• Journal of Korean Society of Forest Science
• /
• v.12 no.1
• /
• pp.1-11
• /
• 1971

The present study was carried out in order to investigate seasonal variation in tannin, sugar and protein contents of persimmon fruits, Five varieties of Diospyros kaki Thunberg, i. e, Buyoo, Wolha, Kapjubackmok, Pyungmuhek, Heuksi, and Goyom (Diospyros Lotus Linne var. typica Makino) growing in Jeonbug area were used as the experimental material. The result are summarized as follow; 1. Maximum tannin contents were 4% in Buyoo, 5.46% in Wolha, 5.4l% in Kapjubackmok, 5.1 % in Pyungmuhek, 9.2% in Heuksi, and 26.1% in Goyom, respectively. Therefore, Heuksi and Goyom were considered to be the most useful as tannin material. 2. The most suitable season for tannin extraction was thought to be July with most varieties but it was August with Goyom. 3. The total sugar contents seemed to increse linearly. Linear regressions are as follows. Buyoo ; $\hat{Y}=0.2394x+3.861$ Wolha ; $\hat{Y}=0.3093x-1.148$ Kapjubackmok ; $\hat{Y}=0.3173x-1.3708$ Pyungmuhek ; $\hat{Y}=0.2796x+0.982$ Heuksi ; $\hat{Y}=0.3233x-3.242$ Goyom ; $\hat{Y}=0.1555x-4.780$ 4. Average crude protein contents of fruits through the year were 5.32% in Buyoo, 4.97% in Kapjubackmok, 4.49% in Goyom, 4.11% in Wolha, 4.02% in Heuksi, and 3.6% in Pyungmuhek, respectively. 5. The crude protein contents tend to decrease gradually after fruit setting.

• Journal of the Korean Wood Science and Technology
• /
• v.2 no.2
• /
• pp.8-12
• /
• 1974

1. If one unity is given to the prongs whose ends touch each other for estimating the internal stresses occuring in it, the internal stresses which are developed in the open prongs can be evaluated by the ratio to the unity. In accordance with the above statement, an equation was derived as follows. For employing this equation, the prongs should be made as shown in Fig. I, and be measured A and B' as indicated in Fig. l. A more precise value will result as the angle (J becomes smaller. $CH=\frac{(A-B') (4W+A) (4W-A)}{2A[(2W+(A-B')][2W-(A-B')]}{\times}100%$ where A is thickness of the prong, B' is the distance between the two prongs shown in Fig. 1 and CH is the value of internal stress expressed by percentage. It precision is not required, the equation can be simplified as follows. $CH=\frac{A-B'}{A}{\times}200%$ 2. Under scheduled drying condition III the kiln, when the weight of a sample board is constant, the moisture content of the shell of a sample board in the case of a normal casehardening is lower than that of the equilibrium moisture content which is indicated by the Forest Products Laboratory, U. S. Department of Agriculture. This result is usually true, especially in a thin sample board. A thick unseasoned or reverse casehardened sample does not follow in the above statement. 3. The results in the comparison of drying rate with five different kinds of wood given in Table 1 show that the these drying rates, i.e., the quantity of water evaporated from the surface area of I centimeter square per hour, are graded by the order of their magnitude as follows. (1) Ginkgo biloba Linne (2) Diospyros Kaki Thumberg. (3) Pinus densiflora Sieb. et Zucc. (4) Larix kaempheri Sargent (5) Castanea crenata Sieb. et Zucc. It is shown, for example, that at the moisture content of 20 percent the highest value revealed by the Ginkgo biloba is in the order of 3.8 times as great as that for Castanea crenata Sieb. & Zucc. which has the lowest value. Especially below the moisture content of 26 percent, the drying rate, i.e., the function of moisture content in percentage, is represented by the linear equation. All of these linear equations are highly significant in testing the confficient of X i. e., moisture content in percentage. In the Table 2, the symbols are expressed as follows; Y is the quantity of water evaporated from the surface area of 1 centimeter square per hour, and X is the moisture content of the percentage. The drying rate is plotted against the moisture content of the percentage as in Fig. 2. 4. One hundred times the ratio(P%) of the number of samples occuring in the CH 4 class (from 76 to 100% of CH ratio) within the total number of saplmes tested to those of the total which underlie the given SR ratio is measured in Table 3. (The 9% indicated above is assumed as the danger probability in percentage). In summarizing above results, the conclusion is in Table 4. NOTE: In Table 4, the column numbers such as 1. 2 and 3 imply as follows, respectively. 1) The minimum SR ratio which does not reveal the CH 4, class is indicated as in the column 1. 2) The extent of SR ratio which is confined in the safety allowance of 30 percent is shown in the column 2. 3) The lowest limitation of SR ratio which gives the most danger probability of 100 percent is shown in column 3. In analyzing above results, it is clear that chestnut and larch easly form internal stress in comparison with persimmon and pine. However, in considering the fact that the revers, casehardening occured in fir and ginkgo, under the same drying condition with the others, it is deduced that fir and ginkgo form normal casehardening with difficulty in comparison with the other species tested. 5. All kinds of drying defects except casehardening are developed when the internal stresses are in excess of the ultimate strength of material in the case of long-lime loading. Under the drying condition at temperature of $170^{\circ}F$ and the lower humidity. the drying defects are not so severe. However, under the same conditions at $200^{\circ}F$, the lower humidity and not end coated, all sample boards develop severe drying defects. Especially the chestnut was very prone to form the drying defects such as casehardening and splitting.

