Seasonal and year-to-year trends of leaf K, Ca, and Mg content in healthy and Mg-deficient Ralls trees were studied in order to obtain more information about the factors which affect the occurrence of Mg-deficiency. Seasonal samples of mid-shoot leaves (without petioles) were taken with 10 day intervals during the period of 1958-1961, from the same trees of two blocks (Block A: Mg-deficient, Block C: healthy) of experimental field, details of which were described in a previous paper(16). Changes of leaf K, Ca, and Mg content from mid-June to early-November indicated that decrease of K, and increase of Ca and total cation (K+Ca +Mg as me) content showed almost linear pattern throughout the season, whereas slow increase at the beginning and slow decrease at the end of the season was exhibited in the case of Mg. Considerable variations in leaf cation content were observed within each season, and variation coefficient of leaf Ca was the greatest, and that of K was greater than that of Mg and total cation. The period between 80-90 days after full bloom would be the time when the least change of Mg was occuring in the leaves, and the period between 110-130 days would be preferable to attain the maximum difference in leaf Mg content between high-and low-Mg trees. Yearly leaf samples were collected at about 85 days after full bloom during the period of 1958-1966, from the same trees (except for Block A since 1964) of the two blocks. Within-season variations in leaf K, Ca, and Mg content were greater than that of between-season, except that Mg in low-Mg trees. The observed variations in the severity of Mg-deficiency from year to year seemed to be associated with variations in leaf Mg content of low-Mg trees. It was observed that the highest Mg content was found in 1961, when the K content was at its lowest and the fruit yield was at its highest, and that a high Ca content was found in 1963, when the lowest Mg and a high K content was found. No significant correlation was found between leaf cation content of each year and yearly climatic conditions, and also between leaf cation content and fruit yields, however, some significant positive correlations were obtained between mean air temperature of each year and Ca content of leaves. The result suggests that variation of air temperature during the growing season is responsible to some of the between-season differences in leaf cation content observed in the present work. There were negative correlations between leaf Ca and K content, and also between Ca and Mg content of leaves from low-Mg trees when nutrient content was expressed as me-percentages of total cation.
1. Morphological differences between seeded and parthenocarpic fruits induced by GA4 and GA7 were documented in Wealthy apple and Japanese pear cv. Shinseiki fruits. GA-induced parthenocarpic fruits were characterized by a larger polar diameter and an equal or smaller transverse diameter than seeded fruits. Cortex thickness of seeded fruits was greater in the basal than median or apical region; whereas, in parthenocarpic fruits cortical thickness was greater in the apical than median or basal areas. The thicker cortex in the basal region of seeded fruit was related to cell number. The apical region of parthenocarpic apples contained a greater number and larger cells and in Japanese pears larger cells than in the basal or median sections. Cell division in the cortex of seeded and parthenocarpic apples ceased 3 to 4 weeks and in Japanese pear 4 to 5 weeks after bloom. 2. Asymmetric fruit growth was induced in seeded and parthenocarpic apple and Japanese pear fruits following a localized application of GA to one side of the fruit 2 weeks after bloom. Both cell number and size increased in the treated side as compared to the non-treated side in both apple and Japanese pear. Greater response was observed in parthenocarpic than seeded fruit. In Japanese pear there was a striking increase in cortex thickness (cells size and number) of the treated side compared to nontreated side even when treated with GA7 4, 6 and 8 weeks after bloom. GA3 failed to induce asymmetric fruit growth in Japanese pear regardless of time of application.
