Journal of the Japanese Society for Horticultural Science
Online ISSN : 1880-358X
Print ISSN : 0013-7626
ISSN-L : 0013-7626
Volume 50 , Issue 2
Showing 1-15 articles out of 15 articles from the selected issue
  • Hiroshi DAITO, Shigeto TOMINAGA, Sukeyuki ONO, Kunihisa MORINAGA
    1981 Volume 50 Issue 2 Pages 131-142
    Published: 1981
    Released: July 05, 2007
    JOURNALS FREE ACCESS
    In common Satsuma mandarin (Citrus unshiu Marc. cv. Sugiyama) trees of open center and hedgerow types, fruits at different locations within the tree canopy was examined from July to December, 1977, in order to obtain fundamental data for rationalizing the practice of tree form management such as planting system, tree form, pruning, etc., and also for improving fruit quality. Studies were also made on tree growth and yield from 1970 to 1977.
    The following results were obtained.
    1. Tree growth in trunk girth was a little better in the trees of open center type than that of hedgerow type, and tree crown enlarged progressively with years in the former while it was kept compact in the latter. Yield per tree of the open center type (which had a larger tree crown volume) was greater than that of the hedgerow type, but yield per 10a was greater for the hedgerow type because of higher planting density.
    2. In either type of tree, respiratory rate of fruits decreased rapidly from the beginning of August to the beginning of September, and thereafter increased gradually up to the end of November. Little difference was observed in the respiratory rate among the fruiting locations within the canopy, except for interior fruits, which showed lower respiratory rate during maturation.
    3. The fruits at the interior and at the top and skirt of the east and west sides were colored well, while those at the top and skirt of the north side were badly colored in the trees at open center type. In the trees of hedgerow type, the fruits at the top and skirt of the east side were well colored, but those at the interior and the top and skirt of the west side tended to have a bad color. Total carotenoid content in peel at the mature stage did not vary with fruiting locations in either type of trees.
    4. Fruit weight at the mature stage was greater at the top of each side and smaller at the interior of the tree crown. No difference in fruit weight was observed between the two types of trees and among the quadrants of the canopy. A positive correlation (significant levels; p<0.05, and p<0.01) was obtained between fruit weight and cumulative solar radiation at each fruiting location up to the end of October. No correlation could be obtained between fruit weight and air temperature or fruit temperature.
    5. In either type of trees, degrees Brix of fruit juice at mature stage differed little among fruiting locations, although it was slightly lower at the skirt and interior of the canopy. Moreover, a positive correlation (p<0.05, p<0.01) was obtained between cumulative solar radiation during the mature stage and Brix degree. Between degrees Brix and cumulative air temperature, there was a negative, but not significant correlation up to the middle of November, but there was a significant (p<0.05, p<0.01), positive correlation from the end of November to the middle of December. Between degrees Brix and cumulative fruit temperature, significant, positive correlations were often recognized up to the end of November, and at the middle of December, the correlation became stronger and the degrees Brix tended to increases with fruit temperature.
    6. The titratable acidity of fruit juice at the mature stage, did not differ among fruiting locations within the canopy except that it was lower at the interior of the tree. There was a non-significant correlation between titratable acidity and cumulative solar radiation, cumulative air temperature or cumulative fruit temperature.
    Thus, it appears that at least in the Seto Inland Sea area, fruit quality expressed by degrees Brix and titratable acidity is little affected by the variation in microclimate varying with fruiting locations within the tree canopy in either type of trees used.
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  • Hiroshi DAITO, Shigeto TOMINAGA
    1981 Volume 50 Issue 2 Pages 143-156
    Published: 1981
    Released: July 05, 2007
    JOURNALS FREE ACCESS
    In common Satsuma mandarin trees (Citrus unshiu Marc. cv. Sugiyama) of open center and hedgerow type. compositions of sugars, organic acids and amino acids in fruits at different locations within the canopy were studied during a period from July to December, 1977.
    The results are given as follows.
    1. Sugar constituents detected in the fruit juice were fructose, glucose, and sucrose, and a greater propotion of the total sugars was fructose in the early stage of the fruit growth, but it was sucrose, instead of fructose, at the end of October, regardless of fruiting locations. Glucose content was kept almost constant throughout the period of observation. There was no difference in the total sugar content among fruiting locations in either type of trees.
