Mustards, Brassicas which have 18 pairs of chro-mosomes, are important vegetables in the Orient. In Japan, though they are of relatively minor impor-tance, there are many local varieties and rather wide variations of characteristics in the mustards grown there.
The authors have collected and cultivated about 200 varieties from Japan, China, Formosa and Nepal since 1946, and have investigated their characters. According to their plant size, root forms, tillering ability, and leaf characters, the authors classified them into eight classes and 25 groups, as shown in the table.
(1) Brown mustard
This oil mustard is of world-wide importance and is generally grown for its oil and for flour. It is little grown in Japan, mostly confined in the north-ern part.
(2) Tuberous rooted mustard
Cultivation of this curious vegetable is confined in North China, Manchuria and Mongolia, where the winter is severe (Fig. 1 and 5).
(3) Chinese curled mustard
It is grown in Central China and differs from the curled mustard (5) in respect to its fasciculate growth (Fig. 5).
(4) Narrow leaf mustard
Although resembling to some types of the former (3), it is distinguished in muilified leaves and has been grown in the same region (Fig. 7).
(5) Curled mustard
Possibly of South Asiatic origin. It is frequently grown for a salad in Europe and America, and its several varieties have established themselves in Japan (Fig. 8).
(6) Broad leaf mustard
In China its distribution ranges from the middle to more or less southern parts. It was possibly introduced early into Japan, and has been locally grown in the middle and southern parts (Fig. 9).
(7) Cabbage mustard
It has widely been cultivated in the South-east Asia, especially in South China and Himalaya and has been the most important vegetable for salting, because of the lack of Chinese cabbage and radish production there. Its quality is excellant. In Japan it was introduced from Szechwan, China, about fifty years ago, and has been acclimatized through hybridization with the Japanese varieties. It is becoming important for commercial growing in this country (Fig. 10).
(8) Tuberous stemmed mustard
A wonderful type grown in South China, especi-ally Szechwan Province and Formosa. Its salted products are very delicious, being regarded as the best pickle in Asia (Fig. 1).
All classes except the brown mustard which is considered as the basic type, can be summed up into the following four group based on their characters and distribution.
1. The tuberous rooted mustard which is distrib-uted in the northern part of the Chinese Continent. 2. The Chinese curled mustard and narrow leaf mustard in Central China.
3. The broad leaf mustard, cabbage mustard and tuberous stemmed mustard in South-east Asia.
4 The curled mustard of probably South Asiatic origin.
These four groups would have probably been main stems in the evolution of varieties from the brown mustard.
It may be concluded as follows:
The species of Brassica juncea is a native of Cen-tral Asia, and the variation in the characteristics of mustards occurred in the region from the south to north-east of it's native area. Various forms cultivated at first in this native place have evolved and differentiated into the polymorphic and valuable variations in China.

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When the vine of the chinese yam corrtinues its growth beyond the extreme of its support, it com-mences to hang downwards. The authors have noted that aerial-tubers are formed when the vine is in an inverted position and that the formation is restricted within the part hanging downwards. Based on the above mentioned fact, we have con-ducted experiments in order to clarify the 'effect of direction' of the vine upon the aerial-tuber formation. The results observed may be summarized as follows 1. When the vine is growing vigorously upwards, generally no aerial tubers are formed. Whereas when the vine is inverted artificially, aerial-tubers begin to develop in the axils of the leaves. In this case, the size of aerial-tubers increases by steps and mark-edly as the inverted tip is approached, which denotes that there is no correlation between the size of the aerial-tuber and the leaf area of respective node. Moreover, when the vine is trained in a wave form directing the vine upward and downward alternately, the aerial-tuber formation is restricted to the downward parts of the vine. From these results, it is conjectured that gravity has an important effect upon the formation of aerial-tubers.
2. Chemical analysis of leaves reveals that the rate of flow of carbohydrates from the leaves is more sluggish in the 'inverted vine than in the upward growing vine.
3. To further elucidate our point additional experiments with common potatoes were conducted. When experimental potato plants were allowed to grow downwards in a hanging position a similar aerial-tuber formation occurred.
4. In order to block the translocation of carbo-hydrates from leaves, the tuberous root was removed at an early stage. In this case, aerial tubers are formed not only in the hanging but also even in the upwards growing vine. Chemical analysis of leaves indicated a high accumulation of carbohy-drates in the leaves of treated plants.
5. The aerial-tubers can readily be induced to form in the axils of the leaves by stem cutting or leaf bud cutting; presumably because of the car-bohydrate accumulation.
6. From these results, it is evident that the accumulation of carbohydrates in the above-ground part is the causal factor which induces the forma-tion of aerial-tubers of chinese yam, and in the open field, the accumulation of carbohydrates is induced naturally by dangling of vine.

