• The Plant Pathology Journal
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• v.19 no.2
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• pp.97-101
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• 2003

This study was conducted to determine the efficacy of Epicoccosorus nematosporus for the control of Eleocharis kuroguwai and to evaluate the meteorological factors which affect weeding efficacy in field conditions for three years (1996-1998). The best time to control E. kuroguwai with E. nematosporus as a biological control agent in the field was in July, when temperature ranged from 20.4 to $23.4^{\circ}C$; the surface wetness duration was 12.6-16.1 hours, and application time of 6:00 p.m. and 8:00 p.m.; and weeding efficacy was 81-90%. On 10 June 1996 in Milyang area, where the field experiments were performed, mean temperature was $16.5^{\circ}C$ with 11.3 hours of dew duration. Meanwhile, on 20 Aug. 1996 the temperature was $21.3^{\circ}C$ with 15.4 hours of dew duration. During these periods, the weeding efficacy was recorded at 61.8 and 60.8%, respectively. Time required for complete plant death was 25.8 and 25.6 days at application times 10 June and 20 Aug., respectively. At the time of application on 7,18, and 27 July 1996, mean temperature was 20.4-$23.4^{\circ}C$ with 12.6-16.5 hours of dew duration. The weeding efficacies of these periods were very hi일 with 81.4-90.8%. Three years of field observations from 1996 to 1998 showed that infection in the field can occur at any time through the summer season, although total infection rates vary between months and between years. In 1996, plant infection rapidly increased from 56% on 30 June, 82.4% on 15 July, 94.6% on 15 August, and 92.8% on 15 September under favorable meteorological conditions such as minimum temperature of $17.6^{\circ}C$ and maximum temperature of $27.1^{\circ}C$, with 86% relative humidity and 977.5 mm of rainfall during E. kuroguwai growing season. However, in 1997, the disease incidence was very low because of unfavorable weather conditions brought about by the hot temperature and the low amount of rainfall at 321.5 mm. Disease progress was slow from 24.4% on 30 June to 49.2% at the end of the growing season.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.23 no.3
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• pp.55-65
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• 1978

Upland weed control in Korea has been in dilema with the radical problems prior to weed problems, as it were, poor farming conditions, low yielding, no farmers concern, lack of political cares, and low returns for farming, etc. In these respects, the study was intended to collect all concerns to upland farming conditions and to array all research informations contributed upon Korea upland weeding, and at last interpreted its problems in order of importance. Especially expecting the reasonable and common use herbicides upon the most uplands in Korea, the crop compatibility and weeding efficacy by the most herbicides upon each crops were investigated from the experiment results. Among other interpretations of research results, the most important and first of all acceptance was for the direction and methods of weed research to be rationalized. And that weeding programs in level of upland farmers should be cautionsely and gradually propagated was interpreted to be accepted. Also, for the reasonable development of upland weeding situation in near future, the integrated promotion of upland farming rationalization is suggested by schematic explanations.

• Korean Journal of Weed Science
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• v.7 no.3
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• pp.329-336
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• 1987

Antagonistic interaction between glyphosate and some herbicides in effects of post-emergence application on cut grass and of pre-emergence application on some weed species including barnyardgrass was evaluated with pots in plastic house. By addition of oxyfluorfen to glyphosate, the weeding efficacy on cutgrass was visually evaluated as promotive in both weeding rate and efficacy. However, by alachlor, simazine, gluphosinate or quizalofop-ethyl showed delayed weeding rate, and by paraquat, the promotive in rate but lower in efficacy, respectively. Fresh weights of cutgrass at 30 days after the lower-rate application has generally indicated the lower weeding efficacy than that from glyphosate alone. Even at higher rate application, the addition of alachlor or simazine to glyphosate has still indicated the lower efficacies. As a result of interaction analysis by Colby method, no synergism was detected from any treatments, and the combinations of simazine or paraquat to glyphosate in lower mixing rate showed significant antagonism at 5% probability level of DMRT. On the annual weed species including barnyardgrass, the significant soil-residual weeding efficacies were recognized by addition of any rate of oxyfluorfen, alachlor, simazine and higher rate of quizalofop-ethyl to glyphosate, respectively.

• Korean Journal of Weed Science
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• v.7 no.2
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• pp.236-242
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• 1987

The study was conducted to interprete the fluctuation of weed vegetation in plant-sociological impacts as affected by the mixture use of oxyfluorfen and glyphosate with various dosages. Also, intended to know the real interaction between two herbicides in weeding efficacies. The better efficacy from the above mixture was recognized than from the oxyfluorfen + paraquat mixture on the perennial-sites. In lower rate mixture of oxyfluorfen, the dominance index was increased by the annual grass species (ie. Digitaria), and of glyphosate by the biennial Stellaria and perennial species (ie. Artemisia). Also, the positive maximum action of both oxyfluorfen and glyphosate in various mixture rates was categorized upto 0.55kg ai/ha for oxyfluorfen and 0.35kg ai/ha for glyphosate, respectively. However, the interaction between the above two herbicides recognized actually as negative. Consequently, the use of mixture compound of oxyfluorfen with glyphosate are expected rather to promote the control efficacy of specific weed species, to enlarge the weeding spectrum and to prolong the weeding periods than to reduce the application rate of both chemicals depending on any synergic interactions.