    2. Organic acid constituents detected in the fruit juice were, whether they may be free or in combined form, glutamic, glucuronic, pyro-glutamic, lactic, acetic, pyruvic, malic, citric, succinic, isocitric and α-ketoglutaric acids regardless of fruiting locations and in either type of trees. Citric acid was the main acid, followed by malic acid and glutamic acid, and these three acids strongly determined the fluctuation of the total organic acid content. No consistent tendency could be observed between fluctuations in the main acids or in the minor acids in fruits juice and fruiting locations within a canopy.
    3. At each fruiting location, arginine, glutamine, aspartic acid, threonine, serine, glutamic acid, proline, glycine, alanine, cystine, valine, methionine, isoleucine, leucine, tyrosine, phenylalanine, γ-aminobutyric acid, lysine, histidine, arginine and ammonia were detected in either type of trees. The content of proline increased most remarkably with maturation at each location. There was also a great but inconsistent difference in the amino acid composition among various fruiting locations.
    Thus, at least in the Seto Inland Sea area, no consistent difference in the contents and compositions of sugars, organic acids and amino acids of the fruit juice was found among fruiting locations within the tree canopy in either type of trees used.
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  • Ichiro KAJIURA
    1981 Volume 50 Issue 2 Pages 157-168
    Published: 1981
    Released: July 05, 2007
    JOURNALS FREE ACCESS
    Japanese pear (Pyrus serotina Rehder) is said to be native to Japan. So, the wide genetical variations in harvest season are expected to be observed, and in fact, cultivations and utilizations of late maturing cultivars and those for long storage were recorded in some literatures published in the Edo era (the 18th-19th century). But, nowadays, the narrow periods of fruit supply to the market (about 2.5 months in summer and autumn) and the small number of predominant cultivars (4-5) suggest outwardly that Japanese pear may have the narrow variations. So, to reveal the wide variations in native cultivars and to clarify the historical changes of cultivars from the view point of harvest season, the records of the harvest season on 374 native cultivars and 41 bred ones from four related literatures were evaluated.
    A harvest season of native cultivar was recorded as an actual time at its native provenance. Therefore, it should be necessary to modify this season into really genetical one, based on the geographical and phenological difference of the harvest season in each cultivar. The modified harvest season of each native cultivar was indicated as the harvest season of one of 41 indicator cultivars (Table 2), comparing the harvest season with those of indicators at the same provenance (Fig. 1). To express a harvest season numerically, full season was divided into 22 harvest classes(-5.0: earliest maturing, 5.5: latest maturing), which were assorted into threegroups (early maturing: -5.0--1.3, mid maturing: -1.2-2.2, late maturing: 2.3 -5.5). Ranges and distributions of harvest seasons were compared in the histogram of cultivars against these classes among three historically divided groups, A, B and C (see the foot note in Table 5) and among nine province groups of native cultivars (Table 1) classified according to their provenances (Fig.3).
    Native cultivars indicated the full genetical variations of harvest season from the end of July till the mid of November at the central Japan (Table 2). 43.2 percent of native cultivars were late maturing ones (Fig. 2). Characteristics at the Edo era were a scarcity of early maturing cultivars and an abundance of late maturing ones and those for storage. As compared with the native cultivars, chance seedlings or open pollinated seedlings, found from the late Edo era to Taisho era (1850-1925), showed the higher percentage of early maturing cultivars and the lower percentage of late maturing ones (Fig. 2). The bred ones showed the highest percentage of early maturing ones (Fig. 2). These results suggest that historical changes of cultivars in harvest season are the increase of early maturing cultivars and the decreases of late maturing ones and those for storage, and that the trend of breeding is towards the earliness in harvest season.
    The provenances of late and early maturing cultivars were apt to be situated geographically to the specific areas (Fig. 4). Late maturing cultivars were distributed mainly in Kyushu province and to the coast of the Japan Sea. Early maturing cultivars were mainly found in Kanto and Kansai provinces, and were not distributed in Kyushu province, Shikoku province and the north of Toyama prefecture.
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  • Hiroyuki SASAHARA, Kunio TADA, Masahiko IRI, Taihei TAKEZAWA, Mitsuo T ...