In this investigation, the second crop on 8-year-old Masui Dauphine fig tree were employed to clear up the effects of acetaldehyde or ethylene on hastening the maturity of the fruits. That is, after the treatment with acetaldehyde (500ppm) or ethylene (500ppm) to the fruit at the best time of oleification the respiratory drift, contents of carbohydrates, concentrations of volatile substances such as acetaldehyde, ethyl alcohol and ethylene, and activities of plant growth substances in the fruits were determined unitl the maturity. 1. The maturity of the treated fruits with acetaldehyde or ethylene was markedly promoted in comparison to the untreated fruits. Between these volatile substances tested, acetaldehyde (matured 5 days after treatment) was more effective than ethylene (matured 8 days after treatment). The mature fruits with these chemicals were the same in size, color, and reducing sugar and malic acid contents to those allowed to mature naturally. 2. The respiration rate of the treated fruit with acetaldehyde increased rapidly from the next day of the treatment, reached a climacteric maximum in respiration 2 days after treatment. Thereafter the rate sharply declined, and again rose at maturity. While, those of the treated fruit with ethylene reached a climacteric maximum in respiration 4 days after treatment, thereafter the rate declined. The respiration rate of the treated fruit with acetaldehyde was significantly larger as compared with those of the fruit with ethylene throughout the season. However, respiratory quotients in both treated fruits with acetaldehyde and ethylene at the climacteric maximum were higher than 2.1. 3. The content of reducing sugar in the treated fruit with acetaldehyde increased rapidly on and after the climacteric maximum, and attained a maximum at the maturity. On the other hand, the content of malic acid in the treated fruit with acetaldehyde increased immediately, attained a maximum just before or on the climacteric maximum in respiration, and then decreased abruptly until the maturity. While, seasonal changes in contents of reducing sugar and malic acid in the treated fruit with ethylene were similar to those shown for the fruit with acetaldehyde. 4. As expressed in mg per 100g fresh matter, acetaldehyde and ethyl alcohol contents in the treated fruit with acetaldehyde increased immediately, reached a peak at the pre-climacteric periods in respiration (1 day after treatment), followed by the sharply depression and again rising at maturity. In the treated fruit with ethylene, the contents of acetaldehyde and ethyl alcohol reached a maximum at the climacteric peak in respiration (4 days after treatment). Thereafter the contents decteased abruptly and again rose at maturity. 5. Ethylene concentration in the treated fruit with acetaldehyde also increased rapidly, reached a maximum at the post-climacteric periods in respiration (at the beginning of fruit softening), afterwards the concentration decreased. While, ethylene concentration in the treated fruit with ethylene attained a maximum just after the treatment, followed by the sharp depression and again rising at the beginning of fruit softening. 6. In the treated fruits with acetaldehyde or ethylene, several endogenous growth substances such as IAA, IBA, IAN and GA3 like substances were identified by paper chromatographic method. Moreover, two different unknown growth substances were also detected. The activities of these endogenous growth substances were high at the stage of noticeable coloring in the skin, and were low at maturity. 7. From these data mentioned above, it was concluded that the effect of oleification on hastening the maturity of the fig fruit may be due to high enzymatic activity in the cells of the fruit tissue induced by the volatile substances such as acetaldehyde or ethylene shown in both process of oxidation of fatty acid and of decomposition of sugar.
In order to clarify the effect of time of nitrogen supply on Satsuma orange trees, the gravel culture experiment was carried out for 3 years. Four years old trees were grown under non-bearing conditon in the first year and under bearing condition in the succeeding 2 years. 1. The N supply in culture solution was maintained in three levels such as 40-50, 80-100 and 140 -160 N ppm for 6 months from May to October. Vigorous tree growth and high N content in leaves were found in higher N levels. With increasing supply of N, following changes in fruit quality were observed: (a) Fruit size increased. (b) Rate of flesh weight in a fruit reduced. (c) Break of green rind color delayed. (d) Percentage of soluble solids in juice reduced. (e) Juice acidity increased. (f) Ratio of solids to acid decreased. 2. Trees grown under low N level of 40-50ppm were received high N level of 200-250ppm temporally in each period from May to June (early N raising), from July to August (middle) and from September to October (late). The effect of high N level on tree growth was dominant in the early N raising and not so apparent in the late N raising. The marked tendency was observed in trees that all the flowers were removed in the first year. That is, the early N raising resulted vigorous growth of spring and summer shoots. The growth of summer and autumn shoots was remarkably great in the middle N raising. 3. In the middle N raising, incraese of fruit size and reduction of flesh rate in a fruit were observed. Break of green rind color considerably delayed in late N raising. Juice acidity increased in the order of late, middle and early N raising, while the ratio of solids to acid was reverse. Soluble solids in juice was less in the late N raising, but this tendency was observed in only one year. The raising of N level in culture solution also resulted the increase of N content in spring leaves. The degree of increase was higher in the early N raising than in the middle and late N raising. 4. From the above experimental results, it was indicated that different N status in the period from late April to early August has strong effect on the tree growth of Satsuma orange, and that excess supply of N after late summer may exert unfavorable effect on fruit quality.
