1. Peach and persimmon seedlings were planted in 1/50000 WAGNER pots, which sealed excepting upper and bottom holes through which aeration was regulated to keep the oxygen concentration within the alloted range and gas for analysis was sampled Some of the pots were aerated with nitrogen only and sealed for the lowest oxygen level to be obtained.
2. Top growth of peach seedlings was normal in about 7% or more oxygen per cent and not so much less than that of check plots.
When oxygen level decreased to less than 5%, growth of peach seedlings was remarkably decreased. Further decreasing in oxygen in the soil atmosphere to about 2% resulted in wilting and ceasing of shoot growth after 6 days and defoliation happened after 10 days. After 20 days or more peach seedlings begen to die at last in about 2% oxygen level, whereas persimmon did not show any changing color of leaves and drying to death under the low oxygen concentration as much as 3% during later growing season.
3. Effects of lower oxygen concentration upon the root development were greater than that on the top growth. Under the aerating nitrogen gas only, about 2% oxygen, the peach root became slender and discolored to death. 5% or more oxygen was needed for new root development and 10% or more for normal root development.
The root development of persimmon remained little but did not die in less than 3% oxygen level and it was practically normal in 5% or more oxygen.

View full abstract

Since 1947 the effects of low oxygen concentration which suspend the top growth or dry to death upon the growth of peach, pear, persimmons and apple seedlings have been studied by regulating sealed pots except upper and bottom holes to keep the oxygen concentration within the alloted range. Continuously aerating system used in the present study, which can decrease oxygen level to less than 1 or 2% continuously.
Top growth of peach seedlings was normal in about 7916 or more oxygen level and not so much less than that of check plots. When oxygen level decreased to less than 5%, growth of peach seedlings was remarkably decreased. Further decreasing to less than 2% oxygen level caused wilting to death. As continuous oxygen level less than 1% enongh to ceasing of shoots or roots growth of pear, persimmon or apple can not be obtained under the sealed pots which are regulated by aeration through upper or bottom holes, apparatus for continuous aerating system of prescribed oxygen level was used in this study. Almost none of growth difference, compared with check, was found under the current aerating of 5% oxygen. Ceasing of shoot growth was found in 2% oxygen aerating. Tops of apple and pear seedlings began to wilt in less than 1% oxygen analysed concentration about one week after treatment and began to die after about two weeks, whereas persimmon (D. Lotus LINN.) did not die but showed faded leaf colour or some defoliation only 35 days after treatment of the lowest concentration. Excavated persimmon roots showed comparatively normal development in lower oxygen concentration.

View full abstract

1. Data presented, with which were made by the method as previous same kind of experiments, show effect of soil moisture regulated every day to the alloted per cent of dry weight of soil upon the growth of Mme, cherry seedlings and fig cuttings.
2. Soil moisture showing no increasing of top growth was 10% plots for Mume and cherry trees and 15% plot for fig cuttings Mume and cherry showed proper growth at 20-40 Go and they were resistant for dry soil condition as much as peach seedlings of previous study. But proper growth of fig cuttings was made between 30 and 40% soil moisture on dry basis. In submerged condition, these young trees made very low growth showing the yellow leaves and black roots comparatively sooner after soil moisture was regulated.
3. Mume and cherry seedlings, especially their roots made vigorous growth as grape, peach and chestnut in 20% soil moisture, in which growth of fig cuttings, especially their top growth was very slightly. The top and root ratio in every tree used showed smaller as the soil moisture more decreased. Fig cuttings made the most growth in 40% plot of soil moisture.
4. Results of experiment of last three years on the young seedlings of common fruit trees and stock plants are shown in Table 5.
In lower soil moisture (about 25_??_45% of water capacity), the degrees of growth were different from the kinds of fruit trees as grouped as follows:-
I Good growth group for low soil moisture:
grape, chestnut, peach, Mnme, cherry.
II Intermediate growth group for low soil moisture: japanease pear, apple, fig.
III Poor growth group for low soil moisture: persimon.
In high soil moisture (about 80_??_100% of water capacity, but not increasing to submerging), the degrees of growth were not so much checked and not all the plants which were resistant for low soil moisture showed low growth in wet soil condition as followed:-
I Well growth group for high soil moisture:
persimmon, chestnut, fig, peach, Mume.
II Intermediate growth group for high soil moisture.
apple, grape, persimmon (D. Lotus LINN.)
III Weak growth group for high soil moisture:
cherry.