    1981 Volume 50 Issue 2 Pages 169-175
    Published: 1981
    Released: July 05, 2007
    JOURNALS FREE ACCESS
    Regeneration of intact plants of Zenkoji grapevine was established by meristem tip culture for the purpose of obtaining virus-free plants. Half strength Murashige and Skoog (1962) Medium supplemented with 0.1mg/liter NAA, 1.0mg/liter BA, 0.5mg/liter kinetin, 4.0mg/liter adenine, 30g/liter sucrose and 6.0g/liter agar (Medium I-2) was optimal for the greening and enlargement of inoculated meristem tips. For the subsequent growth, monstrous leaf formation and succeeding multi- shoots formation, it was necessary to substitute 0.2mg/liter IAA for 0.1mg/liter NAA (Medium II-1). The further development of shoots, opening and growth of small leaves, was better on the Medium II-1 but with BA and sucrose concentration reduced by half (Medium II-4). Rooting was induced on Galzy (1964) medium supplemented with 0.1mg/liter NAA (Medium III-1) and the further plant development was better on the same medium but without NAA (Medium III-2). Plants were easily established in soil.
    Repeated multiplication was also achieved by transplanting the fully developed shoots on a half strength MS (1962) medium supplemented with 0.2mg/liter IAA, 1.0mg/liter BA, 0.5mg/liter kinetin, 4.0mg/liter adenine, 15g/liter sucrose and 6.0 g/liter agar (Medium II-2) followed by Medium II-4.
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  • Shosaku HORIUCHI, Shoichi NAKAGAWA, Akihiro KATO
    1981 Volume 50 Issue 2 Pages 176-184
    Published: 1981
    Released: July 05, 2007
    JOURNALS FREE ACCESS
    1. Changes in the intensity of bud dormancy was investigated using cuttings taken from a vineyard or potted vine at certain intervals during autumn and winter. Bud dormancy was deep at the beginning of autumn, but the intensity gradually decreased during a period from late autumn through early winter.
    2. The state of such a dormancy was classified into three phases, i.e. conditional, spontaneous, and enforced dormancy, as proposed by Kondo.
    Spontaneous dormancy was the phase in which cuttings would not burst within 20 days at a favorable temperature, and the dormancy was deepest, the cuttings did not burst in about 70 days at such a temperature.
    Enforced dormancy was the phase following spontaneous dormancy, and the buds would not still burst in fields, while readily burst if exposed to a warm temperature.
    3. The process of the onset of dormancy differed greatly among the positions of apical buds on the shoot. The intensity of dormancy was low in the buds of shoot compared to the basal ones. The onset of breaking period coincided with the beiginning of defoliation.
    4. The starch content increased from 60 to 150mg/g•fw in shoot and from 80 to 100mg/g•fw in bud as the dormancy became deeper, while it decreased to 90 mg/g•fw in shoot and 60mg/g•fw in bud during the breaking period. On the contrary, the sugar content in both tissues was kept at a constant level (20mg/g• fw) during the period of deep dormancy, and increased up to 40mg/gfw during the breaking period.
    5. The endogenous inhibitors present in the shoots carrying dormant buds appeared in Rf 0.6-0.9 (β-inhibitor zone) when the extract from acid ethyl acetate fraction was spotted on a paper chromatogram and developed in a solvent system, isopropanol:ammonia:water=10:1:1(v/v). These substances inhibited the growth of avena coleoptile, germination of Raphanus seed, the growth of rice seedling, α-amylase activity in Avena endosperm, and germination of vine buds.
    6. This inhibitory activity was correlated to the onset or breaking of bud dormancy. When further analysed using thin-layer chromatography in four solvent systems and gas-liquid chromatography, it was clarified that ABA was contained in these inhibiting substances.
    7. Both of oxygen uptake and carbon dioxide production in vine buds gradually decreased from 300μl/g•fw/hr to 200μl/g•fw/hr during spontaneous dormancy. Respiratory activity was kept at a constant rate during the subsequent enforced dormancy.
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  • Nobutomo TAKAGI, Masayasu MORIMOTO, Toru MAOTANI
    1981 Volume 50 Issue 2 Pages 185-191
    Published: 1981
    Released: July 05, 2007
    JOURNALS FREE ACCESS
    Investigations were carried out to clarify factors influencing on the incidence of drought spot of “Muscat of Alexandria” (Vitis vinifera L.). At the same time, histochemical differences between drought spot and sun scald were studied.
