This is a part of the experiments on the physiological effect of rice plant to irrigation. The degree of respirationof the plant cultivated in pots and different conditions was measured by determining the volume of CO₂ expired. The experiments were classified into two divisions, direct sowing and transplanting, and frurther subdivided by the openning time of the irrgation. As to the method of measuring the degree of respiration, we determined the amount of carbon dioxide expired by the rice plant per one hour by introducing it into the barium solution, the concentration of which had been known, and titirationg the solution gy N/10 oxalic acid. The data in the figures thus obtained were converted into per one gram of dry matter for the benefit comparison.The essential points of the results were as follows: 1) In each plots of the direct sowing, the degree of respiration was found to be deteriorated gradually since the 11th of July to the heading 2)In the transplanting plots, the volume of CO₂ decreased in each plot till the 29th of July, but it has a tendency to increase somewhat before the heading 3) In both the direct sowing plots and the transplanting, the volume of CO₂was almost the same till the end of July, but before the heading it was generally found a little more respiration in the transplanting plots than in the direct sowin.4) The degree of respiration seems to have a tendency to be affected by the different conditions of cultivation, especially the abrupt changes in the soil seem to cause the increase of the amount of respiration.

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This paper deals with the inheritance of a variegated strain in rice. From the various results it is certified that the inheritance plays due to the mutable plastids. That is, the stripes are arisen by the habitual change of mutable green plastids to white ones, according to the development of the individuals. On the other hand, the complete green strains are resulted in the recurrent mutation of mutable plastids to stable constant ones. Moreover, some grades or steps are considered in the latter case and rarely some stable green plastids seem to mutate reversibly also into the mutable ones.

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1. this study has been performed on the inheritance of the grain-length and the panicle-length of rice plant. 2. Material used were F₃-F₅, descendants of Kokuryomiyako x Tairyuto. The total numbers of lines and individuals observed were about 960 and 48300 respectively. 3. By the statistical treatment of each line of the progenies, one gene (named Gr) difference was found between these two varieties. Consequently the genotypes of the parents would be assumed as follows: Kokuryomiyako CCgrgr, Tairyuto CCGrGr (C indicates a fundamental gene-complex). 4. The gene Gr is an imperfect dominant gene and has manifold effect to the length of both characters. Its function to the fundamental gene-complex C is multiplicative in deter mining the grain-length and the panicle-length. 5. The values of function of genes C and Gr to each character are indicated on table 4.

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The writer investigated the micro-meteorological conditions in the fields using 3 kinds of windbreaks: they were the board fence, the lattice fence, and the reed fence. The outlines of the results obtained were as follows: 1. The velocity of wind. On the leewardsides of the lattice fence and of the reed fence, the velocity of wind was very small. On the contrary, on the leewardsides of the board fence, the vortex provoked there and adverse wind was severe. 2. The temperature neat the surface of earth. In the daytime, on fine weather, on such wind-weakened field as the leesardsides of the lattice fence and the reed fence, the temperature near the surface of earth is higher than the air temperature. On the open field the temperature near the surface of earth is higher than the air temperature. On the open field the temperature near the surface of earth is between both, and resembles to it which on the seewardside of the board fence. The difference above mentioned was most clearly observed on fine weather and became vague on cloudy weather. In the night the order was opposite. 3. The relative humidity. The relative humidity was compared between on the seewardside of the reed fence and on the open field. The former is higher than the latter every time except a few hours near the noon. 4. The moisture of surface soil. Evaporation on the open field where the wind is severe is larger than that on the field where the wind is weakened. Accordingly the moisture of surface soil decrease according to the force of wind. 5. The others. The author also observed great differences among them on the flying soil, the frost, and the accumulated snow.

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1. It has been studied at the Hokkaido University farm on 1950 that the irrigation affected some crops oats (Kairyohadaka), upland rice (Hokkaiwase), and potato (Danshaku). 2. As the results of this experiment: (1)Oats: Culm length is the highest in the plot irrigated at the three periods, while tillering is the fewest in this plot. The largest yield is obtained in the plot irrigated at the maturing time (120%). Moreover, number of sterile spikelets was increased in the plot irrigated at the three periods.(2) Upland-rice: Culm length in the plot irrigated at the time of seedling stage and the whole period is slightly high, bur in the other plots there is almost no difference. Tillering is the fewest in the plot irrigated at the whole period and there is almost no difference in the other plots. The yield is increased in the plots irrigated at the whole period (136%) and the maturing time (123%). (3). Potato: The yield in the plot irrigated at the blooming time is the fewest (97%) and the largest yield was obtained in the plot irrigated at the growing time (117%). 3. Irrigation under the drought condition brings good effect upon the growth of these crops, but the growth of crops is suffered by the excess of water content of the soil when it rains just after the irrigation.

