Some apple varieties growing in Aomori prefecture show severe bark disorder known as“Sohibyo”, which greatly reduces their production.“Sohibyo”, as here reported, resembles to the pimply and necrotic conditions of Internal bark necrosis which has been shown by BERG and his co-workers to be caused by excessive intake of manganese.
1. Leaf fall of citrus trees as induced by the sulfur dioxide fumigation particularly after the Bordeaux spray was studied with 3-year-old potted plants of Satsuma oranges (Citrus unshiu) and Hassaku oranges (C. Hassaku) respectively. Fumigation was conducted with 0, 1, and 5ppm of sulfur dioxide for 13 days from June 5 to 17 of 1964, 2 hours each day. On half the number of each plot, Bordeaux mixture of 6-6 had been sprayed just before the fumigation on June 5, and water was sprinkled for 3 days following the 7th day from the start of fumigation. 2. In Satsuma oranges, leaves fell down easily even by the single treatment of sulfur dioxide, the trend being more marked by the treatment after the Bordeaux spray. On the other hand, in Hassaku oranges leaf fall did not take place readily by the single treatment of sulfur dioxide. It was however much promoted by the treatment after the Bordeaux spray. 3. In either species, the Cu content of leaves and the rate of leaf fall were much increased with rising concentration of sulfur dioxide in fumigation. The Cu content of leaves was also increased by the Bordeaux spray, but it was not deeply connected with the leaf fall. Therefore, the leaf fall due to sulfur dioxide fumigation in addition to Bordeaux spray might be reduced both to the toxic function of SO2 and that of Cu which was isolated from Bordeaux mixture by sulfur dioxide fumigation.
In order to compare the effects of different soil managements on the growth and yield of Satsuma orange trees, and on the physical and chemical properties of soil, field experiments were conducted for 10 years at the Ehime Fruit Tree Exp. Sta. 1. One of experiments was started in 1952 with 4-year-old trees grown on the sloping diluviatic land. The tree growth estimated from the volume of tree crown in the 10th year, was superior both under the bur clover sod and under the orchard grass with partial clean cultivation, then medium both under the wheat straw mulch and under the weed sod, and inferior under the clean cultivation. The total yield of fruit was best under the bur clover, then better under the weed, and bad both under the orchard grass and under the straw as same as under the clean cultivation. 2. Humus content and pore space in the soil increased markedly both under the bur clover and under the straw than under the clean cultivation. The trend extended deeper in the subsoil under the bur clover than under the straw. The pH and exchangeable Ca and Mg levels in the soil had the tendency to rise up greatly under the bur clover. The exchangeable K content of the soil was increased under the straw, though it was not closely related to the K content of leaves. 3. In the 7th year, nitrate nitrogen content of the soil was greatest under the bur clover, followed by the straw and the clean cultivation in the order. It was, however, less under the bur clover than under the clean cultivation, if the sod was not frequently mowed. Mineralization of soil nitrogen was most active in either surface soil under the sod or mulch. The N content of leaves, however, had no connection with the total inorganic or nitrate nitrogen content of the soil. 4. In the other experiments of 1952-1961, 18-year-old trees grown on the flat field, and on the terraced field were used. The effect of the hay mulch was observed with the former, and that of the weed sod with the latter. As the results, no distinct difference of fruit yield existed between the clean cultivation and these two soil management systems in the first 5 years, while in the second 5 years these two systems were slightly superior to the clean cultivation.
1. Effects of different fertilizer treatments and soil managements on the growth of trees and their development of abnormal leaves were observed with Nijisseiki pears planted in the field. Growth was much promoted by nitrogen application, but not so much by phosphate, potash, lime and magnesia applications. It was also somewhat promoted by mulching, and slightly retarded by sod culture. Abnormal leaves (so-called ljoyo) developed greatly in the third year after planting, regardless of the kinds of fertilizer treatments and soil managements. 2. On the other hand, when observed with plants grown in the pots of large size, growth was greatly promoted by applications of the three nutrients, in the order of nitrogen, phosphate and potash. With increased applications of nitrogen, leaf contents of N and Mg increased and that of K decreased. With increasing phospate application, leaf contents of P and Mg increased. As the application amount of potash was increased, the leaf content of K increased and those of N, Ca and Mg decreased. In the third year after planting, abnormal leaves developed in most of plots except for nonfertilizer, non-nitrogen and non-phosphate, though very slightly in the non-potash plot. 3. In the both experiments above mentioned, the longer the shoot length, the more extremely abnormal leaves seemed to develop in the following year, having no connection with fertilizer treatments.
