• Asian Journal of Turfgrass Science
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• v.25 no.2
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• pp.138-146
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• 2011

This study was carried out to select salt tolerant zoysiagrass breeding lines. Eighty two native zoysiagrasses collected from S. Korea were used in this study. Saline water were prepared by mixing sea water and tap water. ECw levels of saline water treated ranged from 2 to $3dS{\cdot}m^{-1}$. Zoysiagrass planted in pot by sprigging were soaked into the plastic box containing saline water. Winter injury was investigated under the pot condition. Most of Z. japonica types did not show winter injury. But Z. tenuifolia type, Z. matrella type, and Z. sinica type showed winter injury under the pot condition at Cheonan area. NaCl level in soil was increased from 0% to 0.51% by treatment of saline water. Soil ECe measurement showed upto $170dS{\cdot}m^{-1}$. Z. tenuifolia type (Z5034), Z. matrella type ('Konhee', Z4109, 'Semill'), Z. japonica type (Z1055, Z1040, Z1008, 'Zenith', 'Millock') and medium leaf type zoysiagrass (Z6096, Z6118, Z6021, Z6074) resulted in below 30% leaf firing under the saline condition. This approach might be useful for selecting salt tolerant breeding lines.

• Korean Journal of Environment and Ecology
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• v.28 no.2
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• pp.113-122
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• 2014

This study was conducted to clarify the community characteristics of wintering waterbirds in Geum River from September, 2011 to March, 2012 (1st) and from September, 2012 to March, 2013 (2nd). 63 species of waterbirds including raptors were observed during the survey. 50 species of 188,673 individuals recorded during the first survey, and 56 species of 116,611 individuals were recorded during the second survey. The dominant species was high dominance dabbling ducks by Baikal Teals, Mallards, Spot-billed Ducks, Greater White-fronted Geese, Black-tailed Gulls and Common Shelducks. We classified the wintering waterbirds into 9 taxa based on the similar ecological characteristics and analyzed the correlation with temperature. As a result, dabbling ducks, diving ducks and raptors showed positive correlation and herons and waders showed negative correlation. Geese, swans and dabbling ducks were high habitat utilization ratio at the Geumgang estuary barrage upstream area, and diving ducks, herons, waders and gulls were high habitat utilization ratio at the Geumgang estuary barrage downstream area.

• Journal of The Korean Society of Grassland and Forage Science
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• v.35 no.1
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• pp.36-42
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• 2015

This study was conducted from 2013 to 2014 to explore the feasibility of the cultivation of warm-season grass as an annual Korean forage crop, while concurrently evaluating the characteristics and forage production of warm-season grass in Korea. The experimental design was a randomized block design (RBD) with three replications. Five bermudagrass [Cynodon dactylon (L.) Pers.] cultivars, two teffgrass (Paspalum notatum Flugge) cultivars, and a Kleingrass [Panicum coloratum L.] cultivar were compared for forage production and quality in the middle region of Korea. After seeding, the numbers of days until seedling emergence for bermudagrass and kleingrass were observed at approximately day 11 and day 12, respectively. The heading dates of teffgrass and kleingrass were on July 12 and July 26, respectively. The dry matter (DM) yield of bermudagrass Tifton 85 was usually greater than the other entries. The crude protein content (CPC) and total digestibility nutrient (TDN) for the teffgrass cultivars were usually greater than the other entries at all study sites. The acid detergent fiber (ADF) and in vitro DM digestibility (IVDMD) were similar across all cultivars.

• Korean journal of applied entomology
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• v.26 no.2 s.71
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• pp.99-106
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• 1987

