Eun-Ji Bae

Effect of Growth and Nitrogen Use Efficiency by Application of Mixed Silicate and Nitrogen Fertilizer on Zoysiagrass Cultivation

This study was conducted to investigate the effect of silicate mixed with nitrogen fertilizer on improving the growth and reducing nitrogen input of zoysiagrass. Plant height, fresh and dry weight of shoots, roots, and stolons, the number of shoots and total of stolons length were increased with highest in silicate mixed with nitrogen 24 kg/10a than nitrogen 24 kg/10a, and it showed no significance in silicate mixed with nitrogen 18 kg/10a. Nitrogen use efficiency in mixed silicate fertilizer was increased by 25-30% than single nitrogen fertilization. Moreover, the contents of available SiO₂, and organic matters of silicate fertilization on soil was higher than not silicate fertilization on soil. The silicate enhanced the growth and density of zoysiagrass, while it was a crucial factor to affect the chemical property of the soil.

Growth and Contents of Inorganic Nutrient during Cultivation of Zoysiagrass

This research will be utilized as a base line data by researching on growth and the accumulation of inorganic nutrients during the cultivation period of zoysiagrass and also to establish a cultivation strategy of zoysiagrass. It involves the management such as fertilizer and mowing which ultimately led to the difference of growth and accumulation of inorganic nutrients. The accumulation of inorganic nutrients after mowing, the amount of accumulation was small when compared to the amount lost for the shoot, rhizome and root. Difference in the accumulation of inorganic nutrients, but as for K, Ca and Mg accumulation it shows similar aspects to N accumulation. The orders of inorganic nutrients in zoysiagrass were N > K > P > Ca > Mg. The characteristics of inorganic nutrients absorption of such zoysiagrass acts as the foundation of cultivation, and in the aspect of making decisions on the fertilization amount and soil management, it is closely related to the requirement on nutrients. In order to increase the productivity based on the zoysiagrasss growth and density rate improvement, accumulation of inorganic nutrients per growth period needs to be analyzed, and supplying nutrients in an efficient method suitable to the growth period is advisable, so such basic research was necessary.

Morphological Variation and Characteristics of Native Medium-Leaf Type Zoysiagrasses (Zoysia spp.) by Site Environment

It is important for genetic resources to collect and identify in native medium-leaf type zoysiagrasses species distributed in Korea. This study was conducted to investigate morphological variation and characteristics of native medium-leaf type zoysiagrasses from coastal, island and inland regions in Korea. Among them, 75 collected lines was confirmed to have various morphological variations, accessions were classified into 2 main based group coastal and inland regions by morphological characteristics and site environment. Group I included Z. sinica type, this group showed 3.7 mm in leaf width, 29 in number of seed per spikelet and 5.0 mm in seed length. Group II included Z. japonica type, this group showed 4.4 mm in leaf width, 42 in number of seed per spikelet and 3.5 mm in seed length. There is a need for additional research on growth characteristics and the molecular level for the introgressive hybridization between species which confirmed that cross-pollination is possible due to protogyny. The individuals showing variations should be preserved as valuable genetic resources for the expansion of variations in zoysiagrasses, and the results of this investigation on the genetic resources collected will be highly valuable in breeding high quality turfgrass.

Evaluating Pre-silicon Treatment to Alleviate Drought Stress and Increases Antioxidative Activity in Zoysia japonica

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 H₂O₂ 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 H₂O₂ 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.

Turfgrass Probiotics Reduce Population of Large Patch Pathogen and Improve Growth of Zoysiagrass

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.

Damage of Zoysiagrass Mite, Aceria zoysiae on Different Species and Individuals of Turfgrass from Korea with Reference to Turfgrass Genetic Resources Conservation Area

Damage of Zoysiagrass Mite, Aceria zoysiae on Different Species and Individuals of Turfgrass from Korea with Reference to Turfgrass Genetic Resources Conservation Area Jong Ju Kim1, Chae Min Lee2, Young Hack Chung3, Eun-Ji Bae4, Gwang Soo Lee4, Ho Yul Choo1, Byungduk Jeon5, and Dong Woon Lee6* Department of Applied Biology, Gyeongsang National University, Jinju 52828, Korea Korea Forestry Promotion Institute, Daejeon 35209, Korea SM Bio Co, Jinju 52828, Korea Southern Forest Resource Research Center, Korea Forestry Research Institute, Jinju, 52817, Korea Department of Physical Education Leisure, Suseong College, Daegu 42078, Korea Major of Applied Biology, School of Ecological Environment and Tourism, Kyungpook National University, Sangju 37224, Korea

Physiological Characteristics and Growth Performances of Container-grown Seedlings of Broad-leaved Evergreen Cinnamomum yabunikkei and Neolitsea sericea with Different Fertilization Levels

