• Weed & Turfgrass Science
• /
• v.4 no.3
• /
• pp.256-261
• /
• 2015

Trampling stress in turfgrass fields caused by traffics often occurs in zoysiagrass (Zoysia japonica) fields including golf course. In order to know the influences of trampling stress on the growth and development of turfgrass, leaf and root growth, chlorophyll fluorescence, chlorophyll content and 2-DE protein analysis were conducted in the turfgrass plants subjected to various levels of trampling stress from 0 to $9,420J\;day^{-1}$ day. Shoot growth was more highly inhibited by trampling stress than root growth. Although root growth was affected by trampling with weak intensity, the highest root length was observed in the turfgrass treated with weak trampling ($1,570J\;day^{-1}$). Chlorophyll fluorescence (Fv $Fm^{-1}$) was drastically lowered by trampling stress with moderate intensity. Leaf number showed similar tendency with leaf greenness. The number was decreased as the trampling intensity was increased. Shoot dry weight was decreased showing a similar tendency with the result of shoot length. The specific protein expressions under weak trampling were related to the functions of stress amelioration. Heat shock 70 kDa protein 10 and oxygen-evolving enhancer protein 1 were the proteins increased positively under trampling stress.

• Asian Journal of Turfgrass Science
• /
• v.26 no.1
• /
• pp.17-23
• /
• 2012

Large patch caused by Rhizoctonia solani AG2-2 (IV) is one of the most serious diseases in zoysiagrass. The objectives of this research were to evaluate the in vitro fungicidal effect and in field control of large patch disease of Paraffin oil. In the field experiments, paraffin oil was applied with 1 L/$m^2$ after diluted at 5 ml to 20 ml of oil/1 L of water for the control of large patch on Zoysia japonica in golf course. The same material was tested for inhibition of mycelial growth in vitro. Paraffin oil at 0.5% and 2.0% had a fungicidal effect by 43 to 67% on R. solani AG2-2 (IV) in vitro. In two locations of the field experiments, the paraffin oil provided moderate protection of large patch. It was effective in suppressing large patch development by 48.0% in comparison with a water check after one time application on mid-September in golf course. Paraffin oil may be used as an alternative control agent for environment friendly management of large patch on Zoysiagrass in golf course.

• Weed & Turfgrass Science
• /
• v.6 no.3
• /
• pp.249-261
• /
• 2017

To prevent large patch disease, caused by Rhizoctonia solani AG-2-2, in zoysiagrass a fungicide, Tebuconazole and three microbial agents Streptomyces sp. Burkholderia sp. and Streptomyces sp. S8 were applied in commercial turfgrass cultivation field in Sanchung, Gyeongnam, Korea. All treatments showed 50% reduced the pathogen population in thatch layer throughout the yearly cultivation period. Not only reduced the pathogen population, Tebuconazole, Streptomyces sp. Burkholderia sp. and Streptomyces sp. S8 treatment also enhanced turfgrass growth, chlorophyll and proline content. Malondialdehyde contents in each treatment was reduced from 6.2~28.9% when compared with the control. Taken together, reduction of pathogen population in soil lowered the disease incidence or severity, and allowed the turfgrass developed as normal condition. The results suggested that the selected microbial agents may use as biological control and growth promotion agents for the Zoysia turfgrass.

• Weed & Turfgrass Science
• /
• v.3 no.4
• /
• pp.354-361
• /
• 2014

This study was conducted to investigate whether several composted liquid manures (CLMs) are useful for biological control of large patch on zoysiagrass and investigate the chemical and biological factors to suppress large patch in soil treated with CLMs. The CLMs were produced at 4 different facilities for livestock excretion treatments located in Korea. Field experiments were carried out at 5 golf courses located near each facility. CLM and Chemical fertilizer (CF: water soluble fertilizer, 20-20-20) were applied four and three times with N at $12g\;m^{-2}$ per year, respectively. There was significant increase of concentration of K, Na, and Cu of soil treated with CLM compared to CF treatment. Among experimental plots, CN and GG2 plot sites were shown significant higher effect of biological control 80% and 50% respectively against large patch disease. The number of bacteria, Actinomycetes, and fungi in soil at these sites significantly increased and fluorescein diacetate hydrolytic activity was enhanced, while the soil was treated with CLM. The results of this study demonstrated that CLM application has effect on soil to suppress large patch and reduce the use of fungicide in environment-friendly turf management.

