A Japanese pear seedling population of fifteen families consisting of eight individuals per family and their parental cultivars was statistically analyzed with respect to fruit weight, flesh firmness, refractometer index and pH of juice.
Full-sib population analysis performed from 1963 to ′64 indicated that the ratio of variance component due to family to the total of variance was 0.078, 0.265, 0.046 and 0.066 for fruit weight, flesh firmness, refractometer index and pH, respectively.
From the analysis of the same hybrid seedling population and their parents, statistical significance was obtained in offspring-mid-parent regressions and correlation coefficients; the regressions were 1.152, 0.497, 0.644 and the correlation coefficients were 0.687, 0.560, 0.644 for flesh firmness, refractometer index and pH, respectively.
Both the ratio of variance component due to family to the total variance and offspring-mid-parent regression or correlation in the full-sib population are generally recognized as valuable parameters for estimating the heritability. Particularly the latter is generally considered more adequate.
From the results of the experiments, it is concluded that among the four characters flesh firmness has the highest heritability, followed by the refractometer index and the pH of juice, and fruit weight shows the lowest heritability.

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1. In order to clarify the effect of soil moisture on the development of Satsuma mandarin fruit from early autumn to harvest time, pot experiment was carried out with young Satsuma mandarin trees. In 1969, trees were allowed to grow under high, medium and low moisture conditions for 30 days, and in 1970 some of them were grown under low moisture conditions for 10, 20 and 30 days, after which they were grown under medium moisture conditions, and the others were kept under medium moisture conditions throughout the period.
2. Total and reducing sugar contents of the leaves were increased with reduced soil moisture content.
3. Fruit growth was depressed, and soluble solids content of the juice tended to be higher for trees grown under low moisture conditions for 30 days. Titratable acid content in the juice was highest for trees subjected to low moisture conditions for 30 days. Therefore, fruits of high quality were obtained from trees grown under low moisture conditions for longer periods.
4. Total sugar contents (percent of fresh weight) in fruit became higher with reduced moisture content, but there were no significant differences in amounts per fruit between the treatments of differential soil moisture conditions. There were also no significant differences in amounts of acids per fruit between soil moisture conditions. Therefore, fruits of high quality on trees grown under low moisture conditions appeared to result from reduced absorption of water by the fruit.
5. Between treatments, differences were negligible in amounts of sugars per fruit, but the ratio of reducing to non-reducing sugar differed between them. The proportion of reducing sugar became larger with reduced moisture content and the number of days the trees were subjected to it. Therefore, the metabolism of sugars in fruits appeared to be changed by low moisture conditions in September.

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This experiment was undertaken to clarify the mechanism of dry juice sac development histologically and physiologically with Hyuganatsu (Citrus tamurana Hort. ex Tanaka).
1. Dry juice sacs began to appear near the central axis and then spread along the side membranes of the segment. It was found that the epidermal cells of affected vesicles were twisted and dried out, showing comparatively high permeability of membranes to water.
2. It was shown by the test of injecting a given volume of pigment solution into the center of the segment of mature fruit on the tree that the pigment solution moving around seeds from the injected site was translocated into axial bundles through seed bundles in segments with healthy vesicles, while in segments with severe dry juice sacs, it did not move into axial bundles but remained at the injected site.
3. Respiration and ethylene production of vesicles developing fruit rapidly increased from mid May to mid June, although they had markedly been suppressed until early May. They rapidly increased again during the early developmental stage of dry juice sacs, being followed by a decline with the advance of the disorder. Comparing with peel tissue of healthy fruit, respiration rate per unit of fresh weight was higher in that of disordered one. It appeared that more ethylene was produced in vesicles along the side membranes than in those of the other portions of the segments in mature fruit. The diffusion rate of ethylene was markedly increased in segments with healthy vesicles by incising the connecting wall of side membranes along the axial bundle of mature fruit.
4. During the development of dry juice sacs specific gravity of fruit and total soluble solids, total sugars and citric acid contents of fruit with dry juice sacs became much lower than for healthy fruits. In particular, fruit showing the reduction of citric acid content to about 1 percent of the juice was apt to produce dry juice sacs.

