• 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.

• Korean Journal of Weed Science
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• v.13 no.2
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• pp.132-137
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• 1993

Some biological characteristics with respect to tuber formation of Eleocharis kuroguwai Ohwi were investigated. Tuber formation was initiated at the descending time of daily maximum and minimum temperatures, accelerated under the minimum temperature lower than $20^{\circ}C$, and terminated at about $10^{\circ}C$. Tubers produced at the early season were located at deeper soil layers. Large tubers were found at deeper soil depths and required the longer period for sprouting as compared with small tubers. Percent emergence decreased as the emergence depth increased, while percent old-tuber produced during previous years was greater at the deeper depths.

• Korean Journal of Weed Science
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• v.9 no.1
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• pp.34-38
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• 1989

This study was conducted to investigate the tuberization time and the control method for Eleocharis kuroguwai Ohwi. The control methods were compared the shoot cutting and bentazon treatment for E. kuroguwai with untreatment. The initial tuberization time of E. kuroguwai, when E. kuroguwai was planted and without rice planted, was about August 18th and 10th, respectively. When the shoot of E. kuroguwai was cut, the regrowth vigour scarcely revived for the cutting on September 12. The least tuberization of E. kuroguwai, when E. kuroguwai was just planted and planted with rice plant, were on August 28 and August 3 to the top cutting of E. kuroguwai, respectively. Bentazon treatments from July 19 to August 3 hardly induced tuberization of E. kuroguwai, while as the delay of bentazon treatment time the tuberization of E. kurguwai was little by little increased.

• Korean Journal of Weed Science
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• v.30 no.2
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• pp.94-102
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• 2010

Field and pot experiments were conducted to investigate seedling emergence and early growth of Eleocharis kuroguwai panted on different dates. Non-linear regression analyses of observed data against effective accumulated temperature (EAT) with the Gompertz model showed that the Gompertz model works well in describing seedling emergence and early growth of E. kuroguwai regardless of planting date and soil burial depth. EATs required for 50% of the maximum seedling emergence of E. kuroguwai planted at 1, 3 and 5 cm soil burial depth in the pot experiment were estimated to be 54.5, 84.0 and $118.0^{\circ}C$, respectively, and $56.7^{\circ}C$ when planted at 1 cm in the field experiment. EATs required for 50% of the maximum leaf number of E. kuroguwai planted at 1, 3 and 5 cm soil burial depth in the pot experiment were estimated to be 213.3, 249.0 and $291.6^{\circ}C$, respectively, and $239.5^{\circ}C$ when planted at 1 cm in the field experiment. Therefore, models developed in this study thus predicted that if rotary tillage with water is made on 27 May under $+2^{\circ}C$ elevated temperature condition, dates for 50% of the maximum seedling emergence, 5 leaf stage and 5 cm plant height of E. kuroguwai buried at 3 cm soil depth were predicted to be 2 June, 10 June and 12 June. These dates are 1 day earlier for the seedling emergence and 3 days earlier for the early growth as compared with current temperature condition, suggesting that earlier application of herbicides is required for effective control of E. kuroguwai.

• Korean Journal of Weed Science
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• v.3 no.1
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• pp.23-28
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• 1983

To study ecological characteristics of Eleocharis kuroguwai occuring in Korea its propagules were collected from 6 locations from the northern part to the southern part of Korea (Chuncheon, Suweon, Iri, Jeonju, Gwangiu and Milyang) in 1981, cultured and replanted 3 times (May 20, June 5, June 20) in 1982. They flowered from August 5 to August 27 when they were planted on May 20, and from August 20 to August 27 when they were planted on Tune 20. Plant height, number of tillers and top fresh weight/$m^2$ were 50-90cm, 500-875, and 175-750g, respectively when they were planted on May 20, and 40-70cm, 250-625, 325-625g, respectively when they were planted on June 20. Number of tubers per plant were 0.98-1.98 when they were planted on May 20, and 1.81-2.87 when they were planted on June 20. Eleocharis kuroguwai from Chuncheon or Suweon was more open in plant type, shorter in plant height, narrower in diameter of pedicel and shorter in inflorescence than those from Iri, Jeonju or Gwangju. Each of the local collections may be regarded as different ecotype, based on the above differences in morphology and responses in growth and flowering to the planting dates. The results appear to imply that Eleocharis kuroguwai weeds occurring in various locations of Korea are different one another in competitive avility with rice crop.

• Korean Journal of Weed Science
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• v.11 no.1
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• pp.60-67
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• 1991

The experiment was conducted to evaluate weeding effect and to inhibit tuberization of Eleocharis kuroguwai authority by single or systematic applications of several herbicides. E. kuroguwai was controlled above 90 percentage by pretilachlor and butachlor+bensulfuron application at 5-10 DAT(Days after transplanting) followed by bentazon at 50 DAT and weeded 88 percentage by mefenacet+bensulfuron application at 15 DAT. Tuberization inhibition rate of E. kuroguwai was higher at the application of butachlor+bensulfuron at 5 DAT followed by bentazon at 50 DAT than any other applications. The weight variation of E. kuroguwai tubers formed at 15-20cm soil stratum was larger than that at 10-15cm. Tuber of E. kuroguwai was hardly formed at top soil stratum (0-5cm) and deep soil (15-20cm) by the systematic application of bentazon at 50 DAT. Grain yield of rice from systematic application with bentazon at 50 DAT and mefenacet+bensulfuron at 10-15 DAT was similar to that of hand weeded plot.

