In Tokyo, it is generally difficult to get Bartlett pears of high quality, if ripened at room temperature. This investigation was carried out to find a solution of this difficulty, by temporary cold storage or by keeping fruits at various temperatures for after-ripening. Bartlett pears picked from late August to middle of September on three dates in 1962, and on two dates in 1963 in Yamagata prefecture, were transported to the laboratory. In addition to these fruits, one lot of fruits was brought from Nagano prefecture in 1963. On arrival, some of the fruits were after-ripened at a room temperature (higher than 25°C excepting later several days), 20° and 15°C, while the remaining fruits were kept in a cold room at 4°C for one and two weeks, before removing them to the rooms of above mentioned temperatures. Fruits after-ripened at room temperature generally ripened later than those kept at 20°C, and were not uniform in ripeness. Percentage of loss due to rot was also high in these fruits. The ripe fruits were poor in their appearance, flavor and texture, while those ripened at 20°C were good. The result revealed that room temperature was too high for the proper ripening of Bartlett pears, and in turn deteriorated the quality of ripe fruits. Fruits stored at 4°C for one or two weeks before after-ripening ripened quickly and uniformly, and the resulting fruits were good in their appearance and flavor. Even those after-ripened at room temperature after the cold storage had much better appearance and flavor than those ripened at room temperature without cold storage. Fruit rot was also almost controlled by the temporary cold storage. Refractive index of fruit juice was hardly affected by either temporary cold storage or after-ripening temperature. Acid content was decreased by cold storage, and longer the storage period, more the reduction in acidity. Signs of internal breakdown were found in the fruits picked late and stored for two weeks in cold room. It was suggested that Bartlett pears should be kept at 20°C or lower for after-ripening, or stored in cold room for one to two weeks before ripening, to get fruits of high quality in Tokyo or localities having similar climatic conditions to Tokyo.
1. Potassium fertilization experiment was carried out with 35-year-old Satsuma oranges on trifoliate-orange rootstock over a five year period since 1959. Treatment consisted of two plots: One was K-plot where 300g of K2O (potassium sulphate) was applied every year to each tree, and another was non-K-plot where potash was not given. The trees were growing on diluvial terraced soil, in the 30-40cm depth of which there was clayey layer. The soil surface was mulched every year in early June with 15kg of wheat straw per tree. 6kg of dolomite per tree was applied each year for the two years just before the start of the experiment and only in the first year of it. 2. Even at the end of experiment, no marked differences were found between the two plots concerning the tree appearance and the fruit yields. However, fruit size became smaller, peel color developed somewhat earlier and fruit juice contained more sugar after the third or fourth year, in the non-K-plot as compared in the K-plot. 3. Throughout the five years, no remarkable difference of N, P, K, Ca and Mg contents of the peel and flesh existed between the fruits of the two plots. Leaf analysis in August showed also nosignificant difference of the K content. The average content of exchangeable K in the soil of 0 to 30cm depth was 1.05me per 100g of dry soil at the start of the experiment, while at the end of the experiment it was generally as low as 0.6me in the K-plot, and 0.4me in the non-K-plot. 4. The total amount of potassium taken in a tree for five years was calculated considering the removal by fruiting, leaf fall and pruning, as well as the absorption in the newly developed portions of a tree. On the other hand, the total amount of potassium applied to a tree was also accounted, referring to the potash fertilization, straw mulching and decreased amount of exchangeable K in the soil of 0 to 30cm depth. Thus, in the non-K-plot the total amount of potassium taken exceeded that applied. In this case, 0.2me of non exchangeable K per 100g of dry soil seemed to be utilized by a tree. In the K-plot, the result was reverse; the total amount of potassium taken was less than that applied. However, when the availability of potash applied was estimated to be 30 percent, the both amounts became nearly the same.
1. With 12 species of fruit trees, the seasonal changes of sugar and polyhydric alcohol contents of twig barks and leaves were observed at certain intervals by a method of paper chromatography during a period from summer to winter. As the result of it, the content of polyhydric alcohol increased almost proportionally with that of sugar as the season advanced in all of species. 2. In apples, plums, pears, peaches and cherries, a considerable amount of polyhydric alcohol was contained both in summer and winter. The quantitative ratio of it to sugar was nearly 70% in summer and 43 to 73% in winter. In persimcoons and grapes, only a small amount of polyhydric alcohol was contained in summer, but it increased greatly in winter, the quantitative ratio of it to sugar being about 50%. In citrus fruit trees, the content of polyhydric alcohol was very low even in winter. 3. The kinds of sugar contained were almost the same regardless of the species of fruit trees, though the proportion of their contents differed markedly with the species. In every species, fructose, glurose, and saccharose were mainly contained. Raffinose appeared first in September or October and stachyose in November, increasing rapidly toward the end of December.