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1. This study was made from June to October in 1950 on the farm field of Hokkaido University in Sapporo, Hokkaido. 2. Principal weed community in this field consisted of 13 families including 29 species. 3. Perennial weeds showed the tendency to decrease towards summer and to increase again towards autumn. On the contrary, the annual weeds proved the opposite tendency to perennial weeds. 4. Regarding the weeds on a field as a plant community, we could make frequency diagrams for each month, and they show that the weed community was stabilized in spring and autumn, and unstabilized in summer. 5. The dominant speciees in each month were as follows: June Agropyron repens, July Euxolus asendens, August The same, September the same, October Agropyron repens. 6. By surveying the each weed on its frequency and covering ratio, I could classify these weeds in five types: Spring Summer type, Summer Autumn type, spring & Autumn type and Spring Summer Autumn type.

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1. Observations were made on blooming and dropping of flowers and young pods of soy bean plants. 2. Rate of planting, soil moisture, and thinning young buds seeded to have no marked effects on dropping of flowers and pods, so far as the present experiment showed. 3. Soy bean plants cultivated in foot path of paddy fields (Azemame) showed smaller rate or flower and the pod dropping as compared with those grown on upland fields by usual practice. The cause for the difference in dropping may be atributed to the difference in the microclimatic environment. 4. A pronounced decrease in dropping rate was observed in plots under short day. The decrease, however, does not seem to be due to photoperiodism alone; it seemed highly probable to be due to the complex of photoperiodism, temperature, and humidity factors, although further experiments should be necessary before conclusion.

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Studies of the relation of temperature difference between day and night to the seed development in soybean plant, have been carried out. When the daily minimum temperature difference is large, the flowering time was shortened, and the maturation was accelerated, beside the size of seed and the weight of one hundred seeds were increased. The reason for the result above mentioned would be that the lower the temperature of night was, the more the transitorial materials increased, and the respiration decreased then the consumption of stored substances was smaller than that in higher temperature.

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1) The growth of top and root of soybean plant were restricted by cutting-off cotyledons at seedling stage. The effect was observable mot only in the period, directly after cutting but also throughout the whole period of growth. 2) Both the top and the root, were affected. Number of branches, and roots were reduced, and the position of the lowest branching node rose. 3) The percentage of legumes which developed and their yields were decreased in agree with the degree of cutting-trestment: In half cutting plot 73% of legumes developed, producing 66.5% of seeds in weight, compared with thosoe of the control plot and in full plots 55.6% legumes developed, with 51.9% of seeds.

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Experiment was carried out in 1950 on the influence of the day-length and temperature upon the ripening period of soy-beans. Varieties used for material were Kisaya, Norin No. 2 and Iwate No. 2. The plants were grown in soil by pot culture. In the short-day plots, the day-length was limited to 8 hours every day from 8 a.m. to 4 p.m. and in high temperature plots, plants were placed in an unheated glasshouse. Each treatment was conducted from blooming time until maturing time. The results of the experiments are summarized as follows: 1) Yellow and shedding of leaves and maturing were accelerated by both short-day and high temperature treatment and consequently the period from blooming to ripening of pods was also remarkably shortened in every varieties. From the point of acceleration, there was a slight difference between two conditions where the number of flowers were limited or not limited prior to treatment. 2) The growth of pods was accelerated by both short-day and high temperature treatment, but the acceleration was larger in short-day plots. 3) Short-day and high temperature treatment showed no influence on length and thickness of seed harvested, but the seed-width in treated plots was greater than that of control plot. Weight of seed was smaller in treated plots than control plots, and this trend was larger in short-day plots.

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This research was conducted to make clear the influence of soil moistures in the growth and harvest of soybean. Sandy soil (the water capacity was about 28%) was used, and the soil moistures were kept constant at 30%, 50%, 70% and 90% of the water capacity in each experimental plot respectively. The variety used was Summer Soybean No.1. The summary of the results are as following. 1. The soil temperature observed was higher for lower soil moisture, and fell in proportion to the increase of soil moisture. 2. With soil moisture at an extent of 30%, the germination of soybean was somewhat obstructed. 3. The length, number of nodes, and size of main stem of the plant harvested were in proportion to soil moisture. 4. There was generally not large difference in the average date of flowering. 5. Number of flowers, pods, percentage of fructification, number and weight of seeds were bigger in proportion to soil moisture, but dry weight of one hundred seeds, became bigger as soil moisture decreased. 6. There was generally not large difference in the harvest time. 7. Among the chemical components of seeds, oil content was found to increase as soil moisture decreased, but the difference was very little among all soil moisture plots. On the other hand, protein content was large in proportion to soil moisture, and the differences among the lots comperatively great. 8. Taking into account the growth, flowering, fructification, yield and component of seed, there was observed a remarkable differences of effect between 30% and 50% of moisture content. 9. The best results in growth and harvest of soybean, were obtained when the moisture was kept at 90% of the capacity.

