1) Leaves were collected for three years (1950-1952) from leading commercial apple orchards in Aomori Prefecture. Analysis records were taken of the dry matter per cent of nitrogen, phosphorus and potassium in the leaves. 2) The leaves of Rall's Janet proved to have higher nitrogen and potassium content than Jonathan leaves, though the difference of phosphorus contents between varieties was not significant. 3) Most productive orchards showed higher N content in leaves than the less productive orchards. The relation between P and K content and the productivity of orchards was not recognized. 4) Generally, the lower N and the higher Kcontents of orchard leaves are apt to produce the better fruit color, and therefore the N/K values indicated rather clearly the fruit color of the harvest time, but much more investigations might be necessary on this subject. 5) The trees on the alluvial soil orchards had rather higher N, P and lower K leaf contents than on the volcanic ash ones. 6) Sod management of orchard soils was tend to make nitrogen content of leaves significantly lower than clean cultivation. 7) Leaf compositions were highest in 1952 (an on-year after an off-year), lowest in 1950 (an on-year prior to an off-year) and intermediate in 1951 (an off-year). 8) The age of trees seemed to decrease N content slightly, but not so clearly for the other two elements. 9) From June to September, N and P in leaves decreased gradually, but the variation of K content was rather indistinct. The most adequate time for leaf sampling, in the case of nutrient diagnosis, was middle July in Aomori Prefecture. 10) In this study, any correlation could not be found between the leaf content of N, P and K and the amount of fertilizers applied in the same year, because the variations of circumference were so large and not erasable. 11) At the beginning of July, sampled leaves contained the elements as follows; Rall's Janet Jonathan (111 samples) (54 samples) max, mean. min. max, mean. min. N 2.49 3.25 3.98 2.30 3.00 3.84 P 0.115 0.170 0.247 0.096 0.167 0.244K 0.75 1.53 2.18 0.70 1.34 1.85 (dry matter per cent) 12) The lowest level of leaf nitrogen in early July, to get the yield more than 800 bushel per acre, is 2.8 per cent (Rall's Janet) and 2.6 per cent (Jonathan). The relation between P and K contents and the yield was not clear. 13) Hunger signs were not found, even when leaf K was below 1 per cent and P was less than 0.1 per cent. 14) Japanese apple leaves have usually rather high N and low K contents. This might be due partly to the heavy bearing habit of the trees, though the further investigation may be needed on these problems.
Since TIEDJENS' laborious work, it is shown that sex expression of the cucumber plant is determined fundamentally as the varietal pecuriality and more or less variable responding to change of light (intensity and duration), temperature and fertilizer application. Japanese cucumber is divided into two types with respect to the flowering habit, namely“Fushinari”what bears the pistillate flowers on the nodes of the main stem successively after about five- or six-leaf stage and“Tobifushi”what bears the pistillate flower on the first node of the lateral branch and few pistllate flowers on the nodes of the main stem. Lateral branches develop abundantly on the latter type plant and few on the former type plant. The Fushinari type responds to the diminution of light duration and intensity and to the lowering of temperature more prominently than the Tobifushi type. Sex expression of each node is affected on the one hand by the varietal flowering habit and on the other hand by light, temperature and also by the fertilizer application. Sex expression of Japanese cucumber being determined by the varietal nature, on the one hand, it must be interpreted to be of the genetical nature, and on the other hand, being variable responding to light, temperature and fertilizer trea meat, it must be interpreted to be brought about by the inner physiological changes. Results of the experiments conducted by the authors revealed that the manner of the stem training, the amount of nitrogen fertilizer, the diminut in of light intensity, duration, and the defoliation affected the sex expression of Fushinari plant as much as to be significant statistically. In the earlier stage of the development, the staminate flowers appear abundantly and later at the inflection time whence the pistillate flowers begin to be produced more intensively there appear the bisexual flowers. These bisexual flowers seemed to be of the transitory nature from the staminate to the pistillate flower. It is concluded that, the flower of Japanese cucumber is of the hermaphrodic nature and the sex expression shifts according to the nodal physiological condition, being variable responding to the environmental condition and with the age of the plant. Attempts are now undertaken to reveal the physiological conditions which reflect the sex differentiation.
