• Journal of Bio-Environment Control
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• v.20 no.1
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• pp.45-49
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• 2011

This research was carried out to investigate frost damage of mulberry tree (Morus alba) according to topographic characteristics in Buan province. The first bud-break, leafing, blooming and harvest date of mulberry tree in 2010 were two, four, fourteen and eight days later than those in 2009, respectively. These results were that daily mean temperature during March and April in 2010 were lower than those in 2009 by $2.3^{\circ}C$ and $2.4^{\circ}C$. Frost damage of orchards at flat-bottomed valley, flat near hill and lake, and plain were 50.0%,12.0%, and 4.2%, respectively. Also, frost damage of branch of below 15 mm in diameter was serious than that of branch over 16 mm, but orchard at flat-bottomed valley was high as the range of 46.2~54.0%. These results in 2010 were caused by occurrence of below zero temperatures in leafing stage. Since then, many shoots came out at accessary bud on proximal and the top part of the branches. Therefore, frost damage of mulberry tree in Buan province in 2010 was caused by occurrence of below zero temperatures on April and topographic characteristics of orchard.

• Journal of Sericultural and Entomological Science
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• v.28 no.2
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• pp.1-8
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• 1986

This study was conducted to bring light on inducing factors for non-sprouting occured in the mulberry field of Kyungpook Province in 1983. The results are as follws ; 1. In spring, winter buds were suddenly died during germination, necrosis appeared in pholem and cortex of non-sprouting stem and measles at the bottom of non-sprouting stem. 2. The depth of available of soil was more shallow in the non-sproutiong field than in healthy field. 3. There was no signifioant difference between the healthy field and non-sprouting field in siol PH, the content of organic matter, available phosphorous and exchangeble cations. 4. Available boron content in soil was significantly more in healthy field than in non-sprouting field. 5. Boron content in leaf and bark was significantly lower in the non-sproutiong tree than in the healthy tree. 6. The non-sprouting fields were completely controlled by the application of 6kg/10a borax. 7. Cold tolerance of the mulberry tree was higher in the mulberry tree with boron than in the mulberry tree without boron. 8. Mulberry tree in Kyungpook Province in 1983 may absorb water earlier compared with the average year because of high temperature at the end of March, 1983 and they had been damaged by frost injuary due to the lowest temperature (-6.4$^{\circ}C$) on the grass at the beginning of April 1983. As the above results, non-sprouting bud in the mulberry fields of Kyungpook Province in 1983 had been occured by low temperature and boron deficiency and boron deficiency of mulberry trees accelerared the frost injury.

• Journal of Sericultural and Entomological Science
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• v.52 no.1
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• pp.52-58
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• 2014

We analyzed rutin content using mulberry genetic resources. They were grown under the same environment and conditions. Mulberry leaves were collected and then freeze-dried and powdered for rutin test. As a result, mean content of mulberry strains was $0.52{\pm}0.25%$, and the coefficient of variation (CV) was 47.9%. The variation between the strains was greatly severe. Among the tested strains, 'Buyoungsang' was showed the highest content of 1.37%, whereas 'Cheongeunsipmunja' and 'Mujeonsipmunja' were showed the lowest content of 0.06% respectively. The content of rutin of 16 mulberry varieties for silkworm rearing were compared. 'Cheongolppong' was showed the highest content of 0.69%, whereas 'Cheongilppong' was showed the lowest content of 0.14 %. Finally we selected rutin high-containing 9 strains. They are as follows. 'Buyoungsang', 'Yeulbon', 'Dangsang 5', 'A8', 'Aja', 'Seongsu 5', 'Sawonppong 12', 'Hwanyoupjosaengnosang' and 'Hwansipjosaeng' which are more than twice of the overall average content.

