1. Experiments were carried out to clarify the shoot growth, yield and quality of fruits as relat-ed to the quantitative ratio of potassium to nitro-gen (K2O/N) in the solution of sand culture of young grape vines (Variety: Delaware). 2. On non-fruiting vines, when the nitrogen was supplied in proper concentration such as 40 to 80ppm, the ratio of potassium to nitrogen as half to quarter was the best for shoot and root growth, while that of half to one was suitable for the cluster differentiation of the following year. And the injurious effect of surplus nitrogen as applied in 160ppm was reduced by an addition of potassi-um in the same concentration. 3. On fruiting vines, yield of fruits and their quality as to weight of cluster and its color were superior when the ratio was one to two. But, on the other hand, shoot and root growth decreased with an increase of potassium as compared with nitrogen. Consequently, it is desirable to vary the ratio according to the growing stage of shoots and fruits.
This investigation was designed to find the most intelligent and successful way of irrigation in citrus groves, and some related information obtain-ed is reported in this paper. (1) Twelve gallons of water which is common-ly recommended as the amount of pouring-water for a hole was applied in the flat ground and brink soils. In the soil of even texture, the water was distributed in cylindrical form, 2 to 3 feet in diameter and 1 1/2 feet in depth. The moistened sphere differed with the properties of soils, but precisely agreed with the results computed from KOBAYASHI's formula. When the soil had reached a moisture content approximating the moisture equivalent before the irrigation, the applied water could moisten the soil, the volume of which was 3 to 5 times as large as that of the water added. (2) Under dry and hot summer conditions, the drying of the soil progressed at so rapid a rate in the rhizosphere soil that distinct isolation of root zone from the surrounding soils took place. During the midsummer months, the rate of moisture move-ment in the soil seemed to be more important for the use of soil moisture by plants than the amount of water contained in the surrounding root free soil. (3) The minimum hydraulic gradient neces-sary for the effectively rapid movement of mois-ture was about 3 to 7% on the sandy soil deriv-ed from granite, and it was a little varied with the properties of soils or the direction of movement. (4) The rate of upward movement of moisture in the soil was too low to meet the demand of the fruit tree, and so digging of not too deep, at the most 1 1/2 feet in depth, but many water-ing-holes must be more efficient for the water-use of citrus than that of deep but few holes. (5) The branches or twigs of the tree depended closely on the same side of the roots even in the case of water delivery within a tree. Watering-holes, should therefore, be dug evenly in all direc-tions of a tree. (6) The rate of moisture movement in the soil was unexpectedly low, and so the water-dissipating action of the tree overtook its capillary adjustment during the midsummer months. (7) The critical moisture content for the growth of citrus organs such as the shoots, fruits or roots was about 1 to 8 atmospheres of tension, while, that for the movement of soil moisture was 1/2 atmospheres which corresponds to the moisture equivalent of soils. (8) In order to keep the moisture content of rhizosphere soils above the critical point for the growth of citrus trees, that of the surrounding root-free soil should be kept, at least, above the moisture equivalent.