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It is evident in soybean plants that as the intensity of supplemental illumination at night for the purpose of gibing long day decreases lower, the inhibition of blooming due to long-day condition decreases as well. On the contrary, the intensity of the illumination increases higher, the inhibition of blooming increases as well. Furthermore this relation seems to be found more prominently in late-maturing varieties than early maturing ones, even when the supplemental illumination is not so strong. In discussing the influence of day-length, importance of the intensity of light must not be disregarded.

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Studies carried out to fine the differences of effect of between pinching and transplanting upon soybean plants in relation to the plant variety and soil condition. The outline of the results obtained is as follows: 1. Effects of pinching and transplanting as related to the variety. By pinching or transplanting, flowering and fruiting in Imada variety (IVctype)were promoted and yield increased, but in Akazaga variety (IIIctype) inversed results were obtained. 2. Effect of pinching and transplanting as related to soil condition. Pinching or transplanting brought larger yields on alluvial soils (fertile and with moisture) and less yields on diluvial soils (sterile and dry) in Imada variety.

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Soybean plants were cultured with the Hoagland and Arnon's nutrient solution added manganese and boron in the concentration from 0 to 5.0 p.p.m., and the effect of these ions appeared on the growth of plant were investigated until the time of maturing seeds. And the symptomes caused by the deficiency of manganese and boron sere observed in the relation to the different pH values of solution at the flowering time. The results of experiments ate as follows: (1) Interveinal portions of the leaves turned to yellow color and plants were dwarffed in the deficiency of manganese, so that the dry weight of the plant was only 60%of normal one in the flowering time. As a result of such abnormal growth, the decrease of flower buds and incompletion fruit setting occurred just the same. (2) Excess of manganese concentration, such as 2.5 and 5.0 p.p.m. in the nutrient solution indicated a toxic injury. The grey spots appeared on the lower leaves at first, and the symptom developed progressivelly on the higher parts of plants and color of leaves turned to pale yellow as growth advanced. In consequence, the vegetative growth and the reproductive activity reduced in general. (3) A specific shrink of young leaves and reterdation of root development were seen as first pathological symptom of boron deficiency. In the later stage, the stems died down and branches and flower buds dropped off. Accordingly, the deficiency of boron gave an ill effect to the reproduction than the vegetative growth of soybean compared with it in the case of manganese deficiency: for example, the fruits setting decreased to only 5% of normal plant, but the reduction or the dry weight of plant was, on the contrary, about 10%. (4) 0.5 p.p.m. of boron in the culture solution was sufficient for growth of soybean, and the concentrations of 2.5 and 5.0 p.p.m. acted as a toxin on the growth. The first visible symptom of boron toxcity was a slight thicking of the lower leaves and an upward curling of their edges and soon the edges of leaves turn to pale yellow color. Later, the yellow spots became larger by and by and turn to browen. Both the growth and the yield of soybean were severely effected by toxic action. (5) The total content of iron and manganese in the leaves and stems of the plant grown in the nutrient solution with different pH value decreased inversely to the pH value, but the degree of reduction of iron was smaller than that of manganese at the pH7. (6) The total content of manganese in plant had no relation th the degree of manganese deficiency, but the ratio of total manganese to total iron connected to it. The plant grown at the pH7 of culture solution had the highest values of ratio and indicated the heavily demand of manganese, the next values in the ratio was detected at the pH 4 of culture solution, which appeared fair deficiency symptom of manganese, and the slight manganese deficiency was produced at the pH 8 of culture solution and the plants had lowest values in the ratio. (7) The pH values of the nutrient solution had little effects to the deficiency of boron and its content of plants.

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Since 1935, the author has continued studying native (primitive) varieties of several kinds of crops cultivated in localities of unfavorable natural conditions. He has succeeded in breeding a new wheat variety resistant to strongly acidic soils, as well as other new ones highly resistant to drought, each out of those native to Tottori Prefecture. In the present report, the results of his investigations were referred to that were made on a climbing variety of Adsuki bean, one of the native strains found in Tajima District, Hyogo Prefecture, and in the reclaimed lands in Tottori refecture, during the years 1949 and '50. It was observed that on highly acidic soil, which was remarkably short of available phosphoric acid content (as shown in Table 1), the climbing variety grew invariably more vigorously than the ordinary Adsuki variety, without regards to the time of seedling tested (as shown in Tavle2, 3 &4). According to the results obtained, the author advocated the importance of studying native varieties of crops grown in localities of unfavorable natural conditions.