• Horticultural Science & Technology
• /
• v.19 no.4
• /
• pp.535-539
• /
• 2001

To establish the cultural practices of persimmon in heated plastic house, the growth and flower bud differentiation of 4-year old 'Nishimurawase' persimmon tree planted in 80 L pots were investigated. Temperature was kept at above $18^{\circ}C$. The earlier heating induced the earlier flower bud differentiation, while the number of days from bud burst to flower bud differentiation was 70-75 days, which was not affected by the date of heating. The date of flower bud differentiation in 'Nishimurawase' persimmon was May 1, May 21, and June 1 in the plastic house heated from Jan. 15, Feb. 15, and Mar. 15, respectively. The number of flower primordia per bud in the plastic house was 6.2-7.1, slightly fewer than that of 7.8 in the open-field, with the tendency of increasing the number by earlier heating. The days required for the differentiation of the last flower bud primordia from the beginning of differentiation of the first bud were 40-60, and that required for the flower bud differentiation of all buds on the same shoot was 30. The total carbohydrates in shoot increased and the contents of nitrogen decreased, resulting in increased C/N ratio just before flower bud differentiation, and it coincided with the time when the total carbohydates increased above 15%. During two weeks before flower bud differentiaton, The contents of zeatin per 1 g dry matter of shoot drastically increased from $27.2{\mu}g$ to $47.3{\mu}g$, while that of IAA slightly decreased from $188.6{\mu}g$ to $172.4{\mu}g$, and that of GA decreased from $2,225{\mu}g$ to $1,555{\mu}g$.

• The Korean Journal of Pesticide Science
• /
• v.19 no.3
• /
• pp.272-278
• /
• 2015

Colletotrichum gloeosporioides is one of the most serious pathogens of persimmon in Korea. In 2013, 67 isolates of C. gloeosporioides were isolated from infected fruits, leaf and twigs of persimmon (Diosprosi kaki) at Sangju, Gyeongsangbukdo and fungal responses against five fungicides (prochloraz manganese complex, tebuconazole, mancozeb+myclobutanil, fluquinconazole+prochloraz, and tebuconazole+tolyfluanid) were evaluated by their growth on the fungicide-medium. All isolates were inhibited mycelium growth on the medium with each recommended application concentration of flied. $EC_{50}$ (${\mu}g/ml$) of tebuconazole was from 0.02 to 1.04 and average was 0.31. $EC_{50}$ (${\mu}g/ml$) of prochloraz manganese complex was 0.02~0.23 average was 0.078. Average $EC_{50}$ values (${\mu}g/ml$) of Fluquinconazole+Prochloraz (FP) was 0.029. On the basis $EC_{50}$ (${\mu}g/ml$), the correlation coefficient (r) between tebuconazole and prochloraz manganese complex, prochloraz manganese complex and FP, tebuconazole and FP were 0.42, 0.44 and 0.27, respectively.

• Korean Journal of Agricultural Science
• /
• v.13 no.1
• /
• pp.44-51
• /
• 1986

A total number of 916 fruiting bodies of Ganoderma lucidum (Fr.) Karsten grown naturally in Korea were collected to investigate the morphological characters and some other useful characters related to the quality of the fungus and the results obtained are summarized as follows; The host tree showing the highest parasitic rate by the Genoderma lucidum(Fr.) Karsten was oak tree and the parasitic rate of the tree was 86.2%. The order of parasitic rate of the host trees by the fungus next to the oak was peach, chestnut, persimmon and acasia. The size, shape and color of fruiting bodies were varied according to the host trees. The average size of fruiting bodies collected was 40 to 100 mm by 30 to 80mm. The fruiting bodies with pileus size of 60 by 45 mm, pileus thickness of over 10mm, pileus minor axis/stipe length ratio of over 0.65 and pileus thickness/pileus minor axis ratio of over 0.22 were considered having higher commerical values. The external shape of the fruiting body was very important criterion to evaluate the quality of the Ganoderma lucidum (Fr.) Karsten. A great variation in characters such as pileus shape, color, marginal shape, zonation of pileus, pileus thickness, poroid layer of fruiting bodies and shape of stipe were observed from the fruiting bodies of G. lucidum collected in Korea. Further studies will be necessary for the genetic nature of these characters.