Three post-harvest fields each in four rice growing areas, Iri, Naju, Jinju and Taegu were randomly selected and surveyed during December 1986 to examine sclerotial density of Rhizoctonia solani overwintering in the field. Surface soil of $0.09m^2$ area was sampled in each field with three replications and sieved to collect sclerotia. Germiability and pathogenicity of collected sclerotia were examined in the laboratory. Number of sclerotia $({\times}10^6)/ha$ in Iri, Naju, Jinju, and Taegu was estimated from the sample as 2.7, 1.2, 0.7 and 0.6, respectively. Based on sample variance with simple random sampling in each area, number of sampling required for estimating average sclerotial density with the precision of 10% apart from a chance of 1 in 20 was calculated to 41, 132, 232, and 395 for Iri, Naju, Jinju and Taegu, respectively. Percentage of germination of sampled sclerotia on potato sucrose agar (PSA) ranged from 42 to 78% depending on the area, and averaged 60%. About 49% of the germinated sclerotia were pathogenic to a rice cultivar Jinheung that was used to test pathogenicity of the sclerotia. Proportion of viable sclerotia that have both germiability and pathogenicity was thus estimated to 0.29 of total sclerotia collected. R. solani cultures obtained from the sclerotia could be distinguished into three groups based on colony morphology on PSA. Size and number of sclerotia formed on PSA differed between group but were not associated with pathogenicity to Jinheung.

• Journal of the Korean Society of International Agriculture
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• v.23 no.5
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• pp.491-496
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• 2011

Breeding for pear resistance to pear psylla (Cacopsylla pyricola) is one of important objective of the National Institute of Horticultural and Herbal Science breeding program. One hundred thirty three accessions from 15 Asian, Chinese and European pear species were investigated for their resistance against pear psylla. The pear psylla resistance was determined based on the following four characteristics: overwintering adult population, the number of eggs and nymphs, and the degree of soot. The different pear species showed varied resistance to pear psylla. Pyrus calleryana and P. betulaefolia indicated the highest antixenosis as ovipositional preference and antibiosis as nymphal feeding and were the most resistant genetic resources. Likewise the European pears (P. communis), 'Conference' and 'Cascade', exhibited little occurrence and damage by pear psylla. These were proved to be promising genetic materials for breeding resistant cultivars because they had good fruit quality and showed resistance to pear paylla. The observed population of overwintering adult, the number of eggs and nymphs of psylla had significant correlation each other.

• Research in Plant Disease
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• v.10 no.3
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• pp.188-193
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• 2004

The symptom expressions such as yellowish and mosaic spots in overwintering barley have been considered to be a damage by cold or water. However, it had revealed that the symptom expressions were caused by viruses throughout three year nationwide surveys. Barley yellow mosaic virus (BaYMV), Barley mild mosaic virus (BaMMV), and Soil-borne wheat mosaic virus (SBWMV) was detected in 2001-2003 and Barley yellow dwarf virus-MA V (BYDV -MA V) from field samples collected on March in 2003. The results of investigation showed that the incidence of BaYMV was more than 70％ and that of BaMMV and SBWMV was 15.7-37.4％ and 0.7-10.1 ％ in three year surveys, respectively. The incidence of BYDV-MAV was approximately 1 ％ in 2003 only. The distribution of BaYMV was relatively uniform throughout barley fields in Korea, but the incidence of the virus in Gyunggi Province was as low as 19％ compared to 65-85％ in the rest of regions. On the other hand, 70％ of BaMMV was found to be in the west south regions of Korea, Jeonbuk and Jeonnam Provinces. Taken together, both BaYMV and BaMMV were thought to be dominant casual agents in overwintering barley by either single or mixed infections. Previous survey data for BaYMV from 1994 to 1996 indicated that the incidence of the virus was approximately 40％ in Jeonbuk, Jeonnam, and Gyungnam Provinces. Thus, comparing with the results from the recent nationwide survey, the incidence of BaYMV had been rapidly increasing in overwintering barley fields in the southern part of Korea.

• Journal of The Korean Society of Grassland and Forage Science
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• v.38 no.4
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• pp.217-223
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• 2018

This study was conducted to investigate the effect of seeding dates on grassland productivity and botanical composition in oversown hilly pasture located in Pyeongchang of South Korea. Four treatment groups were established based on the seeding dates of grass mixture: T1, August 13; T2, August 27; T3, September 10; and T4, September 24. Evaluation of seasonal changes in grass botanical composition revealed the highest ratios of grass in T1 and T2 (81-100% grass) and the lowest in T4 (46-90 % grass). In the plant length, the first harvest time was longer than other cutting times and last harvest time was the lowest. The total dry matter yield of grass was highest in T2 ($9,042kg\;ha^{-1}$) and T1 ($8,845kg\;ha^{-1}$) and lowest in T4 ($5,086kg\;ha^{-1}$). The findings of the present study suggest that seeding by late August provide the most desirable results for vegetation and grassland productivity in oversown hilly pasture, Pyeongchang of South Korea.

