The critical levels of exchangeable magnesium and calcium saturation related to magnesium deficiency and bitter pit have been described in the previous reports, and these values were applied practicaly to various soils of apple orchards, in Akita area. (1) These critical levels were available for soil survey of Hiraka series (Tuff from the tertiary period) and Kitano series (mixed soil of the Tuff and the humus-rich volcanic ashes), but too high for Hanawa series (humus-rich volcanic ashes). From this study, the revised critical values applied to soil survey as related to magnesium deficiency of the humus-rich volcanic ashes were less than 1.0me for slight symptom and 0.5me for severe symptom, although that of the Tuff and its mixed soils were 2.5me for slight symptom and 1.0me for severe symptom. The critical level of calcium saturation as related to bitter pit was about 10 per cent in Hiraka and Kitano series, but in Hanawa series it was about 5 per cent. (2) The calcium concentration in leaves and shoot bark of young apple trees grown in Hiraka series was very lower than Hanawa series, and the nitrogen was higher slightly. (3) Hanawa soil adsorbed selectively calcium from mixed solution of N-Ca(OAc)2 and N-NH4OAc, and the calcium was more leached by 0.002 N-HOAc and 0.005 N-NH4Cl than Hiraka soil. From these results, the difference of critical level related to calcium and magnesium deficiency between soil type in apple orchards was depend on a difference for ability of cation adsorption by clays.
In three seasons from 1962 to 1964, effect of Peach-thin spray was tested on peach flowers in their different stages of development. Tested flowers wers selected to be in almost the same stage by removing flowers in earlier or later stages. In 1965 and 1966 comparison tests were conducted between morning and mid-day sprays. 1. In 1962, 200 and 800ppm solutions were applied on the flowers in four stages on four Hakuho trees, which were thirteen years old and moderately vigorous. Thinning effect was lowest on flower buds before blooming, high on blooming flowers, and a little less on the flowers five days after blooming than on blooming flowers. Sprays ten days after blooming resulted in heavy thinning. Effect of 800ppm sprays was found to be too severe except on flower buds. Foliar epinasty was observed in the treatments of 200ppm spray in lates and all treatments of 800ppm spray. 2. In 1963, the same trees as in the previous season were used, and 200ppm Peach-thin was applied. Fruit set reduction was almost equal by the sprays at the day of blooming, 2 and 10 days after blooming, while effect was less by the spray 6 days after blooming. 3. In 1964, 200ppm solution was applied on the same trees used in the previous season. Thinning effect was highest by the spray 4 days after blooming and was followed by the sprays 7 and 11 days after blooming in the order. 4. Three season′s tests seem to show that the thinning effect of spray at the day of blooming is almost the same as that 2 days after blooming, and it becomes to be less as the date of spray is delayed, while it is quite variable by the sprays 10-11 days after blooming. 5. Morning and mid-day sprays were compared in their thinning effect on 8 years old Hakuho, 7 years old Okubo, and 4 years old Re-13 trees. Morning spray thinned more than mid-day spray on Okubo. On Hakuho and Re-13 trees, however, differences in fruit set reduction between morning and mid-day spray were not significant.
Six-8 years old Satsuma orange (Ôiwa No. 5) plants which were grown in earthen ware pipes (60cm in diameter×60cm in depth) filled with sandy loam were used in this experiment. Experiments were repeated during July of 1966, August of 1967 and January of 1968 in the dry season. An attempt in the experiments is to decide which watering methods should be taken for keeping water balance in a leaf. Before experiments, the soil was allowed to dry out gradually by withholding irrigation and keeping out of rainfall untill the visible wilting took place. At the beginning of experiments, watering to plants was conditioned by two methods: 1) by supplying to the soil and 2) by sprinkling upon leaf surface. The soil in control plots had been moistened by flooding water near to its field capacity. The water saturation deficits (W. S. D.) in leaves were measured by modified ACKLEY′s and RUTTER and SANDS′s method. Their results are as follows: In the summer experiments, decrease in leaf water deficits was apparent at 30 minutes after watering to soil. In one hour after treatment there was little difference in leaf water deficits between treated and control plots. While increase in leaf water contents had occurred in a brief period after treatment. This tendency was also shown in the winter experiments. However, it took more time to reach the same value in water content or W. S. D. as control plants. W. S. D. and water content in leaves during sprinkling water upon leaf surface reached the same value 3 and 2 hours, respectively, after start of sprinkling water without regard to season. From these results, watering to plants to correct the water deficit in leaves is better to supply to the soil in summer and to sprinkle upon leaf surface in winter. It may be concluded that the greater efficiency in practice can be obtained by sprinkling water overhead both to soil and upon leaf surface.