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An experiment as to the spacing problem in sugar-cane has been studied under the conditions in temperate region. The results obtained on this experiment with Tekcha, Saccharum sinense, are summarized as follows; 1. During about 50 days after planting, the plant is in a preparatory period for settlement and development of the mother stalk until it becomes warm enough to enable the plant to tiller vigorously and to grow rapidly. The growing period continues for about 4 months until it becomes too cool to allow the plant to keep on vigorous growth, and then the plant transfers to the maturing stage which ranges over about 2 months from early Oct. to the harwesting period in Dec. In this period the plant mostly accumulates sugar in its stalk until the green leaf is seriously damaged by the prevailing low temperature, sometimes below the freezing point. 2. The growth curve of stalk length resembles to monomolecular autocatalytic reaction, and the length of stalk at given periods will be calculated from the following formula; [numerical formula] y is the stalk length in cm, and x is the number of days from June 2. to marked differences in the growth of stalk length are recognized among various plots of experiment. 3. The number of tillers increases up to the early Aug., and then is gradually decreases towards the maturing period, showing different rates of survived stalks according to the density of planting hills. 4. The area of a leaf and of total green leaves attains its maximum at late Aug., and then it decreases in the same way as in the numfer of green leaves per stalk. A larger extension of the area of total green leaves per stalk in the growing period, especially in later period, turns out a high content of sugar in harvested stalks. It is also pointed out that late Aug. seems to be very important period from physiological point of view, owing to the greatest number of green leaves and the largest area of totel green leaves per stalk are shown at this period. 5. The number of available stalks per unit area and the rate of perished stalks correlate possitively with the density of planting hills, while the reverse is the case between the density of planting hills and the number of available stalks and ratoons, each per hill. 6. Little comparable differences occur in the weight of a stalk among various plots of experiment, affirming that similar relationship should be secured with the weight of a stalk as was secured with the growth of stalk length. 7. The cane weight per hill is adversely proportionate to the density of planting hills. It means that the more the number of planting hills per unit area increase, the lower the efficiency for absorption of nutrients applied is. 8. A significant positive correlation between the cane yield per unit area and the density of planting hills is found. However, in is reasonably revealed that the cane yield per unit area reaches its maximum at the rate of 3, 600 hills per unit area, and is declines when more cuttings than that are planted to the same area. 9. The brix of pressed juice, on the other hand, lessens as the number of planting hills per unit area increases. Some suggestion as to a remedy for low brix in harvested stalks are referred to standpoints of introducing new improved varieties and applying calcium to the growing plant as a liguid manure in Aug. 10. The apparent sugar yield per unit area reaches its maximum at the rate of 3, 300 hills per unit area, and even so, it is revealed that a striking decrease in sugar yield will arise, if more hills than that are planted to the sane area. 11. Judging from the economical point of view, a profitable sugar yield per unit area may be produced at the spacing of 100 cm × 33 cm, or at the rate of about 3, 000 hills per unit area, in case of the monoculture of sugar-cane in this district. Remark: unit area in this eperiment is 0.25 acre. [the rest omitted]

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In this paper the writer reported and discussed result of cytological observations caried out in 1950 year upon the process of tuberization in the potato plant. The results summarized are as follows: 1) the portions that the cell division in the elongating tuber occurred in the greatest number was the most terminal one, but as soon as the stolons began to swell, the cell division came to be seen not only in terminal, but also pretty numerously in middle and basal portions, and also in the direction of it the rate of redial one to the logitudinal increased. The fact described above shows us a change from the terminal elongation to the lateral development in the tip of stolon from a point of cytological observations. 2) the regions that the dividing cell per one microscopical field was seen in the greatest number were internal phloem parencyma and vascular tissue, and it was supposed that cells formed successively from the cambium in the vascular tissue were organized externally into phloem parencyma and internally into medulla. 3) comparing the direction of cell division in each tissue, the cell division in longitudinal and tangential ones was seen to occur more numerously than in radial at cortex. The fact described above shows us that the external tissue must enlarge to increase the circumference in proportion to the enlargement of internal tissue. 4) the cell division in the enlarging tuber weighed more then about 2g was rarey seen, comparing with it in the elongating stolon or the young tuber, and then it was scarcely found in the tubers weighing upwards of about 30 g. 5) the increasing curves of cell size and number in proportion to the increase of tissue size were expressed by an exponential formula, and the increasing rate of cell number in it was greater than that of cell size. 6) changes of the relative growth tare of above two curves were expressed by a formula Rx=b(R: relative growth rate, x: tissue size, b: constant), and this result shows us clearly that the activity of development is vigorous in young tubers, but weak in large tubers, and also this fact corresponded to it of observations upon the cell division.

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This investigation has been undertaken to know the temperature and its duration to cause freezing injury on potato seedlings of about 40 days old by artificially produced low temperature. The results obtained are summarized as follows. [table] according to this investigation, it seems that the freezing temperature of potato seedling is slightly higher than those of many other crops. Perhaps such a difference may be due to the higher freezing temperature of cell sap in potato seedlings than in other crops. Also the non-hardened condition of materials and the rapid refrigeration as well as the susceptible stage of seedling development may have caused early freezing injury on potato seedlings.