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Gall tissues including wasps obtained from trees of susceptible varieties contained markedly more sugars than the healthy tissues. The sugars in the former were largely composed of glucose, fructose, xylose and ribose, together with a small amount of sucrose for which the content varied with the variety. On the other hand, the latter contained sucrose as the main sugar with little or none of the others. In resistant varieties, not only healthy but also gall tissues contained the sugars at a similar level and with similar constituents to the above mentioned healthy tissues of susceptible varieties.
Sugars contained in the larval body were small in amount and consisted of glucose, ribose and two other unknowns.
Both galls and larvae from the susceptible varieties had large contents of the principal aminoacids and especially the former contained a high level of asparagine.
Aminoacid content of galls from the susceptible varieties was about 6 times as high as that for the healthy tissues. On the contrary, in galls of the resistant varieties the content was very low or at the same level as the healthy tissues.

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An experiment was carried out with young guava trees during the period from 1970 to 1972 with differential supplies of phosphorus as foliar spray to determine the nutrient content, seasonal variation of nutrients and to find out the most productive range.
Increasing the phosphorus supply tended to gradually increase the leaf P content. There was no effect on N and K contents of the leaves. Seasonal changes in the concentrations of N, P, K and dry matter have been studied over an annual growth cycle. The peak concentrations of each constituent in the tissues were found before the growth commenced and after the growth ceased, while minimal concentration was found at the end of the season, i. e., after full maturation of fruit. There were two periods in a year, viz., January-February and July-August when N, P and K concentrations in the leaves were stable. There was a significant increase in yield with application of superphosphate. More yield was recorded under the 4 per cent spray treatment in both the seasons and years. Significant positive correlation coefficients were found between yield and leaf P content. Quadratic regression equations were fitted to the relation between yield and rate of phosphorus application. The most productive range for P values was 0.45 to 0.65 per cent on the dry weight basis.

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Relationships between climatic factors and leaf water potential of satsuma mandarin trees during the winter were studied. The climatic factors were summarized as U^1/2 (wind speed)•ΔC (the difference in water vapor concentration between the leaf surface and the ambient air).
Under conditions where soil water was adequate, leaf water potential before sunrise, which usually showed a fairly constant value around -3 atms during the summer, varied widely from less than -38 atms to -10 atms during the winter, depending upon meteorological factors.
The diurnal changes of leaf water potential are of interest in two ways. In the first place, leaf water potential was affected significantly by wind of high velocity. Secondly, leaf water potential was closely related to U^1/2ΔC when stomata were closed.
When a low temperature coincided with wind of high velocity the stomata were usually opened. Under other conditions, such as when the weather was windy but warm, or it was cold but calm, few stomata′ if any, were opened.

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Relationships between soil factors and leaf water potential were studied during summer for satsuma mandarin (Citrus unshiu MARC.) and maltese blood (Citrus sinensis OSBECK) trees.
1. Leaf water potential measured before sunrise (^ψψmax) was curvilinearly related to the soil matric potential in the main root zone. When soil matric potential dropped below pF 3.5 to 4.0, the slope of the curve began to increase rapidly.
Even under the same atmospheric and soil moisture conditions, leaf water potentials during the day (^ψψmin) were always higher for the trees grown in the granite soil than in the rhyolite soil. The difference described above may be due to the differences in soil properties such as hydraulic conductivity and porosity between the two soil types.
2. Both soil matric potential and ^ψψmax for trees at the site with shallow soil profile continued to fall rapidly as days went on, whereas at the site with deeper soil profile the rate of decrease of the both values began to retard after ^ψψmax reached around -4.5 bars. Since no difference was found in the extent of root depth between the two sites, the difference should be attributed to the supplemental water flow from the subsoil.
3. Root system of a tree was divided into two parts; one was held in moist soil (irrigated daily), the other in dry soil (nonirrigated). The moisture of nonirrigated soil decreased as days went on, the values of ^ψψmax, however, were remained constant according to the proportion of rootlets in moist soil.
4. The submerging treatment was carried out by using trees grown in pots. Initially, ^ψψmin in this treatment was lower than that of control plants irrigated daily. After 5 to 7 days, however, ^ψψmin and leaf diffusion resistance in the submerged plants became abnormally higher than those of controls.

