It has been reported that Alternaria kikuchiana TANAKA, causal agent of black spot disease of Japanese pears drived from variety Nijisseiki, produces host-specific toxin. In this experiment, the host-specific toxic substance was isolated from culture filtrate and mycelium of the fungus. After growing the fungus in potato-decoction medium added 2% sucrose at 25 to 28°C for 18 days, crude toxin was extracted with both ethyl ether from dried mycelium and chloroform from culture filtrate adjusted to pH 3.2 with N/1 HCl. The toxin was purified from acid fraction of crude toxin with column chromatography (silica gel column). As the purified toxin showed single spot by thin layer chromatography, it was regarded as monosubstance. The young leaves of variety Nijisseiki, susceptable pear, responced to the isolated host-specific toxin, but the young leaves of variety Chojuro, resistant pear, did not responce to it.
In 1963 and 1964, effects of some kinds of fatty acids and glycerine, which are main constituents of rape seed oil, on hastening the maturity of fig fruits were studied. Method of application and materials used here were as those indicated in the previous paper. 1. Treated fruits with fatty acids such as linolenic acid, oleic acid and stearic acid were markedly promoted the maturation of the fruits. Among the fatty acids tested, linolenic acid(three-carbon double bond, unsaturated) was most effective than the others. 2. No effect was observed on glycerine treated fruits. 3. Mature fruits treated with fatty acids and glycerine were as good in size, fresh weight, skin color and contents of reducing sugar and malic acid as those allowed to mature naturally.
1. In order to investigate the effects of soils derived from various parent rocks on the growth of Satsuma orange trees, concrete frame experiment was carried out for 9 years from 1957 to ′65. The soils examined were as same as reported in the previous paper. Among the soils, there were considerable differences in physical and chemical properties; soil texture, moisture holding capacity, acidity and constituents of exchangeable cations. This paper deals with the results of leaf analysis during 4 years from 1962 to ′65. 2. Contents of N, P, K, Ca and Mg in the leaves fluctuated in the wide ranges as follows: 2.77-3.49% N, 0.131.-0.203% P, 1.13-1.96% K, 1.97-3.78% Ca and 0.254-0.513% Mg. The trees containing high N content in the leaves showed the depression of Mg absorption. Such antagonism was somewhat observed also K absorption. Whereas, sandy soil produced the trees with low N and high K and P in the leaves. K content in the leaves was remarkably low in the soil which contained rich exchangeable Mg. A soil containing least exchangeable Ca and Mg produced higher potassium leaves than other soils. 3. From the results obtained throughout the experimental period, it was found that there was significant negative correlation in the leaves between N and Mg content, K and Ca, and K and Mg, and positive correlation between P and K. The tendency of adverse interaction was also observed between N and P, P and Mg, and Ca and Mg. The content of Ca and Mg in the leaves correlated significantly (positive) with that of exchangeable Ca and Mg in the soils. Also, the positive correlation was found between leaf P and acid-soluble or total P in the soils. On the other hand, under the condition of soils and fertilizer dressings in present experiment, the more K content in the soils being the less K content in the leaves. This may be affected by other elements, probably nitrogen and magnesium. 4. Judging from the results of leaf analysis, it may be concluded that some different effects of the various soils on the tree behaviors and fruit qualities mainly due to the difference of nitrogen content in the soils and leaves.
1. It is very interested to know the effectiveness of fall and winter sprays of potassium and phosphate on the flower bud formation of Satsuma orange trees. Satsuma orange trees of 19-and 60-year-old, nearly uniform size, growth, and bearing habit and of medium growth were used. The rootstocks were Poncirus trifoliata. 1 or 0.3 per cent solution of KH2PO4 were sprayed from the middle of October to the end of January. The number of flowers, represented as per cent of the number of nodes, increased by the sprays on the harvest time of Satsuma orange in November and December. The more effects were observed on the shoots of weak growth by sprays of KH2PO4 than the shoots of medium growth. From chemical analysis of the shoots sampled in the following January, it was shown that the sprayed shoots contained less nitrogen and much more carbohydrates than the unsprayed shoots. 2. The oil-emulsion has been used as the common spray material for the control scales and other insects and mites. However, it has been also found that there are some deleterious effects on the physiology of the orange and flower bud formation by the oil emulsion spray. 3. Three per cent of oil emulsion diluted from 60 or 95 per cent of the machine oil was used in the experiment. a) The number of flowers, represented as per cent of the number of the nodes decreased on the shoots of medium and weak growth, which was sprayed on January 15 and February 25. There was no effect on the flower formation by the sprays at the time of the flower differentiation in March. b) Oil emulsion was sprayed over the halves of the main branches of each tree on December 24 and January 24. The lateral shoots developed from the sprayed and non-treated branches were defoliated once a month November to February. The number of flowers on the defoliated and sprayed branches were 8 to 18 per cent less than those of the defoliated and non-treated branches. The number of flowers on the shoots defoliated on November were the least.
