• Korean Journal of Weed Science
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• v.15 no.2
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• pp.154-159
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• 1995

Water extracts from Polygonum aviculare and Salix koreansis markedly inhibited the germination of lettuce and rice seeds, indicating the presence of biologically active substances. The biochemical substances such as salicylic and+vanillic acid, tannic acid + gallic acid, p-coumaric acid, p-cressol, sinapic acid and catechol etc. belonging to phenolic compounds were detected in the cultured cells, suggesting that the secondary metabolites can be synthesized in plant cell and tissue culture. In addition, fatty acid like linolenic acid and organic acid such as oxalic acid were presented in the highest amount, 3.7 mg/g and 14.288 mg/g, respectively, which seem to be related to exhibiting phytotoxicity of P. aviculare. Petroleum ether extract exhibited another potential relating to inhibitory effect which needs further investigation. Calli from two plant sources were easily introduced by uses of 1.0 mg/l of 2.4-D and 0.1 to 0.2 mg/l of BAP in MS basal medium which can be implemented for a large scale production through cell culture.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.167-167
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• 2022

Seed production of italian ryegrass has a problem of lodging during ripening and a decrease in quality due to difficulty in drying seeds during harvest. Therefore, in order to produce high-quality Italian ryegrass in paddy fields, it was carried out to reduce the density and solve the lodging problem through transplanting. In this experiment, Lolium multiflorum cv. Kowinearly was transplanted in autumn from a paddy field in Sindong-ri, Gwansan-eup, Jangheung-gun, Jeollanam-do. var. Kowinearly was made into a bed at 90 g/box and stacked in boxes. It was transplanted on October 27th after 2 days of germination at 30℃ and 15 days of seedling and greening. When transplanting, they were transplanted at intervals of 30×14cm. The existing cultivation method, drill seedling, was sowed at a level of 50 kg/ha, and both transplanting and drilling were carried out at a nitrogen fertilization rate of 45 kg/ha. The number of ears during transplant cultivation was 1,016/m² and the drilling tended to be higher at 2,278/m², but this was probably due to the difference in seeding amount. The seed number of an ear tended to be 56% higher in transplantation, which had a significant impact on yield. The seed yield was 2,096 ka/ha in transplantation, which was 21% higher than that of drilling. When looking at the relationship with weed occurrence, there were areas where all the weeds, such as amul foxtail, occurred due to the low density. Even in the same transplanting area, the seed yield was about 1,000kg/ha less in the area where the weeds were abundant. It seems that weed management is important in paddy cultivation. Therefore, it seems necessary to develop an exclusive herbicide for Italian ryegrass cultivation.

• The Plant Pathology Journal
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• v.24 no.4
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• pp.453-460
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• 2008

In the course of in vitro and in vivo screening for bioherbicidal agents, a hyphomycete fungus, Myrothecium sp. F0252 was selected as a candidate for the biocontrol of weeds. The isolate was identified as Myrothecium roridum Tode ex. Fries based on the morphological characteristics and 18S ribosomal DNA sequence analysis and registered as Myrothecium roridum F0252. In order to evaluate the in vitro effect of M. roridum F0252 on germination of ladino clover and white clover (Trifolium repens L.) seeds, spore solution of the fungus was employed in two concentrations, $6.5{\times}10^6$ and $2.5{\times}10^7$ spores per mL and then inoculated to the seeds. The fungal spores inhibited the seed germination, infected the seedlings, and caused an abnormal withering and inhibition of seedling growth. In addition, when the herbicidal activity of crude ethyl acetate extract from the liquid culture was assessed on a mini-plant, duck-weed (Lemna paucicostata (L.) Hegelm.), the extract showed high inhibitory effect at the level of $12.5{\mu}g$ per mL. On the other hand, in vivo herbicidal activity of M. roridum F0252 was evaluated by a whole plant spray method. M. roridum F0252 exhibited strong and broad-spectrum herbicidal activity. The herbicidal values ranged from 95-100% against 7 weeds, including Abutilon avicennae and Xanthium strumarium, and 70-80% against Digitaria sanguinalis and Sagittaria pygmaea. When the nutritional utilization (95 carbon sources) pattern of M. roridum F0252 was investigated, it varied with water activity ($a_w$) and temperature conditions, supplying good, basic information in regard to nutritional utilization for proper cultivation and formulation. Our results showed that M. roridum F0252 might be used as a potential biocontrol agent against weedy plants.