1. Growth, yield and quality of Japanese pears (Nijisseiki) as affected by the concentrations of nitrogen, phosphoric acid and potassium were observed under sand culture. The experiment was conducted for a four-year period with the same trees which were of non-bearing for the first three years and fruited only in the fourth year. The standard constitution of the cultural solution was 80ppm in each nutrient, and the only one of the three nutrients was varied so as to be 0, 20, 40, 80, 120 or 160 ppm in each treatment. 2. The optimum concentration of each nutrient for the vegetative growth of trees was found at 80 ppm or somewhat lower though it varied sometimes with tree age and fruit load. 3. Yield and fruit growth were most superior at 80ppm of each nutrient, while the solids content of fruit juice was highest at 120 or 160ppm of phosphoric acid and at 0 or 20ppm of potassium. 4. The number of seeds per fruit increased with an increasing concentration of potassium, promoting the growth of fruit. 5. From the standpoint of vegetative growth and fruit bearing, the optimum leaf content of nutrients seemed to be 2.0-2.2% N, 0.25% P and 1.8% K.
In the previous reports (34, 35) it is reported that identical processes which induce flower formation in the short-day plant induce in the cucumber plant, at the first step, staminate flower differentiation. Increasing amount of the specific substance brought about by increasing amount of foliage leaves, affects the meristematic tissues, changing their activity from production of vegetative tissues to inception of floral primordia, and it may be that the flower forming substance at lower concentration induces staminate flower differentiation and with the rise of the concentration, bisexual and further pistillate flower differentiation. The specific substance, produced in the young mature leaves, is impelled to transfer by the bud or the young leaves.
Experiments were conducted to determine the optimum physical and chemical properties of the composts for raising seedlings of cucumbers, eggplants and tomatoes. 1. In cucumber, the best growth was obtained from the mixture of 1 soil (volcanic ash soil): 3 leaf-mold (by volume) containing 100mg/l N (ammonium sulfate), 1, 0004, 000mg/l P2O5 (superphosphate of lime) and 400mg/l K2O (potassium sulfate). To obtain the uniform vegetative growth, transplanting of the seedlings to this compost were more desirable after cotyledon fully expanded in sand beds with no fertilizer. The applications of heavy N and insufficient P2O5 inhibited the growth of seedlings, while potassium fertilization in the range of 0_??_800mg/l resulted in no significant differences in growth. Analyses of seedling showed that N, P, K contents of the normally growing 4-week-old plants were 5.3_??_5.9%, 0.5_??_0.6%, 5.7_??_6.6% of dry matter, respectively. 2. Egg-plant grown in a mixture of 3 soil: 1 leaf-mold with 200mg/l N, 2, 000_??_4, 000mg/l P2O5 and 200mg/l K2O made better growth, though statistically it was at par with either treatments viz., 2 soil: 2 leafmold and 1 soil: 3 leaf-mold composts. As in case of cucumber, the application of heavy N and insufficient P2O5 decreased the vegetative growth of egg-plant seedlings, with no positive effects of potassium fertilization in the range of 0_??_800mg/l. N, P and K contents of the normally growing 4-week-old seedlings were 6.0_??_6.9%, 0.4_??_0.5%, and 6.8_??_7.3% of dry matter, respectively. 3. Tomatoes made better growth in a compost, mixture of 2 soil: 2 leaf-mold with 25_??_100mg/l N, 1, 000_??_4, 000mg/l P2O5 and 100_??_400mg/l K2O. N, P and K contents of the normally growing 2-week-old seedlings were 6.4_??_6.5%, 0.5_??_0.6% and 5.1_??_5.9%, and the corresponding figures in 4-week-old seedlings were 5.2_??_5.9%, 0.4_??_0.5% and 6.2_??_7.0%, respectively. 4. A clear negative relationship was found between N and K contents of the seedlings, that is there occurred the depression of K uptake by excess, of N, and vice versa.