View full abstract

1. The studies on the relation between the growth of peach and persimmon seedlings and soil moisture were conducted with methods which had been used in the previous studies at Okitsu. Present studies had another purposes to know the degree of oxygen decreasing in the soil atmosphere owing to the increasing of soil moisture in pots which were sealed excepting upper holes through which the gas for analysis was sampled.
2. Soil moisture showing no increasing of top growth and optimum soil moisture for top growth for peach seedlings were not so much different from those results obtained in previous study at Okitsu. Owing to the out of season for shoot lineal growth of persimmon, the top growth could not be distinguished by the soil moisture regulated.
3. As for fresh weight, peach seedlings showed considerable growth in 15% soil moisture and proper growth in 20% just like as previous studies, but growth of persimmon was rather poor in the soil moisture less than 25%. Owing to the difference from the previous studies at Okitsu which will be due to the difference of soil class between Okitsu and Hiratsuka soil and of soil properties such as waterholding capacity, root growth was not superior to top growth in drying soil moisture.
4. In the first peach experiment oxygen concentration in the pot did not decrease less than 5% because of too poor root development to take place the decrease of oxygen concentration. In the second peach and persimmon experiments, there were some variations in soil moisture in 40% plots in which gas samples of some pots were frequently drawn off as a chain of bubbles in a column of water, indicating that the obtained gas contained less than 5% oxygen. In such case growth of peach seedlings was restrained but those of persimmons were not so much restrained as peach. In the plots or periods in which the growth of seedlings was vigorous (i. e. in 30% and 35% moisture of peach and 25%, 30%, and 35% moisture of persimmon) the oxygen concentration decreased less than 10% but did not so much decrease to restrain the growth of young seedlings. Therefore, it will be concluded in the good aerating soil such as surface soil that decrease of oxygen concentration due to the increase of soil moisture occurs only in the case, in which soil is nearly submerging.

View full abstract

1. In a too close planting apple seedling orchard in Aomori Apple Experiment Station, the growths of red clover under shady condition were investigated during the year 1949 and 1950, being compared with those in exposed field condion. Twenty Wagner pots were devoted to each block.
2. Until buds on the apple trees grew into the stage of “mouse-ear”, there had not been difference in the intensity of light measured with a rucksmeter between the too close planting orchard and the exposed field. After this, with the advance of flattening of apple leaves, the intensity of light in the orchard began to decrease, and in June when the leaves of the apple trees in the orchard completed their growth, it dropped to 50 per cent of the exposed field, the state continuing to fall.
3. In both these years, the decrease of the sun-light in the orchard had the corresponding growth of red clover, Thus, the harvest of red clover in the orchard was treated 20 days later than in the exposed field. But, concerning the height of red clover, the shady ones were taller than exposed ones.
4. In 1949, the green top weight of shady red clover was about 25 per cent of that grown in the exposed field; in 1950, at the frist harvest, 80 per cent, and at the second, 20 per cent.
5. As to those removed from pots, shady red clover showed about 20 per cent and 50 per cent of the growth of exposed ones in 1949 and in 1950.

View full abstract

1. Erosion survey of apple orchards was practiced on the Kashiwagi Hill, Yamagata Village, Minami-tsugaru-County, Aomori Prefecture, during from November, 1950 to March, 1951
2. This hill which lies a part of the sloping apple orchards in Minamitsugaru-County, has 272 acres of land, of which about 200 acres are occupied by orchards. The first apple trees on this hill were planted during 1909 to 1913 after land clearing. From the geological point of view, soils of this hill are volcanic detritus; and from the soil type are classified into two kinds-ando soils and brown podosolic soils. About 80 per cent of the slope, 100 to 200 meters in length, is at an angle of 8 to 25 degrees.
3. The results of. erosion survey are shown in a map. About 32 per cent of total area of the Kashiwagi Hill exclusive farm road was subject to moderate or moderately severe sheet erosion; and 38.4 per cent of it to severe sheet erosion. The approximate acreage and percentage of each erosion condition in apple orchards are given in the following table.

View full abstract

1 Run off soil caused by melting snow was measured on the tillage apple orchards in Yamagata Village, Minamitsugaru-County, Aomori Prefecture during January to March in 1951.
2. Special three plots, 7.2 feet wide and 30 feet long, were established on the 28 per cent Slope. The side and upper ends of three plots were formed by wood borders projecting 25 ems. above the sur-face of the soil and extending 25 cms. into the soil, At the lower ends of each plot a concrete tank to catch everything that run off were built.
3. First melting snow were caught in January 31 and last one in March 25. Melting snow water which were caught into the tank was 12.4 per cent of total water in snowdrift on March 15 and a larger part of the run off soil was caused during 15 to 25 in March.
4. Entire loss of soil by melting snow was 184 kgs. in air dry matter per acre in 1951.

