• Journal of Sericultural and Entomological Science
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• v.13 no.2
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• pp.81-94
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• 1971

This research is conducted to study the effect to rebbuding, death atop, yielding and occurrence of twig blight disease with the interemediate cutting periods of mulberry branch and at the picking levels of leaf remains in autumn. The results obtained are as follows: 1. Re-budding branches are decreased with delaying of interval cutting period, and that more leaves remained lesser both re-budding branches and buds are observed. Therefore, it is better that leaves remained are placed on the upper part of branch, practically with 3-5 leaf remains. It has decreased re-budding branches, in case cutting is conducted in Sept. 20 with picking leaving 3-5 leaf on. 2. With regard that all picking increases the percentage of death atop of the branch and upper half part picking increases slightly over the other treats. Although it seems unlikely to be different in the other treats with cutting period, exception of all picking, it is elucidated better that the all picking after cutting in Sept. 15 represents unusually high, seemingly effected by the temperature contition preferable to the life of twig blight disease along with the lack of branch nutrition caused by the all picking. 3. In view of yielding, it has no difference in autumn yielding with cutting period, but more picking levels of leaf remains, more yielding. In spring yield, both no picking and all picking is the lowest, in spite of cutting period. Each treat produces high yielding except the no picking if rutting is done in Sept. 15 and Sept. 20, respectively; otherwise it is done earlier or later, each treat produces low yielding. It is suggested that yielding ability in following spring affected by the autumn picking because all picking treats represent lower yielding ability than no picking ones except of cutting in Sept. 15 and Sept. 20. With respect to total yield in spring and autumn, it is represented that other treats, among which cutting in Sept. 15 and Sept. 20 is especially high, produce higher yielding than both no picking and all picking. But no difference seemed in leaf remained treats. In these respects, it may be concluded that 3-5 leaf remains after the interval cutting in Sept. 15 to Sept. 20 increases the yielding throughout two seasons and it is suggested that 3-5 leaf remains after cutting in Sept. 5 to Sept. 10 has no difference with no picking and cutting after that day. 4. Diseases in the branch remained are twig blight, massaria-bye, and Die-back, of which twig blight attacks tremendously and slight ouurence in messaria-byo and Die-back. In ouurence of twig blight, it is appeared much in all picking and seasonal occurence high in Sept. 15 with 92.9, and in Sept. 30 with 100 as index, respectively. Also it occurs ,considerably in upper part picking but little occurrence in no picing. 5. It is considered that negative correlation among re-budding percentage. No. of re-budding leaf, and spring yielding is found, seemingly without heavy correlation at -0.42, and -0.27, respectively. However, death atop of branch and occurence of twig blight has little correlation with spring yield. On the other hand, positive correlation highly appeared with the correlation coefficient at 0.8 between occurence of twig blight and death atop of branch.

• Korean Journal of Soil Science and Fertilizer
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• v.46 no.1
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• pp.53-57
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• 2013

A severe defoliation by typhoon in early autumn reduces fruit quality for the current season and reserve accumulations for the next season. This study was conducted to determine the effects of foliar applications during the autumn on alleviating the damages after defoliation. Leaves of 2-year-old 'Fuyu' trees, grown in 50-L pots under a rain-shelter, were 75%-defoliated on September 9. In mid-September and early October, trees were treated either with eight foliar applications of urea or with four alternating applications of urea and $KH_2PO_4$ (urea + KP application), all at 0.5% (w/v). Trees untreated after the defoliation served as the control. The urea applications slightly increased N and P concentrations of the leaves collected on November 6, while urea + KP applications significantly increased P and K concentrations. Foliar applications did not affect fruit growth, but tended to decrease skin coloration. Fruit soluble solids increased by 1.5 and $1.0^{\circ}Brix$ for urea and urea + KP applications, respectively. There was a significant increase in dry weight of fine root for the foliar application treatments but not in those of aerial woods and larger roots. With the foliar applications, N concentration tended to increase in the permanent organs but not P and K, whereas soluble sugars and starch notably increased in shoot, trunk, or fine root regardless of the different applications. Results indicated that the foliar applications could partially help to restore fruit quality and carbohydrate accumulations in the defoliated trees.

