• Korean Journal of Weed Science
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• v.14 no.1
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• pp.49-55
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• 1994

A study was conducted to determine the effect of depth of burial, soil temperature and/or moisture on tuber sprouting of E, kuroguwai. Tubers were evenly distributed in the upper 30cm of soil. Tuber weight increased as depth of tuber formed increased. No dormancy in newly formed tubers was found, whereas mature tubers were dormant. When new tubers were subjected both to continuous $5^{\circ}C$ and to gradual decreasing temperatures regimes ranged from 20 to $1^{\circ}C$ for 30 days, the tubers remained non-dormant. Viability of tubers was reduced when buried at 5cm depth in dry and moist soil conditions, but no reduction was obtained when buried at 25cm depth, regardless of soil moisture conditions employed. Percent sprouting of tubers buried at 25cm depth increased with increasing duration of burial in three soil moisture conditions studied, wherease in dry and moist conditions percent sprouting of tubers buried at 25cm depth increased by 60-day burial and thereafter decreased. In submerged condition, tuber sprouting was greater when buried at 5cm depth than when buried at 25cm depth, and increased as duration of burial increased at the both depths.

• Korean Journal of Weed Science
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• v.14 no.3
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• pp.171-175
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• 1994

Physiological changes in Eleocharis kuroguwai Ohwi as affected by bensulfuron-methyl {Methyl 2-[[[[[(4, 6-dimethoxy-2-pyrimidinyl)amino]carbonyl]amino] sulfonyl]methyl]benzoate} was determined to relate the characteristics with regrowth behavior. There were no changes in relative growth rate(RGR) during the period of growth cessation after application of bensulfuron-methyl. RGR's of the growth ceseased plants caused at 39 and 51 g/ha began to increase in between 25 and 30 days after application (DAA) and between 30 and 35 DAA, respectively. In untreated plant tuber carbohydrate rapidly decreased right after emergence and almost consumed within 40 days. There was no carbohydrate consumption during the period of growth cessation in bensulfuron-methyl-applied plant, but the content started to rapidly decrease with regrowth. Tuber viability lasted for 30 days in untreated plant, while tubers were viable for 60 and 70 days after application of bensulfuron-methyl at 39 and 51 g/ha, respectively. During the period of growth cessation the plants kept minimum respiration and photosynthesis, but with regrowth respiration and photosynthesis were resumed and rapidly increased.

• Korean Journal of Plant Resources
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• v.29 no.1
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• pp.110-127
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• 2016

This floristic study was conducted from April to September, 2014 in 12 days. The investigated area was Mt. Segeolsan (1,261 m) which is the part of Chirisan National Park and its neighbor region, Goan-ri, Sandeuk-ri. Based on voucher specimens, flora of this area consisted of 108 families, 376 genera, 584 species, 5 subspecies, 73 varieties, and 16 forma, totally 679 taxa. 17 taxa were endemic to Korea such as Carex okamotoi Ohwi, Cimicifuga austrokoreana H.W. Lee & C.W. Park., Thalictrum rochebrunianum var. grandisepalum (H.Lév.) Nakai, Fallopia koreana B.U. Oh & J.G. Kim, Asarum patens (Yamaki) Yamaki ex Y.N. Lee, and Stewartia pseudocamellia Maxim. etc. Among these species, C. austrokoreana, T. rochebrunianum var. grandisepalum, F. koreana, A. patens are considered having a southern boundary line of distribution in the Chirisan National Park region. And so Carex okamotoi has main distribution center in the Chirisan National Park region, this study region is assumed important in phytogeography. The useful plants were 633 taxa, ethonobotanic plants were 359 taxa in this area. Invasive alien species were 61 taxa, which were naturalized rate (9.0%) and urbanized index (17.4%).