Recent tests have shown that dipping or spraying with a solution of sodium o-Phenyl Phenol (Dowi-cide A) gives good control of rot in Satsuma orange fruits during storage. From the practical point of view, however, dry method of application is desirable. Therefore, a study on the formula-tion and applying method of OPP for aerosol (smo-ke) has been made. The test material of OPP was packed in a “Citsin smoke candle, ” and released in the air of a closed fumigation chamber, having a space of 4 cubic meters, to sink upon the orange fruits or glass slides. It was shown that a rate of 2gm OPP per cub. m., added with 1gm hexamine and 1gm NH4Cl, is effective and safe. When OPP was smoked at this rate on glass slides, it supp-ressed completely the germination of spores of common green mould (Penicillium digitatum), and the effectiveness lasted for 90days. Treatment of the fruits before storage in December, caused no visible injury to the fruits till the following April and gave control of rots as good as the spraying with Dowicide A. Use of 6gm of OPP alone per cub. m. induced burning, which was avoidable by adding 3gm hexamine to OPP. A preparation, from which NH4Cl was omitted, showed'a tendency to increase the fungicidal effec-tiveness, but it produced an undesirable effect, forming powdery crystals upon the surface of the fruits. When each of OPP and hexamine was packed in separate candles and fumigated together, it was found that effectiveness lowered a little at a rate of 0.4gm of OPP, per cub. m. and powdery cristals blemished the fruit, at a rate of 0.5gm. An addition of hexamine to 0.3gm of OPP per cub. m. did not caused a reduction of the effective-ness. The amount of OPP deposit on the surface of fruits decreased with time; for example, it reduced to quarter after 30 days. This suggests the volatility of OPP. It was confirmed by the fact that OPP deposit on the surface of cover glass inhibited the germination of spores of common green mould on glass slide at distance of about 5 cm in closed chamber. Tests on a practical scale were made in the store houses of the Experiment Station and a commercial grower. Aerosol application of OPP at a rate of 2gm per cub. m. showed good control of rot espe-cially common green mould, almost equal to the spray treatment with Dowicide A. A slight varia-tion of the effecitiveness due to the position of the materials in the store house may be seen.
(1) The relations of harvest time to the quali-ties of sun dried persimmons were investigated in 1955 using the fruits of “Yotsumizo” and “Hirata-nenashi” varieties. These fruits were harvest-ed on October 14, November 4 and November 22. (2) The firmness of fresh fruits were decreas-ed by delaying the harvest time. This value of “Yotsumizo” was always higher than that of “Hi-ratanenashi”. The fruits of “Hiratanenashi” har-vested on November 22 already softened before drying, and were supposed to be not available for commercial drying. (3) The total sugar content in the products of “Yotsumizo” variety significantly increased by delaying harvest, and that of “Hiratanenashi” showed the similar tendency, but it reached almost to the maximum in the products of the second harvest. (4) The crude fiber content in the products of “Yotsumizo” significantly decreased by delaying harvest, but that of “Hiratanenashi” was some-what lower than the former, and showed less difference by changing the harvest time. (5) The water soluble pectin ratio to total pectin content in products showed no correlation to harvest time. This might be explained by the fact that the products of every harvesting lot were analysed after many days of drying and storage in which the activity of pectic enzyme was probably retained. This ratio in “Hiratanenashi” was always higher than that of “Yotsumizo”. (6) The products of the fruits harvested on November 4 showed no remarkable differences in chemical constituents between the lot prepared by sun drying and that prepared by dehydration. (7) In these experiments, it was found that the most desirable materials for drying these varie-ties of persimmons were the second or the third harvest fruits for “Yotsumizo” and the secondd harvest ones for “Hiratanenashi”.
1. In order to make the mechanisms of the occurrence of pithy tissue In root crops clear, with the viewpoint of physiology and ecology, the author investigated various culture conditions in relation to the easiness of its occurrence, by us-ing the “Rapid Red” radish. 2. With the aim of comparingg the effect of fertilizer conditions, the test plots which consisted of double complete three elements, complete three elements, non-potassium, non-phosphate, non-nitro-gen, and no fertilizer were adopted. The growth of the radishes was generally excellent in order stated above, and as a rule the presence of nitro-gen compared with other nutrients superiorly promoted the growth of top and root. Pithy tissues were conspicuously abundant in the plots where the growth was vigorous and the root was enlarged rapidly. 