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In the present paper, the author deals with the experiments to determine the causal agents of “yuzuhada” (hard end or black end like physiological disease) development in Nijisseiki pear fruits. The results obtained are summarized as follows.
1. As to the seasonal changes of osmotic pressure, in the mature leaves, it indicated higher values (ca. 16_??_17 atms.) in May and July and lower values in June (ca. 14 atms.). During May-June the osmotic pressure in the young leaves was approximately two atms. lower than one in the mature l _??_ ves. On the other hand, the osmotic pressure in the fruits was almost constant (10_??_11 atms.) from May to middle July, and after that time gradually increased until it came up to 13. 5 atms. at the harvest period. The moisture content in the leaves decreased by approximately 10 percent from May to September, whereas it increased by about 10 percent in the fruits.
2. The difference of osmotic pressure between leaf and fruit showed a maximum value in July (ca. 6 atms.), and then decreased in August as a consequence of the osmotic pressure of fruit.
3. As to the daily changes of osmotic pressure in hot and dry summer days, it showed a minimum value at 5 a. m., then rose reaching a maximum value at 2 p. m., and then lowered towards evening. The fluctuation of osmotic pressure in the daytime came up to ca. 4_??_7 atms., specially under the dry condition.
4. As to the daily changes of osmotic pressure in the “yuzuhada” tree, though there was little difference in them between the “yuzuhada” tree and the healthy one in the daytime, the gradual declining degree of osmotic pressure towards night in the “yuzuhada” tree was less than that in the healthy one. Consequently, in the former the remarkable difference of osmotic pressure between leaves and fruits was maintained for a longer period.
5. As soon as the soil moisture decreased in the neighbourhood of field capacity, the deficiency of moisture content and the increase of osmotic pressure in leaves was revealed. And under the more decreased soil moisture condition, that is, the so called first permanent wilting point, the moisture content in leaves decreased by approximately 10 percent and the osmotic pressure increased by 5_??_6 atms. The decrease of the moisture content and the increase of the osmotic pressure in fruit was revealed, when the soil moisture decreased till half-way between the field capacity and the first permanent wilting point. Under the first permanent wilting point, the moisture content in fruit decreased by 2_??_2.5 percent, and the osmotic pressure in it increased by 2_??_2.5 atms.
6. When the difference of osmotic pressure between leaves and fruits reached about 5 atms., the decrease of moisture content and the increase of osmotic pressure in fruits was recognized. It has been supposed that Yuzuhada develops when fruits are deprived of their moisture by leaves under water deficient condition. Accordingly, from the above mentioned observations, it was understood that is must be in July and hot and dry summer that “yuzuhada” remarkably develops.
7. Water deficiency in the first part of July produced extremely high “yuzuhada” percentage, and the disorder developed in 20_??_25 days after the treatment (the middle or latter part of August)., Field observation revealed that most of “yuzuhada” fruits developed during August.
8. Pyres betulaefolia stock is known to produce little “yuzuhada” on the Nijisseiki scion grafted on it. The osmotic pressure of leaves of P. betulaefolia was always higher than those of P. serotina and Nijisseiki pear (P. serotina var. culta).
9. Between osmotic pressure of leaves of Nijisseiki grafted on P. betulaefolia and that one grafted on P. serotina