In spite of many extensive studies there is still no clear explanation of what factors produce the condition of cold hardiness in such plants as the woody evergreens. Freezing resistance studies of leaves and shoots of Satsuma orange were made concurrently with microscopic and chromatographic observations during 1962 to 1965. The principal results were as follows: (1) An exposure of Satsuma orange trees to an air temperature of -7.5°C for 3 hours resulted in no leaf damage in January. On the other hand, temperatures near -3°C was found critical in late March as shown in Figure 1 and in Table 1. (2) Osmotic concentration of leaves generally increased during the autumn, reaching a maximum in January and February. Figure 2 shows the seasonal fluctuation of cold hardiness of leaves was associated considerably with that of osmotic concentration. (3) A significant negative correlation exists between osmotic concentration and water content of leaves as shown in Figure 2 and in Figure 3. (4) A marked decline in starch content of leaves in November was closely associated with the sugar increase as shown in Figure 4 and in Figure 5. (5) No seasonal trends in leaves were observed for polyhydric alcohol levels as shown in Figure 5. (6) Chromatograms of sugars from leaves showed fluctose, glucose, sucrose and raffinose as shown in Figure 6. Sucrose showed a marked increase in winter, though it decreased in October and November.
Swiss chard (Beta vulgaris L. var. flavescens D.C.) was grown in gravel culture using Hoagland′s No. 2 solution under polyvinyl plastic growth chambers to investigate the practice of CO2 enrichment of the atmosphere on plant growth. Five chambers were employed with each at 300 (air), 600, 900, 3, 000 and 6, 000 or 30, 000ppm CO2, the concentration being regulated by adjusting the flow of CO2 and air into the chamber. Treatments were for 9 weeks in the early summer and winter experiments and for 24 days in the midsummer experiment. Benchs were maintained above 15°C during the winter experiment. In all experiments, fresh weight and dry weight yields, plant height, and leaf areas markedly increased with increasing CO2 concentrations; but, no significant difference was observed in the number of leaves. In the summer at 3, 000ppm, dry weight yield was five times more than those grown at 300ppm and in the winter the yield was twice as those grown in 300ppm. Fresh weight and dry weight yields did not reach a maximum even at 30, 000ppm. Analyses of leaves at the end of the experiments showed that percentages of the N, P and K on a dry weight basis were nearly the same regardless of treatment.