3. In the spacing test, the spaced plants, in which the growth, especially corpulency of roots was vigorous and the rate of T/R decreased, show-ed much occurrence of pithy tissue, but on the contrary the densely planted radishes showed op-posite tendency. The plants shaded with reed-blind were inferior in growth, and had less occurrence. The plants which were pruned of half of every leaf decreased the corpulency of roots, while the pithy tissue in them occurred not much less than that in the standard one. 4. To clarify the effect of moisture condition of soil on the-occurrence of pithy tissue, the plant-boxes were divided into wet and dry plot, and the moisture of soil in them were controlled by LIVINGSTON's auto-irrigator. The wet one gave more vigorous growth to the top and root of radishes than those'in the dry plot, and showed the evident pithy tissue. The plants grown in wet condition in the be-ginning and then conversed to the dry condition at the maximum root corpulent stage, showed a great deal of pithy tissue, but the others which were grown, continuosly in the wet, condition, showed less occurrence. The mechanism of-this occurrence was probably not the same as in the other cases, , being induced by desiccation. 5. In the study of effects of photoperiodism, the longday treatment (about 16 hours a day) restrained the corpulence of the root compared with that of the shortday treatment (about 8 hours a day) or natural day treatment, and it showed less occurrence of pithy tissues. In spite of the fact that there were many bolting plants in the longday plot, it showed less occurrence of pithy tissue, and it is therefore not absolutely true that the bolting itself induced the occurrence of pithy tissue, as commonly considered. 6. In an attempt to study the effects of sowing time on the occurrence of pithy tissue, the seeds were sown 5 times with the interval of 20 days from February 1. Later the sowing time, more vigorously and rapidly the growth of plants was observed, and the occurrence of pithy tissue was greatly hastened. It was not influenced by num-ber of days after sowing or the growing measure of root, but it 'occurred when the corpulency of the root increased and the rate of T/R reached to a certain level. The integrating temperature at the time of occurrence of pithy tissue in all plots was almost alike, but not exactly. 7. With a few exceptions, it was generally concluded that whatever the environmental condi-tions were, a great deal of pithy tissue were found when their growth was vigorous, and the corpulency of roots were rapid: the occurrence of pithy tissue was highly correlated with corpulency of root, smallness of T/R ratio, low concentration of soluble matter in root, and largeness of diameter of xylem parenchyma cells of root as it was explained in the previous two reports. Those results support the author's consideration that the occurrence of pithy tissue may be ascribed to the abrupt growth concerning the corpulency of roots.
It has been generally said that pithy tissue of the root crops occurs when the plants bolting, but as there are many doubtful points on this problems and in order to clarify the exact nature of correla-tion between both phenomena, the author conduct-ed the following experiments by using “Osaka-shijunichi” radish. 1. The correlation between the bolting which is induced by vernalization in fall and the occurrence of pithy tissue. The seeds which were vernalized in 5, 7, 9, 11 and 13 days, under the temperaure of 3_??_5°C and the non-treated seeds were sown at the same time, and their individual growth was examined, The former treated over 9 days a run to seed, and with the increase of period of cold treatment they exhibited the rising rate of bolting, but it was hard to recognize the difference of occurrence of pithy tissue between the bolting and the non-bolting plants. 2. The seeds were sown in the fertilized and non-fertilized field plots on March 1, 15, and April 1, and their growth were examined. Earlier the sowing time, higher the rate of bolting was observed, but there was no recognizable difference of degree of occurrence of pithy tissue between the bolting and the non-bolting plants in any plots. As a whole, pithy tissue was found remarkably in the fertilized field where the growth was vigorous and the corpulency of the roots was rapid, whereas in the non-fertilized plots where their growth was poor, the occurrence of pithy tissue was rare. From the results of the above two experiments, it seems that the bolting itself is at least not the chief cause of pithy tissue, in the plants used, but it is chiefly due to the corpulency of vigorously growing roots, as stated in the author's previous report.
The utilization of vegetative reproduction method in a breeding work has many advantages. In onions headsets or bulblets are known to occur occasionally under natural conditions, but they are very few in number. ANDREW (1951) reported that headsets suitable for vegetative propagation were produced by clipping off the inflorescences at various stages of development, and subsequently applying growth regulators. However, only clipping off the inflor-escences was found to be as effective as clipping plus addition of growth regulators, for the pourpose of inducing headsets. The normal and the male-sterile individuals of variety Senshu-Hiragata-Otamanegi (a strain of Yellow Globe Danvers) were used as materials in the present experiments. Treatment consisted solely of removing the segments of the spathe and clipping off the inflorescences at the base of the pedicels. Heads were clipped later again to remove flower buds developing subsequent to the treatment. In these experiments it has been indicated that clipping alone may provide some stimulus to induce headset growth in the variety. In nearly all of the male-sterile individuals headsets were harvested by clipping off the inflorescences. On the other hand, no headsets were obtained in a number of the normal individuals by the same treament. Consequently, it seems probable that in this variety headsets may be induced more easily in the male-sterile individuals than in the normal ones by clipping off the inflorescences.