• Korean Journal of Plant Resources
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• v.10 no.4
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• pp.314-318
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• 1997

This experiment was carried out to analyze the essential oils from different parts of Perilla frutescens spp. And to know change of the oil content by a diffenent leaf picking time. The analysis of the essential oils was done with gas chromatography(GC),and the results are as follows. Perilla frutescens spp. contained essential oils mostly in their leaves and stems, although their roots also contained the oils. It was suggested that the optimum leaf-picking time of perilla frutescens var. viridis Mak. on the basis of total essential oils was their flowering period around Aug. 24, and that of Perilla frutescens var. for acuta Kudo was Sep. 14. On the basis of perillaldegyde the optium leaf-picking time of Perilla frutescens var. viridis Mak. and Perilla frutescens var. acuta Kudo was Aug. 24. and Aug. 4. respectively.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.4
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• pp.324-329
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• 1993

Effects of leaf and pod removal on changes in leaf and seed number, and leaf, seed, pod and stem dry weight of soybean [Glycine max (L,) Merr.] cultivar ‘Hwangkeumkong’ were measured at the research farm of Korea University in 1992. The upper 40% and lower 60% of leaves and pods were subjected to treatments at the growth stage of beginning pod(R3). Leaf number and dry weight of lower part were increased by upper leaf-lower pod removal, but seed number and dry weight were decreased. Upper leaf-lower pod removal increased lower stem dry weight and decreased upper pod dry weight. Leaf-seed ratio of the upper leaf-lower pod removal was the highest with 3.54 and harvest index was the lowest with 27% among the treatments. Lower leaf-upper pod removal showed that more assimilates from upper leaves were translocated to lower seeds than from lower leaves to upper seeds in upper leaf-lower pod removal treatment.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.5
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• pp.377-382
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• 1993

Effects of leaf and pod removal on changes in dry weight and on the contents of soluble sugar, starch, protein and oil in leaves and seeds of soybean [Glycine max(L.) Merr.] cultivar ‘Hwangkeumkong’ were measured at the research farm of Korea University in 1992. The upper 40% and lower 60% of leaves and pods were subjected to treatments at the growth stage of beginning pod(R3). Upper leaf-lower pod removal showed the highest leaf and the lowest seed dry weights. Soluble sugar content was no different among treatments in leaves and seeds. The highest starch content was found in leaves of upper leaf-lower pod removal. Protein content was higher in lower leaves than upper leaves and the lowest in seeds of lower leaf-upper pod removal which had the highest oil content in leaves and seeds. These results apparently indicated that photoassimilates were mobilized from upper leaves to lower seeds, and protein sources were moved from lower to upper parts but weak in remobilization from leaves for the long distance translocation during the reproductive growth period.

• Korean journal of applied entomology
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• v.31 no.2
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• pp.174-181
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• 1992

Early, mid, and late maturing soybean varieties were artificially infested with larvae of Delia platura at seeding, and then later development and productivity of soybeans were studied. In addition, in hope to utilize as possible tactics in the management of D. platura in soybeans, cultural factors such as contents of organic matter in soil, soil types, and the use of plastic mulching on the degree of damage to soybean plants by D. platura were examined. Primary leaf damage by the larva delayed the forthcoming vegetative growth but not the blooming which is initiated by the change in day length. Degree of delay in growth was more severe where leaf damage was induced by insect infestation than where artificially excised, apparently owing to simultaneous damage in stems and roots besides primary leaves. Productivity of soybeans also dropped significantly in plants with 25 % or more loss in the primary leaf area by the larva. Both transparent and black plastic mulchings shortened the period from seeding to emergence of soybean thus reducing the chance of possible attack by the larva. Soybean seedlings grown in clay loam or clay were attacked less by the larva than those in other types of soil. High organic matter content in the soil enhanced speed of emergence resulting in less larval damage to the seedling.