The object of this study was to clarify the difference in the temperature patterns in the tunnels covered with different plastic films. Tested films were PVC ordinary film 0.1mm thick, drained (non-drip) film 0.1 and 0.05mm thick, and polyethylene 0.1 and 0.05mm thick. Shape of tunnels was 6m long, 110cm in base width, and 50cm high. Tunnels were set in parallel in an east-west-direction. Temperatures at the height of 25cm above the ground surface and 5cm deep in the soil were automatically recorded. The record showed that day-time air temperature was higher in the drained PVC film than in ordinary PVC or polyethylene film. In cloudy or rainy nights, air temperatures in PVC and polyethylene films showed little difference and were higher than the outside temperature, while in clear nights, temperature in PVC films was higher than that in polyethylene film. An unexpected phenomenon that air temperature in tunnel fell lower than the outside air temperature late in clear nights was frequently observed. Thickness of film affected temperatures in the tunnels, though not so significant in most cases. Relative order of soil temperatures in the tunnels covered with different films was the same as that of the air temperatures. Small tunnels were set on dry sand in order to compare temperature conditions covered with the films, the inner surface of which was free from water droplets. Temperature difference between ordinary and drained films of PVC could not be observed in this case. This result showed that water droplets condensed on the inner surface of the film had a marked effect on the day-time temperatures in tunnels, probably due to their reflection of sun light. Transmission rates of the films to radiation were measured in the range from ultra-violet to infrared. It was revealed that there was little difference between PVC and polyethylene films in transmission rate in the range from visible to infra-red up to about 6μ, while polyethylene was more transmissible to the infra-red longer than 6μ than PVC. It is known that radiation from black body, temperaturue of which is as high as the soil surface under the tunnel, is mostly in the range longer than 6μ and has its maximum at about 10-11μ. Lower temperature in the tunnel covered with polyethylene film than in PVC film in clear nights seemd to be due to its higher transmission rate to the longer portion of infra-red radiation. A probable cause of the phenomenon that air temperature in the tunnels fell lower than the outside air temperatue during clear night was briefly discussed.
The present studies were carried out to ascertain the influence of the early environmental conditions and the cultural treatments upon the morphological and physiological development of the tomato flowers and the flower drop. 1. Effects of the early environmental conditions and the cultural treatments on the morphological development and the premature drop of the flowers. Tomato seedlings (Variety: Fukuju No. 2) were grown at three different night temperatures (17°C, 24°C and 30°C) and/or under different light intensities (100, 74, 49 and 24 per cent of natural day light). The higher night temperature and/or the lower light intensity retarded the morphological development of flowers and hence resulted in forming smaller flowers with smaller sepals, petals, ovaries and especially smaller anthers and heavy flower drop ensued. Tomato seedlings were grown in the soils of three different levels of fertility. The lower became the soil fertility, the smaller became the flowers, with smaller sepals, petals, anthers and especially smaller ovaries and ensued the increased flower drop. 2. Relations between the morphological and the physiological development of the tomato flowers. The seedlings grown at the higher night temperature and/or under the lower light intensity contained the lower level of total sugars and polysaccharides (including starch) in the flowers, stems and leaves. These seedlings had smaller flowers and especially smaller anthers, with mostly abortive pollens and lower auxin content. The seedlings grown in the soil of lower fertility contained the lower levels of nitrogenous constituents in the flowers, stems and leaves and had smaller flowers and especially smaller ovaries. 3. Relations between the flower drop and the morphological and physiological development of the flowers. The flower drop of the seedlings grown at the higher night temperature and/or under the lower light intensity were effectively controlled by the auxin application at full bloom. The flower drop of the seedlings grown in the soil of lower fertility were not effectively controlled by the auxin application at full bloom.
