• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.2
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• pp.67-72
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• 2005

Overwintering capacity, closely related to winter hardiness, of Chinese milk vetch planted with different sowing times and sowing practices was investigated to improve the incorporation into cropping system in Korea. The tolerance to low temperature was evaluated with $LT_50$ using leaf disc leaching method. Dry weight of CMV was reduced remarkably with delayed planting from Sep. 5 to Oct. 20. The differences in tolerance to freezing temperature were not conspicuous among CMV genotypes, however, the differences between genotype (collections at different regions) were due to the plant architecture, mainly to the leaf angle. The crouching genotype collected at central region of Korean peninsula, which showed excellent freezing tolerant, has planophile leaves. The feature of internal constituents of CMV genotypes did not show any noticeable differences with respect to the freezing tolerance which evaluated by leaf disc leaching experiment. To overcome the poor overwintering capacity, tolerant genotype should be developed by selection with considering the plant architecture. The reduction of CMV growth during overwintering period was ameliorated with furrow-sowing under late-sown condition, therefore, when the CMV is inevitably sown late after recommended time, the seeds should be sown on furrow to overcome the cold stress.

• Proceedings of the Korean Society of Crop Science Conference
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• 2000.04a
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• pp.88-89
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• 2000

• Korean Journal of Environmental Biology
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• v.33 no.1
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• pp.53-62
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• 2015

We surveyed butterfly community in a rural area of the southwestern part of Korea to investigate the changes of species composition and their abundances between 2001~2002 and 2014. The butterfly survey was conducted at the same site using a line transect method. There was a significant decrease of the numbers of species and individuals between 2001~2002 and 2014. We categorized each species based on six ecological traits: habitat type, habitat breadth, food plant type, food plant breadth, number of generation per year and overwintering stage. The comparison of number of species using these ecological traits showed no difference during the 10-yr time intervals. However, the comparison of number of individuals for the ecological traits showed the significant differences except for one trait, overwintering stage. We could suspect that the decrease of butterflies in the study area was resulted from the habitat change. To investigate the causal factors and the changes of butterfly fauna, we need a long-term monitoring of the local butterfly community.

• Korean Journal of Agricultural Science
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• v.47 no.3
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• pp.625-632
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• 2020

This test was conducted to determine the appropriate conditions of temperature, storage period, and soil moisture content when using cold storage of potted mother plants of as a means of sufficient dormant breaking and safe overwintering of the strawberry (Fragaria × ananassa Duch. cv. Sulhyang) mother plants. In the treatment by temperature for the dormant breaking of strawberry mother plants, the survival rate of natural overwintering was 91%, whereas the survival rate was 100% at 0, - 2, and - 5℃. As the storage temperature was decreased, the plant height of the mother plants became shorter which tended to decrease after planting. Survival of the mother plants was possible at - 5℃, but after planting, the growth and number of daughter plants decreased significantly. The number of daughter plants was highest at 22.8 per plant at - 2℃ storage. The strawberry mother plants could be stored for up to 8 months in cold storage. However, when the mother plants were stored for a long period, the number of daughter plants was small. When they were stored for 4 months, the growth of the mother plants was vigorous, and the number of runners and daughter plants was high. When the water content of the soil was less than 10 percent (%, w/w) in the cold storage of the pot, the survival rate was 85 percent, which was high due to the dryness. The survival rate was 100 percent at 30 and above, and the growth of the mother plants after planting and the number of daughter plants were high at 30 to 50.

• Research in Plant Disease
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• v.13 no.2
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• pp.98-103
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• 2007

Grapevines will experience various types of winter damage. Some winter damages are caused by mechanical injury, freezing temperatures or poor vine vigor. This research was conducted to find out the appropriate control methods through selection of resistant rootstocks and improvement of overwintering methods for the control of crown gall disease on 'Kyoho' grape. The crown gall symptoms were not found when three stock plants of grapevine SO4, 5BB and 3306 were inoculated with $10^4cfu/ml$ of Agrobacterium vitis strains (YK2823, YK3312, LMG259, HKA234). But when they were inoculated with higher concentration $(10^6 cfu/ml)$ of A. vitis, irrespective of stocks plants, crown galls were formed all of them and the gall size was much smaller than that of kyoho. Three stock plants were selected as resistant based on above mentioned. Covering trunks and branches with rice straw and insulating coverlet was the most effective method for prevention of crown gall disease. This treatment minimized the ambient temperature changes on grapevine trees during winter season to $9.6^{\circ}C$ and the normal plant growth was due to the absence of freezing injury.

• Korean Journal of Medicinal Crop Science
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• v.13 no.6
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• pp.287-292
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• 2005