• Korean Journal of Environment and Ecology
• /
• v.16 no.1
• /
• pp.10-21
• /
• 2002

This study was intended to investigate injury rates of landscape trees planted in the reclaimed seaside areas and to analyse their causes in planting environment. The planting environment such as soil properties, reclaimed depth of soil, soil hardness, salt consistency of soil, and drainage system were surveyed in 8 reclaimed seaside areas in the middle and southern regions of the country. Injury rates of 42 species, 1,233 trees and growth of branches in 6 species. 130 trees were measured and analysed to fond out salt-resistant trees in the reclaimed lands. The results of the survey are as follows; the average injury rate of evergreen trees was 32%. which was much lower than that of deciduous trees as 52%. The lower injured trees in the 8 reclaimed lands were Pinus thunbergii, Pinus parvinora. Juniperus chinensis 'Kaizuka', Pinus koraiensis, Acer trifdum, Koelreuteria paniculata and Metasequoia glyptostroboides. The higher injured trees were Acer palmatum, Magnolia kobus. Lagerstroemia indica, Diospiros kaki, Cercidiphyllum japonicum, Sorbus commixta, Prunus yedoensis, Pinus desinora, Chaenomeles sinensis, Albizzia julibrissin and Zelkowa serrata. At least the mounding of 1.7m depth of soil is needed from the tidal saline soil to the roots of trees to protect trees from salt injury Roots of trees were found to have infiltrated to 0.77m under the soil of which solidity was over 4.5kg/㎥. And 22 of total 25 soils were acid from pH 3.72 to pH 5.85. Injury rate of trees was much higher when they were detached from the sea, and planted on the drainage.

• Korean Journal of Environment and Ecology
• /
• v.11 no.1
• /
• pp.46-60
• /
• 1997

The purposes of this research are to select the appropriate kinds of landscape woody plants for afforestation artificial ground and to find out the way of developing planting-tree area of artificial ground through test planting and case study. The summary of the research is as follows; As a result of observing the state of trees' growth, trees on artificial grounds grow as well as, or even better than those on natural grounds. The kinds of trees which represent better growth states on artificial soil of rooftop test area are Thuja occidentalis, Prunus armericana var. ausu, Acer palmatum, Viburnum sargentii for. sterile, Buxus microphylla var. koreana, etc. In addition, soils than on natural soils. As a result of investigating the tree's growth state according to soil beds of artificial soils, shrubs don't represent distinct differences. They show that shrubs can be planted on 30cm soil bed. The rest of trees no differences according to the variation of soil beds, and they are in normal condition or have slight damage. This means that though arbor planting area of artificial ground is made 45~60cm, it is possible for trees to grow on it. In consequence of analyzing the cases on areas of landscaping artificial grounds, as the appropriate kinds of trees for afforestation artificial ground, Diospyros kaki, Hibiscus syriacus, Syringa dilatata, Magnolia kobus, Acer ginnala and cornus alba are selected in Capital region, and Nandina domestica, Taxus cuspidata, Ilex crenata, Viburnum awabuki, Aucuba japonica and Euonymus japonica are selected in southern region. In addition, Juniperus chinensis, Zelkova serrata, Juniperus chinensis var. kaizuka, etc. are selected regardless of regional character. In accordance with the state of soil it shows great difference, namely, fertilization once or more a year and irrigation for drought is advantageous to tree's growth. This research represents that it is necessary that standards related to landscaping artificial grounds are subdivided. In addition to it, the plan for revising related to regulation is drawn up.