So called“Abnormal defoliation”of Satsuma orange was studied by sand culture method under the different levels of manganese and calcium in the nutrient solution. The growth of young tree correlated negatively to the concentration of manganese. In these cases, it appeared that the inhibition of growth going to remarkable as the concentration of calcium become lower. When the concentration of manganese more increased, the more roots fall into decay, and the brown spots and chlorosis were observed in leaves. At the same time, the negative correlation was found betweeen the concentration of calcium and the occurrence of these symptoms. In the plant body, it was observed that the manganese content in fibrous roots and leaves become higher than the other parts, it seemed to accumulate in fibrous roots. Manganese content in plant correlated with the concentration of manganese in nutrient solution. It seemed that the absorption of manganese was carried independently of the needs of plant life. When the high level of manganese in nutrient solution, the manganese content in plant correlated negatively with the concentration of calcium in nutrient solution. From the results mentioned above, it was concluded that the“Abnormal defoliation”of Satsuma orange may be due to the excessive absorption of manganese. And it is affected by the concentration of soluble manganese in the culture media.
In order to study the mechanism of male-sterility in Satsuma orange, the critical period of the degeneration of pollen grains and anther tapetum was determined. The results obtained were summarized as follows: 1. The microspores at the vacuole stage were variable in size, and their sizes at the stages of vacuole appearance and vacuole disappearance were about 20.88 and 27.08μ, respectively. 2. The great majority of sterile pollen grains investigated at the stage of pollen maturity could be included in the medium-sized group (from 22.5 to 27.5μ in diameter). 3. The degeneration of pollen grains might take place at the vacuole enlarging stage, thereafter, they showed little or no increase in their own size and became empty medium-sized pollen grains. 4. During the stage of vacuole disappearance, a few microspores with starch granules and a large number of microspores without starch granules were observed. The latter became sterile throughout thecourse of pollen grain development. 5. The tapetum remained cellular and the tapetal cells became to be polynucleated at the pollen-tetrads stage. Breakdown and disappearance of the tapetum occurred at the vacuole enlarging stage and after the pollen mitosis stage, respectively. 6. It may be concluded that the critical period of the degeneration of tapetal cells and pollen grains of Satsuma orange is the vacuole enlarging stage of microspores.