• Korean journal of applied entomology
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• v.32 no.3
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• pp.338-347
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• 1993

The study was to investigate the bionomics, host plants, and oviposition preference of Hishimonus sellatus Uhler. It has 5 generations under natural conditions and the peak of the 3rd generation was observed about mid and late August. Its average developmental durations were 80 days in spring, 69 days in summer, and 77.8 days in autumn. The lengths of each stage were 0.8mm in eggs, 0.9mm in 1st instar, 1.4mm in 2nd instar, 2.1mm in 3rd instar, 2.5mm in 4th instar, 3.2mm in 5th instar, 4.1mm in female, and 3.8mm in male. Hishimonus sellatus overwintered as egg in Morus alba, Humulus japonicus, and Zizyphus jujuba begining mid October, and attacked the shoot of M. alba and H. japonicus about mid and late May, migrated to the Zizyphus jujuba from late June to early July. Female oviposites 32~62 eggs into epidermis of shoot, vagina and vein during their life. The preferred host plants of H. sellatus were Humulus japonicus, Morus alba, Zizyphus jujuba, and ligustrum obtusifolium. Highly preferable oviposition site was H. japonicus, M. albal, Z. jujuba, and L. obtusifolium, etc. On audlt longevity, the host plants as H. japonicus, M. alba, and Z. jujuba were 43$\pm$2 days and A. brevipedenculata, C. mimosoides, L. obtusifolium, V. rosa, A. sinicus and, A. graveolens were more than 25 days, and other host plants were less than 20 days.

• Korean journal of applied entomology
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• v.44 no.3 s.140
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• pp.231-235
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• 2005

This study was conducted to obtain the optimal spray time for Pseudaulacaspis prunicota (Maskell) (Homoptera: Diaspididae) in early seaon in Jeju. Oviposition time of overwintered females and activity of hatched nymphs of P. prunicola were monitored, and the phenology data were compared with the outputs estimated by a degree-days model of P. pentagona (Targioni-Tozzetti)). Overwintered females of P. prunicola began to lay eggs from mid to late April, and the eggs started to hatch from early May followed by the active migration of the hatched nymphs during mid May. The phenological events of P. prunicola in early season were likely comparable with those of P. pentagona reported in southern Korea and in central Japan. A degree-day model, which predicts the proportion of >50% hatched egg batches of P. pentagona (y=1[exp(-(-a+bx))]; y, proportion; x, degree-days based on $10.5^{\circ}C$ from 1 January; a=-18.80 and b=0.073), accurately described the migration time of P. prunicola hatched nymphs. Thus, it is considered that the degree-day model can be used for predicting the optimal spray time for P. prunicola in early season.

• Journal of Sericultural and Entomological Science
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• v.45 no.2
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• pp.80-84
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• 2003

The component and content of free sugar in mulberry fruits were evaluated. In all accessions, fructose and glucose were identified as the major free sugar. The ratio of two components appeared in the same level. But CV (coefficient of variation. ％) of fructose and glucose were 23.6％, 23.4％, respectively. It might suggest that varietal variation exists in sugar contents. The mean of total free sugars were 9.11${\pm}$2.14％. Among the tested 49 accessions, ‘Geunanosang’ showed the highest total free sugars in 14.67％, whereas ‘Cheongsipyung’ showed the lowest total free sugars in 5.57％. Also fruity characteristics as well as total free sugars to select the desirable mulberry varieties for the production of fruit were researched and analyzed. From that results, four suitable varieties such as ‘Hwansipchosaeng’, ‘Junggojo’, ‘ Kaery-angchosaengsipmunja’, and ‘Geunanosang’ were selected.

• Journal of Sericultural and Entomological Science
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• v.45 no.2
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• pp.75-79
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• 2003

Fatty acids analysis was carried out with mulberry seed. As a result, palmitic acid, stearic acid, oleic cid and linoleic acid were detected as a major fatty acid. Their rates of composition were 8.8${\pm}$3.3, 4.2${\pm}$1.6, 5.8${\pm}$2.3 and 81.2${\pm}$6.9(％), respectively. The unsaturated fatty acids such as oleic acid and linoleic acid were abundant in mulberry seed. Paticularly, five accessions including ‘Gukkwang’, ‘Jaelaenosang’, ‘Sangbansibmunja (Jeonnam) ’, ‘Neunggeum’ and ‘Suwonnosang’ were observed only with linoleic acid. Unsaturated fatty acids are known to have physiological effects decreasing the serum cholesterol. From the above result, we confirm that mulberry fruits have abundant unsaturated fatty acids and anthocyanin pigments, and they are of great value as functional food resources.