• Horticultural Science & Technology
• /
• v.29 no.4
• /
• pp.306-310
• /
• 2011

This study examined the changes in the distribution of nitrogenous compounds in various parts of 3- and 4-year-old persimmon (Diospyros kaki cv. Fuyu) with fruits (fruited) and without fruits (defruited). The effect of the changes was then related to the storage and their reutilization for new growth in the following year. From June 15 to November 1, the partitioning of amino acids among perennial parts of fruited trees was inconsistent, whereas that of defruited trees was characterized by a significant increase. Compared with the fruited trees, amino acids accumulated in the perennial parts of defruited trees were 1.66 g and 3.48 g more in 3- and 4-year-old trees, respectively. Of the total proteins increased during this period, the proportions distributed to the perennial parts of the tree were less than 50% for fruited trees, but they were more than 90% for defruited trees. Roots were the strongest sink for proteins; percent proteins in the roots amounted to 94 in defruited 3-year-old trees and 76 in 4-year-old trees. Compared with the proteins accumulated in perennial parts of fruited trees, those of defruited trees were 1.64 g more in 3-year-old and 2.58 g more in 4-year-old trees. During this period, the nitrogenous compounds decreased by 0.50-0.56 g in the leaves of fruited trees, while they increased by 0.66-0.78 g in their fruits. During the new growth from April 10 to June 10 of the following year, amino acids decreased both in the fruited and defruited trees. Proteins, especially in the root, decreased in the trees that had been previously defruited. More amino acids and proteins were found in the newly grown parts of the defruited trees. Compared with the fruited trees, the defruited trees accumulated nitrogenous compounds more in roots than in the other parts of the perennial parts. The reserve nitrogenous compounds contributed to the new shoot growth and fruit set in the following year.

• Research in Plant Disease
• /
• v.10 no.4
• /
• pp.209-216
• /
• 2004

The circular leaf spot of persimmon is occurred almost every place where persimmon is cultivated, especially the disease outbreak severely in southern part of Korea. The disease reveals unusually long incubation period after pathogen invade into leaf tissue and no practical control measure is available once the symptom has appeared. Most of the farmers just follow the suggested spray schedules calculated on the basis of weather condition of ordinary years. Therefore the damages due to circular leaf spot greatly differ year after year. In this article, we tried to describe and summarized the investigation on the circular leaf spot pathogen, Mycosphaerella nawae, related to disease outbreak such as overwintering of pathogen, inoculum formation and spread, incubation period after infection, and secondary inoculum. With the summary of these results, we suggest the disease cycle of circular leaf spot of persimmon. The pathogen overwinters in diseased leaves as mycelial form or pseudoperithecial premodium. The pseudoperitheria become matured in spring as the temperature raise and forms asci and ascospores. The maturation of pseudoperithecia are closely related to the temperatures during March and early April. The ascospores completely mature in early May and the ascospores released when the pseudoperithecia absorbed enough moisture after rainfall. The release of ascospores are diverse greatly with the variation of maturity of pseudoperithecia. Generally the spore start to release from middle of May to early of July. Duration of ascospore release is depend on the weather condition of particular year, especially amount and number of precipitation. The ascospores produced from pseudoperithecia is known to the only inoculum for circular leaf spot disease. But according to the results obtained from our investigations, the conidia formed on the lesions which incited by natural infection. This conidia are infectious to persimmon leaves and formed identical symptom as natural infection. The time of producing secondary inoculum of circular leaf spot of persimmon is considered too late to develop new disease. Generally the importance of secondary inoculum is low but the conidia produced in early September are competent to develop new disease and new infection also significantly affect to harvest of persimmon. The importance of circular leaf spot disease is recognized well to farmers. The approaches to control of the disease should be initiated on the basis of the knowledges of inoculum dynamics and ecology of disease development. The forecasting system for circular leaf spot is need to be developed.

• Research in Plant Disease
• /
• v.10 no.4
• /
• pp.272-278
• /
• 2004

The disease development of Anthracnose of sweet persimmon in relation to release of conida of Colletotrichum gloeosporioides were observed in a farmer's field located in Jinju from 1998 to 2002. The conidia started to release from early April and reached maximum in June to late July. The amount of conidia production reduced drastically from early August. The number of conidia trapped was closely related to amount of precipitation at the same period and number of new infections on the emerging branches and young fruits in orchard. The conidia released during the April was not effected to disease occurrence of persimmon tree but the spores produced from inoculum source after early May significantly important to the infection of the pathogen on emerging branch and this infection was directly related to infections on young fruits. Consequently the early infections on the branches brought severe occurrence of Anthracnose in the orchard. Most of the infected fruits were dropped in unripe state. The earlier infection caused the earlier fruit drop. The rate of fruit drop was reached up to 84.1% in August when the disease was occurred severely. Anthracnose of sweet persimmon also occurred in market shelf and storage warehouse. The anthracnose fruits are presumed to be infected while in orchard. Because the symptom formed on the fruit was too tiny to eliminate, the infected fruits were involved in storage boxes and anthracnose gradually developed in storage condition. The rate of diseased fruit observed in Jinju area were 1.2 to 1.6%.