    1. Large amount of irrigation caused a marked increase of drought spot. However, other factors, such as solar radiation, number of berries and leaves of the vine, and soil aeration, had no detectable influence on the incidence of this disorder. Intermittent mist could not reduce the occurrence of drought spot in spite of low WSD in the treated vines.
    2. Root pruning in summer resulted in severe water stress in the vines and showed a tendency to decrease the incidence of drought spot.
    3. When berry growth was accelerated by girdling on bearing shoots, the occurrence of drought spot increased. In the majority of cases, there was close relationship between the incidence of drought and berry size during the second stage of thegrowing season.
    4. WSD was not different among arms in a vine. However, the occurrence of drought spot was different among them, being more severe for the basal arms.
    5. Accumulation of suberin was found in injured tissues and tissues adjacent to injured tissues of drought spot. On the other hand, no suberin accumulated in tissues of sun scald.
    These results suggest that other factors aside from water status of vine play an important role in the development of drought spot.
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  • Hisafumi UEDA, Ryuji NAITO
    1981 Volume 50 Issue 2 Pages 192-198
    Published: 1981
    Released: July 05, 2007
    JOURNALS FREE ACCESS
    The purpose of this study was to confirm the effect of shoot vigour on the induction of seedless berries by the pre- and post-bloom gibberellin (GA) applications to clusters in Muscat Bailey A grape and also to explain the mechanism of the effect by substantial evidences.
    1. When the GA treatment was applied to clusters of Muscat Bailey A vines receiving cane pruning, higher percentages of seedless berries were obtained in the clusters of strong shoots sprouted from the distal nodes of each cane than in those of weak shoots from the basal nodes. Further, this trend was consistent through 3 years′ experiments in various conditions such as 2 timings of prebloom GA application, 2 concentrations of GA and 2 levels of vine vigour. However, such a difference in the percentage of seedless berries between the clusters of strong and weak shoots was not detected in the spur-pruned vines through 2 years′ experiments with 2 timings of prebloom GA application. This is presumably due to a narrower margin of vigour between the strong and weak shoots in the vines of spur pruning than those of cane pruning.
    2. It has been known that a high proportion of florets are usually composed of more than 3 carpels (loculi) in the clusters of Muscat Bailey A and we found that the percentage of seedless berries increased with the increment in the number of carpets per berry in the GA-treated clusters of the cultivar.
    3. The number of seeds per berry in the non GA-treated clusters of strong shoots was smaller than that of weak shoots in cane-pruned vines of both Muscat Bailey A and Delaware. On the contrary, the number of carpels i.e. the number of ovules per berry in the clusters of strong shoots was larger than that of weak shoots in Muscat Bailey A; the berries of 3 or more carpels were extremely dominant in the former whereas those of 2 carpels in the latter. On the other hand, the number of seeds per carpel decreased in inverse proportion to the increment of the number of carpels per berry in the clusters of both strong and weak shoots in Muscat Bailey A. Further, when the berries having each equal number of carpels were compared between the clusters of strong and weak shoots, fewer seeds per berry were found in the former than in the latter in each class of carpel numbers.
    4. From these results, it can be said that the ovules contained in the florets of strong shoots are larger in the number per ovary but lower in fertilization potential than those of weak shoots in Muscat Bailey A. Moreover, it seems most likely that the less potent ovules may be responsible for the higher percentages of seedless berries which were consistently obtained when the GA treatment was applied to the flower clusters of strong shoots.
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  • Yoshisato OOTAKE
    1981 Volume 50 Issue 2 Pages 199-207
    Published: 1981
    Released: July 05, 2007
    JOURNALS FREE ACCESS
    Morphological changes in leaves were investigated to clarify the effect of temperature on head formation in chinese cabbage.
    1) Seedlings of Chinese cabbage (cv. Nozaki-Kohai No. 3) were grown in a phytotron at day/night temperatures of 30/25 (high), 23/18 (medium), and 15/10 (low) °C.
    2) Leaves showed the most rapid growth at the high temperature, while the rate of leaf production was highest at the medium temperature. Thus, the plants were larger at higher temperatures soon after the start of the temperature treatment, but after 5-6 weeks the plants were largest at the medium temperature.
