• Korean Journal of Weed Science
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• v.30 no.3
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• pp.215-224
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• 2010

A greenhouse experiment was conducted to determine the effects of medium components and shade treatment on the growth, contents of total phenolics and flavonoids, and 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging activity of Youngia sonchifolia. Substrates combined with coco peat and perlite (ratio 70:30 or 50:50, v/v) showed higher plant length, leaf area, and fresh weight than single substrate (P<0.05). Shade treatment also significantly reduced plant height, root length, leaf areas, and fresh weight (P<0.05) with increasing of the degree. Shading treatment, however, increased contents of total phenolics [mg ferulic acid equivalents $kg^{-1}$ dry wt.] and total flavonoids [mg naringin equivalents $kg^{-1}$ dry wt.] in shoot parts of Y. sonchifoli, showing 110.2 to 119.2 and 128.3 to 146.7 mg $kg^{-1}$, respectively. The antioxidant potential of the methanol extracts from the plants dose-dependently increased DPPH free radical scavenging activity, and the activity was higher in shoots (50.2 to 80.8%) than in roots (47.7 to 49.8%), and in shading treatment than in no shade.

• Weed & Turfgrass Science
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• v.3 no.1
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• pp.29-40
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• 2014

Research was initiated to investigate early establishment characteristics and germination pattern of Kentucky bluegrass (KB, Poa pratensis L.). Fifteen cultivars were evaluated under alternative conditions (8 hours light at $25^{\circ}C$ and 16 hours dark at $15^{\circ}C$). Significant differences were observed in germination characteristics and germination pattern among KB cultivars. A final germination percentage differed in cultivars, being 75.25 to 89.50%. The first germination was initiated between 6 and 9 DAS (days after seeding). As for the first germination percentage, 'Brilliant' and 'Midnight II' produced 14.50% and 23.00%, respectively, while the others were most below 5%. Days to 75% germination were between 15.08 and 28.80 DAS. 'Excursion', 'Midnight II', 'Odyssey', 'Midnight' and 'Courtyard' were fastest. The slowest cultivar was 'Voyager II', being over 28 DAS, which were 13 to 14 days slower than the fastest ones. Considering the first germination percentage, days to the first germination, days to 75% germination, and germination pattern, 'Midnight II', 'Excursion' and 'Midnight' were regarded as excellent cultivars under alternative conditions. From this study, information on differences in germination characteristics and patterns would be practically useful for a golf course construction when established with KB.

• Weed & Turfgrass Science
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• v.3 no.1
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• pp.19-28
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• 2014

Research was initiated in greenhouse to investigate effects of polymer, calcium, perlite and chitosan on the growth of Kentucky bluegrass (KB). A total of 24 treatment combinations were used in the study. Treatments were made of water-swelling polymer (WSP), calcium, perlite, and chitosan in soil organic amendment (SOA). Significant differences were observed in germination rate, turfgrass coverage, turfgrass density and top growth among treatments. Germination rate, density and plant height varied with time after seeding. A proper mix of WSP is considered to be lower than 3% for turfgrass coverage and density. Regarding survival capability and top growth, however, it was good under 6%. Overall KB growth was more influenced by calcium and perlite than chitosan. Calcium and perlite were the most effective elements for early survival capacity and turfgrass density, respectively. But no effect was found by chitosan. Top growth increased with three elements, being perlite > calcium > chitosan. The chitosan was effective in early germination, but there was no effect on top growth until 3 weeks, when compared with others. A further study is needed for investigating the effect of these materials on the growth characteristics in mixtures of sand and SOA before a field application.

• Weed & Turfgrass Science
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• v.2 no.3
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• pp.274-282
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• 2013

Research was initiated to investigate early germination and establishment characteristics of perennial ryegrass (PR, Lolium perenne L.). An alternative condition was applied in Experiment I with 8-hr light at $25^{\circ}C$ and 16-hr dark at $15^{\circ}C$ (ISTA condition). Experiment II was conducted under $5^{\circ}C$ to $25^{\circ}C$ (natural condition). Significant differences were observed in germination percentage, germination speed and germination peak time. Seed germinating vigor was 66.00 to 93.75% under ISTA and 66.25 to 93.50% under natural conditions. Germination speed, measured as days to germination of 50% through 90%, was much faster with 'Pennant II', 'Brightstar II', 'Sonata' and 'Accent II' under ISTA conditions. But it was faster only with 'Pennant II' and 'Brightstar II' under natural conditions. Germination peak time ranged 1.48 to 5.65 days under ISTA, while 2.17 to 10.63 days under natural conditions. Regardless of growing conditions, the shortest cultivars in peak time were 'Sonata', 'Pennant II', and 'Brightstar II' and the longest one 'Revenge GLX'. Considering germinating vigor, early germination speed and germination peak time, 'Pennant II', 'Brightstar II', 'Sonata' and 'Accent II' were regarded as excellent cultivars under ISTA conditions, while 'Pennant II' and 'Brightstar II' under natural conditions.

• Korean Journal of Weed Science
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• v.14 no.1
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• pp.8-15
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• 1994

The mode of safening action and potency of the 1, 8-naphthalic anhydride(NA) were investigated in corn(Zea mays) and soybean(Glycine max) treated with herbicide bensulfuron[2-{{{{{(4,6-dimethoxy-2-pyrimidinyl)amino}carbonyl}amino}sulfonyl}methyl}benzoic acid] and imazaquin[2-{4,5-dihydro-4-methyl-4-(1-methylethyl)-5-oxo-1H-imidazol-2-yl} 3-quinolinonecarboxylic acid]. Seed dressing with 0.2%(w/w) NA showed successful protection in corn against injury from herbicide bensulfuron and imazaquin but not in soybean. Safening factors of NA against bensulfuron and imazaquin were 10.2 and 5.0, respectively, in corn, while they were both 1.3 in soybean. In vivo, Glutathione-S-transferase(GST) activity of NA-treated corn and soybean increased 1.8-and 1.3-fold, respectively, but the activity was not affected by the herbicides in vitro. Acetolactate synthase(ALS) levels of NA-treated corn was increased 1.3-fold, but not changed in soybean. Tolerance of ALS activity to the herbicides was slightly greater in ALS obtained from NA-treated corn than that from the untreated, whereas the difference was not found in soybean. A significant increase of ACCase due to NA occurred in corn, but not in soybean. The herbicides did not affect in vitro ACCase activity.