The purpose of this study was to identify optimum fertilization technology for Neolitsea sericea and Cinnamomum yabunikkei, which are major species of broad-leaved afforestation trees. Depending on the treatment of water soluble fertilizers (N:P:K = 19:19:19, v/v/v), changes in root collar diameter, plant height, dry weight, and seedling quality index were measured as growth characteristics and changes in photochemical efficienty and chlorophyll content as physiological characteristics. After analyzing growth characteristics the highest root diameter and plant height growth were observed in 1.5 gL concentration in the case of N. sericea, and 1.0 g・L -1 in the case of C. yabunikkei. The H/D ratios in these fertilizer concentrations showed 7.0 cm・mm -1 for N. sericea and 9.3 cm・mm -1 for C. yabunikkei, which were significantly higher than any other concentrations. N. sericea and C. yabunikkei had high total dry weight, 5.92 g in the 1.5 g・L -1 treated area, and 6.01 g in the 1.0 g・L -1 treated area, respectively. The T/R ratio and seedling quality index were also significantly higher in the fertilization treatment area of high dry weight. As a result of analysis of physiological characteristics the photochemical efficiency and chlorophyll content were lower than those of healthy leaves in both species, with high values of 1.5 g・L -1 in the case of N. sericea, and 1.0 g・L -1 in the case of C. yabunikkei. According to the overall results of this study, the optimum fertilization level varies depending on the nutritional needs of respective species, and the fertilizer application rates of water soluble fertilizer suitable for the production of 2-year-old containerized seedling of N. sericea and C. yabunikkei were 1.5 g・L -1 and 1.0 g・L -1 , respectively. However, it is difficult to predict the adaptation characteristics of the trees to long-term changes when using fertilizers, because this study is the analysis of the short term responses from 2 year old young seedlings. In addition, they are cultivated in greenhouses or nursery field; in this case, it is believed to be necessary to study the response of trees to rapid changes of future climate. Additionally, since the response to fertilizer concentration varies greatly depending on the tree species, it is necessary to continuously study major tree species in Korea and other species that are sensitive to climate changes.

Improvement of Growth and Soil Environment by Topdressing and Tillage in Zoysiagrass (Zoysia japonica) Cultivation Field

To establish the soil management system for the efficient sod production, survey on the growth of zoysiagrass by different soil managements was conducted in repeated cultivation field with regard to soil physical properties. Soils were subjected to four types of management methods, which include ① rolling ② topdressing ③ topdressing + rolling ④ topdressing + tillage + rolling. The topdressing + tillage + rolling treatment significantly ameliorated soil physical properties such as bulk density, porosity and solid phase as compared to rolling and topdressing + rolling treatments, and was not significantly different from the topdressing treatment. Further growth and density of zoysiagrass except for the root dry weight in topdressing + tillage + rolling treatment were significantly higher than that only in rolling treatment. Topdressing + tillage + rolling treatment significantly increased the number of shoot as compared to the other treatments. Therefore, combined topdressing and tillage soil management practice should be conducted for the production of zoysiagrass in repeated cultivation field.

Seed Yields and Germination Rates of Native Ecotype Collections for the Development of High-Yield Seeded Variety of Zoysiagrass in Korea

Seed Yields and Germination Rates of Native Ecotype Collections for the Development of High-Yield Seeded Variety of Zoysiagrass in Korea Eun-Ji Bae, Jeong-Ji Han, Su-Min Choi, Kwang-Soo Lee, Yong-Bae Park, Geun-Mo Yang, and Joon-Soo Choi * Southern Forest Resources Research Center, National Institute of Forest Science, Jinju 52817, Korea Department of Green Landscape Architecture Science, Dankook Univ., Cheonan 31116, Korea

Damage Report on a Newly Recorded Coleopteran Pest, Aphanisticus congener (Coleoptera: Buprestidae) from Turfgrass in Korea

Aphanisticus congener is a newly recorded buprestid (Coleoptera) insect pest of turfgrass in Korea. This buprestid pest was initially found from turfgrass conservation site in a greenhouse in Jinju, Gyeongnam province, Korea in July, 2014. The Aphanisticus in the family Buprestidae is a leaf miner. A. congener is the close species of A. aeneus which was firstly reported as sugarcane leaf sucker in India. A. congener was active from early July to late August in the greenhouse. Damage by the insect led to drying out and browning of turfgrass leaf because larva fed on cell sap of leaves and adult fed on leaf surface. A. congener damaged Zoysia japonica, Z. sinica, Conodon dactylon, and Poa pratensis when adults were artificially released into potted turfgrasses in the laboratory. In green house, A. congener damaged Z. japonica, Z. macrostachya, Z. matrella, Z. sinica, Conodon dactylon, and hybrid zoysiagrass. However, no damage symptoms were observed from the same turfgrass accessions in the nearby field of the greenhouse. Thus, the new coleopteran pest may be a warm-adapted pest for turfgrass, damaging turfgrass leaf only in warmer conditions.