    3) The position on the stem of the first one of the folded leaves, which make the “small head” (embryonic head), varied with temperature conditions; the lower the temperature, the lower the position of the first folded leaf.
    4) The leaf shape of Chinese cabbage is determined by the relationship between lamina width and midrib length. Lamina width was largest at the medium temperature, while midrib length was larger at higher temperatures. Consequently, the ratio of the midrib length to the leaf width (lamina width) decreased proportionately with the decrease in temperature.
    In Chinese cabbage, as opposed to cabbage and lettuce, the midrib of the leaf does not reach the leaf apex as the “midrib”. It is thought that the ratio of the midrib length to the leaf width is more suitable than the length-width ratio of the leaf in considering the effect of temperature on the leaf shape of Chinese cabbage.
    5) From the leaf shape and the position in which the first folded leaf was observed, it is thought that the head formation physiologically starts earliest under lower temperature conditions.
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  • Satoru TOKUMASU, Fumika KAKIHARA, Masahiro KATO
    1981 Volume 50 Issue 2 Pages 208-214
    Published: 1981
    Released: July 05, 2007
    JOURNALS FREE ACCESS
    The present study was undertaken to reveal the change of dormancy when seeds are desiccated and/or preserved in fruits in cruciferous crops. Materials used were rape, leaf mustard, potherb mustard, and cultivated and wild types of Japanese grand radish. After the harvest of mature fruits, they were divided into two groups. In one group seeds were isolated separately from fruits, and in the other group seeds were left intact in fruits. Then, seeds in each group were placed either at ordinary humidities in the room or at low humidities in the desiccator (containing silica gel). After that, seed germination tests were conducted at 10 day intervals during 6 to 22 months according to different species.
    As the result, in all species except wild radish, isolated seeds in the room (regarded as a control) reached 100% germination in one to 4 months after harvest. However, wild radish did not attain the complete removal of dormancy, remain ing at certain percentages around 80% or so.
    In rape, when seeds were stored in the desiccator, the removal of dormancy was accelerated. In leaf mustard, potherb mustard and wild radish, however, the removal of seed dormancy was suppressed by desiccation. In cultivated radish, desiccation had no effect on seed dormancy.
    In rape and leaf mustard, the removal of dormancy was delayed in seeds preserved in fruits as compared with isolated seeds. In potherb mustard, and culti vated and wild radishes, there was recognized no difference in the response of removal of dormancy between seeds isolated from fruits and those preserved in fruits.
    When fruits of rape were stored in the desiccator, the accelerative effect of desiccation on the removal of seed dormancy was weakened by the suppressive effect of fruits. In the case of leaf mustard, seeds with fruits in the desiccator showed a strong supression of removal of dormancy due to the multiplication of suppressive effects of both desiccation and fruits. Potherb mustard and wild radish both of which had no difference in dormancy between seeds with fruits and those without fruits in the room also had no difference between them in the desiccator. That is, seeds were equally affected by desiccation even if they were with or without fruits. These findings suggest that desiccation and fruits work on the removal of dormancy independently of each other. If so, the existence of two different kinds of germination -inhibiting substances can be assumed: one which is affected by humidity and the other which is maintained by preservation in fruits.
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  • Yukihiro FUJIME, Tadahiko HIROSE
    1981 Volume 50 Issue 2 Pages 215-224
    Published: 1981
    Released: July 05, 2007
    JOURNALS FREE ACCESS
    Effects of diurnal variation of temperature during the early growing stage on curd formation and development of ‘Nozaki-Wase’ cauliflower and ‘Wase-midori’ broccoli and relation between plant growth and thickening growth of curd were investigated.
    1. Plants with 5 leaves were grown for 35 days at 15°, 20°, 25° and 30°C in the 1st period of a day (9 hours from 8:30 a.m. to 5:30 p.m.) and at 15°C (cauliflower) and 20°C (broccoli) in the 2nd period of a day (15 hours from 5:30 p.m. to 8:30 a.m.). Curds of cauliflower were formed by the end of temperature treatment when plants were grown at 15° and 20°C in the lst period, but not when grown at 25°C and 30°C. Flower heads of broccoli were not formed regardless of temperature in the 1st period.