• Korean Journal of Weed Science
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• v.14 no.1
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• pp.16-22
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• 1994

Ninty three species of domestic weeds were collected and screened for antimicrobial, antitumor, antioxidant and herbicidal activities. Among them, few showed antifungal activities. Cuscuta japonica showed inhibitory activity against Alternaria mali, Ambrosia artemisiifolia and Geranium sibiricum against Phytophthora capsici, Aster yomema and Aster pilosus against Phytophthora parasitica. Ambrosia artemisiifolia, Artemisia princeps, Artemisia capillaris, Ludwigia prostrata, Chrysanthemum zawadskii, Bidens frondosa, and Geranium sibiricum showed broad antibacterial activities. Carex chordorhiza, Artemisia capillaris, Persicaria nodosa, Senecio koreanus, Pariicum bisulcatum, Geranium sibiricum showed antiblebbing activity on human chronic leukemia K562 cell, among them, Persicaria nodosa was the strongist. Angelica decursiva, Equisetum arvense, Cimicifuga heracleifolia, Persicaria nodosa, Geranium sibiricum, Oenothera odorata, Cyperus sanguinolentus showed antioxidant activities. Ludwigia prostrata and Peucedanum terebinthaceum showed strong herbicidal activities.

• Korean Journal of Weed Science
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• v.15 no.1
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• pp.63-72
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• 1995

This study was carried out to isolate the soil bacteria degrading herbicide napropamide [N,N-diethyl-2-(1-naphthoxy)-propionamide] from the clayey loam soil tested and to clarify the characteristics of the napropamide-degrading bacteria. Twenty strains of the gram-positive and the gram-negative bacteria were isolated and identified from the clayey loam soil tested. Most of them were vigorously proliferated at 100ppm of napropamide and two strains of Staphylococcus spp., Corynebacterium spp. II and Other spp. II were very tolerated to napropamide even at the concentration of 1500ppm. Staphylococcus spp. II and Actinobacillus spp. II of the isolated bacteria degraded more than 20% of the treated napropamide. These two strains could not utilize napropamide as sole nitrogen sources, but could use this compound as sole carbon sources. Napropamide was rapidly decomposed by Staphylococcus spp. II at one-time application and at three-time application of napropamide, but wasn't at two-time application of napropamide.

• Korean Journal of Weed Science
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• v.15 no.4
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• pp.298-304
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• 1995

This study was carried out to make the most of them as the fundamental data for reasonable weed control when population of weeds was observed in the alternated fields of lowland and upland. The annual and the perennial paddy weeds in the continuous paddy rice field remarkably decreased when compared to that in the alternated field of paddy rice and soybean. The longer was the duration of upland field condition, the less was the population of lowland weeds and the more was the population of upland weeds. Biennial weeds in the contiuous paddy rice field were less than that in the rotated field of paddy rice and soybean, and this tendency was clear in Alopecurus aequalis Sobol. In the continuous cropping of paddy rice, population of biennial weeds in the culverted field was higher than that in the unculverted one, but in the continuous cropping of soybean this tendency was vice versa.

• Korean Journal of Weed Science
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• v.16 no.1
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• pp.1-7
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• 1996

In order to get basic information for establishing weed control methods in greenhouse, weed distribution was surveyed at 42 greenhouses in 10 cities and counties of Gyeongnam and Junnam area from September to December, 1995. Sixty nine weed species in 23 families which were composed of 28 annuals, 16 biennials and 25 perennials were identified. Broadleaf weed species was 50 species, followed by 8 species in grasses, and 11 species in sedges. Cruciferae was the most widely occurring family belong to 9 species, followed by 8 species in Compositae, Cyperaceae and Gramineae, respectively, 6 species in Polygonaceae, and the other 17 families have 1~3 species. The dominant weed species occurred in greenhouses based on summed dominance ratio of weeds were Cardamine flexuosa var. fallax, Digitaria sanguinalis, Eleusine indica, Stellaria aquatica, Centipeda minima, Mollugo pentaphylla, Portulaca oleracea, Rorippa islandica.

• Korean Journal of Weed Science
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• v.15 no.1
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• pp.13-18
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• 1995

This experiment was carried out to investigate occurrence ecology and control of soil-flakes in flood-direct seeded rice field. The occurrence of soil-flakes were inhibited in blue light of 450nm wave length and promoted in red light of 660nm wave length. The diatoms of Pinnularia spp. largely occurred in low fertilizer level and which much more increased when nitrogen was mixed with thinly soil depth. The diatoms of Pinnularia spp. were effectively controlled by carbamate and triazine herbicides when treated in pre-emergence of soil-flakes. Beside, triazine herbicides, simetryne, dimethametryn, prometryne 5g ai/10a showed high control effect in pre and post-emergence of soil-flakes. Expecially, In water-direct seeded rice pyrazosulfuron-methyl molinate simetryne 5.37% GR and dimepiperate bensulfuron dimethametryn 7.643% GR showed high control effect on the soil-flakes when treated at 10 days after seeding and didn't showed rice injury.