• Korean Journal of Weed Science
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• v.13 no.1
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• pp.26-35
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• 1993

Differences in weed occurrence was investigated among five types of rice (Oryza sativa L.) cultivation. The five types employed were three transplanting cultivations such as conventional hand transplanting, machine transplanting with 30-day-old seedling, and machine transplanting with 10-day-old seedling and two direct-seedings such as flood direct-seeded rice by pregerminated seed and dry direct-seeded rice by dry seed. Weed specie, occurred varied from 7 to 20, depending on the different cultivation types. Weeds were more diverse in transplanting with l0-day-old seedling than in other transplanting cultivations and in direct-seeding than in transplanting practice. Dominant weed species also varied with cultivation types. In transplanting cultivations Scirpus juncoides Roxb., Echinochloa crus-galli (L.) P. Beauv., and Eleocharis kuroguwai Ohwi were dominant, whereas occurrence of annual weeds such as Cyperus difformis L. and Monochoria vaginalis Presl. aside from the three weed species increased in direct-seeded cultivations.

• Korean Journal of Weed Science
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• v.15 no.4
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• pp.254-261
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• 1995

The nationwide weed survey was conducted in lowland rice fields over whole country of Korea in 1992 in order to determine a change of weed community and to identify a major dominant weed species and/or problem weed. Based on morphological characteristics of weeds, population ratio of broad leaf weed was 42.6%, grasses weed-9.0%, sedges-33.4% and others were 15.0%. Annual weed was 33.4% while perennial weed was 66.6% in terms of life cycle of weeds. Meanwhile, there was different weed occurrence as affected by planting method of the rice plant. In hand transplanted paddy fields predominant weed species was Sagittaria trifolia L., Monochoria vaginalis Presl., and Aneilema japonica Kunth. In machine transplanted rice fields of infant and young rice seedling Eleocharis kuroguwai Ohwi. and S. trifolia L. were more predominant. There was high occurrence of M. vaginalis, Echinochloa crus-galli L., and Leesia japonica Makino in water seeding while E. crus-galli and Cyperus serotinus Rottb. were predominant weed species in dry seeded rice. Monoculture of the rice plant would cause to high occurrence of E. kuroguwai, S. trifolia, M. vaginalis, E. crus-galli, and Sagittaria pygmaea Miq and there was higher population of S. trifolia, S. pygmaea, M. vaginalis, E crus-galli, and E. kuroguwai in double cropping system based on rice culture. In particular, there was high different weed occurrence under different transplanting times. E. kuroguwai, S. trifolia, S. pygmaea, M. vaginalis, and C. serotinus were higher population at the transplanting of 25 May and S. trifolia, E crus-galli, C. serotinus, and M. vaginalis at 10 June and S. pygmaea, E. kuroguwai, M. vaginalis, S. trifolia, and E. crusgalli at 25 June in Korea, respectively. Autumn tillage in terms of tillage time would cause more predominant weed species such as S. trifolia, E. kuroguwai, M. vaginalis, and S. pygmaea while spring tillage was higher population of E. kuroguwai, S. trifolia, E. crusgalli, M. vaginalis, and S. pygmaea. In plain area of paddy field there was higher occurrence of E. kuroguwai, S. trifolia, M. vaginalis, E. crus-galli, and S. pygmaea and in mid-mountainous area S. trifolia, E. kuroguwai, M. vaginalis, E. crus-galli, and Ludwigia prostrate Roxb. while in mountainous area S. trifolia, M. vaginalis, Potamogeton distinctus Ben., E. kuroguwai, and E. crus-galli were. In 1992 the most ten predominant weed species at the rice field of Korea based on summed dominant ratio(SDR) were E. kuroguwai > S. trifolia > E. crus-galli > M. vaginalis > S. pygmaea > C. serotinus > L. prostrate > P. distinctus > A. japonica > Scirpus juncoides Roxb.

• Korean Journal of Weed Science
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• v.2 no.2
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• pp.160-168
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• 1982

Nine combined dosal levels of Paraquat and Oxyfluorfen were compared on pear orchard to control Digitaria adscendens Henr, and others, namely Commelina communis L., Erigeron annuus L., Echinochloa crusgalli P. Beauv var. oryzicola Ohwi, etc.. By treating as an early-postemergence, the mixtures showed higher control effects than 85% of the whole weeds, but the control effects in the mono-treatments of respective herbicide were only 20% or so. On the other hand, as a late-postemergence, the control rates were fluctuated from 31% to 94%. However, there was no significant difference in Spearman's rank correlation coefficients between both efficacies. Thus indicate that the action style of synergistic effect was not influenced by the application time, and the levels of mixtured dosages should be adjusted by the application times and interfering conditions.