1. Root activity of grapes during the dormant period was measured by the respiratory activity of roots in relation to their absorption ability of nutrients. 2. Roots became active with increasing soil temperature as the season advanced. When the soil temperature reached 12°C late in March both respiration and nitrogen absorption of roots became very active, though new roots did not still appear. 3. From the standpoint of shoot growth, berry set and yield of vines planted in pots with loamy soil, the most suitable application time of chemical nitrogen such as ammonium sulphate was in December or January rather than in February or March.
Seri, Oenanthe javanica D. C., is a herbaceous perennial plant which belongs to Umbelliferae. It is a native of Asia, north of Japan proper and extends southward to Korea, China, Formosa, India, Indonesia and archipelagoes or the Queensland of Oceania. Wild seri grows on marsh land in streams and basins and has been utilized in Japan for vegetable during the winter since the Mannyo Era (645-759 A. D.). Seri is commonly cultivated in Japan, Korea and China, and occasionally in Indo-China, Sumatra and the Malay peninsula for use as a potherb. FUJIWARA described in his“Engishiki”published in 928 A. D. that seri cultivation in Japan had already begun as early as in the 10th century. Nowadays, its commercial cultivation is found in urban areas throughout the Honshu, Japan′s main land, and its acreage totaled about 60 hectares in 1962. In this experiment, 26 cultivated and 80 wild strains were collected from about 90 different locations in Japan and were cultivated in paddy bed under the same environmental condition in Sakai, Osaka prefecture (N 34°34′). The morphological differences between the cultivated and wild strains were studied from October, 1961 to January, 1962. The geographical differentiations within each of the cultivated and wild strains were also investigated. The results obtained are summarized as follow: 1. Plant habit of seri could be classified into three types of erect, medium and prostrate. Most of the cultivated strains showed the erect type and none of the prostrate type was found among them, whereas only a few of wild strains showed the erect type for this character (Table 2). 2. With respect to plant height and length of leaf petiole, the cultivated strains generally showed higher values than the wild strains (Table 3 and 4). They were more vigorous than the wild ones and tended to grow rapidly. Leaflets of the cultivated strains also tended to be larger in size and more round shape than those of the wild strains (Table 5). 3. Three main color of leaves and leaf petioles, reddish brown, light brown and green, could be distinguished. In both the cultivated and wild strains, the majority of plants had brown leaves or leaf petioles, which in some plants had pigmentation either on leaves or on petioles, in others had it on both parts, and a few of both cultivated and wild strains had green leaves and petioles. The former showed higher percentage of plants with green leaves and petioles than the latter (Table 2). 4. No apparent relationship between any of the abovementioned characters and geographical conditions of the native habitat was observed in both cultivated and wild strains. 5. The cultivated strains generally had more useful characteristics as a vegetable crop than the wild ones. Especially the cultivated strains from Sendai, Tokyo, Kyoto and Matsue cities were more vigorous than other cultivated strains and maintained green leaves during the winter and their leaflets were broad and desired rounded shape. They were attractive and worth growing. It may be assumed that growers in these areas have been raising their own strains by careful selection roguing from thier own fields.
