown throughout the winter and were cut in next spring. And then 13 days old soybean seedlings were transplanted in each treatment field on $4^{th}$ June. Crimson clover, hairy vetch and rye mulch treatments reduced weeds density compared to control (73.0%, 98.0% and 85.3% respectively), on $26^{th}$ May. However, weed inhibition rate of crimson clover mulch treatment was sharply decreased to 4.17% on $6^{th}$ August, while hairy vetch and rye mulch treatments were continued high weed inhibition rate with 87.6% and 72.0% respectively. There was no inhibition effect of perennial, winter annual and broadleaf weeds inhibition in crimson clover mulch treatment. Height of soybean in crimson clover, hairy vetch and P.E. mulch treatment was 6.9%, 20.2% and 22.0% higher than that of control. But height of soybean in rye mulch treatment was lower than control on $13^{th}$ July. At harvesting, yields of soybean were in order of hairy vetch mulch treatment${\fallingdotseq}$ P.E. mulch treatment > crimson clover mulch treatment ${\fallingdotseq}$ rye mulch treatment > control.

• Korean Journal of Environmental Agriculture
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• v.27 no.1
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• pp.72-79
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• 2008

Phytosociological study was carried out to investigate the structural characteristics of Humulus japonicus community in the Middle area of Korea. The vegetation data of total 67 $relev\acute{e}s$ were analyzed by the $Z\ddot{u}rich$-Montpellier school's method. Upper layer plant communities of Humulus japonicus were classified into four community groups : Humulus japonicus-Artemisia princeps community, Chenopodium album community, Setaria viridis-Echinochloa crus-galli community and Typical community. Lower layer plant communities were classified into five community groups : Galium spurium-Stellaria aquatica community, Equisetum arvense community, Persicaria theunbergii community, Echinochloa crus-galli-Digitaria ciliaris community and Typical community. According to the results of canonical correspondence analysis by vegetation and environmental factor, Setaria viridis-Echinochloa crus-galli community of upper layer was distributed throughout the soil with high relative light and soil hardness. Chenopodium album community appeared in the soil with high pH. Galium spurium-Stellaria aquatica community of lower layer was formed in the high soil pH. Persicaria theunbergii community and Echinochloa crus-galli-Digitaria ciliaris community were distributed in the soil with high moisture.

• 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.

• Korean Journal of Weed Science
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• v.17 no.1
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• pp.112-123
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• 1997

Chemical pesticides have been re used for a long time to protect crops from diseases, insects, and weeds ; ample and secure supply of foods in present days would not be possible without them. However, concerns on the risk of using chemical pesticides rising steadily in recent years forced discard many of them and seek an alternate, environment-friendly control strategies. Microbial pesticide is regarded as one of the most promising methods because if properly developed, it will be effective, cheap, and environment-safe. Currently, about 180 microbial pesticides are under development throughout the world and at least 20 of them including B.t. and antibiotics are registered in Korea. This paper discusses some of the successful examples, intriguing problems, and future prospects of microbial pesticides.

• Korean Journal of Weed Science
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• v.30 no.3
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• pp.266-271
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• 2010

This study was conducted to improve weeding effect by rice bran farming technique. In the weeding effect experiment by application timing control of rice bran and soybean cake, weeding efficacy was the highest at the treatment of conventional application of rice bran. The treatment of soybean cake with rice bran was unfavorable, but Echinochloa crus-galli occurred little at the treatment of soybean cake at 5 days after transplanting, so it is thought that further study about inhibitor of early E. crus-galli occurrence in soybean cake is necessary. Cultivating weeder was effective at the treatments of rice bran and soybean cake together, of which weed occurrence was more than conventional rice bran, and precise experiments about cultivating weeding time and method will be necessary.