Tomato seedlings (var. Fukuju No. 2) were exposed to temperatures of 40°C and 45°C for 1, 3 (in one day), 6 (3 hours each in two days), or 15 hours (3 hours each in five days). The high temperature treatment was given when the first flower of the first cluster had just begun to bloom. These temperature treatments induced no visible injuries on the plants and did not affect the plant growth. Treatment of 40°C for 1 hour did not actually reduce both percentage of fruit setting and yield, but all other treatments reduced yields, and the reduction in yield was enhanced with increasing temperature and duration of treatment. Reduction in yield at the temperature of 40°C and 45°C for 3 hours was remarkable as compared with those for 1 hour. Germination test of pollen on artificial medium revealed that the treament of 40°C for 1 hour was enough to decrease percentage of pollen germination. Considering the effect of high temperature on various stages of flower development, the buds of 8 to 9 days before anthesis were highly susceptible to high temperature, and the percentage of fruit setting at that stage was reduced by even the treatment of 40°C for 1 hour. From this fact, together with the result of pollen germination, it was suggested that even 40°C for 1 hour was injurious, and might reduce the percentage of fruit setting in tomato.
Histological studies of onion scale leaf and leaf sheath were carried out in relation to the response to photoperiod. 1. The stomata and the palisade tissue developed well in the foliage leaf blade, but they did not differentiate in leaf sheath. The stomata were clearly found in the leaves of 7mm in length, but not in the leaves of 3mm, and the palisade tissue differentiated in the leaves longer than 3mm. 2. The remarkable differences were found in number and size of parenchyma cells and intercellular space between the tissue of scale leaves and of foliage leaf sheath. Foliage leaf sheath consisted in less number of parenchyma cells and much more intercellular space than scale leaves of corresponding leaf location. The size of parenchyma cells in leaf sheath were fairly constant and small in spite of their age, while a lot of isometric cells in scale leaves grew much larger with the development of bulb. 3. It was found that the number of cell layers in transversal section of leaf sheath tended to increase gradually from outer leaf to inner one. This tendency was more remarkable in the scale leaf than in leaf sheath. 4. In the scale leaf tissue vascular bundle did not develop sufficiently, that is, the vessels and sieve tubes were not found so clear as those in foliage leaf sheath. 5. A great number of undifferentiated parenchyma cells were found in the terminal part of scale leaves. When the plant was shifted from long day condition to short day condition, they elongated and developed to palisade tissue. This showed that the development of leaf blade tissue was inhibited in the scale leaves by long day condition. 6. It was shown that long day treatment induced a rapid increase in plant height followed by scale leaf formation, but the initial scale leaf differentiated immediately after the growth increment per unit time in plant height arrived at a maximum. 7. From the results mentioned above, the physiological mechanism of bulbing was discussed.
From his histological observation on the seed coat of varieties of turnip KONDO (1933) found that there are two types, that is Type A; in which epidermal cells of the seed swell with water and Type B; in which epidermal layer appears to be only membranous. The seed coat of the Type A is dominant over the Type B in turnip (SHIBUTANI 1952). In the previous paper on local varieties of turnip, the author reported that varieties of the Type A are distributed in the western Japan, while those of the Type B in the eastern Japan. Both turnip and non-heading mustard (n=10group) belong to the same group in Brassica. For this study the author collected several local varieties of non-heading mustard in Japan and investigated their various characters, especially the histological type of the seed coat, in order to establish the relation between the kind of non-heading mustard and the type of the seed coat and to discuss the distribution of seed-coat type in Japan. The results of the investigation are summarized as follows: 1. The local varieties of non-heading mustard in Japan are classified as shown in table 4. 2. The epidermal layer of the seed coat in varieties belonging to B. pekinensis, B. chinensis, B. campestris, and B. narinosa is of the Type B in most of the cases, with a few cases of the Type A (Hiroshimana and Yamato-mana) and of the mixed type (for example, Sangatsuna). 3. The seed coat of varieties belonging to B. japonica is of the Type A in every case, so that it is certain that the seed-coat of B. japonica is fundamentally of the Type A unlike other species. 4. In B. Rapa and B. campestris varieties distributed in the eastern of Japan produce seeds of the Type B, while those distributed in the Kansai region produce seeds of the Type A. 5. From this investigation on non-heading mustard in Japan, it is concluded that varieties distrib uted in the eastern Japan produce seed of the Type B in general, while those distributed in the western Japan produce seeds of the Type A, similar to the distribution of seed-coat type in local varieties of turnip. 6. Many of these varieties have hairy leaves. so that it is presumed that these local varieties have originated from a hairy variety. 7. The bolting season of varieties cultivated in the warm region, except for Kyona group, were usually earlier than those of varieties cultivated in the cool region. 8. Based on the above mentioned results, the author discussed on the origin of B. japonica and the gene of the Type A.
