• Title/Summary/Keyword: Weed Science

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Rhizosphere Enhances Removal of Organic Matter and Nitrogen from River Water in Floodplain Filtration (홍수터 여과를 이용한 하천수의 질소와 유기물 제거에 미치는 근권의 효과)

  • Jeong, Byeong-Ryong;Chung, Jong-Bae;Kim, Seung-Hyun;Lee, Young-Deuk;Cho, Hyun-Jong;Baek, Nam-Joo
    • Korean Journal of Soil Science and Fertilizer
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    • v.36 no.1
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    • pp.8-15
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    • 2003
  • If contaminated river water is sprayed over a floodplain, the microbial processes can simultaneously remove organic matter and nitrogen during the infiltration through the sediment profile. The effect of rhizosphere on the removal of organic matter and nitrogen from contaminated river water was investigated using floodplain lysimeters. River water was sprayed at a rate of $68.0L\;m^{-2}\;d^{-1}$ on the top of the lysimeters with or without weed vegetation on the surface, Concentrations of $NO_3$, $NH_4$ and dissolved oxygen (DO), and chemical oxygen demand (COD) and Eh in water were measured as functions of depth for 4 weeks after the system reached a steady state water flow and biological reactions. A significant reductive-condition for denitrification developed in the 30-cm surface profile of lysimeters with weeds. At a depth of 30 cm, COD and $NO_3$-N concentration decreased to 5.2 and $0.9mg\;L^{-1}$ from the respective influent concentrations of 18.2 and $9.8mg\;L^{-1}$. The removal of $NO_3$ in lysimeters with weeds was significantly higher than in those without weeds. Vegetation on the top was assumed to remove $NO_3$ directly by absorption and to create more favorable conditions for denitrification by supply of organic matter and rapid $O_2$ consumption, In the lysimeters without weeds, further removal of $NO_3$ was limited by the lack of an electron donor, i.e. organic matter. These results suggest that the filtration through native floodplains, which include rhizospheres of vegetation on the surface, can be effective for the treatment of contaminated river water.

Evaluation of No-tillage Rice Cover Crop Cropping Systems for Organic Farming (벼 유기농업을 위한 무경운 피복작물 작부체계 평가)

  • Lee, Young-Han
    • Korean Journal of Soil Science and Fertilizer
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    • v.43 no.2
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    • pp.200-208
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    • 2010
  • The objectives of this study were to evaluate no-tillage cover crop cropping systems for organic farming in paddy. The experiment was performed at Ihyeon series (silt loam: 9.1% sand, 73.0% silt and 17.9% clay) which affected by different management practices. Planthopper population per 20 plant was significantly higher 65.3 for conventional tillage with chemical compounds (control) compared with 3.4~9.6 for no-tillage treatments (without rice straw or green manure, amended with rice straw, hairy vetch, rape, rye, and Chinese milk vetch). Also, disease severity of sheath blight was significantly higher 10.5% for control compared to 0.7~2.9% for no-tillage treatments. Four weed species, namely Monochoria vaginalis, Ludwigia prostrata, Rotala indica, and Aneilema keisak occurred in no-tillage paddy, whereas Monochoria vaginalis occurred in control only. The pH, available phosphate, and microbial biomass C in paddy were steeply decreased in response to submerging, but increased at first heading stage. Soil $NH_4$-N content at first heading stage was significantly higher in no-tillage treatments compared with control. The grain yield was significantly higher in 4.30 Mg $ha^{-1}$ for control than other treatments. Meanwhile, rice productivity was significantly higher in 2.69 Mg $ha^{-1}$ for no-tillage amended with Chinese milk vetch compared to other no-tillage treatments. The number of panicle per plant, grain number perpanicle, and percent ripened grain were highly related for increasing the yield of rice. These results show that Chinese milk vetch was optimum cover crop for organic farming in no-tillage paddy.