The experiments were carried out during 1962-1965, to clarify the daily and seasonal changes of the water saturation deficit (W. S. D.) of leaves, as an index of the degree of water deficit in Satsuma orange trees. And further observations were made on the relationship between W. S. D. of leaves, climatic factors and soil moisture. The results obtained were summarized as follows: 1. Daily changes of W.S.D. of leaves in summer were rose in a steady curve with sunrise, and maximum value was found to occur around noon, thereafter, values were gradually descended, and minimum value was observed around 6.00P.M. each day. On the other hand, its changes in winter were smaller than that in summer, although, the tendency was almost similar to that observed in summer. 2. On the seasonal changes of W.S.D. of leaves, during the period from early to late February, its values were definitely ascended, and it might be mainly due to the low temperature and cold wind. And its values in early February were found to have the highest in winter period, but thereafter to late March, W.S.D. of leaves were gradually descended. In early May, however, W.S.D. of leaves were ascended rapidly and formed a peak, it seemed to be closely related to the drought of spring and sprouting a current shoots, but thereafter to late June, its values were slightly descended. During the period from early July to late August, under the condition of high temperature and drought, W.S.D. of leaves were notably ascended, and the trend was most remarkable in early August, its values in this period were the highest one. W.S.D. of leaves in September were considerably high compared with that in October, thereafter from early October its values were descended. 3. In the winter half (Nov.-Apr.), W.S.D. of leaves had the high negative correlations with the air temperature, soil temperature, precipitation and saturation deficit of water vapour pressure. On the contrary, W.S.D. of leaves in the summer half (May-Oct.) had the high positive correlations with the air temperature, soil temperature and saturation deficit of water vapour pressure. 4. W.S.D. of leaves in autumn and winter were ascended with the increasing of cold wind velocity, also, its values were ascended with the increasing of hours of exposed to the cold wind. Further, velocity of transpiration stream in shoot was increased by the exposed to the cold wind, and its velocity was diminished with the decreasing of soil moisture. 5. W.S.D. of leaves in summer had a very high negative correlation with the soil moisture, therefore, by the use of curved regression equation, it was possible that the soil moisture is presumed with the W.S.D. of leaves. When the soil moisture was between field capacity and moisture equivalent, changes of W.S.D. of leaves were very small, and then W.S.D. of leaves were slowly ascended with the decreasing of soil moisture in less than moisture equivalent. Thereafter, its values were extremely ascended, being accompanied with a marked decreased of soil moisture to the wilting point. In addition, when the W.S.D. of leaves were reached 8.0 per cent, the trees showed visible symptoms of wilting in leaves, and its values reached 10.0 per cent, showed visible symptoms of wilting in fruits. In the winter period, however, no correlation could be found between W.S.D. of leaves and soil moisture, accordingly, the ascension of W.S.D. of leaves in winter were might be mainly due to the climatic factors.
1. In order to determine the effect of phosphorus application in connection with soil reaction, an experiment, which consisted of factorial combinations of three levels of phosphorus (Ca(H2PO4)2) and four levels of soil pH, was carried. 2. Regardless of the level of phosphorus application, the favorable soil pH for the growth of plant based on shoot growth and net increase of fresh weight was around 6. 3. With increasing the P-level, the P2O5 concentration in the soil increased naturally, especially at lower pH 4-5. 4. Shoot growth was not affected by the phosphorus application, while net increase of fresh weight was only slightly increased by it. 5. However, insoluble and soluble organic-P in a whole plant, and soluble-N and especially insoluble-N (mainly protein-N) in the leaves were increased by raising the P-level. 6. Therefore, though the phosphorus application did not affect the external growth of plant, it seemed to be related to syntheses of organic N and P compounds.
Satsuma orange trees which would be induced abnormal defoliation showed two different types of characteristic spots on the leaves during fall to winter. One is light brown small spot and another is reddish brown spot. These affected leaves were abscissed from winter to spring. It was also found that the roots of these trees were falling into decay. The leaves of the affected tree were containing much manganese, in almost all cases, having high level of more than 100ppm of manganese in dry matter basis. Soil pH was low and water soluble manganese content was high. It may be said that the remarkable increase of water soluble manganese in the soil is related to the decrease of soil pH. Furthermore, manganese contents in the leaves may be related to water soluble manganese in the soil. In our observations, when water soluble man ganese in the soil was over 10ppm, manganese content in leaves was over 100ppm. From the viewpoint of mentioned avove, it seemed that the“Abnormal defoliation”would be induced by manganese toxicity. One of the main causes of it may be the increase of soluble soil manganese which due to the increase of soil acidity. And, the increase of soil acidity may be caused by heavy application of fertilizers and insufficient application of liming materials.