This studies were made to determine the rela-tionships between the characters of onion bulbs, especially size, shape, condition of neck or soluble solids content, and their sprouting during the storage period. Experiments were carried out during 1951_??_1954 and the variety used was “Sapporo-ki” onion that was widely distributed in Hokkaido. The results may be summarized as follows: 1. In the case of the same variety cultivated and stored by the same method, the amount of sprouting during storage was scarcely related to the size of the bulbs (Table 1, 2). 2. The amount of sprouting was considered to be connected with the shape of bulbs; for the .standard, round type of this variety, total losses which were caused by sprouting and decay were always lowest (Table 3, 4, 5). 3. There was a tendency for bulbs having a relatively good solid flesh with firm necks to be less susceptible to sprouting and shrinkage during storage than those with relatively soft flesh or necks (Table 6). 4. Total soluble solids were determined at this trials by the hand sugar refractometer as a method for rapid determination. There appeared to be a positive high significant correlation (r=+0.653:D. F.=24) between soluble solids and dry matter content, and soluble solids' appeared to increase from top to base of bulb, and from outer to inner scales (Table 7, 8). 5. There appeared to be a negative, high signi-ficant correlation between soluble solids content and the amount of sprouting during storage (Table 9). And soluble solids content was found to be close-ly related to total sugar content, with special reference to reducing sugar, or soluble nitrogen content (Table 7, 8). 6. With the sprouting of bulbs, the content of sugar, nitrogen or dry matter components were observed to transfer gradually from top to base and to decrease very much in the outer or inner than middle scales. And soluble solids content in each part of the bulbs decreased in parallel with the tendency to be shown in each part for non-sprouting period (Fig. 2, 3, 4; Table 10). 7. Observations in this experiments have indi-cated that it appears to be possible to some extent to estimate the general level of sprouting during storage, by determining soluble solids content by the hand sugar refractometer at harvest time, on the condition of same variety under same cultural management.
There have been some papers on the chemical analysis of gladiolus corm, DENNY (1933), FAIRBURN (1934), LOOMIS (1934) and YASUDA.YOKOYAMA(19 55), but the relation between the chemical compo-sition and the germination percentage was not clear. This study was undertaken to find the relationship of the chemical composition to germination percen-tage. The corms were planted early in February, and were dug up on Aug. 6, and Sept. 5, 1955. These corms were divided into three lots. Lot I was placed in a thermostat at a temperature of 35°C for 10 days and then placed into a refrigerator at a temperature of 2°C for 23_??_25 days. Lot II was placed in a refrigerator for 33_??_35 days, and lot III was used for control. These corms (var. Atom, Bo Peep, Jonquil, June Day, and White Gold) were planted immediately after the treatment, and their germination was recorded. This result was reported in the previous paper. Each of these sample was analyzed for wate content, starch and sugars before planting. The result of chemical analysis is shown as fol-lows: 1. There was no difference in the water content of the corms in the three lots regardless of variety. 2. Reducing sugar content decreased during high temperature treatment, but increased after cold storage. 3. Non-reducing sugar increased during cold sto-rage. The amount of reducing sugar was propor-tionate to the germination percentage of the corms. The larger the amount of reducing sugar the higher was the germination percentage of corms for June Day and White Gold dug up. on Aug. 6, and for Atom, Bo Peep, June Day, and White Gold dug up on Sept. 5. 4. Starch decreased in inverse proportion to the increase of total sugar content during cold, storage.