1) It is well known fact that the sand dune orchards suffer often from their poor productivity and occasional water droughts. This survey has been undertaken, for four commercial orchards in Akita Prefecture, to study the relationships between soil structure and plant growth to find the suitable management measures for those orchards. 2) Soil profile consists of distinct three layers of almost common textures and properties in each orchard. The thickness of each layer is, however, peculiar to every orchard. 3) The blackish brown first layer seems to be most important as regard to nutrient supply source, because it contains fairly much organic matter and total nitrogen, and shows favorable physical properties, and plant roots penetrate well throughout it. 4) The fertility of the second and the third layers is much lower than the first, but their aeration is mostly very favorable for root growth, unless they hold too much soil moisture. The depth of root development in each orchard seemed to vary depending mainly on the depth of water table. This fact must be cosidered to be very important when one selects his orchard site. The deep penetration of roots in the lower layers of sand dune area is arrested chiefly by the excessive soil moisture caused by higher water table of the orchard. 5) Leaf analysis suggested the mineral contents of leaves in these orchard were normal and fertilizing practice in these orchards seemed to be quite suitable. 6) Some chlorotic leave in an orchard had higher potassium contents and lower calcium contents, though its cause could not yet be explained 7) In the sand dune area, the selection of orchard site and the fit care for the soil management may be most important factors to improve its productivity and to preclude the possibility of droughts.
Uniting process in the stem piece grafting of Japanese pear on common stock was investigated in 1951-1953. Development of new tissues was examined at every other week intervals after grafting. Successive observations revealed that the uniting process of the grafting proceeded in the following sequences. At first, callus was vertically formed at the interface of the scion and the stock, then very vigorous callus formation was observed at the base of the scion about six weeks after grafting. After eight weeks, very minute amount of xylem of the scion started to develop, and new shoot of about 10cm. long with 8-10 leaves developed from the scion. In about ten weeks, both the scion and the stock developed new xylem tissues 200-300μ in the scion and 60-80μ in the stock in thickness. Radial growth in the stock was eccentric; growth in the side below the scion was thicker than that of the opposite side. It was found that the union between the scion and the stock had been completed about three months after grafting.
In order to study the regional adaptability of strawberry varieties, the authors investigated the processes of differentiation and development of flower-clusters and flower-buds in the three varieties… Misuzu No. 2 (Strain 1-54), Shunko No. 2 (Strain No. 2-5) and Mimakigahara No. 1 (M-1). Plants raised in the beds at Nagano were set in the five plots…in the open plot of Nagano (elevation 360m), in the frame plot at Nagano, in Sugadaira (1399m), in Kitamimaki (650m), and in Iiyama (313m). In Shunko and Mimakigahara, most of the terminals of lateral branches on the main stems formed flower-clusters but in Misuzu, some of them failed to form flower-clusters. In this varietiy, number of laterals were as much as that of the other varieties, but their development was rather slow, and slower ones seemed to be unable to form flower cluster. Time of flower cluster differentiation of the laterals of the main stem followed that of the terminal and continued until the beginning of cold winter. In the following early spring, flower-clusters were formed on the terminals of the lateral buds of higher orders (2nd, 3rd and etc.). On the plants in the frame, however, clusters were formed continuously in the winter season, and branches of higher orders (4th or even 5th) bore flower buds. In Sugadaira, Kitamimaki and Iiyama, where period of cold winter or snow cover was long, the number of flower-clusters formed were generally small. Misuzu bore smaller number of flower-clusters than Shunko and Mimakigahara in every regions. This character seemed to be inherent to the variety and did not affected by the environmental conditions. Yields were correlated to the number of flowers opened, and the latter depended on the number of flower-clusters formed.
1. Replanting of young fig trees following removal of old fig trees has been recognized as a hazardous undertaking by some growers. As there was no evidence, this experiment was conducted to confirm it. 2. In the pot experiment, fig trees grew less vigorously in the fig orchard soil than in the orchard soil of other fruit tree. Trees of both plots were given enough fertilizers with manure and lime. 3. Fig trees in the plot of fig orchard soil fumigated with chloropycrin grew as much as in the other plot. This result was different from the case of citrus trees replanted in the soil of the same citrus grove (MARTIN, 1949). 4. The young fig trees of poor growth were affected with nematodes without exceptions. 5. Sand culture experiment showed that water extract of fig tree roots or fig orchard soil did not affect the growth of young fig trees. 6. Judging from the experiments, the poor growth of fig trees replanted in a fig orchard soil is considered to be largely due to nematode injury.