• Korean journal of applied entomology
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• v.52 no.4
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• pp.371-377
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• 2013

Occurrence of adult alfalfa weevil, Hypera postica Gyllenhal, was observed at Chinese milk vetch field, and host plant preference of its $1^{st}$ generation adult was observed at greenhouse and Chinese milk vetch field. The over-wintered adult of the weevil appeared from late March and peaked in mid April while the $1^{st}$ generation adult appeared from late April and peaked in late May. However, the occurrence of over-wintered adult was very low contrary to the $1^{st}$ generation adult which was very high with some variations among observed years. In greenhouse, host plant preference of $1^{st}$ adult generation of H. postica was evaluated with 11 different seedlings. H. postica was found to occur in significantly higher number on Chinese cabbage seedling followed by soybean, and kale at 7 days after releasing(DAR). Corn, crown daisy and sorghum were found to be the least preferred with nil occurrence of the weevil. Seedlings damage rate by H. postica feeding at 7DAR was the most severe on Chinese cabbage(60.0%) followed by soybean(50.0%), kale(30.0%), foxtail millet(16.7%), proso millet(13.3%) and lettuce(3.3%) significantly. Also, seedlings damage rate by H. postica at 7DAR in Chinese milk vetch field had shown the similar trend with Chinese cabbage(46.7%), soybean(43.3%), kale(23.3%), foxtail millet(13.3%) and proso millet(13.3%) in greenhouse significantly. Accordingly, results on host plant preference of H. postica from this study can be used as a basic information for safe cultivation of upland crops at near or around green manure crop field.

• Korean journal of applied entomology
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• v.47 no.1
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• pp.51-57
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• 2008

This study demonstrates a variability in efficacy of mating disruption against the oriental fruit moth, Grapholita molesta, populations infesting apples cultivated in differential environmental conditions. Throughout the growing seasons, trap catches of G. molesta male moths and damaged leaf and fruit were examined to evaluate the efficacy of a commercialized mating disruptor. Treatment of the mating disruptor significantly reduced the trap catches of male moth in treated plot, compared to those of the untreated plot. This reduced trap catches were significantly correlated with leaf and fruit damage. Moreover, the highest host damage occurred in June just after the highest overwintering adult peaks in both plots. The treatment of mating disruptors in Chungsong effectively disrupted the overwintering population in April and May, resulting in no noticeable host damage during the following growing seasons. However, there was a marked difference in host damage between two plots, especially in late seasons. Variation in the efficacy of mating disruption technology in terms of host damage appeared to be related with nearby pheromone-untreated orchards, which may result in the immigration of gravid females.

• Journal of The Korean Society of Grassland and Forage Science
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• v.30 no.3
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• pp.217-226
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• 2010

The purpose of this study was to suggest the growth characteristics, seasonal distribution and botanical composition of wildflower pastures. The experimental wildflowers were 34 species (1 turfgrass species, 4 native wildflower species and 29 introduced wildflower species). The experiment was administered in the Chungnam National University experimental field from October, 2007 to December, 2009 and the result is as follows: The length of the wildflowers was within the range of 7-52 cm and they bloomed into six to ten colors but the species of blooming wildflowers and flower colors and blooming periods were simplified during from August to November. Their tendencies were obviously observed two years later (2009) but among them especially the colors, seasonal anthesis distribution and continuation of wildflower became a problem. The botanical composition of wildflowers, turfgrass, and weeds came to 20%, 67%, and 13% each one year later (2008) and two years later (2009) 16%, 72%, and 12% each. Being grounded upon this result, in case of wildflower pastures of autumn seeding, it is more important to maintain the color, seasonal distribution, and permanence of wildflowers occurring due to annual wildflower reduction after wintering in two years, let alone in the establishment year.