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1. The curve for daily variation of the amount of insolation on the southern and northern slopes is symmetrical to the noon line, regardless of inclination and month. The largest of the amont of insolation appears at noon. But in June, its amount on the northern slope is smallest at noon, taking the form of a concave in the case of inclinations more than 55. if the inclination of the slope becomes steeper, the sunshine exists only in the early morning and in the late evening.
On the southern slope, in the warm season, the duration of sunshine decreases as the slope inclination increases; in the cold season, the times of sunrise and sunset become similar for all slope inclinations as it is on the flat surface.
2. On each slope situated in southwest, west and northwest (southeast, east and northeast), the times of sunset (sunrise) is the same as it is on the flat surface, while, as the slope inclination increases, that of sunrise (sunset) comes to be later (earlier) than that on the flat surface.
The time when the amount of insolation becomes greatest, comes to be later (earlier) than on the flat surface, as the slope inclination increases. Therefore, these slopes are favoured with the amount of insolation in the afternoon (in the morning).
3. The relation between the inclination of the slope and the amount of insolation is as follows: In the cold season: The amount of insolation on the northern and northwestern (northeastern) slopes is smaller than on the flat surface, and decreases as the slope inclination increases.
On the southern and southwestern (southeastern) slopes, its amount is greater than on the flat surface, the greatest amount is on that slope which is perpendicular to the sun. So it is greatest at the inclination near 60°.
The amount of insolation on the western (eastern) slope lies about halfway between northwest (northeast) and southwest (southeast) slopes.
In the warm season: The amount of insolation is less on every inclination in all directions than on the flat surface and decreases as the inclination of the slope increases.
4. As to the yearly variation of the amount of insolation, the amount on the northern, northwestern (northeastern) and western (eastern) slopes is greatest at the summer solstice and least at the winter solstice throughout every inclination in all directions. Its amount on the southern slope is largest at the summer solstice and least at the winter solstice when the slope inclination is small; as the slope inclination increases, two maxima come to appear before and after the summer solstice. As the slope inclination increases still more, the amount of insolation becomes largest at the winter solstice and least at the summer solstice as seen at 90° inclination.
5. In the cold season, the daily total amount of insolation, is largest on the southern slope throughout every inclination in all directions, the amount of insolation becomes less in the following order, southwestern (southeastern), western (eastern) and northwestern (northeastern) slopes, and the northern slope takes the least. In the warm season the southern slope takes the least and the western (eastern) slope takes the largest.
6. The yearly total amount of insolation, is least on the northern slope, throughout each inclination of the slope. The southern slope takes the largest amount up to 70° inclination, but over the degrees, the largest amount appears towards the southwestern and southeastern slopes.
Thus, as the inclination of the slope increases, the distribution of the amount of insolation takes the form of a heart, and it becomes gradually flat as the inclination increases further.
7. The amount of insolation received by a trunk of a plant is larger on its northern side than on its southern one, in the warm season about June or July.
In the cold season, the northern side of a trunk takes no sunshine all the day

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Since 1949, domestic apple seedlings have been tested on their root-stock values, comparing with the seedlings of M. Sieboldii, which are used com-monly as apple root-stocks in our country.
The result of this test shows that the former is never inferior to the latter in respect to stock per-formance. Besides, apple tree on apple seedling root-stocks are apt to grow rather uniformly, while M. Sieboldii stocks produced dwarf tree in a few cases. Consequently, the believes among some grow-ers that apple seedlings are unfavorable as root-stocks for the poor uniformity of trees, might be incredible.

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(1) This study was carried out in order to clarify the effects of length of storage (shipping) period from termination of the cold temperature treatment to the planting; and the effects of tem-perature during the storage, on flower forcing of tulip bulbs for export.
(2) In the first experiment, the treated bulbs-of three varieties (Feu Brilliant, William Pitt, and Bartigon) were planted after 0, 15, 30, 45 and 60 days storage at room temperature from September 15 th, when the cold temperature treatment had been completed.
In the 15 days storage plot, growth was most excellent and flowering was earliest. In the plot planted immediately after the treatment (0 day storage), growth was slow owing to high temperature of September and flowering was not so early. In the 30 days storage plot, growth was good and flowering was early, butl;rather irregular due to unusual high temperature in the latter part of November. In those three plots, vigorous root growth started at about the end of November regardless of the planting time. As earlier planting was unfaborable for its poor early growth, planting after 15_??_30 days storage seemed to be superior for flower for-cing of the treated tulip bulbs.
In 45 and 60 days storage plots, root growth was delayed, because the bulbs were planted so late that the disks had swollen at the planting time and temperature became low. But growth of root and nose was very regular and excellent, and flowering was not so delayed.
(3) In the second experiment, the treated bulbs were stored at 10, 15, 20, and 25°C for a month, and the effect of storage temperature on subsequent growth and flowering was studied.
It was found that 10°C was most favorable, 15° and 20°C came to the next (flowering was delayed a little), and 25°C delayed flowering decidedly.
(4) From these results, it was suggested that the tulips bulbs which had been treated by the cold temperature until September and then were ship-ped from Japan to U. S. A. at about 10_??_15°C (preva-iling temperature during shippment) for a month, could be easily forced to bloom in late December and January, if they were planted on arrival, and were forced in greenhouse from early November.