Cloning and Characterization of a 5-Enolpyruvyl Shikimate 3-Phosphate Synthase (EPSPS) Gene from Korean Lawn Grass (Zoysia japonica) (들잔디 5-Enolpyruvyl Shikimate 3-Phosphate Synthase(EPSPS) 유전자 클로닝 및 특성)

  • Lee, Hye-Jung;Lee, Geung-Joo;Kim, Dong-Sub;Kim, Jin-Beak;Ku, Ja-Hyeong;Kang, Si-Yong
    • Horticultural Science & Technology
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    • v.28 no.4
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    • pp.648-655
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    • 2010
  • This study is the first comprehensive report on the molecular cloning, structural characterization, sequence comparison between wild and mutant types, copy number in the genome, expression features and activities of a gene encoding 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) in Korean lawn grass ($Zoysia$ $japonica$). The full length cDNA of the EPSPS from Korean lawn grass ($zj$EPSPS) obtained from a 3' and 5' RACE method was 1540 bp, containing a 1176 bp ORF, a 144 bp leader sequence (5' UTR) and a 220 bp 3' UTR, which was eventually decoded 391 amino acid residues with a molecular mass of 41.74 kDa. The Southern blot detection of the $zj$EPSPS showed that the gene exists as a single copy in the Korean lawn grass genome. Sequence comparison of the $zj$EPSPS gene demonstrated that the glyphosate-tolerant mutant (GT) having a Pro-53 to Ser substitution in the gene seems to have a preferred binding activity of the enzyme to phosphoenol pyruvate(PEP) over glyphosate, which allows the continuous synthesis of aromatic amino acids in the shikimate pathway. From the Northern blotting analysis, the $zj$EPSPS was found to be highly expressed, with continuous increase until 36 hours after 0.5% glyphosate treatment in both wild and mutant samples, but 1.5-fold higher EPSP synthase activity was observed in the tolerant mutant when exposed to the glyphosate treatment. The molecular information of the $zj$EPSPS gene obtained from this study needs to be further dissected to be more effectively applied to the development of gene-specific DNA markers and zoysiagrass cultivars; nevertheless, the glyphosate-tolerant mutant having the featured $zj$EPSPS gene can be provided to turfgrass managers for weed problems with timely adoptable management options.

Rice Growth and Yield at Different Cultural Methods under No-tillage Condition (벼 무경운 재배시 재배양식에 따른 생육 및 수량)

  • 박홍규;김상수;백남현;석순종;박건호;이선용
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.41 no.4
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    • pp.420-428
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    • 1996
  • This study was conducted to investigate the response of growth and yield of rice under five different cultural methods, machine transplanting(MTNT), puddled drill seeding (PDSNT), drill seeding on soil surface (DSNT) , broadcasting on soil surface (BSNT) under no-tillage paddy condition and conventional machine transplanting(MTT) in Jeonbuk series(siltyloam soil) from 1993 to 1995. Soil hardness was higher in no-tillage soil and increased with highly difference between tillaged and no-tillage soil with deeper soil depth. Bulk density was heavier in no-tillage soil and porosity was higher in tilled soil than that of the control. The rate of effective tiller was higher in MTT, following MTNT, PDSNT, DSNT and BSNT. Weed occurrence was more serious in no-tillage soil, than that of tillaged soil. The rate of lower internode length was lower in DSNT and BSNT and was similar with MTT in PDSNT and MTNT. Height of center gravity in terms of lodging tolerance was lower in direct seeding than in machine transplanting. Depth of buried culm was shorter in no-tillage soil, especially in DSNT and BSNT. Total amount of root was higher in MTT, following MTNT, PDSNT, BSNT and BSNT and the distribution rate of root in shallower soil layer was higher in no-tillage soil, especially in BSNT and DSNT. Field lodging occured highly in BSNT, following DSNA, PDSNT and MTNT with high lodging scale in DSNT and BSNT. Panicle number per unit land square meter was the highest in MTT and the least in BSNT. Ripened grain ratio was low in BSNT and DSNT due to heavy lodging. Yield of milled rice was 93% in PDSNT, 87% in DSNT, 81% in BSNT and 96% in MTNT, compared with 534kg /10a in MTT.

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Introducing Strip Cropping for Decreasing the Damage of the Continous Corn Cultivation (옥수수 연작지에서 Fall panicum의 발생과 연작 피해 방지를 위한 대상작의 도입효과)