1. To clarify the suitable physical properties of bed soil for muskmelon cultivation, six plots which consisted of factorial combinations of two sizes of clod (0<diam._??_2mm and diam. =3-6mm), and three kinds of soil conditioner (not added, 0.05% poval and 12% manure) were established, and effects of these treatments on the growth, the fruit weight and quality, and the nutrient absorption of muskmelon were investigated. 2. With 3 to 6mm clod, the growth of plant as measured by the dry weight of the whole plant, the fruit weight, and the accumulations of phosphorus, calcium and magnesium in the whole plant were slightly increased as compared with the case of using the clod (0<diam. _??_2mm). Manure application (12% by weight) to the soil consisted of both sizes of clod markedly decreased the growth of plant, the fruit weight, the concentration of 2 % acetic acid soluble calcium, and the accumulations of nitrogen and calcium in the whole plant. On the contrary it markedly increased the concentrations of NO3-N, available phosphorus, exchangeable potassium and magnesium, and the electrical conductivity of the soil. As far as this experiment concerned, poval application to the soil consisted of both sizes of clod did not affect the physical properties of soil, so that the growth of plant, and the weight and quality of fruit seemed to be not influenced. 3. The interaction of clod size and soil conditioner was observed in the growth of plant, the fruit weight, the soluble solids and external appearance of the fruit, the calcium concentration, and the accumulations of nitrogen, phosphorus and calcium in the whole plant. That is, the means of the fruit weight in the plots of S-N, L-N, S-P and L-P were 797, 774, 805 and 785g, respectively, on the contrary those in the plots of S-M and L-M were 338 and 538g, respectively. The interaction of clod size and soil conditioner on the other effects was the same as the one above. Judging from these results, in the case of using the clod (0<diam. _??_2mm), the concentration of soluble salts in the soil must be kept in a low degree. 4. To clarify the relations between larger sizes of clod and fewer volumes of manure, nine plots which consisted of factorial combinations of three sizes of clod (diam. =3-6mm, 10-15mm and 30-35mm), and three levels of manure application (0, 3 and 6% by weight) were established, and effects of these treatments on the growth, the fruit weight and quality, and the nutrient absorption of muskmelon were investigated. 5. With 3 to 6mm clod, the growth of plant as measured by the dry weight of the whole plant, and the fruit weight were slightly increased as compared with the case of using the larger sizes of clod. The soluble solids and external appearance of the fruit were not affected by clod size. 6. Though the accumulations of phosphorus and potassium of the whole plant were slightly increased with increasing the application amounts of manure, the growth of plant, and the weight of fruit were not increased, nor the quality of fruit was improved. Judging from these results, the suitable clod size for muskmelon cultivation seemed to be 3 to 6mm in diameter.
(1) The author bred up a new amphidiploid plant at the progeny of the cross between“Fuyo” (H. mutabilis) (2n=92) and“Momiji-Aoi”(H. coccineus) (2n=38). (2)The main characteristics of this new amphidiploid plant named“Momiji-Fuyo”were as follows: This amphidiploid plant showed heterosis. The stem resembled H. mutabilis which are shrublike. The color of stem, petiole and vein were intermediate of the parents. The flower color was beautiful like H. coccineus. The petal size and flower size across were larger than the parents. The flowering period was longer than the parents, about 110 days. The calyx was 5-toothed like the parents. The number of bracteole was intermediate of the parents. The pollen fertility was higher and the size of the pollen grains was larger than the parents. The seed number per pod was intermediate of the parents. The seed shape was similar H. mutabilis. The seeds had many hairs on their surface like H. mutabilis, but their color was darker than H. mutabilis and their size was larger than H. mutabilis in length, width and thickness. (3) In these amphidiploid plants, the chromosome configuration at MI of PMCs showed 65II with no irregularities. The chromosome number in root tips was 2n=130. (4) The author would like to propose that these new amphidiploid plants be given the Japanese name “Momiji-Fuyo”and scientific name H. muta-coccineus KUWADA.
1. Experiments on the seed germination of some palms (Butia capitata, Phoenix canariensis and Washingtonia robusta) were carried out. Germinations of Phoemix canariensis seeds and Washingtonia seeds are easy, but that of Butia capitata seeds shows a little difficulty caused by the dormancy or some other inhibiting factors. 2. The optimum temperature and days required for germination are 30°C and about 60 days in Butia capitata, 30-35°C and about 20 days in Phoenix canariensis, and 25-35°C and 8 days in Washingtoniarobusta, respectively. 3. Sand and vermiculite are better for Phoenix and Washigtonia while clayey soil is preferable for Butia as the germination bed. 4. There are some differences in the morphological and anatomical structures of seeds among the species experimented. Therefore the process of germination must vary depending on the species. The germination of Washingtonia robusta seeds is easy as the structure of its seed is simple like that of cereal seed.