• Asian Journal of Turfgrass Science
• /
• v.8 no.1
• /
• pp.1-11
• /
• 1994

Studies were conducted to evaluate the effect of priming and preimbibition on gerraination of unscarified and KOH-scarified zoysiagrass (Zoysia japonica Steud.) seeds, respectively. Germi-nation percentages at 35˚C of seeds primed in $KNO_3$ and Ca($NO_3$)$_2$ were significantly higher than that of untreated seeds. The optimum conditions for priming unscarified seeds were in aerated $KNO_3$ solution at O4 M for 4 days at 20˚C. No additional benefit of $GA_3$ on increasing germination was not found in seed priming with solution of $KNO_3$ + $GA_3$ or in seeds preimbibed with $GA_3$ after priming. Scarified seeds preimbibed with distilled water(DW) for 4 days at 20˚C germinated higher and with fewer days to 50% of total germination(T 50) than untreated seeds. Preimbibition with $GA_3$ solution at 50 ppm for 4 days at 5, 10, 15 and 20˚C enabled up to 97% of seeds to germinate and reduced days to T 50 about 1.1 to 1.2 days at 35˚C Especially, seeds preimbibed with $GA^2$˚$_3_2_1$$\times$ had greatly higher germination and lower T 50 than untreated or DW-preimbibibed seeds at 30˚C, which is inadequate to germination in general. Preimbibed seed performance was unchanged after storage at room temperature for 50 days. Seeds preimbibed with GA $_3$ had higher rate of seedling emergence and faster growth of shoot than untreated seeds after sowing at 30˚C in growing medium in growth chamber.

• Journal of Plant Biotechnology
• /
• v.34 no.1
• /
• pp.75-80
• /
• 2007

The release of genetically modified organisms ($GMO_{s}$) into the environment has the potential risks regarding the possibility of gene transfer from $GMO_{s}$ to natural organisms and this needs to be evaluated. This study was conducted to monitor the possible horizontal gene transfer from herbicide-resistant zoysiagrass (Zoysia japonica Steud.) to indigenous microorganisms. We have first examined the effect of field-released GM zoysiagrass on the microbial flora in the gut of locust (Locusts mlgratoria). The microbial flora was analyzed through determining the 165 rDHA sequences of microorganisms. The comparison of the microbial flora in the gut of locusts that were captured at the field of GM zoysiagrass and of wild-type revealed that there is no noticeable difference between these two groups. This result indicates that the GM zoysiagrass does not have negative impact on microbial flora in the gut of locust. We then investigated whether the horizontal gene transfer occurred from GM zoysiagrass to microbes in soil, rhizosphere and faecal pellets from locusts by utilizing molecular tools such as Southern hybridization and polymerase chain reaction (PCR). When the total DNAs isolated from microbes in GM zoysiagrass and in wild-type zoysiagrass fields were hybridized with probes for bar or hpt gene, no hybridization signal was detected from both field isolates, while the probes were hybridized with DNA from the positive control. Absence of these genes in the FNAs of soil microorganisms as well as microbes in the gut of locust was further confirmed by PCR. Taken together, our data showed that horizontal gene transfer did not occur in this system. These results further indicate that frequencies of transfer of engineered plant DNA to bacteria are likely to be negligible.

