• Weed & Turfgrass Science
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• v.5 no.3
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• pp.170-176
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• 2016

Superintendents have used a silicate fertilizer to improve a resistance of turfgrass against several diseases, drought damage and wear stress. This study was conducted to evaluate the effect of liquid fertilizer containing silicate (LFSi) on changes of turfgrass quality and growth by investigating visual quality, chlorophyll content-chlorophyll a, chlorophyll b, and total chlorophyll, root length, shoot length, dry weight of clipping, and nutrient content in leaves tissue. Treatments were designed as follows; control fertilizer (CF), SiF-1 (CF + $1ml\;m^{-2}$ LFSi), SiF-2 (CF + $2ml\;m^{-2}$ LFSi), and SiF-3 (CF + $4ml\;m^{-2}$ LFSi). As compared with CF, soil chemical properties, visual turfgrass quality, chlorophyll content, and dry weight of clipping of LFSi treatments were not significantly. Contrastingly, shoot density, root length, and the content of nitrogen or potassium were increased by application of LFSi. The content of Si in the tissue was positively correlated with potassium content or shoot length, and similarly shoot density positively with chlorophyll content or visual quality, respectively. These results suggested that the application of LFSi improved the turfgrass quality by increasing shoot density or K content in leaf tissue of creeping bentgrass.

• Weed & Turfgrass Science
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• v.1 no.4
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• pp.18-23
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• 2012

To determine the effect of winter green manure crops for tillage and no-tillage organic pepper cultivation in plastic film house, five different green manure crops were cultivated during winter season. In nutrition composition of green manure crops, total nitrogen contents were higher in Vicia hirsuta and Vicia angustifolia than any other crops. The average dry weights of green manure crops were 8.3 ton per ha in tillage and 7.0 ton per ha in no-tillage, among green manure crops that of Secale cereale was the highest. Fertilizer supply was depended on the biomass of the cultivated green manure crops and nutrition contents, total nitrogen supply of V. angustifolia was 226 kg and that of S. cereale was 251 kg per ha in tillage field. In no-tillage field, N-supply of V. angustifolia was 197 kg and that of S. cereale was 222 kg per ha. In yield components of red pepper, fruit numbers per plant were 55.5 in green manure crop tillage and 37.0 in no-tillage cultivation. Among green manure crops, the yield of dried red pepper was the highest for V. angustifolia in both green manure crop tillage and no-tillage cultivation.

• Weed & Turfgrass Science
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• v.3 no.3
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• pp.246-252
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• 2014

This study was conducted to evaluate the effects of two amino acid fertilizers on the growth of creeping bentgrass and N uptake. Fertilizer treatments were designed as follows; non-fertilizer (NF), control (CF), recommended amount (ALF), double amount (2ALF) of amino acid liquid fertilizer (AaLF), recommended amount (ASLF) and double amount (2ASLF) of amino acid liquid fertilizer contained with saponin (AaSLF). Turf quality of treatments of AaLF and AaSLF such as turf color index, chlorophyll index and root length was similar to the treatment of CF. Dry weight and content, uptake and availability of N were investigated highest in the 2ALF and 2ASLF. These results suggested that foliar application of AaLF and AaSLF was enhanced turf quality and growth of creeping bentgrass by stimulating uptake and availability of N.

• Korean Journal of Weed Science
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• v.7 no.1
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• pp.3-11
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• 1987

The study was conducted to identify growth habit of Monochoria vaginalis gathered from three different locations (Suweon, Jeonju and Milyang). The plant height, number of leaves and dry weight of M. vaginalis gathered from three different locations were greatly affected by the seeding dates. The earlier the seeds of M. varginalis sown, the greater M. vaginalis grew, In general, the earlier seeding dates produced significantly longer plant height, number of leaves and dry weight than those of later seeding dates, showing no difference in the collection of weed seeds in different locality. The earlier seeding dates resulted in the earlier flowering, but the interval between dates of seeding and flowering decreased progressively as the seeding times were delayed. Seed production was not significant among three locations and but seeding date on June 15 produced th highest seed production as compared with other seeding times. No. of flowers and capsule per pot among yield components were two major factors affecting seed 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 Weed Science
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• v.30 no.4
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• pp.380-389
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• 2010

