1. The taro, in Japan, has many synonyms, as the cultivating history is old. So we tried, since 1945, to survey the 205 varieties of the taros collected all over this country, China, Formosa and southern islands, and to classify them in order to clear up oecological significance according to shape of leaves and tubers, chromosome numbers, and bud mutation.
2. Green colour degree, distribution of anthocy-an, crookedness of neck part of leaf-stalk, wilting of leaves and maturity are clearly different among varieties.
3. Shape of the corm has three types: round, cylindrical, and multiple-headed. Lateral tuber varieties(the corm is coarse and does not develope so large) and Akame in corm-tuber varieties (both corm and tubers are able to eat) are round, corm varieties (growth of lateral tubers is poor and few) are cylindrical, and only Yatsugashira and Shogaimo are multiple-headed. Lateral-tubers of Hasubaimo, Kurojiku and those of round shape line of Ishikawa-wase and Dotare are, too, in good shape.
4. Outbreak of lateral tubers is, naturally, different by maturity speed but only Hasubaimo is late in spite of its early maturity. Of second lateral tubers from first tubers, Kurojiku group has the most numbers.
5. From shape of flower organs, we think Eguimo and Okinawa-aoguki are Colocasia antiquorum Schott. var. trpica of Engler classification, the other lateral tuber varieties are var. globulifera, and corm-tuber varieties are var. esculenta.
6. Bud mutation is lately found; mutation of
anthocyan ditstribution on petiole at Yamagatataimo, Tonoimo and Akame, and mutation of out-break of lateral tubers at Yatsugashira. But we have not found the mutation changed to a remote variety group.
7. Chromosome numbers of these varieties studied by the Kyushu university have their important significance in this classification.
8. The varieties, in Japan, are classified from these above standpoints as follows.

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The effect of thiamin application on the respiration of the following three kinds of horticultural plants, potatoes, sweet potatoes and kidney beens, has been studied by the conventional WARBURG manometry.
The results obtained were as follows:
1. The thiamin solution of moderate concentration added to the leaves and roots, increased their respiration.

2. The calculated data on metabolic rapidity by the conventional WARBURG method, indicates that the thiamin solution added moderately advances the metabolic activities of the plants.
3. By adding thiamin, the values of respiratory quotient of leaves are approaching to 1.0. In my opinion, this result seems to indicate that thia-min is useful for decomposition of sugar or smooth oxidation of carbohydrates in leaves.

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1. From July, 1947 to August, 1950, the author observed the air temperature near the ground and the under-ground on the field, on the persimmon orchard of the southwestern slope and on the orange orchard of the northeastern slope, once or twice a month on a fine day, at every two hours for 24 hours running, and examined the daily variation of the temperature on each of the slope.
The state of its distribution almost agrees with that of the amount of insolation, and the differ-ence of temperature on the upper and lower parts of the slope being so small, the average differ-ence proved to be about 1°C daily.
2. The daily average temperature is, at each slope, the highest in August both on and under the ground. On the ground and up to 10cm under it, it is the lowest in January, and near 50cm under the ground, it is the lowest in February.
3. The diurnal range of the temperature is, at every slope, the largest' on the ground sur-face, and the partial difference is also large. It decreases as it goes up or down from the ground, and especially it decreases suddenly as the sta-tion becomes deeper, and becomes zero about 50cm under the ground, which shows the depth of daily permeation of heat.
Every month the diurnal range of temperature is large on the field in the southwestern slope, and is the smallest on the orange orchard in the northeastern slope, and it is about medial of the two, on the persimmon orchard in the southwes-tern slope, but in the cold season, every diurnal range is small.
The diurnal range was large about April and August and the smallest in February.
4. The difference of temperature between each observation point is the largest on the ground sur-face, and becomes gradually smaller as it goes up or down, but up to 10cm from the surface or under the ground it is large. This is especially large in April and August when the diurnal range is large, and is small in cold seasons.
5. I examined the vertical distribution of the air temperature near and under the ground of each slope.
The vertical distribution of the daily average temperature showed simply, at every observation point, an incoming radiation type in spring and summer.
An outgoing radiation type was shown under the ground in autumn and winter, but towards December and January when the amount of the incoming radiation is small, the air temperature near the ground also showed the outgoing radia-tion type, and the northeastern slope already showed it in September earlier than the other slopes.
6. In warm seasons -in spring and summer, the vertical distribution of the average temperature in the daytime showed the incoming radiation type almost without exception, but in the persimmon orchard, part of the outgoing radiation type or a type approximate to it was shown.
The vertical distribution of average temperature during the night showed the outgoing radiation type at every part of the underground, and the air temperature near the ground showed simply the outgoing radiation type in March and April, but in May instead of showing simply the outgo-ing radiation type as Dr. R. GEIGER brought for-ward a minimum air temperature appeared about 10cm about the surface of the ground.
After June when it is warm, the outgoing radiation type hardly came to appear in the air temperature near the ground.
In autumn and winter, every daytime showed the incoming radiation type, but on the north-eastern slope, the time to show the incoming radiation type became shorter and shorter.
During the night, except in September, every observation point showed the outgoing radiation type.
7. I fully observed the air temperature near and under the ground in summer within and without the persimmon orchard in the southwestern slope, and plainly showed the special character of the distribution of the temperature in the orchard