• Korean Journal of Weed Science
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• v.5 no.2
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• pp.96-102
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• 1985

A study on the competition-ecological classification of the 10 prominent paddy weed species around bulrush (Scirpus juneoides) to simplify the weed problem concept for the rice production. A serial assessments on the competition ability in space and dry matter production(nutrient depletion) of respective weed species and paddy rice, and the data were used to compute the phenotypic similarity by Single Link Clustering method. Both growth response of weed species in mono- and under the paddy rice standing was very similar (r = 0.969), but the reduction rate as affected by paddy rice standing was negatively correlated with the ability in space-competition(r=-0.513). Dendrogram of 10 weed species based on the phenotypic similarity computed in 4 characters in mono- and under the paddy rice standing was also similar, as Echinochloa c., Ludwigia p., Cyperus s., and Scirpus m. in I-group, Eleocharis k., Scirpus j, in II-group, and Juncus e., Potamogeton d. in III-group, respectively. Also, that of paddy rice to 10 weed species showed Fimbristylis m., Scirpus j., Eleocharis k., Scirpus m., Juncus e. in I-group, and Ludwigia p., Potamogeton d., Monochoria v. in II-group, respectively. The integrated dendrogram by the above two data indicate the I-group with Fimbristylis m., Scirpus j., Eleocharis k. and Juncus e., as higher growth response with relatively lower competition ability to paddy rice, II-group with Cyperus s., Echinochloa c., Potamogeton d., and Ludwigia p., as higher both in growth and competition, and the last, III-group with Monochoria v., and Scirpus m., as lower growth but higher competition, respectively.

• Korean Journal of Weed Science
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• v.14 no.4
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• pp.233-238
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• 1994

The experiment on sprouting and emergence properties of Eleocharis kuroguwai was conducted at laboratory and greenhouse conditions in 1993. Most of tubers had the apical dominance of buds at sprouting and had the competitive relationship for mesocotyl elongation. When pyrazosulfuron was applied on soil surface, all of apical buds were killed, but the first and second lateral buds survived to 50% and 90%, respectively, and the third lateral buds were almost at presprouted state. The tubers at 10-15cm deep soil emerged 1 week late and 35% low in emergence rate compared with the tubers at 2-5cm deep. As the plants emerged from the deep soil, the mesocotyl and the roots were distributed at deep soil more or less. Among the tubers buried at 10cm and 15cm deep soil, 25% and 30% respectively were not emergerd due to the suspension of mesocotyl elongation. Although the roots and shoots were removed from the tubers at the stage of 20cm high, all of mother tubers emerged again even 2 weeks late.

• Korean Journal of Weed Science
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• v.14 no.4
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• pp.272-279
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• 1994

In order to compare the biological properties of benfuresate and cinosulfuron as herbicides for the chemical control of Eleocharis kuroguwai, some experiments were conducted at greenhouse and field conditions in 1993. Benfuresate and cinosufuron moved to 2cm and 6cm deep in paddy soil and inhibited the growth of E. kuroguwai. Benfuresate was absorbed into the roots of E. kuroguwai. whereas cinosulfuron was absorbed into not only the roots and shoots but also the mesocotyls. After the emergence was inhibited by the soil application of herbicides, the percentage of regrowing numbers was higher at cinosulfuron than at benfuresate, whereas the growth rate was higher at benfuresate on the contrary. Benfuresate brought about complete death of buds as a killing type, but cinosulfuron produced lots of abnormal shoots as an inhibiting type. Benfuresate was able to apply on soil surface from the preemergence to the early stage of 2cm high, but cinosulfuron was able to use from the preemergence to the stage of 15cm high. The foliar application of cinosulfuron showed a good control effect, but it induced a severe phytotoxicity to rice. A good control effect of Benfuresate/bensulfuron GR lowered at the late stage, but that of cinosulfuron/mefenacet/dymron GR at the early stage maintained until the late stage of 65 days after transplanting.

• Korean Journal of Weed Science
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• v.12 no.1
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• pp.1-7
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• 1992

The experiment was conducted to investigate effects of bensulfuron-methyl{methyl 2-((((((4,6-dimethoxypyrimidin-2-yl)amino)carbony)amino)sulfonyl)methyl)benzoate}on bud sprouting, percent regrowth, and regrowth from growth cessation in Eleocharis kuroguwai. Application of bensulfuron-methyl resulted in sprouts of two of three lateral buds in addition to the apical bud of E. kuroguwai. With bensulfuron-methyl the culms elongated from the sprouted buds were killed soon after emergence. However, the buds remained biologically active. During the period of growth cessation the tuber buds respired in a minimum rate, but respiration began to increase with regrowth. At regrowth increase in the respiration was greater in the lateral buds than in the apical bud. Days required to regrowth was 35 days in the suppressed apical bud when applied at the rate of 51 g a. i. ha bensulfuron-methyl, while the suppressed lateral buds sprouted first and second required 29 and 28 dyas, respectively. After regrowth number of new culms was two to three times greater in the lateral buds than in the apical bud.