Experiments were carried out to clarify the effects of nitrogen supplied in various growth stages on the growth and yield of green soybean, cabbage, turnip, and cauliflower in sand culture outdoors. 1. In green soybean, the beginning of flowering and harvesttime were delayed by withholding nitrogen in the former half of growth period. Especially, when the nitrogen supply was discontinued for 2-3 weeks immediately before flowering, the yield of pods was decreased. But there was no decrease in yield in treatments withholding nitrogen after flowering. 2. As to autumn sown cabbage, weight of head at harvesttime was considerably smaller in treatments withholding nitrogen during the rapid growth period or outer leaves, from early April to early June. But when nitrogen was not supplied after early June (rapid growth period of head leaves), and in winter months, there were no significant differences in the weight of heads as compared with the control supplied with nitrogen throughout all stages of growth. 3. In turnip, both growth of top and yield of roots were suppressed, if nitrogen supply was stopped at any stage of growth. But, in treatment withholding nitrogen for 2 weeks before harvesting, yield of roots was better than that of the control. 4. In cauliflower, growth of curd was suppressed when nitrogen was not supplied immedately before harvesting.
The experiments were conducted to evaluate the effects of irrigation, temperature and shading on the acidity and the potassium content of tomato fruits (var. Fukuju No. 2) from plants grown in pots containing 13 litres of volcanic ash soil. Plants were placed under the treatments during the period between the flowering stage and the incipient colour stage of fruits on the second truss. All fruits were harvested at the incipient colour stage. 1. On the beginning of experiment in 1966, each pot was left over night after sufficient watering and weighed. Deficit from this weight of pot was determined daily thereafter. Irrigation was made in three ways to compensate the deficit daily and when it reached 1.5 and 2.5 kg per pot, respectively. The titratable, total and combined acidities of fruits, expressed on fresh weight basis, from the plants irrigated daily were the lowest in three treatments and the highest were those of fruits from the plants which were not irrigated until 2.5kg of moisture was lost. The same trend was found for the potassium content. The titratable acidity represented as a percentage of the total acidity was not affected by these treatments. Although neither timing nor amount of irrigation was so strictly regulated on the experiment in 1965, the changes of the acidities caused by irrigation treatments were found almost the same with those of 1966 experiment. In order to make certain of the possibility of dilution effect of irrigation on the acidities and the potassium content, the above determinations were recalculated on dry weight basis. In this case, effects of irrigation could not be observed. This suggested that the changes of the acidities and the potassium content on fresh weight basis were mainly dependent on the differences of moisture content of fruits, that is, the explanation by dilution effect. The more frequent the irrigation was, the lower the refractometer reading and the greater the fruit weight. pH showed no apparent changes. Gelatinous pulp weight expressed as a percentage of whole fruit was not affected by treatments. 2. In the experiment of temperature, the plants in pots were held all day in 1964, and for eight hours in the daytime daily in 1965, respectively, in the rooms controlled at 20°C or at 30°C. In both experiments, the titratable, total and combined acidities and the potassium content of fruits at 30°C were higher than those of fruits at 20°C. The titratable acidity percent was also higher at 30°C than at 20°C. pH of fruit juice was higher and fruit weight was lower at 30°C than at 20°C. Differences of temperature brought no significant change of the gelatinous pulp percent. 3. In the experiment of shading effect, light intensity was lowered to 50 or 25 percent of that of unshaded control by the screen of lawn. Shading effects were small, if any, on the acidities and the ptassium content of tomato fruits. The stronger the extent of shading, the lower the fruit weight and the greater the gelationus pulp percent. Changes of the titratable, total and combined acidities of tomato fruits enveloped in aluminium foil bags during their development had almost the same pattern with that found on the fruits developed under natural light condition.
This studies were conducted to obtain some informations about properties of a selective herbicide, CMMP (Solan) for tomatoes. (1) Tomato plants were susceptible for CMMP at 3 to 5 leaves stage, but increased in tolerance with age advanced and found to be more tolerant at 7 to 8 leaves stage. In general, tomato plants grown in the greenhouse were more susceptible than field grown plants. (2) The differences in susceptibility for CMMP were not recognized among the six tomato cultivars, Hikari, Sekaiichi, Fukuju No. 2, Kurihara, Best of all and Ponderosa. (3) No injury to tomato plants were observed after spraying CMMP at flowering time and both yield and quality of tomatoes treated with CMMP were almost the same that of non-treated plants (weeding by hands). (4) Herbicidal activity of CMMP at high temp. (30±3°C) was more effective than low temp. (20±3 °C). (5) Effect of rainning after spraying CMMP was observed on herbicidal activity and it was confirmed that no rainning time is necessary for 3 hours after spraying CMMP to susceptible plants (such as panic grass of 5 to 10cm in heigh) and for 6 to 24 hours to tolerant plants (such as panic grass of 40 to 45 cm in heigh). (6) The relation between the effect of CMMP and light intensity was more important, and high intensity of light during treatment with CMMP accerelated weeding much more than low light intensity. (7) Effect of CMMP as soil treatment was proved on weeding of crucifer but not practical, and residual activity in soil continued for about 20 days. CMMP was much more effective when it was sprayed directry to leaves and stems than when used as soil treatment.