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Seasonal trends of soluble sugar fractions in satsuma mandarin peels from August to December were investigated in relation to fruit development and peel puffing.
1. In the flavedo tissue, concentrations of sucrose as well as total and reducing sugars were relatively low from August to early September, followed by a rapid increase in October. At the harvest time, they were 22.7 per cent for reducing sugars, 11.4 per cent for non-reducing sugars and 34.1 per cent for total sugars, when expressed on a dry weight basis. The amount of non-reducing sugars augmented to a maximum in mid November and declined thereafter. On the other hand, soluble sugar concentrations of albedo tissues were 19.3 per cent for reducing sugars, 7.5 per cent for non-reducing sugars and 26.8 per cent for total sugars.
As for the seasonal change in sugar content, there existed a certain similarity between flavedo and albedo tissues. The onset of sugar accumulation, however, was one or two months earlier in the albedo than in the flavedo. In the albedo tissues, the sugars gradually increased to a maximum in November.
2. The beginning of sugar accumulation in Wase Satsuma peel was earliest, followed by Ikeda Satsuma and then by Natsudaidai and Iyo. A decline in sucrose content was observed at harvest time in all the varieties except Wase Satsuma.
3. Based on the results of qualitative tests performed by gas-liquid chromatogra- phy, it was concluded that in the Ikeda Satsuma peel, reducing sugars consisted mainly of fructose and glucose whereas non-reducing sugars consisted principally of sucrose. Among these three sugars, any considerable differences in per cent of dry weight were not observed until mid November. At the harvest time, however, the sucrose content became lowest, glucose intermediate, and fructose highest in the flavedo tissues.
4. The sugar contents of flavedo and albedo were both higher in puffy than in non-puffy fruit. Sugars were contained more abundantly in the tissue of stem end than in that of either stylar or equatorial portion.

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Several articles (8, 13, 14, 16, 17, 22, 29, 30, 31, 32, 33, 34) have been reported on the effect of bagging on characteristics of pear fruit. In the previous reports of this series (5, 6) some results have been announced concerning the influence of rainfall and irrigation during a dry season with high temperatures on daily change in size of bagged and un-bagged fruit and also on the quality of harvested fruit.
The present experiment was performed to confirm the effects of bagging with different kinds of paper, such as paraffin-coated paper and newspaper, on the diurnal fluctuation, size and quality of fruit using ten and eleven-year-old Shinseiki pear trees.
Results obtained are described as follows:
1) Though little influence on diurnal fluctuation in fruit diameter was observed with paper bags, in the earliest stage before the middle of June the rate of growth was highest in fruit enclosed with paraffin paper bags. During the later stage of fruit development, however, the un-bagged fruit slightly excelled over the bagged fruit in growth. Consequently the former showed similar size to the latter at harvest, though the fruit in the newspaper bag was a littler larger than that of the others.
2) Variation in fruit temperature was marked in the daytime. On June 11, 1968 a maximum temperature of 30°C was attained in the fruit enclosed with the paraffin paper bag, and 27.5°C with the newspaper bag: they were remarkably high as compared with the controls of 25.5°C. On August 12, a fine day of high temperature, the maximum temperature of the open air rose to 32.7°C, and under the condition of being exposed directly to sunlight, fruit temperature attained 36.0°C in the controls, 34.0°C in the newspaper bag (2.5°C lower than the air temperature inside the bag), and 44.0°C in the paraffin paper bag (9.0°C higher than the air temperature inside the bag).
3) In general, the relative humidity inside the paraffin paper bag in the daytime was much higher than that of the open air. The difference of the humidity between inside and outside the bags was 38 percent at the maximum temperature. On the other hand, in the newspaper bag the change of the moisture condition directly reflected that of the outside air through the bag paper. Namely, moisture retention of the latter bag was inferior to that of the former bag.
4) Although in the early stage sugar content was highest in fruit bagged with paraffin paper, at maturity it was lowest for it and highest for the non-bagged fruit. Non-reducing sugar content at harvest was highest for the fruit with newspaper bagging amongst all the treatments.
5) The ratio of fruit diameter increment during the latter stage (from June 21 to the harvest time) to the diameter of the harvest time, was larger in un-bagged than in bagged fruits. This tendency was shown remarkably in 1969 when higher temperatures and longer cumulative hours of sunshine were found during the period of the later fruit developmental stage than for an ordinary year. It can be reasonably assumed that under such a high temperature condition bagged fruit was affected in its growth by the excessively high temperature inside the bag, especially in the paraffin-coated paper bag.
6) During the early stage of fruit growth, when the air temperature did not rise high enough to inhibit the fruit development, bagging, especially using paraffin paper bag, showed a favourable effect on the fruit growth because it resulted in better thermal conditions. During the later stage, however, the temperature of the fruit rose rapidly to the excessive level of about 40°C, when bagged with paraffin paper exposed directly to the sunshine. Thus, in this stage, extremely high temperature caused by the bagging inhibited the growth and accumulation of sugars in the fruit.

