• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.6
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• pp.821-832
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• 1997

The aim of this study was to separate or purify some bioactive compounds from flowers of alfalfa(Medicago sativa L.) and to test of the isolated compounds on alfalfa for their autotoxicity and on Echinochloa crus-galli for their allelopathy for seed germination and seedling weight. Using thin layer chromatography(TLC) of $CHCl_3$ extracts, the most inhibitory band to alfalfa seed germination was determined. Germination inhibition of this extract suggested a complex chemical interaction. Separation and purification of compounds with CHCl$_3$ extract of fresh alfalfa flowers were conducted by a silica gel TLC, and microcrystalline cellulose TLC(MCTLC), followed by droplet countercurrent chromatography(DCCC) bioassay. Preliminary identification was done by high perfomance liquid chromatography(HPLC) on the most inhibitory fractions in DCCC. Ferulic acid, caffeic acid, vanillic acid, rutin, narringin were identified in fraction 5 and ferulic acid, caffeic acid, vanillic acid, rutin, coumarin in fraction 6. The phytotoxicity of their individual compound was tested on alfalfa and Echinochloa crus-galli seed germination and seedling weight. Coumarin and ferulic acid showed the most inhibitory effect on alfalfa seed germination and Echinochloa crus-galli seedling fresh and dry weight. These compounds may be, at least in part, involved in autotoxicity and allelopathy.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.21 no.2
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• pp.277-280
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• 1976

In order to obtain the fundamental informations on the nodulation and its effect on growth of pulse crops in volcanic soil, 6 legume crops were planted in the newly reclaimed land of Cheju-do. The attached nodule weight was in the order of senna, pea, soybean (hill), white clover and kidney beans.

• The Korean Journal of Pesticide Science
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• v.18 no.1
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• pp.26-32
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• 2014

This study was conducted to evaluate pest control efficacy of environment-friendly agricultural materials (EFAMs) according to their spray time and frequency against alfalfa weevil, Hypera postica Gyllenhal, at Chinese milk vetch field in Miryang, Korea. Larva, pupa and adult of H. postica occurred more in year 2010 than those in 2011, and the larval population peaked 5 days faster in year 2010 than on $10^{th}$ May in 2011. Control efficacies of EFAMS sprayed on various time and in several frequencies to H. postica during April in 2010 were 73.6%, 71.9% and 66.2% at single spray in early, middle and late April, respectively and ranged from 77.1% to 78.9% when sprayed twice. With three times spray the control efficacy averaged 87.2%. Control efficacies of EFAMs with a single application in early, middle and late April in 2011 were 57.9%, 66.8% and 65.2%, respectively and ranged from 73.7% to 76.8% when sprayed twice. Control efficacy averaged with 82.7% when EFAMs were sprayed for three times. Accordingly, control efficacy of EFAMs against was increased with increasing spray frequency. Among the tested, Ungsamee(R), Wangjoongwangeco(R) and Muchungjidae(R) with a single application showed relatively higher control efficacy with a 4 to 16% lower control rate than a chemical insecticide, etofenprox 20EC. Therefore, Ungsamee(R), Wangjoongwangeco(R) and Muchungjidae(R) can be effectively used for management of H. postica when sprayed at early April for high occurring population and middle April for low occurring population with a single spray.

• 월간낙농육우
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• s.63
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• pp.13-14
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• 1987

• 월간낙농육우
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• s.113
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• pp.76-79
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• 1991

• 월간낙농육우
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• s.44
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• pp.39-42
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• 1985

• 월간낙농육우
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• s.45
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• pp.46-48
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• 1985

• 월간낙농육우
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• s.43
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• pp.21-24
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• 1985

• Korean journal of applied entomology
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• v.52 no.4
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• pp.371-377
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• 2013

Occurrence of adult alfalfa weevil, Hypera postica Gyllenhal, was observed at Chinese milk vetch field, and host plant preference of its $1^{st}$ generation adult was observed at greenhouse and Chinese milk vetch field. The over-wintered adult of the weevil appeared from late March and peaked in mid April while the $1^{st}$ generation adult appeared from late April and peaked in late May. However, the occurrence of over-wintered adult was very low contrary to the $1^{st}$ generation adult which was very high with some variations among observed years. In greenhouse, host plant preference of $1^{st}$ adult generation of H. postica was evaluated with 11 different seedlings. H. postica was found to occur in significantly higher number on Chinese cabbage seedling followed by soybean, and kale at 7 days after releasing(DAR). Corn, crown daisy and sorghum were found to be the least preferred with nil occurrence of the weevil. Seedlings damage rate by H. postica feeding at 7DAR was the most severe on Chinese cabbage(60.0%) followed by soybean(50.0%), kale(30.0%), foxtail millet(16.7%), proso millet(13.3%) and lettuce(3.3%) significantly. Also, seedlings damage rate by H. postica at 7DAR in Chinese milk vetch field had shown the similar trend with Chinese cabbage(46.7%), soybean(43.3%), kale(23.3%), foxtail millet(13.3%) and proso millet(13.3%) in greenhouse significantly. Accordingly, results on host plant preference of H. postica from this study can be used as a basic information for safe cultivation of upland crops at near or around green manure crop field.

• Korean Journal of Environmental Agriculture
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• v.18 no.2
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• pp.185-190
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• 1999

Autotoxic substance(s) from alfalfa(Medicago sativa L.) plants reduces germination and growth of adjacent new alfalfa after alfalfa. The autotoxic chemical(s) in alfalfa are clearly unknown. Our objective was to improve the sensitivity of an alfalfa seedling bioassay for evaluating autotoxic leaf extracts. We determined critical extract concentrations that inhibit seed germination and seedling growth, compared two different culture media, and evaluated the effects of extract sterilization on the sensitivity of the assay, by using streptomycin and autoclaving method. An agar medium in petri plate gave better responses of germination and seedling growth to the extracts than using filter paper in the plate. On agar medium, the concentration of extract required to reach 50% inhibition of root length was 2.7 g $kg^{-1}$, and of germination and hypocotyl length were 3.8 and 9.9 g $kg^{-1}$, respectively. Leaf extracts with 100 ppm streptomycin stimulated germination significantly compared to Leaf extract alone but reduced root length of control by 43%. Root length was more sensitive to the autotoxin(s) than was germination or hypocotyl length. These results suggest that agar medium mixed with extract and sterilization by autoclaving could be improved the consistency and precision of bioassay, and that root length was the best parameter of autotoxic effect of alfalfa leaf extract.