• Korean Journal of Weed Science
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• v.9 no.2
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• pp.130-140
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• 1989

1) Dormancy brocken weed seeds were planted in soil at 15 days interval from June to December in 1986 and 1987 and test of normality and normal distribution curve were made to determine seasonal distribution characteristics of weed emergence in fields. Monthly emergence distribution pattern of each species can be concluded as following normal distribution equations. E. crusgalli $y={\frac{1}{2.52{\sqrt{2{\pi}}}}}e^{-{\frac{(x-10.057)^2}{12.7}}}$ E. indica $y={\frac{1}{2.17{\sqrt{2{\pi}}}}}e^{-{\frac{(x-9.16)^2}{9.45}}}$ A. lividus $y={\frac{1}{7.74{\sqrt{2{\pi}}}}}e^{-{\frac{(x-10.06)^2}{15.46}}}$ S. nigrum $y={\frac{1}{2.7{\sqrt{2{\pi}}}}}e^{-{\frac{(x-9.695)^2}{14.58}}}$ C. busrsa-pastoris $y={\frac{1}{2.83{\sqrt{2{\pi}}}}}e^{-{\frac{(x-9.02)^2}{16.02}}}$ D. sanguinalis $y={\frac{1}{2.8{\sqrt{2{\pi}}}}}e^{-{\frac{(x-8.58)^2}{15.67}}}$ S. viridis $y={\frac{1}{2.72{\sqrt{2{\pi}}}}}e^{-{\frac{(x-9.36)^2}{14.8}}}$ C. album $y={\frac{1}{2.596{\sqrt{2{\pi}}}}}e^{-{\frac{(x-8.07)^2}{13.48}}}$ P. oleraeda $y={\frac{1}{2.45{\sqrt{2{\pi}}}}}e^{-{\frac{(x-10.83)^2}{12.01}}}$ 2) Emergence peak period of weed species tested were from the end of May to early August and yearly variation of emergence was observed in E. crus-galli, S. viridis, S, nigrum, and P. oleracea and this fact may more related to rainfall pattern rather than temperature.

• Korean Journal of Weed Science
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• v.16 no.1
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• pp.21-27
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• 1996

This experiment was conducted to find out an effective propagation method for reed(Phragmites communis Trin.), ensuring a continuous herbicide screening for reed control. Reed propagation methods were compared under a greenhouse condition using tour different materials; seeds, rhizomes, depressed stolons of P. japonica Steud., and stem cuttings. Although reed seeds were easy to harvest and store, their germination rate(${\leq}$5%) was very low and seedling growth from the seeds was slow. Rhizomes were difficult to harvest and their harvest time was limited from November to March. Furthermore, reed propagation using rhizomes had problems of a relatively low germination rate(46%), no uniformity in size and shape, individual differences at the early stage of growth, and difficulties in material storage. Rate of reed growth from rhizomes was higher in commercial soil mix(Boo Nong soil) than in sand or in sand+upland soil(1:1). Depressed stolons of P. japonica had a moderate germination rate(65%) and were relatively easy to harvest. However, their harvest time was limited only from August to September. Propagation method using stem cuttings had several advantages over the above methods using other materials. Reed plants could uniformly be propagated from the stem cuttings with a relatively high germination rate(75%). Stem cuttings of central nodes showed a higher germination rate compared to those of upper or lower nodes. Stem cuttings from the field should be used immediately after harvest, since their germination rate decreased rapidly when they were stored under a wet- or a dry-refrigerated condition. Furthermore, the germination of stem cuttings tended to decrease when they were collected from the field after August. This indicates that there is a limitation of harvest time for stem cuttings. However, a year-round propagation of reed using stem cuttings is possible if parent plants are grown in a greenhouse, and thus herbicide screening for reed control could continuously be performed.

• Korean Journal of Weed Science
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• v.6 no.2
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• pp.110-123
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• 1986

To know the ecological pattern of bulrush (Scirpus juncoides Roxb.) seeds and overwintreed stumps in germination and sprouting responses as affected by different temperature (7 trt.), light intensity (5 trt.), shading intensity (S trt.), light quality (specturm spectrum; 6 trt.), soil acidity (7 trt.), stump sizea (weight base; 5 trt.), and molding depth (6trt.), respectively, this serial studies were conducted by use of growth chamber, incubator, Wagner pot and petri-dish. Most efficient treatment was obtained from 25-$35^{\circ}C$ temperature, higher light intensity in 2-11 klux range, 95% shading intensity, clear and yellow film for seeds/clear and blue film for stumps, soil pH 5.53, 3-4g stump weight, 0-5% wxygen concentration, 1 ㎝ flooding depth for seeds, and 1-1.5cm molding depth for seeds/0.5-1.0 cm molding depth for stumps, respectively, among others.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.2
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• pp.127-133
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• 2003