Transgenic herbicide-resistant sweet potato plants [Ipomoea batatas (L.) Lam.] produced through a biolistic transformation were used in this study. The objective of this research was to find out a rapid and reliable assay method for confirming glufosinate-ammonium resistance. The techniques tested include whole-plant bioassay, one leaf bioassay, and leaf disk bioassay. Parameters investigated in this study were leaf injury and ammonium accumulation at 1 and 5 days after treatment of glufosinate-ammonium. In the leaf disk bioassay, leaf injury of the transgenic line 7171 was 1.9-fold less affected by glufosinate-ammonium than the wild type. The leaf injury of 7171 in one leaf and whole-plant bioassays was 59- and 92-fold less affected by glufosinate-ammonium, respectively, compared with that of the wild type. Leaf disk, one leaf, and whole-plant bioassays showed that ammonium accumulation of the 7171 was 2 to 20-, 4 to 43-, and 6 to 115-fold less affected by 0.5-5 mM glufosinate-ammonium than that of the wild type. All three bioassays successfully distinguished the resistance from the transgenic lines, but one leaf bioassay is the simplest and quickest. Leaf injury and ammonium accumulation were the same in leaves 1, 3, 5, 7, and 10 of 3 mM glufosinate-ammonium treated plants or nontreated plants. The one leaf bioassay was chosen as the standard procedure for future confirmation of resistance in transgenic sweet potato because it is a rapid and reliable assay.

• Korean Journal of Weed Science
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• v.10 no.2
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• pp.93-98
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• 1990

Interspecific competition between E. colona and rice was determined over four growth stages in replacement series. No competition between the two species as measured by plant height, leaf area and dry weight occurred by 30 days after seeding (DAS) at all the density combinations studied. At 45 DAS reductions in leaf area and dry weight of E. colons due to the competition occurred at the density combinations where number of competing E. colons plant was less than that of rice. However, there was a great increase in leaf area and dry weight of E. colons at the density combination of one E. colons competing with four rice plants at 60 DAS. As the number of E. colons plants increased, the leaf area and dry weight of E. colona decreased resulting from intraspecific competition between E. colons plants. Although rice absorbed more nitrogen than E. colons up to 30 DAS, the reverse was observed from 45 DAS. A relatively small amount of phosphorous was absorbed by both rice and E. colons, but the amount of phosphorous taken up by E. colons was greater than that taken up by rice. E. colons absorbed extremely high amount of potassium when compared to rice.

• Weed & Turfgrass Science
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• v.6 no.3
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• pp.262-271
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• 2017

This study was conducted to evaluate incorporation ratio of soil amendment 'Profile' to improve soil physicochemical properties and turfgrass growth. The soil amendment was added 0 (sand only), 3, 5, 7, and 10% to USGA Green-spec green sand soil. As incorporated with more 'Profile' amendment, soil electrical conductivity (EC), cation exchangeable capacity (CEC), capillary porosity and total porosity of root zone were increased than those of control, while bulk density and hydraulic conductivity decreased. Turfgrass index and clipping yield of creeping bentgrass grown in sand soil incorporated with 7% 'Profile' were improved than those of control. Correlation coefficient of turf color index and incorporation ratio of the soil amendment 'Profile' was found to show significantly positive correlation. These results indicated that application of the soil amendment 'Profile' to sand soil in golf course green improved turfgrass growth and quality by increasing CEC and porosity of root zone.

• Korean Journal of Weed Science
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• v.5 no.1
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• pp.19-23
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• 1985

Soil temperature was higher in clear or blue polyethylene film and bare soil than in black or green polyethylene film and straw mulching. Light transmission was low in black, blue or green colored polyethylene film and straw mulching. Germination of weeds was generally high under clear polyethylene film but black polyethylene film inhibited the germination. Germination of Portulaca oleracea, Setaria viridis and Amaranthus retroflexus increased under blue polyethylene film but inhibition of germination was observed in Erigeron canadensis, Avena fatua, Chenopodium ablum, Digitaria sanguinalis and Echinochloa crusgalli. Green polyethylene film mostly inhibited germination of weeds except A, fatua, C. album and E. canadensis. The greatest number of weeds emerged was obtained in clear polyethylene film, next in bare soil but green or blue polyethylene film inhibited the emergence of weeds. However, no emergence of weeds was observed under black polyethylene film. The highest dry weight of weeds was obtained in clear polyethylene film, next in bare soil, but green or blue polyethylene film and straw mulching caused suppression of weed growth. No weeds were grown under black polyethylene film.

• 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.