  • Lim, Keun-Bal;Lee, Hyun-Jun;Ahn, Byung-Suk;Sung, Byung-Ryul;Shin, Jae-Sun
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.25 no.2
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    • pp.97-104
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    • 2005
  • This experiment was conducted to introduce strip croppings fur decreasing the damage of the continuous com cultivation at the experimental field of Grassland and Forage Crops division, National Livestock Research Institute from 1999 to 2000. Introduced mps for strip cropping to the continuously com cultivated field were red clover (RC), alfalfa(AL), and mixture of grass md legume. Fall panicum(FP), which is one of warm season's weeds was focused on its emerged quantity in com field changed by the level of soil water content and degree of the continuous corn cultivation. The ranges of yearly gained forage fresh yields including weeds like mainly FP were 119.4 ${\~}$ 169.6 in the continuous cultivation with com and rye and 64.9 ${\~}$ 83.3 ton / ha in the corn mono-cropping. Meanwhile, the percentages of pure com in continuous com cultivation plot were only $31-38\%$. This was for the mainly emergence of FP in the continuously com cultivated field. The ranges of average fresh yield of emerging FP were 45.6${\~}$63.4 ton/ ha in the continuously com cultivated field which were over the ranges of yields of rye, 28.2 ${\~}$ 41.6 ton/ ha. The dry matter yields of red clover, alfalfa and mixture with grass and legume introduced for strip cropping were 10.2, 10.6 and 10.6 ton / ha, respectively and these were about the 1/4 average fresh com yield. After strip cropping of red clover, alfalfa and mixture with grass and legume, the yields of corn increased to 56, 82, 88 and 79 ton / ha, respectively and com yield was much better in the alfalfa strip cropping.

Italian rygrass의 파종비율과 다른 예취빈도가 초년도에 있어서 혼파초지의 수량 및 식생비율에 미치는 영향 ( The Effect of Different Seeding Rates of Italian ryegrass and Cutting Frequency on the Yield and Botanical Composition of Pasture Mixtures in the Firs

  • 조무환;김동암
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.4 no.1
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    • pp.51-61
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    • 1983
  • This experiment was carried out to determine the effects of different seeding rates of Italian ryegrass (Lolium multiflorum) and cutting frequency on the dry matter yield botanical composition of pasture mixtures in first harvest year. The experimental design was a split-plot design with three replication. The main plots were two seeding rates of Italian ryegrass at 0.3 and 1.0kg per 10a and the sub-plots were 3, 4, and 5 cutting frequency. The experiment was undertaken over a period 12 months from September 1981 to August 1982. The results obtained are summarized as follows: 1. The different seeding rates of Italian ryegrass had no effect on total day matter yield. 2. Over the experimental period, the total dry matter yield of pasture mixtures was increased with increasing the cutting frequency, but there was no significant. 3. It was found that dry matter yield of weeds clearly decreased with the high seeding rate of Italian ryegrass over the experimental period. 4. The high seeding rate of Italian ryegrass showed the trend toward the high yield of Italian ryegrass, and the low yield of orchardgrass and ladino clover. 5. At the early stage of the experiment, the botanical compositions of orchardgrass and ladino clover were decreased with the high seeding rate of Italian ryegrass. But at the final stage they were not influenced by the seeding rates of Italian ryegrass. From the above results it is suggested that the high seeding rate of Italian ryegrass give a good effect on the early forage yield and weed control, and the high cutting frequency maintain desirable botancial composition of orchardgrass and ladino clover in the pasture mixtures with Italian ryegrass.

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History of the Korean Society of Applied Entomology for its First Fifty Years (한국응용곤충학회의 첫 50년 역사)