A kind of chinese cabbage named To-pe-tsai (Brassica chinensis cultivar To-pe-tsai) is one of the most common vegetables in Formosa. It′s reproductive behavior appears to depend upon a lower temperature. This study was designed to secure the effects of temperature and daylength on the flowering and fruiting of To-pe-tsai. Experimental items were as follows: 1) Studies on the capacity to respond to the temperature at 10°C after germination. The ages of young seedling exposed to a low temperature were as follows: (a) the one having the main root, 1 mm long, (b) the cotyledons fully expanded, (c) the 1st leaf, 2cm long, (d) the 2nd leaf, 2cm long. 2) Effect of daylength after chilling of seedling on flowering behavior. Plants were first exposed to a temperature of 4°C for 3 days, followed by an exposure to a sufficient number of days of 8hr daylength or natural daylength of 15 to 16hr. 3) Effect of an insufficient chilling on flowering behavior. Plants were chilled at 10°C for 24, 48 and 72hrs, and then grown under constant temperature of 23°C. 4) Effect of various temperature on flowering behavior after chilling. After sufficient chilling at 4°C in dark room, plants were grown under different constant temperature of 15, 23 and 30°C in Phytotron. The results obtained were as follows: 1. When the plants are exposed to 10°C for 3 days at the age of 12 days (1st leaf, 2cm long) after sowing, followed by the exposure to high temperature of 23°C, together with 15 hr-daylength, they can proceed most rapidly, about 10 days, to flower bud differentiation and bolting, and come in to flower after 30 days. 2. After chilled at 4°C, the bolting and flowering of plants is promoted by the long day treatment, and is delayed by short day treatment. 3. The plants form an abnormal flowers both in the case exposed to insufficient chilling or grown at high temperature after complete chilling. 4. The characteristics of an abnormal flower are as follows: (a) the size of abnormal flower is smaller than the one of a normal flowers, (b) the petales and normal pollens are always absent, but the stamens and stigma grown relatively large, (c) the internode length of two flower stalks is extremely short, so the flowers grow together and sometimes the inflorescence fasciates on the base part of flower stalks, (d) the flower buds become black and wither, and then fall off before anthesis, (e) the fruiting does not occur normally.
It had observed that after flowering, the axillary buds were growing vegetatively in C-genome varieties of Brassica. This phenomenon is called“Semi-vegetative growth”. In this experiment, semi-vegetative growth was studied. Several varieties with different ecotypes in C-genome were used. The seeds were sowed in Autamun 1967 and the plants were grown in green house. And these plants were used as materials. Observation was made from 15th May to 15th July, 1968. The axillary buds were collected several times during the period and the morphological and histochemical changes of the shoot apex were studied. The results were as follows: (1) Semi-vegetative growth was observed in all C-genome varieties used. (2) In this period, tunica layers of the shoot apex were increased from 2 layers to 3 layers which represents the vegetative growth in C-genome variety. So, it was cleared that the growth phase transfered from reproductive growth to vegetative growth. (3) This fact was also clearly recognized by histochemical observation of the shoot apex.
Experiments were performed to compare the influence of ammonium nitrogen supplied in various growth stages, on the growth of turnip and cabbage in the sand culture outdoors. The growth period from the sowing time middle in April to the harvesting time middle in June was divided into four periods about two weeks each, and ammonium nitrogen was supplied in any one of the four periods, respectively, nitrate nitrogen being supplied for the remaining periods. The control treatment was supplied with nitrate nitrogen throughout all stages of growth. When ammonium nitrogen was supplied in the stage from the sowing time to immediately after emergence, many seedlings with cotyledons exhibiting abnormal appearance were produced, and considerable number of these seedlings died. In any subsequent growth stage also, ammonium nitogen supplied lowered growth rate as compared with the control, though not so severer as in the emergence stage. In the leaves of plants supplied with ammonium nitrogen, the concentration of nitrate lowered rapidly, while, ammonium and soluble organic nitrogen accumulated. When nitrate was given again to these ammonium seedlings, their growth rates were restored rapidly, however, they could not catch up with the control. In the leaves of these plants, the concentration of nitrate increased quickly, and ammonium concentration decreased considerably. When ammonium nitrogen was supplied at the emergence stage of tomato and cucumber, their growth rates were lowered, and at higher concentrations of ammonium, even germination percentage decreased, and further, seedlings with cotyledons exhibiting abnormal appearance increased.
With four kinds of soil, namely sand, sandy loam, loam and clayey loam, the effects of nitrogen sources on the top growth, tuber-formation and-thickening of sweet potatoes planted in wooden frame were investigated. 1) The plants supplied urea and nitrate ammonium obtained better result than sulfuric ammonium in tuber-formation and-thickening in all kinds of soil. It may be due to the following facts that the plants supplied urea and nitrate ammonium maintained the moderate top growth during the tuberformation period from mid-July to mid-August, and the enhanced top growth during the tuber thickening period. 2) Photosynthetic activity of the plants supplied sulfuric ammonium was comparatively high during the tuber thickening period, however, the yield of tuber, especially that of large tuber, was inferior to the plants supplied nitrate ammonium or urea, owing to the heavy repressed leaf area. 3) From the results of this experiment, it was also confirmed that both tuber-formation and-thickening are closely correlated with the process of top growth, as it was recognized in the previous works.