In this paper the metabolism of gibberellin and nucleic acid was studied with special reference to the bulbing phenomenon of onion plants. 1. Gibberellin-like substances, among which the principal substance was considered to be the gibberellic acid (GA3) from the Rf value, were found in the 80% alcohol extracts obtained from oth the terminal part of buds and the leaf blades of onion plants. Following transfer to long days there was a rapid increase in gibberellin-like substance level to a maximum at about 10th day, being followed by a fall to a value below that of the short day controls. The younger the leaf age, the more the content of gibberellins. This tendency was shown in either plants grown under long or short photoperiod. On 30th day after photoperiod treatment, plants grown under short photoperiod was higher than under long one. 2. It was shown that the levels of gibberellinlike substances in the terminal part of buds and in the leaf blades were lower with the increase of daylength on 20th day after various photoperiod treatment. 3. When gibberellin was supplied to the plants with the injection method every 5 days, it was shown that the leaves, especially leaf blades, elongated remarkably, resulted in the increase in the ratio of leaf blade length to leaf sheath length under short day, whereas the bulb formation under long day was retarded with the application of higher concentration of gibberellin. 4. With the progress of plant growth, the content of RNA and DNA in the terminal part of buds gradually increased under short day, whereas RNA decreased in contrast with the rapid increase in DNA under long day. 5. Nucleic acid level was correlated with the increase in daylength, that is, the longer the daylength, the more remarkable the increase in DNA and the decrease in RNA. 6. The higher the temperature, the more vigorous the plant growth and the more the increase in RNA and DNA. Consequently the effect of temperature on the bulb formation is different from that of daylength. 7. The bulb formation was more promoted in the plants supplied with exogenous kinetin solution than in the plants with water. The higher the concentration of kinetin solution, the more the bulbing was advanced.
The present studies was designed to elucidate the effect of naphthaleneacetic acid, sucrose and boric acid for preventing the occurrence of pithy tissue. It is necessary for us to avoid sun in order to produce the desired effect of NAA. The aqueous foliar spray solution contained NAA, sucrose and boron. separately and in combination, to give the final concentration of 50ppm, 2-5%, and 5ppm respectively. When the plants were sprayed with the solution containing boric acid and/or sucrose, the thickening growth of roots showed an increasing tendency, but the occurrence of pithy tissue could not be prevented. NAA was mainly effective in preventing the occurrence of pithy tissue. The treatment with these mixed solution for preventing the occurrence of pithy tissue and for decreasing the inhibition of the thickening growth in the root is recommended to be made after unfolding of four leaves. Foliar spray of NAA brought about the high percentage of pectic substances and a high degree of esterified pectin in the flesh tissue. This result supports the views that auxins are closely related to the esterification of pectic substances in the cell wall and act as senescence inhibitor to some extent. As the non-pithy tissue treated with NAA solution had a number of meristematic tissue on area basis in a cross section, the esterified pectin was high in content. This results supports the view that NAA is useful for delaying the process of maturation, and the main function of sucrose in feeding the phloem, and finally boron facilitates the transport of applied sucrose and NAA. The same experiment has been repeated every year and the same results has been obtained.
Deterioration of cucumbers (varieties, Aohushinari No. 2 and Tokiwa No. 2) held at various temperatures was investigated by the external and microscopic observation and chemical analysis. The results obtained are as follows. 1. Cucumbers held at 11°-13°C kept the best quality of those held at various temperatures. The total storage life of fruits held at 3°-5°C was the shortest, because they were suffered the chilling injury during the exposure at those temperatures for a certain period. Cucumbers overwrapped with polyethylene film (0.03mm in thickness) and held at 11°-13°C had maximum satisfactory storage life. The fruits on these conditions were edible for more than 40 days and had the longest duration time of marketability which was the most important factor when fresh fruits and vegetables were preserved. If fruits were removed to chilling temperature after being held at 11°-13°C for several days, the total storage life of them was made slightly longer than those held at 3°-5°C continuously from the first day of the storage. Pitting is one of the characters of the chilling injuries of cucumber and severe surface pittings were reported by EAKS, but merely small surface breakdowns were observed in this experiment. 2. It seems that the chilling injury of cucumbers will advance according to the following conditions. When cucumbers are held at 3°-5°C for about 10 days, in the first place the amount of organic acids in cucumber decreases and pH value increases and then the tissue of fruits breaks down. This change in organization of cucumbers begins from the cell under the skin of fruits and gradually internal breakdown developes. The first indication of external deterioration of cucumbers is the appearance of small droplets of muddy exudation on the surface of fruits, after that some molds occur on their surface and they fall into decay at last.