    2. After plants were grown for 35 days in diurnal variation of temperature, a half of them at each temperature regime was planted in open field, and another half planted in the field and covered with a plastic tunnel. The higher the temperature of the 1st period during the temperature treatment, the more the budding and maturity of curds (or flower heads) were delyayed, and this tendency was more notable in cauliflower than in broccoli. Budding and maturing of curds (or flower heads) of both kinds of plants regardless of temperature treatments occurred nearly at the same time with or without plastic covering.
    3. Matured curd weight of cauliflower had a tendency to increase as the 1st period-temperature during the early growing stage was higher, while it was not affected by plastic covering after planting in the field. Weight of matured flower head of broccoli was hardly affected by the temperature of the lst period during the early growing stage and plastic covering after planting. Cauliflower plants which had reached the early curd-forming stage by the end of the temperature treatment formed normal curds, while most of the plants which had not reached this stage at that time formed leafy and fuzzy heads.
    4. Significant correlations were recognized in cauliflower between matured curd weight and number of unfolded leaves at budding (r=0.37, P<0.001), stem diameter at curd maturity (r=0.62, P<0.001) and total number of leaves at curd maturity (r=0.32, 0.001<P<0.01), and in broccoli between weight of matured flower head and stem diameter at the maturity of flower head (r=0.51, P<0.001) but not between weight of matured flower head and plant growth at budding.
    5. From these results, it is concluded that for producing large curds of cauliflower. at least for an early cultivar, the plants must be cultured to differentiate an adequate number of leaves before curd formation and then to thicken stems as large as possible until curd maturity.
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  • Hideo IKEDA, Takaya OSAWA
    1981 Volume 50 Issue 2 Pages 225-230
    Published: 1981
    Released: July 05, 2007
    JOURNALS FREE ACCESS
    Twenty species of vegetable crops were grown in solution culture for 5 to 9 days in combination of 3 levels of NH4NO3 and 2 levels of pH, and their absorption of NH4-N and NO3-N were compared together with the resultant change in solution pH.
    The preference between NH4-N and NO3-N in N absorption was different among vegetables. Classification of vegetables based on the N absorption was as follows: a) Vegetables which absorbed NH4-N selectively or dominantly irrespective of solution pH: strawberry, sweet corn, melon, cucumber, lettuce, mitsuba (Cryptotaenia japonica Hassk.), celery, garland chrysanthemum, and seri (Oenanthe javanica DC. b) Vegetables which absorbed NH4-N dominantly at pH 7.0 but absorbedboth forms of N almost equally at pH 5.0: eggplant and tender soybean. c) Vegetables which absorbed NO3-N selectively or dominantly irrespective of solution pH: spinach, chinese cabbage, and turnip. d) Vegetables which absorbed NO3-N dominantly at pH 5.0 but absorbed both forms of N almost equally at pH 7.0: pea, kidney bean, water melon, tomato, and cabbage. e) Vegetables which absorbed NH4-N dominantly at pH 7.0 but absorbed NO3-N dominantly at pH 5.0: sweet pepper. When NH4-N was being absorbed dominantly, solution pH decreased gradually. After plants had exhausted NH4-N in the culture solution, solution pHremained unchanged or rather increased.
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  • Hiromichi OSHIO, Fumio NII, Hisao NAMIOKA
    1981 Volume 50 Issue 2 Pages 231-238
    Published: 1981
    Released: July 05, 2007
    JOURNALS FREE ACCESS
    The physical and chemical properties of kuntan (rice hull characoal) and its application to the rooting medium of soilless culture were investigated.
    Kuntan showed microporous structures under the electron microscope. Light weight, good air permeability and moderate water holding capacity of Kuntan seemed to be ascribed to its porous structures.
    From the measurements of particle size and three phase (solid, moisture and air) distributions, Kuntan was proved to be good medium for soilless culture, unless its poraus structures were destroyed.
    Cation exchange capacity (CEC) and maxium water holding capacity were higher in kuntan obtained at higher temperatures beyond 500°C. While pH and water soluble K2O content apparently increased with increasing temperature.
    In water immersion test pH became constant within 24 hours, on the other hand, EC and soluble K2O continued to increase gradually with immersing time, indicating the existence of hardly soluble potassium in kuntan.
    In application of urea to the new kuntan, ammonification occured rapidly, but nitrification was negligible with scanty nitrification. In the old kuntan once used in melon cultivation, however, some nitrification was observed.