• Korean Journal of Plant Resources
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• v.32 no.5
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• pp.478-485
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• 2019

As environmentally sound agriculture emphasize gradually as well as the importance of environment, many studies on weed and soil nematode control of new concept which does not affect adversely environment are in progress. For this purpose, plant seeds which are representative weed species in field were selected and treated with microwave having generating capacity of $17.73kw/m^3$, and investigated germination rates of weed seeds and the number of soil nematode according to soil moisture contents, soil depth and irradiation times. The microwave effect on the germination rates was extremely high in soil moisture content of 40% and irradiation time over 40 seconds for irradiation time, while soil depth did not affect germination rate. In view of the results so far achieved, it seems that universal dispersed microwave system is effective for the control of weed seeds.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.28 no.3
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• pp.319-322
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• 1983

Species-area and species-quadrat number curves were used to determine the minimum sampling size and the minimum quadrat number for weed data collection in transplanted rice. In both cases, characteristic curves that first increased abruptly and then leveled off as fewer species were added with increased sampling size or quadrat number were obtained. Using these techniques, it was determined that three quadrats each 0.3㎡ (0.5m ${\times}$0.6m) in area were needed to adequately represent the weed community when it was sampled at rice heading.

• Journal of The Korean Society of Grassland and Forage Science
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• v.16 no.1
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• pp.9-16
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• 1996

'This experiment was canied out to investigate the effects of endophyte status(end0phyte-free and -infect) and cutting frequency(3, 4, 5 and 6 timeslyear) on the agronomic characteristics, DM yield and weed development of tall fescue(Festuca arundinacea Schreb.) at the Experimental Field of Grassland and Forage Crops Division, National Livestock Research Institute, Suweon, from 1993 to 1994. 'Ihe results obtained are summarized as follows: DM yield of endophyte-infected tall fescue was slightly higher than that of endophyte-free tall fescue. DM yield of two tall fescue varieties was significantly decreased with frequent culting(p<0.05). Weed development of pasture tended to be decreased with endophyte-infected tall fescue and infrequent cutting, and endophyte-infected tall fescue had a good adaptation to the poor environment. Based on the results of this experiment, it is suggested that a slight increase in forage yield could be obtained from endophyte-infected tall fescue and endophyte-infected tall fescue was more persistant than endophyte-free tall fescue under poor conditions.

• Korean Journal of Weed Science
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• v.12 no.3
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• pp.292-308
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• 1992

Recently agricultural situations are being placed in unfavourable socio-economic environment as followed by rapid decrease of rural population, poor labor quality and high wages of rural society due to high speedy industrialization of social structure in Korea. In addition to those circumstances, under the UR system to be expected in the early future, free trade of agricultural products will be faced inevitably in Korea. Practically prices of rice as a principle food in this country are expensive about three times compared to those of foreign rice markets, and so how to increase the international competitiveness and food supplies are important problems to be solved rapidly. Accordingly an urgent goal is reduction of agricultural production cost by the improvement of labour productivity as a labour saving and cost down cultivation methods as the direct seeding cultivation in rice. But there are many problems in the direct seeded rice cultivation. The important things to be improved in that cultivation are development of rice varieties with lodging tolerance, effective seedling stand, weed control, irrigation management and fertilizing and so on. Moreover agricultural basis as irrigation facilities, land consolidation and farm machineries must be improved for the stability of rice cultivation in the future.

• Weed & Turfgrass Science
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• v.7 no.1
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• pp.72-75
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• 2018

Balloon flower (Platycodon grandiflorum) is one of minor crops in Korea. Only four ACCase inhibiting herbicides are registered for P. grandiflorum and the farmers usually use general but unregistered herbicides which can cause critical phytotoxicity. So, this study was conducted to investigate effects of alachlor and pendimethalin on germination and early growth of P. grandiflorum. To evaluate the effect of alachlor and pendimethalin, two herbicides were treated to the seeds in petri-dish and soil. In the petri-dish, alachlor completely inhibited the germination as well as pendimethalin inhibited the germination slightly but not significantly. In case of soil application, alachlor inhibited germination and plant height of P. grandiflorum significantly as well as pendimethalin inhibited plant height and root length significantly. We showed the possibility of phytotoxicity of alachlor and pendimethalin to P. grandiflorum and strongly suggest that two herbicides should not be used to the cultivation of P. grandiflorum. Unregistered herbicides should not be used for weed management and additional researches for screening of safe herbicide to minor crops should be conducted as soon as possible.