On account to harvest cauliflower curds from late spring to midsummer, studies were conducted to know suitable varieties and ages of plnats to be grown in the regions of high altitudes, in 1950 and 1952. Time of flower bud differentiation and its development were extensively examined on the samples collected periodically from different plots. It was found that the early varieties were most desirable in the region. To obtain splended flower curds in the spring crops plants having five or more leaves must be set in the field when minimum tempererature is about 5°C. Flower buds differentiated in the plants when mean temperature was about 10°C, and curds were harvested when mean temperature was 18-20°C. In the region of 1, 200m high above the sea level, it was possible to harvest curds even in midsummer when plants were set out late in the spring. The experimental results show that flower bud differentiation was induced when the plants received periods of cool temperature below 17°C. As for the minimum sizes or ages responsible to cool temperature of Early Snow Ball type, plants should have five or more leaves. It seemed that the buttoning and leafy curds were caused by imperfect induction of flower differentiation.
The blooming of bean flowers in natural conditions usually occurred about midnight to sunrise, but this blooming time varied according to the temperature of day and night, when the higher temperature of day continued until evening, the perfect tripping in next morning and setting of flowers decreased. The activity of pollens showed the highest at the stage of anthesis and 10 hours before it. The germination of pollen grains and growth of pollen tubes were favoured under wet conditions and moderate temperature, and optimum ones were 94_??_100% and 20_??_25°C.
This study was designed to secure the effect of light break on prolonging and forcing of the cut flower. For prolonging of short day plant, two varieties (early variety“Yoshino”and late variety“Edo”) of chrysanthemum were selected. The experimental lots of light break are as follows. (1) Lighted from 8p.m. to 9p.m. (2) from 10 p.m. to 11p.m. (3) from 12p.m. to 1a.m. (4) from 2a.m. to 3a.m. (5) from 4a.m. to 5a.m. (6) from 6a.m. to 7p.m. (7) control. The light break treatment was began on August 15 and was ceased on Oct. 10. Some plants from each lot were dissected to observe floral initiation, and flowering date of each of lot was recorded successively. The inhibiting effect was the most remarkable in the 4th lot. For the late variety“Edo”, in the 4th lot the mean flowering date was Dec. 16, while for control that was Nov. 6. For forcing of long day plants, Aster Savatieri and Shasta daisy were selected. In this case, the experimental lots were as follows. (1) Lighted from evening to 9p.m. and from 3a.m. to morning. (2) Lighted from 11p.m. to 12a.m. (3) Lighted from 1a.m. to 2a.m. (4) Lighted all night and (5) control. For aster the result was not clear, but for Shasta daisy forcing effect was observed in relation to the length of lighted time, being not so distinct by light break.
1. Experiments were carried out in order to clarify the influences of the forms of nitrogen supplied on the growth, yields, and leaf inorganic constituents of several vegetable crops, in sand cultures under glass. Materials tested were tomato, kidney bean, turnip, spinach, cabbage and onion. As for treatments, seven nutrient solutions with different proportions of NO3-N and NH4-N were prepared by combinations of NaNO3, (NH4)2 S04 and NH4NO3 Their ratioes were as follows: 10: 0 (all NO3-N), 9:1, 7:3, 5:5, 3:7, 1:9, 0:10 (all NH4-N). The total nitrogen content of all solutions was the same (140 p.p.m.), and all known nutrient ions were provided in constant proportion except Na and SO"4, All treatments were repeatedin triplicate. 2. In crops tested, plants supplied with larger proportion of NO3-N (10:0 to 5:5) made excellent growth, and generally, among them, there was no significant difference. On the contrary, plants supplied with more NH4-N(3:7 to 0:10) were stunted in growth, and among them, the more NH4-N ratio increased, the more decreased the growth. 3. Injurious symptoms of excess NH4-N in the spring and fall crops emerged earlier and developed more rapidly than those of winter crops. Usually, all NO3 plant produced light-green colored foliage, and with increased proportion of NH4-N, foliage became blue green or darker green step by step, but at the extreme such as 1:9 to 0:10 treatments, plants caused leaf-burning and subsequent defoliation. Moreover, anthocyanin pigments developed in cabbage, and leaf surface were rather uneven and leathery in turnip and kidney bean. Roots also sufferedfrom injuries of excess NH4-N, consequently, with disorder of water absorption of root, leaves tended to curve upwards and withered. 4. As to inorganic constituents in the leaves, analyses showed definitely that an increased proportion of NH4-N resulted in a larger percentage of total nitrogen and phosphorus, with exception of onion, but smaller percentage of calcium and magnesium. And between potassium and forms of nitrogen, there was not so definite relation as with above nutrient elements, due to complicated antagonism among cations such as K, •Na, •NH4• and so on.