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The study was carried out to clarify the effects of various compositions of nutrient solution on the growth, content of nitrogen, phosphorus, potassium, calcium, and magnesium in plant tissues and n/w (nutrient absorption (me)/water consumption (l)) of these five elements in head lettuce, tomato, eggplant, and sweet pepper.
The crops were grown in a balanced solution at a horticultural experimental station in Japan (treatment 1) and in a nutrient solution which was based on the reports of recent experiments (treatments 2 and 3).
The results are summarized as follows:
1. The differences of growth, yield, nutrient absorption and n/w of nitrogen, phosphorus, potassium, calcium, and magnesium among the experimental plots in each crop were not noticeable. But selective salt absorption by different crops was observed.
2. The differences of selective salt absorption of different crops were found in the n/w of nutrient elements. Especially, it was remarkable in the case of calcium absorption, and the n/w of calcium was found to occur in the following order: tomato>eggplant>sweet pepper>head lettuce.
3. A reverse tendency between the n/w of calcium and potassium was found at the growing stage of plants.
4. In tomato and head lettuce, the n/w of nutrient elements was found to be decreased as the age of plants advanced. But in eggplant and sweet pepper, the n/w of nitrogen and calcium was constantly increased when fruits were harvested at an immature stage.
5. The balanced solution of horticultural station in Japan could be used with no trouble for growing plants in this study. When the results of this study were scrutinized in detail, it seemed that the growth of head lettuce was not effected by a low calcium level solution. Moreover, the increase of calcium ratio of nutrient composition in tomato was favorable to the production of fruits.

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Young, one-week-old seedlings of‘Shishiomaru (Notocactus submammulosus var. pampeanus) and rooted cuttings of‘Sankakuchu’(Hylocereus trigonus) were used as scions and stocks respectively.
The basal end of the scion and the top end of the stock were cut transversely, and the scion was placed onto the stock in such a manner that the cut ends of vascular bundles of both graft components were in close proximity (1), or they were stepped 1mm or 3mm apart sideways from each other (2).
(1) Graft union in case of the close proximity grafting method.
Callus cells were observed in the graft region 2 to 4 days after grafting. Callus cells derived from both graft components soon adhered and developed into callus. Procambial cells were first observed in the callus on the 8 to 10th day of grafting. The procambial cells continued to increase in number, and finally connected with the existing cambium of the graft components rectilineally.
By the 12th day of grafting, the procambial cells differentiated into vessel members, sieve tubes and cambial cells. The strands of these differentiated cells developed into new vascular bundles“Connecting vascular bundles”, and all of the grafts completed graft union.
(2) Graft union in the stepped case.
Even when both vascular bundles of scion and stock had not been placed in direct contact with each other, some of the grafts completed vascular connection after passing through the same process as in the former case. However, most of the grafts displayed no further development beyond either of the following stages. a) Cell adhesion was completed, but no cyto-differentiation was observed in the callus till the end of the experiment. b) Certain cells of callus which were oriented just under the vascular cut end of the scion differentiated into a meristematic cell nodule. The nodule did not develop further, so the vascular connection could not be completed.
In cases where vascular cut ends of graft components were stepped 1mm and 3mm transversely away from each other, the rates of vascular connected grafts to all survival grafts were no more than 30% and 10% respectively.