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  • Yutaka SHINOHARA, Yoshio SUZUKI
    1981 Volume 50 Issue 2 Pages 239-246
    Published: 1981
    Released: July 05, 2007
    JOURNALS FREE ACCESS
    Effects of light and nutritional conditions on the ascorbic acid content in hydroponically grown lettuce of butterhead type (Luctuca sativa L. cv. Edogawa or Okayama) were investigated. With increasing levels of shading, the fresh weight and number of leaves decreased, the shape of leaves became narrower and ascorbic acid and sugars content decreased markedly, while nitrate nitrogen content inclined to increase. Plants grown in 1/4 strength standard nutrient solution were inferior in fresh weight and number of leaves to those grown in 1/2 strength solution. Though ascorbic acid and sugars content was higher for plants grown in 1/4 strength solution at higher light intensities, the effect of nutrient concentration gradually disappeared with increasing shading level.
    Diurnal changes in leaf constituents were studies on sunny and cloudy days. The contents of ascorbic acid, sugars and chlorophyll were higher in the daytime and lower during the night, while nitrate nitrogen content increased in the night time. These tendencies were more clear on the sunny day than on the cloudy day.
    The relations between the contents of ascorbic acid, sugars, nitrate nitrrogen etc. were discussed and possible techniques of practical use for improving the quality of hydroponically grown leaf vegetables were also discussed.
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  • Hiromichi YAMAMOTO, Mutsuo IWAMOTO, Shiko HAGINUMA
    1981 Volume 50 Issue 2 Pages 247-261
    Published: 1981
    Released: July 05, 2007
    JOURNALS FREE ACCESS
    Nondestructive internal quality measurement by acoustic impulse response method was examined. Using apples and watermelons, several forms of the acoustic indices were compared with the results of constant speed uniaxial compression tests with cylindrical flesh specimens and sensory ratings. It was found that there were highly significant correlations among acoustic indices, apparent Young′s modulus (E'app), breaking stress and sensory firmness.
    There were not any significant differences in the internal textural qualities of apples among ripeness classes which were evaluated by external appearance by experts of the fruits. Therefore, it is concluded that this nondestructive method has the advantage of being capable of evaluating internal textural qualities which are difficult to evaluate from external appearance.
    The improved method of measuring flesh firmness by means of constant speed uniaxial compression test instead of hand-operated puncture testers has a good effect on the correlation between the acoustic indices and flesh firmness.
    For apples, the indices which have more compensation for density than previously proposed indices gave increased correlation coefficients with internal textural qualities.
    This acoustic impulse response method can be used as a nondestructive internal quality evaluation instead of the mechanical resonance method. The simplicity of this method is of great advantage to practical use.
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  • Tomoaki MATSUO, Saburo ITOO
    1981 Volume 50 Issue 2 Pages 262-269
    Published: 1981
    Released: July 05, 2007
    JOURNALS FREE ACCESS
    Four polymeric tannins prepared from young fruits of persimmon, banana, carob bean and Chinese quince were shown, in addition to having some properties of condensed tannins, to produce precipitate in methanolic solution by addition of K2HPO4, to form anthocyanidins on acid treatment, and to release the thioethers of flavan-3- ols by means of toluene-α-thiol treatment. It is suggested from these results that each tannin is a proanthocyanidin polymer and should be called flavanan or flavonan tannin instead of condensed tannin. Among the fruit tannins tested, loquat-tannin was an exception; it appeared to be a proanthocyanidin oligomer.
    Three methylated tannins from young fruits of banana, carob bean and Chinese quince were similar in molecular size (Mw=1.4-1.0×104, Mn=0.7-0.2×104), while methylated kaki-tannin is thought to be a slightly higher polymer.
    In comparison with kaki-tannin which mainly consists of catechin, catechin-3-gallate, gallocatechin and gallocatechin-3-gallate with the ratio of about 1:1.2:2.1:2.2, banana-tannin consists of catechin and gallocatechin with the ratio of about 1 to 1.3 and carob bean-tannin consists of catechin-3-gallate, gallocatechin and gallocatechin-3-gallate with the ratio of about 1:3.3:4.6. Chinese quince- and loquat-tannin appear to be composed of only catechin.
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