In order to make clear the characteristics of transpiration of head forming vegetables such as lettuce, cabbage and chinese cabbage, their transpiration amount was measured by the transpiration chamber method in Taketoyo fields, Aichi prefecture in 1962. This paper deals mainly with the transpiration of lettuce. Varieties used were Great Lakes 659 (head lettuce) and Kakichisha (asparagus lettuce). The results obtained are as follows. 1. Transpiration amout and water requirement of head lettuce were less than those of asparagus lettuce. This tendency was found as well in the other heading vegetables as shown in Table 2. This is due to the fact that either amount of transpiration per unit dry matter weight or per unit leaf area of head lettuce was less than that of asparagus lettuce as shown in Tables 2 and 4. 2. Moisture content of heading lettuce was normally 2-3% higher than that of asparagus lettuce, owing to the higher moisture content of its heading parts as shown in Table 1. So it may be said that heading vegetables require less water than non-he ading ones. 2. The maximum transpiration amount per plant per day (from 6 a. m. to 6 p. m.); 322g in head lettuce and 462g in asparagus lettuce, appeared on May 30 when it was fine all day. The maximum relative transpiration rate appeared on July 8, when the lettuce was in the midst of heading or 15 days after the start of heading, as shown in Table 4. These facts suggest us that the transpiration amount per plant will be highest on a fine day when the lettuce is in the midst of heading. 3. Transpiration amount increased usually with the growth of plant, until the heading stage of head lettuce as shown in Table 4 and Fig. 3. Decrease of the transpiration after head formation might be due to the low transpiring power of old outer-leaves and of heading part in head lettuce. Young leaves transpired more water than old ones as shown in Table 3, when the transpiration was measured by the chamber method as shown in Fig. 2. 4. Among many characters of a plant, leaf area highly correlated with transpiration amount per plant in usual. Particularly, in the case of head lettuce, area of outer old leaves had the highest correlation with transpiration per plant as in Table 5. 5. Among meteorological factors, solar radiation had the highest correlation with transpiration amount as shown in Table 6.
Leaves of healthy tulip plants “William Pitt” (WP) in shooting stage (shoot-length 5-10cm above the ground) were inoculated with leaf- or petal-sap expressed from freeze-dried tissues of suspected tulip plants for the purpose of knowing if the latter is actually virus-infected. By the partial break (Fig. 1, left) that subsequently appear on the WP flower, it was judged whether unusual coloration in flower or foliage of the suspected plants was due to virus disease or of inherent nature. 1. When leaf-sap from yellow (“Golden Harvest”) or white tulips (“Mrs. Grullemans” and “White Duchess”) bearing red lines or sprashes on petals was inoculated, no WP flowers showed partial-break. On the other hand, leaf-sap from these varieties showing leaf streaks produced partial-break on WP flower. Therefore, it seems unlikely that red lines or sprashes on petals of yellow or white varieties are due to virus disease. 2. It was demonstrated that blotched or feathered flowers of dark purple tulips (“Queen of the Night” and “Van der Neer”) had been caused by virus infection, bacause WP flower showed partial-break by the inoculation of leaf-sap from these plants. 3. It was also demonstrated that the flower symptom of bi-colored variety “Pink Beauty” in which ground color was visible in the pink area was due to virus disease. 4. Leaf-sap from tulips of Parrot “Sunshine” and Double Late “Nizza” without leaf streaks did not produce partial-break on WP flower, suggesting that the flower variegations are not due to virus infection but due to the inherent nature of these varieties. 5. It has been said that some “Rembrandt” tulips were derived from virus-infected Darwin tulip. In the present study, however, leaf-sap from “American Flag” plant bearing normal foliage did not cause flower breaking in WP, while leaf-sap from the plant bearing streaked foliage produced partial-break on WP flower. Therefore, it seems to assume that flower breaking of “American Flag” is not due to virus infection. 6. “Gudoshnik”, one of the varieties of Darwin Hybrid, exhibits a wide range of variation in flower color. Leaf- or petal-sap from some individuals of this variety did not produce partial-break on WP flower upon inoculation. The color variation may be due to the inherent nature of this variety. 7. With the exception of “Hydra”, leaf-sap from all varieties tested that are called “Variegated-Leaved” did not produce partial break on WP flower, irrespective of the variegation in leaf color is regular or irregular. They are “Cochinille”, “Peach Blossom”, “Purple Kroon”, “Rose Luisante”, “Yellow Prince”, and “William Pitt”. Of course, WP was readily infected by sap-inoculation from “Rose Luisante” plants that have either leaf streaks in green area other than leaf variegation or broken flowers. These facts may suggest that “Variegated-Leaved” might have been selected from genetical mutants.