  • Boo, Kyung-Saeng
    • Korean journal of applied entomology
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    • v.51 no.2
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    • pp.171-190
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    • 2012
  • The Korean Society of Applied Entomology (KSAE) celebrates its First 50 years history this year, 2011. It began in the year 1962, as the Korean Society of Plant Protection (KSPP) to discuss all aspects of plant protection including entomology and plant pathology. At that time it was one of the earliest scientific ones among agricultural societies in Korea. Before liberation from the Japanese colonial rule there were a few scientific societies for Japanese scientists only in the Korean Peninsula. It seemed that there was a single exception, in medical field, formed by and operated for Korean ethnics. Right after the liberation, Korean scientists rushed to form new scientific societies in the fields of mechanical engineering, architecture, textile, internal medicine, biology, etc. in 1945, mathematics, chemistry, metallurgy, etc. in 1946, and so on. But agricultural scientists had to wait for more time before setting up their own scientific society, Korean Agricultural Society(韓國農學會), comprising all agricultural subfields, in 1954. They had annual meetings and published their own journal every year until 1962. Then those working in the plant protection field established their own KSPP, right after their section meeting in 1962. At that time the total number of participants for KSPP were only around 50. KSPP scientists were interested in plant pathology, agricultural chemicals, weed science, or bioclimate, besides entomology. They had annual meetings once or twice a year until 1987 and published their own journal, Korean Journal of Plant Protection (KJPP), once a year at the earlier years but soon gradually increasing the frequency to four times a year later. Articles on entomology and plant pathology occupied about 40% each, but the number of oral or posters were a little bit higher on plant pathology than entomology, with the rest on nematology, agricultural chemicals, or soil microarthropods. There also had a number of symposia and special lectures. The presidentship lasted for two years and most of president served only one term, except for the first two. The current president should be $28^{th}$. In the year 1988, KSPP had to be transformed into the applied entomology society, Korean Society of Applied Entomology (KSAE), because most of plant pathologists participating left the society to set up their own one, Korean Society of Plant Pathology in 1984. Since that time the Society concentrates on entomology, basic and applied, with some notes on nematology, acarology, soil microarthropods, agricultural chemicals, etc. The Society has been hosting annual meetings at least twice a year with special lectures and symposia, from time to time, on various topics. It also hosted international symposia including binational scientific meetings twice with two different Japanese (applied entomology in 2003 and acarology in 2009) societies and the Asia-Pacific Congress of Entomology in 2005. The regular society meeting of this year, 2011, turns out to be the 43rd and this autumn non-regular meeting would be the 42nd. It has been publishing two different scientific journals, Korean Journal of Applied Entomology (KJAE) since 1988 and the Journal of Asia-Pacific Entomology (JAPE) since 1998. Both journals are published 4 times a year, with articles written in Korean or English in the first, but those in English only in the latter with cooperation from the Taiwan Entomological Society and the Malaysian Plant Protection Society since 2008. It is now enlisted as one of those SCI(science citation index) extended. The highest number of topics discussed at their annual meetings was on ecology, behavior, and host resistance. But at the annual meetings jointly with the Korean Society of Entomology, members were more interested in basic aspects, instead of applied aspects, such as physiology and molecular biology fields. Among those societies related to entomology and plant protection, plant pathology, pesticide, and applied entomology societies are almost similar in membership, but entomology and plant pathology societies are publishing more number of articles than any others. The Society is running beautifully, but there are a few points to be made for further improvement. First, the articles or posters should be correctly categorized on the journals or proceedings. It may be a good idea to ask members to give their own version of correct category for their submissions, either oral or poster or written publication. The category should be classified detailed as much as possible (one kind of example would be systematics, morphology, evolution, ecology, behavior, host preference or resistance, physiology, anatomy, chemical ecology, molecular biology, pathology, chemical control, insecticides, insecticide resistance, biocontrol, biorational control, natural enemies, agricultural pest, forest pest, medical pest, etc.) and such scheme should be given to members beforehand. The members should give one or two, first and second, choices when submitting, if they want. Then the categories might be combined or grouped during editing for optimal arrangement for journals or proceedings. Secondly the journals should carry complete content of the particular year and author index at the last issue of that year. I would also like to have other information, such as awards and awardees in handy way. I could not find any document for listing awards. Such information or article categorization may be assigned to one of the vice presidents. I would rather strongly recommend that the society should give more time and energy on archive management to keep better and more correct history records.

Research on Methods of Developing Quadrangular Culm of Bamboos (사각죽조성(四角竹造成)에 관(關)한 연구(硏究))

  • Chong, Hyon-Pae
    • Journal of Korean Society of Forest Science
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    • v.10 no.1
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    • pp.7-16
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    • 1970
  • There are 19 species of bamboo in Korea, among which few are of commercial value. The Phyllostachys has wide range of utilization, for sea weed production, industrial production of various bamboo wares, etc. The total export from Chenla-Namdo to some more than ten countries was recorded 204,000,000 won worth in 1969. As civilization develops so does the techniques of bamboo works, and they in turn accelerate the demand for bamboo wood of better quality. In the light of this trend, the author attempted to make bamboo plants to develope a quadragular culm with elaborate design as disired instead of the original round one, with the expectation that it might be widely welcomed by hand workers, interior decorators. Here are some facts found out in this experiment: 1). The greater the diameter of the shoot at the eye level was, the better result was brought, and as shown in Fig. 5 the rate of success was 72% with the shoots of 7.5 cm thick. 2). The shoots of 30 cm in length showed 100% of success, developing into a desired quadrangular culms without fail(See Fig. 6). 3). The intensity of wood fiber increased as time lapsed, without receiving any influence by the weather (See Fig. 7, 8). 4). During the growing, the culm proved to be flexible enough to bend up to 90 degree (See Fig. 9). 5). In an attempt to promote the value of bamboo by decoration, the author tried to impress rectangular indents on the culm. The indention using a qudangular board 1cm smaller in width than the shoot diameter gave 100% success (See Fig. 10). 6). Design experiment was also successful both in coloration and impressing and the resulting designs delicately depended on the kinds of chemicals used and their combination (Table 2) (See Fig. 12, 13, 14). With the above mentioned findings, the author concludes that the mass production of quadrangular bamboo culm is quite a promissing as an new industry to develope bamboo works to a more valuable one. This research was carried out with the research fund provided by the Ministry of Education in 1969.