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In this experiment we obtained the results that the secondary growth of potato tuber is induced by the treatment of 25 and 20 times of normal concentration of culture solution for 24, 28, and 72 hours and 15 times for 72 hours respectively, while it is scarcely induced in the plots of 15 times for 24 and 28hours, and is not affected with 10 and 5 times.

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It is mot at all uncommon to find potato tubers with very irregular shape of sprout tuber, due to the senility of the tuber during storage being kept for a long duration over their rest period. It seems quite clear, accordingly, that an attack on the problem f the problem of the senility and on the effect of external conditions, by which the tuber produces such abnormal sprouting, is a practical necessity in the agricultural field. In the present paper are described the behavior of carbohydrate contents, together with the variations of soluble and protein nitrogen fractions in the tuber. And at the same time the respiration rate of the sprout was also determined. The experimental results obtained may be summarized as follows: (1) Under the condition of humid storage, the growth of the tender sprout was accelerated enormously, resulting in high contents of reducing sugar, soluble nitrogen and moisture at the expense of a decrease of starch and protein nitrogen in the tuber. Under these conditions the senility of the tuber was very striking, though the shrinkage of the tuber wes inconsiderable in appearance. (2) under the condition of dried storage, on the other hand, due to the check of longitudinal growth of the sprout, new growth may form an irregular lump on the mother tuber and be progressively developed to the typical sprout tuber after the storage of two months. In such a small sprout tuber the contents of starch and protein nitrogen were high, while moisture, sugar and soluble nitrogen contents were low. According to the shrinkage of the tuber due to the dehydration and the consumption of the reserve substances, the senility of such a tuber was also striking. (3) under the conditions of dried and high temperature storage, being accompanied with the decrease of reducing sugar content and the accumulation of starch for a very short period, a remarkable retardation of the longitudinal growth and a rapid acceleration of the lateral growth of the sprout was recognized. And at the same time a rapid falling off in the rate of respiration was ascertained. (4) judging from the results described above, it seems reasonable to assume that the formation of the abnormal sprout, such as sprout tuber, might be due to changes of the reserve substances in the mother tuber and of the respiratio rate of the sprout and tuber according to their storage conditions.

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So far as the writers are aware, few detailed accounts seems to have been given, as yet, of the physiological nature of sweet potatoes. In the hope of catching sight of some fundamental informations for the improvement of its cultivation, the present investigation was undertaken with sweet potatoes of the variety"Gokoku". In the present paper are described the behavior of reserve carbohydrate contents, together with the variation of moisture contents, amylase activities, pH value of the pressed juice and the respiration rate of sweet potatoes during their growing season. Moreover, the progressive growing status of shoots and root tubers, in contrast to the inner physiological status, were also traced. The experimental results obtained may be summarized as follows: 1. At the early stage of growth, in spite of the rapid growth of the shoots, the growth of the root tuber was inconsiderable. Both the reducing and the non-reducing sugar contents, as well as the moisture, were rich at this stage, while the starch content was not prominent, and the pH value of the pressed juice was small. 2. In accordance with the vigorous growth of the shoots, the increase of the fresh weight of the root tuber was resulted, and at the same time a remarkable increase of starch content was recognized at the expense of a decrease of the reducing, non-reducing sugars and moisture contents. General weakening of the amylase activity and an evident decline of the respiration rate were ascertained, while the pH value of the pressed juice showed a little higher value than before. 3. By the reduction in the vital force of the shoots with the termination of the growing season, the growth rate of the root tuber progressively became less. Under such conditions, low content of the reducing sugar was recognized, while the non-reducing sugar and moisture contents showed higher value. The starch content decreased a little, but the amylase activity was also abundant. The pH value of the pressed juice was somewhat low and a rapid falling off in the rate of respiration was ascertained.

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From Sept. 1950 to March 1951 experiments were carried out to explain the impossibility of succession cropping of the wild horse-radish due to the growth hindrance in some parts of the mountain district, Fukui prefecture, performing various observations and investigations, manure tests, and spectro-analysis to crop plants and soil in which they were cultured. The results are summarized as follows: 1. From microscopic and other tests, this hindrance seemed to be physiological and to be caused by the deficiency of nutrient substances. 2. This hindrance was scarcely recognized in the soil from granite and quartzite, but mainly from sand rock. 3. N, P, K and Ca were hardly recognized to be efficacious for this hindrance. 4. This hindrance seemed to be caused by the deficiency of many metallic elements, available and essential, especially Mg, Mn, Zn, etc. from the results of specrto-analysis to crop plants, soil, and extracted soil by 0.3 mol acetic acid in which they were cultured.