The experiment was made to test how morphologically some amino acids (10-4% methionine, glutamic acid or asparatic acid) and 0.1% glucose put into the culture medium had effects on the primordium differentiation and the“initial cell group”formation of advantitious roots, in case of cuttings of Portulaca grandiflora. The same experiment was done to test how morphologically temperature had effects on them. Three glass boxes were used, in which several flasks of cuttings were put: one box was kept 25°C, another 35°C and the other at the shade temperature. Distilled water and 0.1% glucose were used as the culture medium. 1. There were not any correlations between thickness of the stems and the number of the vascular bundles, and also between the number of the vascular bundles and the one of the primordia differentiated. 2. Primordium differentiation stage tended to be slow in it coming by adding 10-4% methionine or glutamic acid to the culture medium and in coming throuth the test at 25°C. 3. The number of primordia tended to be depressed by adding 10-4% methionine, glutamic acid or asparatic acid each to the culture medium at the shade temperature and to be promoted by adding 0.1% glucose to the culture medium without any relation to 35°C, 25°C and the shade temperature. 4. In case of cuttings cultured in distilled water, most primordia tended to differentiate near the cut, but by adding 10-4% methionine, glutamic acid, asparatic acid or 0.1% glucose each to the culture meditm, most primordia tended to differentiate less near from the cut. These phenomena did take place without any relation to 35°C, 25°C and the shade temperature. 5. The growth of“initial cell group”tended to be depressed by adding 10-4% methioinn, glutamic acid or asparatic acid each to the culture medium, and to be promoted by adding 0.1% glucose. Under the control of temperature, the growth of it tended to be depressed at 25°C and to be promoted at 35°C.
Explants of cyclamen tubers were cultured aseptically on solidified medium, and the possibility of reducing microorganism activity present in the tissue by means of a curing treatment and minimum contact innoculation was examined. At the same time, the effects of NAA and adenine sulfate given in aqueous solution prior to innoculation and the effects of temperature on the organ forming activity of explants were investigated. 1. Curing of the explants not only reduced infection by microorganisms and necrosis of the explants, but also increased the rates of organ formation and the number of organs appreciatively. 2. Minimum contact innoculation of explants reduced infection considerably when explants had been cured for 24 hours. 3. NAA, when used alone, stimulated bud formation at 0.1mg/l, and root formation at 1mg/l. This root inducing effect of 1mg/l NAA was shifted to a bud inducing effect when adenine sulfate was supplied, in combination, at 20 and 100mg/l. When used alone, 100mg/l adenine sulfate inhibited organ formation completely. However, most of the organs formed under the influence of 0.01mg/l NAA were roots when the latter was given in the medium even with adenine sulfate at 20mg/l. 4. Among the temperatures used, diurnal alternation of 20°C day and 10°C night temperature proved best for organ formation. 5. The possibility of applying this technique to vegetative propagation was discussed from a horticultural view point.