View full abstract

During late July and early August in 1950, leaf samples of Jonathan and Rall's Janet, the two lea-ding varieties in the Nagano Prefecure, were collected from commercial orchards, and their chemical com-position was determined in order to obtain some informations about the nutritional condition of the trees from which the samples were collected.
The contents of nitrogen, phosphorus, and potassium in the leaves of the two varieties were as follows:
Jonathan (121 samples) Rall's Janed (102 samples) Lowest Highest Mean Lowest Highest Mean N 1.91% 2.79 2.34 2.30 2.98 2.59 P 0.12% 0.23 0.164 0.12 0.24 0.181 K 0.69% 2.14 1.35 0.76 2.33 1.37
Comparison of chemical composition in twenty pairs of the two varieties in which the ages of the trees, cultural practices and other conditions seemed to be corresponding, revealed that N, P and K contents of Rall's Janet were significantly higher than the ones of Jonathan. (Table 2)
The age of trees affected slightly the N and P content in Jonathan and P content in Rall's, the trees the older, the contents in the leaves the less.
Potassium content in the leaves was low in Kamitakai county, and was decidedly high in Nagano city and Ina district. Twelve out of 223 samples were less than 1.0% in potassium content, most of which were found in the Kamitakai county. Phosphorus content was low in northern part of Kamitakai county, and was generally high in Higashi-Chikuma county and Nagano city
There was no correlation between the content of natritional elements in the apple leaves and the amount of the elements applied in the year as fertilizers.
There was no ceifference between the leaf composition of apples grafted on Malus Sieboldii (Mitsuba-kaido) stock and the ones grafted on M. prunifolia (Maruba-kaido) stock. Positive correlation was found between nitrogen and phosphorus content in the apple leaves in both, varieties.

View full abstract

In addition to many polyploid flowers which were described in previous I to IV reports, several new ones obtained in 1950 are summarized as follows:
_??_

View full abstract

It is already known that some bulbous triploid plants found in native flowers, for instance, lilies, daffodils etc., are popular with their peculiar charac-teristcs of enlarged flower shape or vigorous growing.
In the same view, several new triploid plants were created artificially by crossing between our induced tetraploid and normal diploid plants. Some characters of these plants are explained as follows:
_??_

View full abstract

The soils of the apple orchards in Aomori Prefecture may be classified into three kinds; that is, ando soils, brown podzolic soils and alluvial soils. They have been studied with regard to both physical and chemical properties respectively. The soils show various mechanical compositions. Alluvial soils are rather clayey, ando soils and brown podzolic soils being loamy. The reaction is mostly acidic or weakly acidic. The contents of the main nutrients of the surface soils are as followings:
highest lowest average Humus 22.75% 3.13% 10.26% N 0.806% 0.112% 0.457% P₂O₅ (soluble in 1/5 N HCl) 0.0672% 0.0064% 0.0244% K₂O (ditto) 0.2557% 0.0319% 0.0861%
These contents generally decrease with depth.
From the data obtained it may be concluded that the orchard soils of Aomori Prefecture have rather desirable properties for apple growings, both chemically and physically.

View full abstract

1. In kunder'd White variety, the inflorescence primordia were formed in the begining of May, when they were planted in the end of March or the middle of April.
2. The primordial flower spike were formed at the time, as soon as the 2 nd normal leaf appeared or just before it.
3. About one month later from the flower bud differentiation, the pollen and ovule formations began, and a few of the top flower buds on a spike stopped their growth after ten days, while the others were developing to be ready. for flowering 9 days after.
4. The flower buds no more developed at the various stages before the pollen and ovule formations.
5. The new corms were growing rapidly as soon as the flowers faded, and their growths continued until the end of September or-the begining of October.
6. The corms from axial bud awaked their growth later than the center did, and the growth of the former continued growing to the middle of October.
7. The cormel growth started rapidly as soon as the flower faded and continued its growth until Nobember.

View full abstract

(1) The shade-culture by dark box was carried out in order to know whether the flowering date of gladiolus concern of the day length.
(2) The varieties tested were Peligrina (early flowering), Hecter (medium flowering), Golden Cup (late flowrng), but the difference in varieties was not found in the control.
(3) The munber of flowers of each variety was zero without Hecter, while the flower buds which are die leave differentiate in the stem, after the experiments were ended.
(4) Consequently, if the flower buds which died were produce by bad outer environments, it is not recognize that the gladiolus flower does not bloom by the shade-culture.
(5) The reduce in the leaf number, leaf width. and the height of gladiolus by shade culture is earlier than the control, but the fairly days are necessary to show the similar result.

View full abstract