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Hairy vetch is one of the best winter legumes as green manure or as cover crop, especially for the dune or sandy field in the snowy Hokuriku district. However, the high cost of seed has been the greatest handicap to its more extended use compared with the other crops. In the past, before the war, large quantities of hairy vetch seed have been imported from Korea, and a little was produced in the Sado Island, Japan. But in recent, years, after the war, the home production of the seed has become of interest. In more recent years, however, it has been observed that seed production is almost impossible at several experimental farms in Japan. Therefore, a study was performed by the authors for the purpose of tracing the difficulty of seed production. In the present paper, the authors gave accounts first, on morphology of its flower and on the relation between its fertilization and flowering, and secondly on the relations between fertilization or seed formation and some environmental factors for cultivation, and also on insect's visitation during its flowering season. The results are summarized as follows: 1) Hairy vetch is a proterogynic plant, but the gynoecium and the antheridia preserve their ability of fertilization when the plant is isolated from insects. 2) the individual plant has about 2000 flower-clusters in a desirable conditions, and the floret number averages about 30 per flower-cluster, while the podding florets among them are less than one, and the number of full ripened grains averages 2 or 3 per pod. 3) In the past, it has been believed that the seed growing in the hairy vech plant is influenced by climate, especially, by high temperature and humidity during its flowering season. And the reasoning to attribute its sterility to over moisture, has been confirmed by the Sado comparison of the precipitation and the duration of sun-shine in Korea (Saishu-Island), and other districts in Japan. Moreover, it has been indicated that the Hokuriku district resembles to Korea (Saishu-Island) in the climatic conditions during the flowering season of hairy vech. 4) In general, the early flowers or those which have bloomed during a long spell of fine weather are fertile in high percentage, but the late or those in rainy weather are low. However, this relation somewhat differs according to the degree of thickness of the plant growth. 5) when the plant grows in a suitable condition, viz. being thinly seeded or supported with a fine crop, the fertilization percentage parallels to the number of blooming flowers in each stage of flowering. And the climatic conditions affect a little the fertilization. 6) When pollination is performed by hands or by the useful bumble-bees, the fertilization percentage is high in the fine weather, but it is very low or the flowers become sterile perfectly in the rainy weather. 7) it is not clear that the high temperature exerts a bad influence upon the fertilization of hairy vech during the flowering season in Hokuriku district. 8) the shaking of the plant body by sind or by hand has no effect on fertilization of hairy vech. 9) hairy vech is a close or self fertilizing plant, but the fertilization is impossible when the plant is isolated from insects in wire cage, notwithstanding the stigma being covered with pollen grains at the flowering time. This is an interesting problem and the fact that the insect's service in this case differs from that ordinarily found in the "insect-pollinated flower or entomophilae"is a noteworthy phenomenon when considered botanically. 10) The length of calcar of hairy vetch is longer than that of red clover, and the length is 11-14mm. [the rest omitted]

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(1) The author studied on "Italian rye grass" at Sumiyoshi Meadow and experiment field of Faculty of Agriculture, University of Miyazaki. (2) Growth of the grass and its regrowth power were vigorous. (3) Optimum sowing time of no-soiling plot and that of soiling plot are in October and November respectively. (4) Maximum soiling yield per one tan of three times soiling was 5, 800kg. (5) Mixturesowing plot with ten sho (about 1.8L.) of rye grass seeds and with 0.15go of rape seeds is the best pasturage on soiling yield and the starch value. (6) The weight of seeds produced per 1/100 tan was 695gr (about 3.6L.).

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In the eastern half of Hokkaido, it is usual to till the pasture for crop rotation either early in spring or late in autumn after harvesting of hay. A trial trilling was made in the middle of August, followed by immediate seeding of winter rye which was to be ploughed in as green manure. Potato was planted on this trial field ploughed in next spring, giving an yield of 474.8 kan per tan, while it was only 344.8 kan per tan on a field where potato was raised for several successive years and 587.3 kan on the control area of pasture which was ploughed early in spring as usual in the same year. It is conclusive, therefore, that the trial field had a better harvest than the field of successive potato cultivation, but a poorer harvest than the pasture ploughed early in spring.

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Two new varieties, "Karafuto No.2 "and "Karafuto No.3" of the hard spring wheat were bred at the Central Experiment Station in South Saghalien. "Karafuto No.2 " was produced from a varietal cross, in 1935, of Italian Spring × Garnet Ottawa 452 by S.SHINDO and "Karafuto No.3"from a varietal cross, in 1936, of Italian Spring x Reward Ottawa 928 by the same breeder. "Karafuto No.2"averaged to be about 20 percent more productive than the Garnet Variety in South Saghalien and proved to be best for cultivation its north eastern region. "Karafuto No.3"equalled in its jield to the former and was characterized by its especially large grains (38.2g per 1, 000 percent grains). This variety matured, however, about 3 days later on the average than "Karafuto No.2"and was recommended to cultivate in the warmer south western region of South Saghalien.