The purpose of this study is to investigate the positive or negative effects of 5-aminolevulinic acid(ALA) on the growth of several crops and weeds, by applying a seed soaking treatment, foliar treatment, and application timing, while comparing biological activity between ALA produced by chemical synthesis (Synthetic-ALA) and extracellularly-accumulated ALA by overexpressing the hemeA gene isolated from Bradyrhizobium japonicum(Bio-ALA). Seed soaking treatment of ALA in barley (five cultivars) and wheat (five cultivars) had not shown positive effects at lower concentrations, 0.05 to 0.5 mM as well as negative effects at higher concentrations, 1 to 30 mM. In rice, there also was no positive effect by seed soaking treatment of ALA at lower concentrations, although the rice became damaged by an application of 5 and 10 mM ALA. Growth in barley cultivars, Ganghossalbori, Naehanssalbori, Songhakbori, Saessalbori, and Daehossalbori were increased up to 14%, 19-51 %, 17-64%, 18-23%, and 22-38% by ALA foliar application at lower concentrations, 0.05 to 0.5 mM, respectively. On the other hand, the growth in barley cultivars was inhibited by ALA foliar application at higher concentrations. Barley responded more positively to ALA foliar application than wheat and rice. The growth stimulation caused by ALA seed soaking treatment was less than by ALA foliar treatment. ALA treatment at the 1.5-leaf stage increased growth of barley by 19-58%, while pretreatment to seeds, post-emergence treatment at 3 days after seeding, 3-leaf stages, and 5-leaf stages had not shown positive effects. Thus, the positive effects of ALA on barley were dependent greatly upon the timing of application and its concentration. Monocots weeds were more sensitive to ALA foliar treatment than dicotyledonous weeds. A monocot weed, Setaria viridis L. was the most susceptible plant to ALA while a dicotyledonous weed, Plantago asiatica L. was the most tolerant. No significant difference in biological activity between bio-ALA and synthetic ALA on barley, wheat, rice, and weed, Ixeris dentate tested was observed. Thus, ALA produced by microorganisms would be a potent substance to be used effectively in agricultural production.

• Korean Journal of Weed Science
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• v.12 no.2
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• pp.183-187
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• 1992

This study was conducted to evaluate the effect of systematic herbicide application and polyethylene(PE) film mulching in direct seeded Angelica gigas Nakai. Freshly-collected-seed showed 86% of emergence rate and required 18 days of emergence duration. Cold treatment of seeds increased emergence rate by more than 90% and shortened 2 days of emergence duration. Paraquat) 1,1'-dimethyl-4,4'-bipyridylium dichloride was the most effective when applied just before emergence of A. gigas and provided 96% of emergence rate and 91% of weeding effect when applied 23 days after seeding. Soil applied herbicides used did not cause any phytotoxicity on emergence with application of 2-fold recommended rate and gave more than 90% of weeding effect. Black PE film mulching gave excellent emergence rate and weeding effect, and shortened emergence duration by 8 days.

• Korean Journal of Environmental Biology
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• v.23 no.4
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• pp.383-389
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• 2005

The effect of different mulching materials on mungbean production was studied. The general objective was to assess the ecological effects of mulching materials in sustainable mungbean production. Specifically, the study aimed to determine the effects of different mulching materials on the chemical, physical and biological soil properties, on weed control and yield, and to identify mulching materials that are environmentally friendly in mungbean production. The experiment was conducted at the Fruit and Vegetables Seeds Center, Science City of $Mu/tilde{n}oz$, Nueva Ecija, Philippines from May to July 2004. The initial soil chemical properties were: pH of 6.4, 2.0 percent organic matter content, 0.10 percent total nitrogen, 22 ppm phosphorus, and 370 ppm available potassium. The soil microbial loads were $8\times10^4\;CFU\;g^{-1}$ for bacteria and $14\times10^4\;CFU\;g^{-1}$ for fungi. Mushroom spent mulch increased soil organic matter with an average of 3.13 percent, nitrogen with an average of 0.16 percent and the highest number of bacterial count with $3.4\times10^8\;CFU\;g^{-1}$. Use of mulch, except rice straw mulch, generally increased mungbean yield. The best mulching material for high yield production of mungbean was black polyethylene plastic film, although environmentally unfriendly.

• The Korean Journal of Food & Health Convergence
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• v.4 no.4
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• pp.26-30
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• 2018

To have more insight into the nature of plant, plant scientists carry out phytosociological studies on such plant species. The phytosociological studies on Tridax procumbens. Linn was carried out at Imo State University, Owerri, Imo State between the months of July and September, 2018. Tridax procumbens Linn grows abundantly in the areas under tropical climate and supported by a sandy-loam soil. Morphological features showed a range of variations. Phytosociological investigation showed a Tridax- Mitracarpus-Digitaria plant community. Tridax procumbens was positively associated with Digitaria horizontalis, Mitracarpus scarber and Vernonia cinera. The Inter-relationship of T. Procumbens was thus determined. This study therefore is a contribution to the general ecology of the plant. Phytosociological studies helps plant scientist to have more knowledge into the nature of plant species. This study is a contribution to the general ecology of the plant Tridax procumbens. The study also shows that it has close association with mitracarpus Scarber and Digitaria horizontalis. More work should be carried out to find out if these plant species flower and produce seeds at the same time or not.