To investigate the effects of heat conservation materials on freeze damage and weed occurrence during overwintering in Saururus chinensis, Temperature difference was $6.9^{\circ}C$ in chaff, and was lower than those ranged from 9.7 to $14.4^{\circ}C$ in other materials. Heat conservation index, calculated from average temperatures below $-10^{\circ}C$ of earth's surface during the winter, was higher $1.7^{\circ}C\;and\;1.5^{\circ}C$ in chaff and lagging, respectively than in straw. Preservation of water is greater $9.6{\sim}26.1%$ in covering than in open field, and it increased in the order of lagging > chaff > straw among heat conservation materials. The survival rate of rhizome was increased in the order of 99% in lagging > 75% in chaff > 58% in straw, 32% in open field after overwintering, budbreak began fast, and the numbers of total budbreak per unit area were greater 22 times in lagging than 35.0 units in open field. Weeds occurrence was decreased in covering, i.e., $12.0{\sim}33.2\;units/m^2,\;7.3{\sim}10.7\;kg/10a$ of dry weight, and $5.6{\sim}6.4\;hours/10a$ of labor input compared with $157.2\;units/m^2,\;28.9\;kg/10a$ of dry weight, and 65.7 hours/10a of labor input in open field. Growth of top part was better in covering than in open field, and the number of tillers per unit area showed $347{\sim}396$ compared with 293 in open field. Marketable yields of dried stem and leaves and rhizome were higher $69{\sim}87%\;and\;58{\sim}88%$, respectively in covering than in open field, and among heat conservation materials, those were highest in lagging.

• Journal of Wetlands Research
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• v.14 no.4
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• pp.687-698
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• 2012

This study was conducted to monitor and prevent outbreak of insect pestsin dredged soil dumping area after completion of dredging construction in Masan City. Monitoring was carried out using tent trap, colored sticky trap, and CDC light trap. A total of 217,073 individuals belonging to 23 species from 10 families in 3 orders were collected. In overwintering survey using tent trap, 3 species were collected. 2 species (Leptocera fuscipennis (Haliday) and Ephydra japonica Miyagi) of them were outbreak species. In color sticky trap, more than 96% of total individuals were comprised of five species: Urolepis maritima Walker (43%), E. japonica (19%), Fucellia sp. 1 (13%), Philotelma sp. 1 (10%), and Homalometopus sp. 1 (9%). In CDC light trap, three dominant species were Homalometopus sp. 1 (91%), Glyptotendipes tokunagai Sasa (6%), and L. fuscipennis (1%), representing about 98% of the total. To prevent damage caused by outbreak of insect pests, we carried out ecological control methods such as covering the fresh soil in outbreak area, using light trap, pumping up water and so on, minimizing use of thermal fogging and insect growth regulatorwhen the insect pest population was rapidly increasing.

• Korean journal of applied entomology
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• v.59 no.2
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• pp.133-138
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• 2020

In 2016, the two-spotted cricket was approved as a general food ingredient by the Korean Ministry of Food and Drug Safety. Additionally, the two-spotted crickets have high protein content (60%) and can be reared throughout the year even during the overwintering period. In this study, storage conditions were set in case cricket breeding was not possible due to problems such as breeding space and labor costs, and selection oviposition mats to determine high fecundity rates and low cannibalism rates for the eggs were investigated. The oviposition mat was mostly composed of soil (p < 0.05). Less than 62 crickets per 10 litters were found to be best suited for 1 day of spawning, based on the cannibalism rate of the eggs during the egg laying period. The results from the hatched eggs indicated that the hatching extended 12 to 14 days, and the best hatching rate was approximately 85% when stored at low temperatures(16℃) for 10 days. An efficient production proposed method that established the best oviposition mat and egg storage method for the cricket.

• Korean Journal of Agricultural and Forest Meteorology
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• v.11 no.4
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• pp.221-232
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• 2009

The geographical distribution of freeze risk determines the latitudinal and altitudinal limits and the maximum acreage suitable for fruit production. Any changes in its pattern can affect the policy for climate change adaptation in fruit industry. High-definition digital maps for such applications are not available yet due to uncertainty in the combined responses of temperature and dormancy depth under the future climate scenarios. We applied an empirical freeze risk index, which was derived from the combination of the dormancy depth and threshold temperature inducing freeze damage to dormant buds of 'Changhowon Hwangdo' peach trees, to the high-definition digital climate maps prepared for the current (1971-2000), the near future (2011-2040) and the far future (2071-2100) climate scenarios. According to the geospatial analysis at a landscape scale, both the safe and risky areas will be expanded in the future and some of the major peach cultivation areas may encounter difficulty in safe overwintering due to weakening cold tolerance resulting from insufficient chilling. Our test of this method for the two counties representing the major peach cultivation areas in South Korea demonstrated that the migration of risky areas could be detected at a sub-grid scale. The method presented in this study can contribute significantly to climate change adaptation planning in agriculture as a decision aids tool.

• Horticultural Science & Technology
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• v.16 no.4
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• pp.517-519
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• 1998

This experiment was carried out to find out the effects of heat conservation materials (burying in soil, lagging, lagging +straw, nonwoven fabric, nonwoven fabric+straw) on freezing damage, labor saving, and crown gall occurrence of 'Kyoho' grapes. Temperature differences in burying in soil and lagging with $2.8^{\circ}C$ and $6.4^{\circ}C$, respectively and were considered favorable for over-wintering of grapevines. Heat conservation index in lagging +straw and burying in soil calculated from degree-hours below $-10^{\circ}C$ was 5 to 7 times higher than that of open field. Budbreak started earlier in lagging with+straw and nonwoven fabric+straw covering, and percent budbreak was increased by 22% and 7%, respectively, as well as higher than burying in soil. Diameter of bearing mother branch and length of internode and daughter branch were gross or long with soil and lagging straw and nonwoven fabric+straw. Cane growth was enhanced by burying in soil and lagging with+straw treatment. Crown gall occured higher in soil covered grape vines Labor saving was obtained in lagging with as much as 44% compared to burying in soil.