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Studies were carried out in order to clarify the optimum concentration and time of spraying of maleic hydrazide (MH) as sprouting inhibitor of onions for storage. The results obtained were as follows:
1. Experiment on the concentration: 0.05_??_0.8% solutions of MH (as sodium and diethanolamine salts) were sprayed on onion plants nineteen or seven days before harvesting. Onions were har-vested when about 70% of leaf stalks have failed down. At the harvesting time, there found no significant difference in growth and yield of bulbs among the plots sprayed with various concentrati-ons of MH, and no chemical injury was observed on all the plots.
After storage (in December), onions sprayed with higher concentrations of both salts (0.1% or more) were inhibited their sprouting, and onions sprayed with 0.8% of sodium salt and with 0.2%. or more of diethanolamine salt showed little sprouting. But higher concentrations tended to result more rot of onions in storage. Therefore percentage of bulbs with commercial value were higher in the plots sprayed with 0. 4%o of sodium salt and 0. 1% of more of diethanolamine salt.
From the above mentioned results, the optimum concentration of MH may practically be 0.4% of sodium salt and 0.2% of diethanolamine salt, when 70_??_90 liters of solution was sprayed per acre.
2. Experiments on the time of spraying: At various times since 43 days before harvesting, 0.1 and 0.5% solutions of MH were sprayed on onion plants. Earlier spraying (30 days or more before harvesting) induced chemical injuries on leaves and bulbs of the plants, and reduced the yields of bulbs, and moreover increased percentage of rotted bulbs. From the results obtained, the optimum time of spraying of MH may practically be 1_??_3 weeks before harvesting.

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According to the first appearance of pollen ger-minating power two distinct types exist in plant. In the first type pollen germinating power appears before anther dehiscence, while in the second type it appears after anther dehiscence.°Cucumber be-longs to the first type and egg-plant to the second. Studies of pollen germinating power in°Cucumber and egg-plant were°Conducted from two days be-fore anthesis, to show the effect of different tem-peratures, on pollen germinating power.
Pollen was taken from anthers at different stages of anthesis and sown on artificial medium (1% agar, 16% sucrose and pH 6.2-6.4 in°Cucum-ber, 1% agar, 8% sucrose and pH 5.6 in egg plant).
In°Cucumber the maximum of pollen viability was recognized at anther dehiscence or immedi-ately after. When the male flowers were placed at different temperatures for 21 hours prior to the following flowering morning (anther dehiscence), no marked difference was recognized in pollen via-bility (Fig. 1). When the temperature treatments were°Carried out from 39 hours before anthesis, pollen viability varied with the temperature (Fig.2). High temperature shortened the pollen longevity, while low temperature prolonged it. The maximum height of pollen viability was observed in male flowers at 20-25°C. The relationship between pollen viability and temperature was°Confirmed by altering temperatures at anther dehiscence (Fig. 3). In egg plant anther dehiscence and anthesis were variable according to temperatures. But anther dehiscence occurred generally before anthesis. Pollen germinating power rose immediately after anther dehiscence. Anthers, graded in three groups according to amount of pollen scattered, were first placed at 20 and 30°C for one day and later placed at 25°C. The results showed that high temperature for one day shortened pollen longevity more than low temperature and anthers scattering abundant pollen grains were in an ad-vanced stage of maturation (Table 1). When an-thers treated at 25°C and 15°C from two days before anthesis, to the flowering morning, were placed at 20°C, the influence of previous tempera-ture was recoginzed in pollen maturation (Fig.4). According to the temperature from anther dehis-cence, the pollen viability and longevity varied (Fig. 5). These facts were noted in the from day to night temperature decline graph (Fig. 6 and 7). The temperature appropriate for pollen maturation seems to be approximately 20°C.
From the above mentioned results, it may be°Concluded that pollen germinating power (pollen viability) and longevity vary with the temperature from two, days before anthesis to old flowers.

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