1) In the hope of obtaining new ornamental types of hardy Hibiscus, interspecific crosses were made between H. mutabilis L., an arboreal species of eastern Asia, and the perennial herbaceus species of North American origin, including H. militaris Cav., H. coccineus Walt. and H. moscheutos L. 2) Reciprocal crosses between the three herbaceous species resulted in the high percentages of fruit setting and the capsules obtained contained a number of well-developed fertile seeds, which germinated quite normally in every case. 3) Interspecific crosses between H. mutabilis and the three herbaceous species were successful only when the former was used as a mother plant. The percentage of fruit setting, the number of seeds obtained, and the viability of the seeds were all inferior to the corresponding figures in the mutual crosses of the North American species. 4) In the crosses, H. mutabilis×herbaceous species, better seed production was found in the later period of flowering season, whereas there were no appreciable seasonal differences in the self-pollination of each species and the combinations of the herbaceous species.
The previous experiments with Chrysanthemum (var. Ginpa), a short-day plant, showed that LD leaves exert an inhibition on the action of floral stimulus produced in SD leaves. The present experiment suggests that LD leaves would produce some floral inhibitors, acropetally transmissible like floral stimulus. The plants of Ginpa chrysanthemum with some 22 leaves fully expanded were subjected to localized SD treatments. 1. Seven or three upper leaves were exposed to SD, while the remaining leaves to LD. When seven leaves were given SD, initial stem elongation and the rate of leaf differentiation were slightly less, while the number of days to bud appearance was almost the same, as compared with the results when the entire plant was given SD. When three leaves were given SD, lower LD leaves exerted inhibition on stem elongation and less pronounced inhibition on the rate of leaf differentiation, the plants thus showing growth of rosette-type. No flower bud was observed during the 82 days of experiment, while some of the plants wilthout lower LD leaves produced the flower buds. These results seem to support the idea that floral inhibition of lower LD leaves results from the effects of some transmissible inhibitor produced in LD leaves. 2. Three or 7 upper leaves were exposed to LD and all of the others to SD. When three leaves were given LD initial stem elongation and the rate of leaf differentiation were slightly less, but afterwards more, as compared with the results when the entire plant was given SD. Flower bud initiation was delayed. When seven leaves were given LD, stem elongation was much reduced, while the rate of leaf differentiation was slightly lower only in the initial stage of treatments. The upper LD leaves grew larger than those of the former and plants showed a rosette-type growth. No flower bud was observed during the experimental period. Floral inhibition by upper LD leaves seems to be caused by an inhibitor produced in the LD leaves through its effect on the action of floral stimulus at the apex, since the promotion or inhibition of growth is unlikely to be due to mere dilution effects of LD leaves on floral stimulus. 3. It is suggested that the ratio-floral stimulus/inhibitor at the apex may play a significant role in the process leading to flower bud formation and in plant growth.
There are two types of fruits in non-astringent Kaki. One is the mature fruits of non-astringent cultivars which become edible naturally on the tree. The other type is the fruits of astringent cultivars which were treated with alcohol, carbon dioxide or warm water, or were over-ripened, stored frozen, or dryed after harvest. In the present report, tannin cells of these non-astringent fruits were examined microscopically and placed into five classifications according to the appearance of their protoplast and cell wall. 1) Brown: The protoplast is coagulated, shrunken and brown. Found in fruits of non-astringent and astringent cultivars which form brown specks in flesh when they mature (Fig. 1). 2) Shrunken: Whole tannin cell is shrunken and the protoplast is coagulated. Found in dryed fruits (Fig. 2). 3) Coagulated: The protoplast is coagulated. Found abundantly in fruits treated with carbon dioxide (Fig. 4-lower), alcohol or warm water (Fig. 3 -lower). Also found in dryed or frozen stored fruits and in fruits of non-astringent cultivars (Fig. 3-upper, 4-upper). 4) Plasmolyzed: The protoplast is not coagulated and is plasmolyzed easily. Found abundantly in over-ripened (Fig. 5) or gamma ray irradiated fruits and in fruits of non-astringent cultivars which do not form brown specks when they mature (Fig. 6). Also found occasionally in fruits treated with alcohol and in fruits of non-astringent cultivars which form brown specks. In this case, the astringent substance is not coagulated in tannin cells, but when plasmoptysis occurs it coagulates instantaneously (Fig. 7). 5) Ruptured: The cell is ruptured and the protoplast exudes. Found in frozen stored fruits (Fig. 8).