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1) Boron deficiency of grapevine (so called “Ebi” disease in Yamanashi Prefecture) has become epidemic recently in Yamanashi Prefecture. Many instances of the disease varying markedly in symptoms and severity were found in 1951. Then, details of symptoms, vine and edaphic con-ditions in relation to the occurence of the disease and controlling measures, were studied in the Horticultural Branch, Yamanashi Agricultural Experiment Station and on commercial vineyards from 1951 to 1954.
2) Typical symptoms of the disease were: (1) cap of resish brown color remaining on calyx at anthesis, (2) poor germinative power of pollens, (3) slight- or non-setting of berries, (4) setting of small seedless berries, (5) leaf mottling, and in severe case, leaf burn, short internodes, and die-back of canes.
Infestation of phylloxera and Rosellinia necatrix were frequently found on the roots of abnormal vines.
3) Results of the survey on the relation of soil moisture to the disease were not conclusive in
this study, but it was generally observed that the drought at the blooming period accelrated the incidence of the disease.
4) Large number of severely affected vineyards had been supplied with excess of lime or potassium or both without manure for several years.
5) Boron contents in the leaves decreased gradually from preblooming to post blooming time. In the deficient vines, it was low and a half as much as in the normal ones. It seemed that the critical level was 12_??_13 ppm on dry weight base in late July.
6) Calcium, potassium, and nitrogen contents in the abnormal leaves were generally lower than those in the normal ones. Ca:B ratio and K:B ratio in the abnormal leaves were two to three times as high as those in the normal ones.
7) Available boron content in the soils of de-ficient vineyards was about a half as low as that in the normal ones, and the critical level seemed to be 0.2_??_0.3 ppm.
8) There found no difference in pH value between the deficient and the normal vineyards.

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(1) To find out the relations of the chemical constituents to the qualities of the dried persim-mons prepared with several varieties by dehydration, sugar, pectin and crude fiber contents in the products were determined by chemical analysis in 1954.
(2) It was found that the sweetness of the products did not depend upon the fructose-glucose ratio but simply upon the total sugar content. The total sugar content was high in the varieties Yamatohyakume, Hiratanenashi, Saijo and Yotsu-mizo while it was comparatively low in Dojohachiya, Yokono and Atago.
(3) Although there were no remarkable differences in total pectin content among almost varieties, there were found considerable differences in soluble pectin. This amount was high especially in Yotsumizo and Ichida, but low in Gionbo, Atago, Dojohachiya and Yokono.
(4) There were rather small differences in crude fiber content among the varieties, but this content in Tateishi and Yamatohyakume was seemed to be somewhat low.
(5) From the results of these analytical experiments, it was supposed that the qualities of dried persimmons would be almost expressed by the combinations of total sugar, soluble pectin and crude fiber contents. However, among these three components the total sugar was definitely important.
(6) The average fructose-glucose ratio was 1:0.89 in the pulp portion of products while it was 1:6.15 in powdery deposit (white bloom) on the surface of products.

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The further experiments of NAA sprayings on apple varieties (Jonathan, Delicious, Starking, Richard, and Golden Delicious) were carried out at the Economic Farm of Iwate University in 1953, to find out the best stage of spraying and the optimum concentration of NAA for fruit thinning and to know the effects on the leaves.
The results obtained were as follows.
(1) The optimum concentrations of NAA were:
10 ppm…… for Jonathan, Delicious, Starking and Richard
20ppm…… for Golden Delicious (further experiments needed)
The best stage for spraying was about one or
two weeks after full bloom as in the previous report.
(2) The effects on the leaves were different among the varieties. “Epinasty”, a special phenomena of hormonal effect, appeared as soon as NAA was sprayed, but disappeared after one week. It was probable that NAA was absorbed through the leaves, then caused the fruit drop, because the spray on the leaves exclusive was as effective as the one on both fruits and leaves.
(3) It was found that the chemical thinning of Jonathen, Delicious, Starking and Richard was promising, but hand thininng after the spraying was necessary.

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In the present paper, the results of the experi-ments on the relation between oxidation-reduction potentials, Fe^.. and H₂5 contents in soils, and the submersion tolerance or excess-moisture injury of the fruit-tree roots are reported with special reference to fig, peach, pear, apple, persimmon and grape. The results are summarized as follows.
1. The growth of fruit-tree shoots were stopped by excess-moisture or water-lodging in the soils having following values of Eh₆
Fig 360_??_370m. v.
Peach 330_??_350m. v.
Pear and Apple 260_??_280m. v.
Persimmon 200m. v.
Grape 170_??_180m. v.
Shoot growths of pear, apple, persimmon and grape were inhibited gradually from the neigh-bourhood of ca. 300m. v.
2. Fe^..-formation in soils increased as the oxi-dation-reduction potentials failed, and the amount of Fe^.. extracted by HCl (pH 3) solution was ca. 20mg at 300m. v., ca. 30mg at 200m. v. and 60_??_70mg at 100m. v., per 100g. dry soil. There-fore, the root system of fig or peach was impeded mainly by oxygen-deficiency before Fe^.. was formed abundantly in soil. On the other hand, the impediment of root system in the case of pear or apple was derived from a large amount of Fe^.. formed by remarkable reduction in soils, and moreover, when approximately 30 mg Fe^..
was formed in soils on persimmon or grape.
3. When the soils were water-lodged, the higher organic matter content in soil, the more rapid Eh falling and more the amounts of Fe^.. and HsS formed. Accordingly, the more high organic matter content in soil, the more remarkable the injury of root system of fruittree caused by excess-moisture.
4. Fig and peach were susceptible, pear was middle and grape and persimmon were resistant. Parallelism between resistance of root system to Fe^.. and H₂S, and submersion tolerance of root was found. And it was suggested that the differ-ence of resistance to excess-moisture injury was caused by the difference of oxidation power of root towards the exterior.

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