Protocorm-Pieces of Cymbidium pumilum ROLFE and rhizome-tips of Cymbidium goeringii REICHB. F. were cultured aseptically in the dark. Chemical control of the organ formation in these cultures was studied. The results obtained were summarized as follows: 1) Cymbidium pumilum; On the basal medium (KNUDSON C+NITSCH microelement) shoots were formed in a half of samples after 8 weeks, while no root was formed. Addition of NAA markedly affected their organ formation. Low concentrations of NAA (below 0.1mg/l) promoted shoot formation. With increasing concentration from 0.1 to 0.6mg/l, root arose and the number of shoot decreased. Root formation was most abundant at 0.6mg/l, where root formation scarcely occurred. Still higher concentration suppressed completely both shoot and root formation. Shoot formation was also improved respectively by addition of 0.01mg/l 2, 4-D, 0.01 mg/l gibberellin, 10-3M L-arginine, 10-3M L-aspartic acid and 1mg/l ascorbic acid. Addition of kinetin showed no remarkable effect. 2) Cymbidium goeringii; Rhizome-tips of C. goeringii cultured on the basal medium always developed into rhizomes without shoot formation. Addition of 10mg/l kinetin led most of samples to shoot formation. Whereas low concentration of NAA tends to promote the growth of shoot in combination with 10mg/l kintin, high concentration of NAA tends to counteract the stimulating effect of kinetin on the shoot formation. Incorporation of 10-3M L-arginine and L-aspartic acid stimulated shoot formation slightly. Growth of rhizome was improved by addition of 10-3M L-tryptophan and 0.1mg/l biotin to some extent.
The study was purported to clarify the meaning of respiratory pattern as an index of physiological state of harvested fruits, and the relation of ripening phenomenon to respiration was investigated with various fruits including several species of which respiratory pattern had not been clear. This paper reports the results obtained with Japanese persimmons. 1) Three cultivars of persimmon fruits, two astringent (Atago, Miyazakimukaku) and a nonastringent (Hanagosho), were stored at 20°C, and productions of carbon dioxide and ethylene in individual fruits were measured. Carbon dioxide production increased during the ripening in most materials used, but the time of increasing seemed to be different from the fruits of typical climacteric class, it began at late stage in ripening process and eached a maximum rate at over-ripe stage. 2) Increase of ethylene production occurred in the course of ripening. The time of increase, however, considerably preceded the onset of respiratory rise, and nearly corresponded to the beginning of softening. 3) Development of peel color, and rapid increase of carotenoid pigments in the pulp also markedly preceded the respiratory rise. 4) Effects of application of respiratory inhibitors and pyruvate on the respiration of pulp tissue slices of Hanagosho fruits changed greately during the ripening. 5) When glucose-U-14C and citrate-1, 5-14C were applied to the pulp slices (Hanagosho), CO2 production from the former increased during the ripening, but that from the latter showed remarkable decrease. 6) Fluctuations of organic acids were observed. In Hanagosho pulp, citric acid disappeared and fumaric acid increased at advanced stage of ripeness. Malic acid content tended to increase to some extent. In Hiratanenashi fruits (astringent cultivar), both malic and citric acids contents showed marked decrease when the fruits softened. 7) Ratio of protein-nitrogen to total nitrogen in the pulp showed a little increase during the ripening. 8) It was discussed that the respiratory rise in Japanese persimmons would associate with the senescence of fruits, and the pattern differs from typical climacteric phenomenon.
1) Astringency appeared again after boiling whole fruits which had apparently lost their astringency with the warm water treatment. 2) From the warm water treated fruits, the contents of coagulated tannin cells were collected by sieving the blended flesh in water. Under microscopic observation it was found that the protoplast in the tannin cells had jelled. This substance was insoluble in cold water, methyl alcohol, ethyl alcohol, ether, acetone and formamide, but it was soluble in hot water, dilute hydrochloric acid, methanolic hydrochloric acid and ethanolic hydrochloric acid. 3) Almost equal amounts of the tannin substances were extracted by 1% methanolic hydrochloric acid from the warm water treated fruits as from the untreated astringent fruits. Also, both extracts were equally astringent by taste. 4) The astringency reappeared when the protoplast gel in the tannin cells was dissolved in hot water. More than 90% of the tannin substances were dissolved in 100°C water. 5) Astringency reappeared with the destruction of the protoplast gel in the tannin cells by supersonic waves. About 40% of the tannin substances were dissolved in cold water in 15 minutes by supersonic waves. 6) These results suggested that the removal of astringency by warm water treatment was not due to chemical changes of the tannin substances such as polymerization or condensation but was due to the gel formation of protoplast in tannin cells.