• Korean Journal of Agricultural Science
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• v.42 no.2
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• pp.87-92
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• 2015

This study was conducted to evaluate the herbicidal efficacy of carfentrazone-ethyl mixtures in direct-seeding flooded rice. The efficacy of three different carfentrazone-ethly mixtures was greater than pyrazosulfuron-ethyl pyriminobac-methyl GR (PP GR). Weeding efficacy of three different carfentrazone-ethly mixtures was more than 96.9%. No phytotoxic effect was observed in the rice based on the plant height and the number of tillers. Yield of rice un three different carfentrazone-ethly mixtures application was more than both in the PP GR and in the hand weeding. Based on these data, three different carfentrazone-ethly mixtures can be applied to provide an effective weed management in direct-seeding flooded rice.

• 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.

• The Plant Pathology Journal
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• v.19 no.2
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• pp.92-96
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• 2003

The study was conducted to determine the cultural conditions and the effect of inert fillers for melanization and sporulation abilities of sodium alginate pellets, and the weeding efficacy of the formula in the field. Melanin production of E. nematosporus was affected by striking frequency. Percentage of melanized beads was increased to 80.6% at higher rpm up to 180. The melanized pellets produced more conidia with abundant mucilage than unmelanized pellets. Shaker culture of Epicoccosorus nematosporus with sodium alginate yielded a total of 55 mg per 100 pellets. Percentage of melanized pellets was highest with 81.0% and 83.3% of melanization, when wheat bran and rice polish were amended and produced the conidia with 65.4 and 68.4 mg per 100 pellets, respectively. When 1 L of conidial suspension of 6.0$\times$$10^5$ conidia per ml was applied on 30-day-old plants in a plot, 74.5% of the plants were killed within 20 days, whereas, its melanized sodium alginate pellets killed 57.8% of the plants in the same period. The number of tuber formation of Eleocharis kuroguwai in the untreated control plots was 128.5 per plot, but those of the plots treated with conidial suspension and melanized pellets were 22.1 and 39.7, respectively, at the end of the season. Results of this study showed that melanization of mycelia-mixed sodium alginate are an important sporulation factor in E. namatosporus as a mycoherbicide.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2002.11a
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• pp.53.2-54
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• 2002

• Korean Journal of Weed Science
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• v.3 no.2
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• pp.199-207
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• 1983

To select appropriate herbicides for adzukibean and mungbean, a series of experiments was carried out in both field and pot from 1980 to 1983. Tolerance to the herbicides tested was highest in soybeans and followed by mungbean and adzukibean in the order. Pre-emergence herbicides showed relatively low phytotoxicity were chlorambem, linuron, and metribuzin for adzukibean and alachlor and butachlor for mungbean. Post-emergence herbicides showed no external phytotoxicity for adzukibean and mungbean were alloxydim, Dowco 453, fluazifop, etc.. For mungbean, terbutryn (1.5 kg, a.i./ha) which is pre-emergence herbicide showed the best weeding control efficacy but some possible phytotoxicity. Among post-emergence herbicides, acifluorfen (300 g, a.i./ha) showed the best weeding efficacy with no yield reduction though some phytotoxicity which recovered within 20 days. Compared to single herbicide application, the mixture or systemic treatments of herbicides showed much higher weeding control efficacy and seed yields: the systemic treatments of linuron (500 g, a.i./ha) / Dowco 453 (180 g, a.i./ha) or linuron (500 g, a.i./ha) / fluazufop (260 g, a.i./ha) for adzukibean and the mixture treatment of alachlor (1.31 kg, a.i./ha) / acifluorfen (150 g, a.i./ha) for mungbean, respectively.

• Korean Journal of Weed Science
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• v.15 no.4
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• pp.270-277
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• 1995

The research was carried out in tray in greenhouse equipped with Auto Foggy Systems(SAE KI RIN Co.) and the results were summarized as follows. 1. The number of leaves and fresh weight of Chinese cabbage were not different, but the plant height was increased due to foggy condition. 2. Plant height was decreased in 40 and 60 days of weed competition by foggy condition, the number of leaves was not different. And, shoot fresh weight was decreased by in all the duration of weed competition under foggy condition. Especially, that was greater in 40 days. 3. The shoot fresh weight was decreased by pendimethaline and napropamide application under foggy condition. Also, the number of leaves was decreased at 60 days after transplanting by pendimethaline application under foggy condition. 4. Pendimethalin, napropamide and alachlor treatments were not different in the weeding efficacy between non-foggy and foggy conditions. Trifluraline showed lower weeding efficacy by seedling emergence of large crabgrass as the days of treatment got longer under foggy condition.