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1. Experiments were carried out in order to clear the varietal difference of the effects of day length on the root development in the rice seedlings, by means of water culture in the test tube. 2. Results obtained were summarized as follows: In the case of 24 hrs. Day-length, number of roots and weight of dry matter of both root and top increased in the short day variety, on the contrary, there was no increment in the day-nertral variety. (Table 1, 2 &3.)

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It has been pointed out by yamasaki, one of the authors, that the seeds of winter wheat are less resistant to the toxic action of KClO₃ than those of spring ones. In the present study, however, it is found that the seeds bore on winter wheat which is vernalized and sown in spring show much resistance to the toxicant, i. e., behave as seeds of spring wheat. This is believed to be due to the vernalization as well as spring sowing. Because, in the spring typed wheat, the seeds produced from spring soeing are more resistant to the toxicant than those from winter sowing, but the former shows less resistance comparing with those from vernalized plants, sown in spring. Further, the vernalized seeds of wheat, as a rule, being proved more resistant to the toxicant, than nonvernalized ones, it is duly assumed that the after-effect of the vernalization can be detected by testing the resistance to the toxic action of KclO₃ with the seeds bore the vernalized plants, i. e., the seeds for next generation of the plants concerned.

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By statistical treatments of 11 years' data of wheat crop experiments conducted by the same cultivating methods every year, I confirmed that grain-fulfilness has the largest influence on yields, and that rather lower temperatures in tillering periods, more sunshines in maturing seasons, and less rainfalls in harvesting times give good effects on grain-fulfilness.

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1. In the present report, the statistics of rice production per unit area (koku/tan) for fifty six years from 1893 to 1948 in the eight counties in Aomori Prefecture were analyzed with the definition of bad harvest informed by the complementary and introduced seedings were used and the adjusting and managing the rice crop was imperfect, many paddy-fields turned into seeds-mixed fields. This was found much in the late rice zones. 5. The rice's sterility was brought about by the gush of cold water, the submergence, the water-stagnation and drought, of rice fields. 6. The increase of disease, blights and weeds was recognized in every zone.

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We may consider two cases in correlations of rice characters in local phase, the first according to the results here obtained, was the local correlations between the mean rice characters and environmental conditions, and the second was the local correlations vetween the characters of a rice variety and environmental characters. We refer here only to the first case. 2. The characters which showed distinct positive correlation with mean heading date of rice are as follows; accumulated temperature for the period from seeding to heading. Mean temperature of the season of cultivation, hours of sunshine of the season of cultivation, harvesting date, seeding date, trsnsplanting date, period of maturity, panicle length and weight of thousand grains. The characters which showed no correlation with mean heading date of rice were as follows; culm length, number of panaicles, yield per tan, the period from seeding to heading and the period from planting to heading, and the character which showed a negative distinct correlation was latitudial index. 3. The character which showed positive correlation with mesn culm length of rice was panicle length, and that showed negative correlation was number of panicles per tsubo, and the other characters were independent. 4. The characters that showed positive correlations with mean numbers of tillers per plant were as follows; number of panicles per tsubo, plant growth index 1(culm length x no. of panicles per tsubo), and plant growth index II (culm length x no. of panicles per plant), hours of sunshine of the cultivation period and yield per tan. 5. Taking in account the correlation coefficient of rice characters in local phase, the influence of number of panicles per plant was found greater than that of culm length on the mean yields per tan of the locality. 6. From the conception of soil fertility the author separated the conception of the crop yielding efficiency. And he thought that the mean yield per tan of the prectural experiment station should indicate the crop yielding efficiency of the locality, and the characters which showed distinct positive correlations with the yield per tan crop yielding effiency were as follows; culm length, number of panicles per plant, growth index 1, plant growth index II, difference of daily temperature, markings of soil profile, markings of surfacial soil and fertility expressed by Fukuoka method. And the characters which showed a little negative correlation with yield per tan were as follows; the periods from seeking to heading, the periods from planting to heading, quantity of nitrogen in the standard fertilizer of the station and percentage of total nitrogen in the soil.

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The results of our experiments in which the cotton seeds were subjected to the action of ultra-short electromagnetic waves of 3 metres for 10, 20, 30, and 40 minutes, the seeds being placed between two Cu plates in the parallel Hartray circuit, showed that waves exerted, in each case tested, a fabourable influence on the growth of plants and on the opening of flowers and that of bolls. especially these waves emitted for 20 minutes exercise the most favourable action on the development of cotton plants.