• Korean Journal of Medicinal Crop Science
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• v.13 no.6
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• pp.217-225
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• 2005

This study was carried out to investigate the genotoxicity in comet and in vitro micronucleus assay and mutagenicity in Ames test of the extracts from leaves and stem of Morus alba L. The samples showed a very weak cytotoxicity on the NIH/3T3 cells by SRB assay. The cell viability of the extracts and fractions from leaves and stems of Morus alba L. was 80% over at $500\;{\mu}g/ml$, and that of the chloroform fractions from leaves and stems showed lower than others. The genotoxicity at $250\;{\mu}g/ml$ of 100% EtOH and water extracts on the NIH/3T3 cells in comet assay was about 40% compared to positive control, and most fractions from 100% EtOH extract of the leaves showed stronger genotoxicity than that offractions from the stem. The genotoxicity with S-9 mix in vitro micronucleus assay of the 100% EtOH and water extracts form Morus alba L. did not indicate any significant difference as compared with control group. The cytokinesis-binucleated cells were showed in the hexan, chloroform, ethylacetate and butanol fractions from the extract of the leaves without S-9, and sample with S-9 showed CB cells in the chloroform fraction from the leaves. In the Ames test, the water and 100% ethanol extracts of Morus alba L. did not have a strong mutagenicity in TA98 and TA100, but the fractions of organic solvents of the ethanol extract had $10{\sim}26%$ of mutagenicity on the TA100 strain.

• Journal of Sericultural and Entomological Science
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• v.18 no.1
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• pp.1-5
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• 1976

This work was carried out to investigate how the effects on the growth af branches and the yield of mulberry leaves are shown, when two of each dwarf and normal branches are thinned out in sumner or early autumn. The results obtained are summarized as follows. 1) In mulberry trees after spring pruning: in case of thin out branches in summer and harvest in autumn (42 days after treatment), (1) The average length of branches in thin out trees showed 19% increase by autumn, which turned out to be 11% higher than that of non-thin out did (8%) (2) The thin out treated mulberry trees presented 9% increase in total yields of summer and autumn, when compared with those of the non-thin out trees. 2) In mulberry trees after sumner pruning: in case of thin out branches in early autumn and harvest either in autumn (15 days after treatment) or in late autumn (28 days after treatment), (1) The average length of branches showed about 6∼7% and 8%, intercase by autumn and late autumn, respectively. Thus no effects of thin out treatment could be recognized in growing of branches. (2) The thin out treated mulberry trees presented about 6% increase in total yields of early autumn, showing no significance through, when compared with those of ron-thin out treatment. Whereas the total yields of early autumn and late autumn showed 12% increase with significance at the level of 5% by thin out treatment. (3) As above mentioned, the thin out of mulberry branches brought about a good effect on yields of mulberry leaves, though less on average length of branches. It may be considered that the thin out treatment makes improve the living condition in mulberry trees and in turn induces photosynthesis actively, which results in increase the weight of leaves.

• Korean journal of applied entomology
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• v.58 no.4
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• pp.335-339
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• 2019

The white peach scale (Pseudaulacaspis pentagona) is a significant pest of trees belonging to the Rosaceae family. We investigated the effect of ten insecticides on hatching rate of first instar white peach scale larvae (crawlers). The insecticides are Dinotefuran WG, Benfuracarb WG, Pyrifluquinazon WG, Clothianidin SG, Buprofezin WP, Buprofezin+Imidacloprid SC, Buprofezin+Etofenprox WG, Buprofezin+Thiacloprid SC, Benfuracarb+Buprofezin WG, Acetamiprid+Buprofezin EC. We observed that several crawlers emerged in early May, with the average number being 45.7. Hatching period was approximately 14 days, and the hatching success rate was approximately 77.7%. Overwintering females produced an average of 58.7 eggs. All insecticides achieved 100% mortality in crawlers. Our results suggest that these insecticides can effectively control white peach scale when used at the crawler stage.