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1. The flower type of syriacus was classified into 3 groups and 9 types based on the investigation of 54 different clones.
Group I. Single flowered type (25 clones)
I-a Narrow petal type (7 clones)
I-b Medium petal type (13 clones)
I-c Broad petal type (5 clones)
Group II. Semi-double flowered type (20 clones)
II-a Gion-mamori type (4 clones)
II-b Hanagasa type (7 clones)
II-c Rose type (9 clones)
Group III. Double flowered type (9 clones)
III-a Irregular type (2 clones)
III-b Chrysanthemum type (3 clones)
III-c Pompon type (4 clones)
2. The Group I (Single flowered type) could also be divided into three sub-groups according to the number of petals per flower, viz. i) number of petals 5 (basic number) (9 clones), ii) number of petals 5-6 (12 clones) and iii) number of petals 8-11 (4 clones). Even in flowers with petals twice as many as the basic number, petals were of the same size as basic one and were arranged in a single row, so that the flowers remained single in appearance. The size of flower was the most variable in this group, ranging continuously from 7.6 to 13.3cm in diameter (Table 1, Fig. 1, 2, 3 and 6).
3. The Group II (Semi-double flowered type) consisted of flower type in which inner petals were much smaller than outer single-row petals. Those with a small number of inner petals were classified as Type II-a (Gion-mamori), while those with large number of inner petals as Type II-b (Hanagasa). In Type II-c (Rose), inner petals were somewhat larger in size than II-a and b and some of them were originated from the style. Type II-a was as fertile as the flowers of Group I, while II-b rarely produced seeds and II-c never produced seeds (Table 2, Fig. 4 and 5).
4. In Group III (Double flowered type) inner and outer petals were of the same size. In Type III-a (Irregular), styles of about 1/3 of the flowers were transformed into petals. In Type III-b (Chrysanthemum), petals were rather smaller and were more or less regularly arranged, and styles of 1/2-2/3 of the flowers turned into petals. In Type III-c (PomPon), the small spherical flowers possessed the smallest but numerous petals, and the whole style was transformed into petals. Some examples of prolification were found in the last type; such flowers consists of more than 70 petals (Table 3, Fig. 7 and 8).

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In the previous paper, it was reported that significant variation in patterns of carbon dioxide and ethylene production exists among melon cultivars in the course of fruit ripening. The present study describes changes in the production of low-boiling point volatiles in four cultivars of Raifu, Prince, Elizabeth, and Honey King melons harvested at different stages and stored at 20°C. For determination of volatiles, fru ts were confined individually for 4-6 hours and head space gas was with-drawn and analyzed by gas chromatography.
While the kinds of volatiles detected in the course of ripening were the same among the cultivars examined, the amounts and the patterns of volatiles production were different, and the difference was especially conspicuous between Raifu, which showed a typical respiratory climacteric, and the other three cultivars which were considered to be non-climacteric.
Volatiles production in Raifu fruits increased rapidly during the climacteric period, reaching a maximum 1-3 days after the peaks of ethylene and carbon dioxide production, and then declined as the senescence of the fruits progressed.
In Prince and Elizabeth fruits, volatiles production exhibited a similar trend and increased gradually with progressive ripening after the peak of ethylene production.
In Honey King fruits, volatiles production was at very low level and was detected only when the fruit became over-ripe about 17-19 days after harvest. In abnormally softened fruit (called fermented fruit), volatiles were detected early with a rise of respiration.
More volatiles production during ripening was found in fruits harvested at advanced maturity than for those harvested earlier, while the kinds of dominant substances differed among cultivars.

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Japanese apricot (mume) fruits are usually harvested in the mature-green stage and processed as umeboshi (a kind of pickle) or used for liquer production before the fruits ripen. While yellowed and softened ripe fruits lose salability and the fruits are quite perishable, a storage method has not yet been developed. The purpose of the present study is to clarify the requirements for proper handling and storage of mume fruits, and to investigate the mechanism of mume fruit chilling injury which has unique characteristics at low temperature. This paper describes the general aspects of external and internal changes occurring in storage at various temperatures. Five cultivars of mume fruits were picked at the ordinary mature-green stage and packed with perforated polyethylene bags.
The fruits ripened with a sharp increase of both carbon dioxide and ethylene production at 15°C, while shelf-life varied markedly among cultivars ranging from 6 days to over a month. At 10°C, ripening was delayed markedly, the production of ethylene and carbon dioxide dropped noticiably and the climacteric pattern was obscure. At 5°C and 1°C, ripening was suppressed and occurrence of chilling injury or decay limited the shelf-life. Unlike other commodities, chilling injury of mume fruits developed much sooner at 5-6°C than at 1°C, while the time of occurrence and the degree of incidence varied markedly with cultivars and other factors.
Pulp slices of healthy-appearing fruits which had been stored at various temperatures for various periods were prepared, and oxygen uptake and carbon dioxide output were determined at 30°C. Respiratory quotients for slices prepared from 10°C- and 15°C-stored fruits did not change notably, but the RQ for 1°C-stored fruits showed a striking increment during storage, reaching a peak as high as 3 or more. At the period when RQ increased abnormally, sugar content and ethylene production also increased considerably, suggesting the existence of physiological turning even in the healthy fruits stored at low temperature. Similar but less marked changes were found in the fruits stored at 5°C.

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