• Asian Journal of Turfgrass Science
• /
• v.24 no.1
• /
• pp.16-23
• /
• 2010

Mowing is an important practice in golf course management. Mowing interval and height can affect net photosynthesis of turfgrass and finally shoot density, tillering, rooting and regrowth of turfgrass. The objectives of this study were to investigate the regrowth rate of zoysiagrass shoot under different mowing height for determination of proper mowing frequency. Recommended mowing interval were calculated by a rule that no more than 33% of the above ground height be removed in a single mowing. Daily shoot growth of zoysiagrass at 10 mm mowing height were 2.1~4.7 mm (July), 1.9~2.9 mm (August), 0.9~1.5 mm (September), and 0.6 mm (October). These results indicate that recommended mowing interval were 1.1~2.3 day for July, 1.7~2.4 day for August, 3.5~5.4 day for September, and 8.5 day for October, respectively. Daily shoot growth of zoysiagrass at 15 to 17 mm mowing height were 4.0~5.3 mm (July), 2.9~4.5 mm (August), 1.4~3.7 mm (September), and 1.3 mm (October). These results indicate that recommended mowing interval were 1.4~1.9 day for July, 1.7~2.5 day for August, 2.3~6.3 day for September, and 6.8 day for October, respectively. Daily shoot growth of zoysiagrass at 18 to 21 mm mowing height were 3.5~4.7 mm (July), 2.9~4.9 mm (August), and 1.5~1.8 mm (September). These results indicate that recommended mowing interval were 1.9~2.6 day for July, 1.8~3.1 day for August, and 5.9~7.0 day for September, respectively. Daily shoot growth of zoysiagrass at 50 mm mowing height were 4.6~4.9 mm (July), 5.0~6.5 mm (August), and 2.5~4.7 mm (September). These results indicate that recommended mowing interval were 5.1~5.4 day for July, 3.9~5.0 day for August, and 5.3~9.8 day for September, respectively.

• Proceedings of the Korean Society of Plant Biotechnology Conference
• /
• 2005.11a
• /
• pp.348-348
• /
• 2005

• Weed & Turfgrass Science
• /
• v.4 no.4
• /
• pp.360-367
• /
• 2015

This study was performed to determine the effects of silicon on zoysiagrass after the application of drought stress. The daily amount of water or scilicon solution was 150 ml per a pot. For 14 days, plants were treated with 0.1 and 1.0 mM silicon (Si) and with distilled water for control and the drought only-treatment. Afterward, the plants in Si and drought treatment were exposed to a 21-day under drought stress condition but the plants in control received water. The results indicated that the growth and the moisture and chlorophyll contents decreased in the drought only-treatment and 0.1 mM Si compared to the control. However, 1.0 mM Si showed an increase in the growth with a significant increase of water and chlorophyll contents. The MDA and $H_2O_2$ concentrations and electrolyte leakage decreased, while the radical scavenging capacity increased in 1.0 mM Si. 1.0 mM Si showed little to no differences in the growth and no differences in water and chlorophyll contents, electrolyte leakage, MDA and $H_2O_2$ concentrations and antioxidant capacity compared to the control. These results suggested that application of silicon is useful for drought tolerance improvement of zoysiagrass under drought that is occurring in turf fields.

• Weed & Turfgrass Science
• /
• v.6 no.2
• /
• pp.130-135
• /
• 2017

In the current study, we surveyed the status of graveyard lawn maintenance in Korea. The lawn maintenance information was obtained from the vicarious companies registered on the internet portal site and the Forestry Federation of Korea, and the questionnaire investigation from Primary Agricultural Cooperatives (Nonghyup). In all provinces surveyed, individual graves were maintained on a $66m^2$ (20 Pyeong) basis. The vicarious maintenance of graveyard lawn was carried out 1~5 times a year, and the maintenance cost increased as the number of times increased. Mowing the grass around a grave (Beolcho) was mainly done before the Korean Thanksgiving Day (Chuseok). The number of Beolcho was steadily increased from 2013 to 2015, and the price was getting higher and higher. Gyeonggi province had the highest cost, and Jeolla had the lowest cost. Regardless of the year, the number of orders received were higher in Gyeongnam > Gyeongbuk > Jeonnam province in order. Most of the reason for requested Beolcho was because the client lives in the area far from the graveyard. The direction of the cemetery was very varied. According to the survey, the all grass were zoysiagrass (Zoysia japonica), and grass coverage rate of the graves was 35.4~71.9%. Through questionnaire investigation, the reason why the density of grass was lowered was because the periodic management of weeds and fallen leaves was insufficient. Further research on the maintenance of graveyard in the future will be necessary.