• Journal of Environmental Science International
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• v.29 no.3
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• pp.219-228
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• 2020

The purpose of this study was to investigate the effects of defoliation treatment on the growth and yield of strawberries. There was a remarkable growth in the above-ground part and root of untreated strawberry plants possibly due to higher amount of photosynthesis, while overall plant growth was suppressed as the level of defoliation treatment increased. In both the "Seolhyang" and "Maehyang" cultivars examined, defoliation treatment resulted in small fruits and a low number of fruits per plant. Notably, 50% defoliation significantly reduced the number of fruits per plant to 8.2, compared to 13.8 in untreated plants. Defoliation treatment also negatively influenced the fruit quality including color, sugar content, and solid-acid rate. However, no significant changes in fruit firmness was observed in either cultivar. Therefore, retaining enough leaves without defoliation treatment can be important to increasing fruit yield, producing high quality fruits and saving labor required for defoliation.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.21 no.2
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• pp.258-268
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• 1976

This study was conducted in order to know the ecology and to establish the control method of Potamogeton distinctus A. BENN. The tubers of Bog pond weed was almostly located at soil depth of 10 cm to 20cm, germination rates and number of formed tubers were different according to transplanting depth of soil. Effects of herbicides application on weeds were different according to leaf-stage of pondweed, and the pondweed were withered to death by absorption of Avirosan into the leaves. It was suitable to keep water depth at 3cm level until about a week after Avirosan application.

• Korean Journal of Agricultural Science
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• v.18 no.1
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• pp.1-9
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• 1991

This experiment was aimed to develop possible methods to control the maturity of grape berries through the application of exogenous plant growth substances and physical treatments such as defoliation or girdling. 1. Chlormequat and paclobutrazol increased anthocyanin but did not affect soluble solids contents and maturity. Girdling enhanced maturation and solids accumulation whereas defoliation delayed maturity. Solids content of berries in defoliation treatment did not reach to the level of other treatments even when fully ripened. 2. Ripening of grapes is greatly delayed for 20 to 30 days by the application of auxins (2,4-D and fenoprop) compared to the untreated control. Uneven ripening of berries in those clusters was observed when the concentration of auxin was over 50 ppm. Thus, about 30% of berries remained green until the normal berries were overripened. 3. Gibberellin did not affect the maturity of grape berries but maturity was greatly delayed when GA was applied with auxins. Also, uneven coloration between berries was observed such as in the application of auxin alone. 4. Ethephon application combinded with calcium at veraison showed no effect on berry ripening but increased anthocaynin contents. It can be concluded that harvest time of 'Campbell Early' grapes can be effectively extended by delaying the maturity through the application of auxin.

• Journal of Bio-Environment Control
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• v.23 no.4
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• pp.309-313
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• 2014

This research was conducted to establish recommendable side shoot management methods in the growth and yield of tomato in winter. A cherry tomato, $^{\circ}{\times}Unicorn^{\circ}{\pm}$ (Monsanto Korea, Korea) was cultivated in coconut coir in the form of bag as substrate. There were four treatments related to side shoot removal methods; 1) To remove all side shoots and also each one of three leaves which gives shade to each cluster attached below (UP-FL), 2) To remove all side shoots and also each one of three leaves which gives shade to each cluster only with fruit attached below (UP-FR), 3) To remove all side shoots (AS-All), and 4) To remain two leaves of each side shoot coming from right below each cluster (AS-Part). The number of malformed leaves were more in UP-FL, UP-FR, AS-All, and AS-Part in descending order, which showed the severe the removal of leaves the more the malformed leaves. The malformed leaves were diminished after the development stage the second or third cluster bloomed. The yields until fifth cluster were not different among the treatments. Therefore removal of side shoots and leaves recommends not to be done severely in early growth stage when tomato plants are cultivated in winter.