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Study on Cultural Method of Summer Buckwheat Planted in Spring (여름메밀의 춘파재배법 연구)

  • Keun-Yong Park;Rae-Kyung Park;Byeong-Han Choi
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.37 no.2
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    • pp.149-154
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    • 1992
  • Buckwheat has been a popular favorite food crop in Korea for a long time. The objective of the study was to investigate the effects of climatic conditions and cultural methods on grain yields of summer buckwheat variety Sinnong 1 planted during the spring season in Suwon, Korea from 1989 to 1991. Frost minimum temperature of late April was -0.3$^{\circ}C$ in 1990 being very low as compared with 3.7$^{\circ}C$ of the normal year, and affected early growth of the seedlings emerging from the soil surface. In late May of 1990, the frost minimum temperature was 7.3$^{\circ}C$ being low as compared with 8.8$^{\circ}C$ of the normal year, and also induced cold injury to fertilization and grain filling. Total precipitation 374.5mm of mid and late June, 1990 provided serious damage to the grain filling and maturing buckwheat seeds and along with causing seed sprouting before harvest. However, the climates of 1989 and 1991 were very good for the growth and development of spring-sown buckwheats. When summer buckwheat cultivar Sinnong 1 was planted on April 20, 1989, its highest grain yields 268-292kg /10a were harvested from the plots of seeding rate 8kg /10a, drill seeding and polyethylene film mulching, and the mean grain yield of the plots was 238kg /10a in 1989, but 64.3kg in Suwon, and 40.2kg /10a in Muan in 1990. In 1991 maximum grain yield 277kg /10a was produced from the April 15 planted and vinyl-mulched plot, and 255kg /10a from the April 25 planted and non-mulched plot. Herbicide Alachlor-sprayed plots produced lower grain yields than no weed control and manual weeding plots. Mechanized drill-seeding saved 83~84% in planting hours as compared with manual broadcasting 21.6 hours /ha, and produced 9% more in grain yields from the two-season croppings of mechanized drill-seeding culture being 364kg /10a in total yields per year.

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Optimum Application Level of Dicamba Herbicide for Control of Calystegia japonica in Silage Corn Field (사일리지용 옥수수 포장에서 메꽃 (Calystegia, japonica) 방제를 위한 Dicamba 액제 적정 시용수준 구명)

  • Seo, S.;Chung, E.S.;Kim, J.G.;Kang, W.S.;Kim, W.H.
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.19 no.3
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    • pp.259-264
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    • 1999
  • A field experiment was carried out to determine the optimum application level of dicamba herbicide for efficient control of Calystegia japonica in silage corn field. Six treatments of application levels (0 ; control, $0.75{\ell},\;1.0{\ell},\;1.25{\ell},\;1.5{\ell},\;and\;2.0{\ell}/ha$) were arranged at National Livestock Research Institute, RDA, Suwon in 1995. The hybrid silage corn was DK 729, and dicamba herbicide was applied at 5~6 leaf stage of corn. The growth of corn was poor in control plot, and the days for tasseling and silking were delayed 1~4 days when compared with the plots of herbicide application. The control efficiency of Calystegia japonica was excellent as 74.3~94.6% in the plots of dicamba application. A slight injury of herbicide was observed at early stage of corn when applied at $1.25{\ell}$ and $1.5{\ell}$ of dicamba per ha, and severe injury was found at $2.0{\ell}$ of dicamba. Forage dry matter(DM) yield, and length of ear in the plots of dicamba treatments were significantly higher than those of control. The DM yield of control(4,866kg/ha) was only about 30% of dicamba treatment plot (14,960~16,340kg/ha). However, there was no yield difference among dicamba application level. The percentage of ear to total DM yield was ranged from 33.6 to 39.4%. With application of herbicide, the contents of crude protein and nitrogen free extract were increased, and that of crude fiber was decreased in stover. However, nutritive value of corn ear was very similar among all treatments, regardless of herbicide treatment. From the above results, it is recommended that optimum application level of dicamba herbicide was $0.75{\sim}1.0{\ell}/ha$ for efficient control of Calystegia japonica and for silage corn production without herbicide injury.

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