Using plants propagated from crown-tubers or cuttings, the authors studied the factors affecting the dormancy of axillary buds of dahlia. After the plants were grown under the photoperiod of 10, 11, 12 or 13 hours for various days after decapitation, their lateral shoots were cut off at the lowest nodes. All the plants were then transferred to 14-hour day-length. As shown in the previous papers, dahlia is a non-obligate short-day plant. The optimum photoperiod for its flowering is13 to14 hours, and the lower critical photoperiod is about 12 hours. When dahlia plant is grown under photoperiods shorter than the lower critical length, its top growth is much inhibited, and flower buds formed remain blind. The lower critical photoperiod of the plants propagated from cuttings was about 12 hours. When the plants were grown under a photoperiod of 12 hours or less for 70 to 80 days, their axillary buds became dormant. The lower critical photoperiod of the plants propagated from crown-tubers was longer than that of the plants propagated from cuttings. And the axillary buds of the former became dormant more easily than those of the latter. When the plants propagated from crown-tubers were grown under 13 hour day-length for 80 days, some of their axillary buds did not sprout. When all the mature leaves were removed after 60 to 70 days of short-day treatments, the axillary buds sprouted and grew better than those of intact plants. However, if the plants remained under short-day for 80 days, the axillary buds did not sprout either even if all the leaves had been removed These facts suggest that mature leaves exposed to short photoperiods may produce some substance which inhibits sprouting of axillary buds. And it seems that this substance moves from mature leaves to axillary buds or near the buds and accumulates there, causing the buds to rest.
This report is concerned with the effects of storage temperature or humidity upon the occurrence of Hassaku oleocellosis and also with the results of several treatments tested for the prevention of oleocellosis. 1. The injury of Hassaku fruits caused by oleocellosis was far more slight in the storage room in case of the low temperature (5°C) storage immediately after picking at the end of December than in the storage at natural room temperature, but oleocellosis occurred severely at the period from March to May shortly after putting out of fruits from the storage room of low temperature, and this injury after storage was more severe in April than in March. 2. When the air temperature is low after storage, the injury is only slight even in the later season, and on the other hand the injury became severe when fruits were kept at high temperature (25°C) immediately after picking in December, or after short period storage in January. 3. Immediately after putting out from the storage room of low temperature, fruits were kept at the controlled conditions which were combinations with 3 levels of temperature (5°C, 15°C, 25°C) and 2 levels of relative humidity (61-86%, 91-100%). Fruits kept at high temperature and low humidity were apparently more susceptible than those at low temperature and high humidity, and the effect of temperature seemed to be more dominant than that of humidity. 4. The storage room temperature was maintained at 3 levels (10°C, 15°C, 20°C) during 4 days just before putting out of fruit from the storage room, but these treatments were not effective at all for the prevention of oleocellosis occurring after storage. On the contrary, a remarkable decrease of occurrence of Hassaku oleocellosis was seen, putting out of fruits after the storage temperature (5°C) had been hightened to 10°C at the rate of 1°C a day, But a sufficent effect was not always seen with various conditions of temperature after putting out of fruits. 5. The above mentioned results suggest that the occurrence of oleocellosis is probably due to the great difference between the air temperature after storage and the fruit temperature in storage rather than to the length of storage period. 6. For the purpose of the prevention of oleocellosis, the effects of several treatments applied to fruits were studied immediately after putting out from the storage room of low temperature. These treatments are bagging with Polyethylen film, Wax coating, dipping, with O. E. D (5%), Stop-scald (0.2%), Metrose (0.5%) or coating of Acrylic acid resin. Consequently the Wax and Acrylic acid resin are noticeably effective for the control of oleocellosis and these treatments seems to be worthy for practical use.
Squeezing treatment had been employed to obtain juice from fruits. In the case of berries such as passion fruit and grape, the operation is difficult and the yield low owing to their flesh texture. A method, to make the squeezing operation easier and to raise the efficiency by melting the flesh using commercial cellulase and pectinase, was studied. (1) In the case of passion fruit, optimal amount of the enzyme preparation for practical use was 1 per cent of the pulp, under the condition of pH 3.8 (pH of the native pulp), temperature of 29° and shaking treatment with reciprocal shaker (150rpm, 8cm of amplitude) for 120 minutes, on the other hand, with grape, sufficient amount was only 0.1 per cent of the pulp (pH 4.6) by shaking for 60 minutes at 31°. (2) Compared with the contrast, the efficiency ratio was 10 per cent with passion fruit and as high as 30 per cent with grape. The specific gravity of the juice was higher according to the accelarated extraction of coloring matters, sugars, acids and other substances such as pectic substances. (3) Favorable efficiency in passion fruit was observed by the use of macerozyme and in grape brought also by pectinase, though in the former pectic substance was more easily extracted and in the latter it disintegrated into containing as trace even by the addition of 0.1 per cent.