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Studies on the leaf of tobacco affected by shading, which was grown under three sets of light intensities made of covering with Victoria Lawn cloth, were performed, three successive experiments being made during 1949 and 1950. Tobacco plants under observation showed marked effects upon their internal structures as well as other properties of leaves. The results are as follows. 1. The area of the leaf surface increased to a marked extent, viz. 30% and 80% for the ectively, compared with the control ones grown without covering. 2. The thickness of the leaves was remarkably reduced by shading. The leaves grown under stronger light had more palisade cells per unit of length, and longer palisade and spongy mesophyll than those in the poorer light. Mesophyll quotient (palisade/spongy)was found larger in the leaves under feeble illumination and smaller in those under stronger illumination. The epidermal cells of both the upper and lower sides of the leaves grown under feeble light were slightly reduced in dimention and their thickness. Measured volume of intercellular space in percent of the volume of whole leaf tissue showed was found to increase in the leaves under reduced illumination. The leaves under shading has smaller number of stomata per unit area, the size of stomata cells being larger, compared with those of the leaves under stronger light. 3. Leaves of the control plants without shading gave larger fresh and dry weight of substance per unit are, and also larger specific gravity of tissue powder in comparison with those grown under shaded conditions.

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Experiments were made with Wagner's 1/2000-are pots, the soil being fertilized with ammonium sulphate calcium superphosphate normally. Potassium was supplied in the form of sulphate, the quantity of which varied according to the plot from 0 to 8 grams per pot, expressed as K₂O. Seedlings of a variety of American yellow-leaf tobacco were transplanted in these pots in May, 1950, and were harvested in July. It was observed, that the height of the plant, the total number of useful leaves on a plant and the mean length of stem-internode altogether decreased as the potassium supply was increased. Number of cells per unit area of the leaf epiderm were larger in the plants grown with greater amount of potassium. The leaf thickness measured on the middle leaves was maximum in the plant supplied with 4 grams of potassium fertilizer; with larger amount or potassium, the thickness decreased. The fresh weights of the middle and top leaves were reduced by excessive amount of potassium. Potassium content of leaves increased in parallel with the amount of potassium fertilizer. Total nitrogen, nicotine and glucose content showed no definite relations with the amount of potassium supply. The nicotine/total-nitrogen ratio was found highest in the samples taken from the middle leaves grown with 2 grams of potassium fertilizer, with larger amount of the fertilizer the ratio becoming lower. The ash content and its water soluble alkali degree showed maximum values in the leaves from the 4 grams fertilizer plots.

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1. this experiment was made in order to know of the influence of temperature on sprouting and elongation of stem cuttings and runner cuttings of various characters in hop plants. 2. Sprouting process varied with temperature and characters of cuttings. Stem cuttings sprouted earlier than runner cuttings at high temperatures on the whole. But this difference was not so large. Both sprouted at very low temperature. 3. Elongation of sprocets varied remarkably with temperature. At the temperatures below 15°C elongation fell behind, and at higher temperatures above 25°C it was speedy and stems became slender. The temperatures between 17-20°C seemed most suitable for their growth. Stem cuttings grew earlier and stronger than runner cuttings on the whole. 4. At the temperatures lower than 15°C the roots did not grow, while at 17°C and above the root grown were first found. Runner cuttings gave better results in growth of root.

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The present experiments were conducted with the object of determining the cause for varietal difference in speed of seed germination. The experiments performed in connection with this study were grouped into two parts, namely (a) the relation between germination and glycolysis in rice seed and (b) the type of germination. The results obtained are summarized as follows. (1) the differential speed of germination of each variety has the same tendency as the strength of glycolysis in endosperm and amylase activity in embryo and endosperm. (2) the type of germination seems to be influenced by the presence of endosperm, that is, at the high temperature (30°C) the radicle appears previous to the plumule while at the low temperature (15°C) this sprouts more quickly than that on filter paper. But on the germination of the embryo cut off from the endosperm, regardless the temperature, the plumule appears previous to the radicle. The term "germination" is used in this paper to mean the phenomenon in which the plumule or the radicle appears when the rice seed is placed on filter paper or in water.

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The author is studying the cytogenetical research of Mentha genus, and the results gained in the last year are as follows: 1) somatic chromosome number of commercial species "Hokushin", Mentha arvensis L.var vulgare BENTH, being urged to cultivate in Hokkaido since 1937, is 96. 2) somatic chromosome number of Chinese commercial species, M. arvensis L. Var.Vulgare BENTH is 96. 3) these two are in relation of triploid to old commercial species, "Kitami-akamaru" and "Kitami-shiroge", M. arvesis L. var. vulgare BENTH. And therefore, the creation of triploid will important for the breeding of Japanese peppermint.

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It was reported in the writer's previous report that the germination of seeds of the three crops, namely, Abel, esculentus, Abel. Manihot and Nori-Asa, stored in dry state occurred very slowly as like as that of hard seeds. In this paper the results of some experiments on the cause and mechanism of it were reported. The materials were the seeds stored rot 3 years. Even if the seeds of Manihot were stored in dry state, the germination was good. But in esculentus and Nori-Asa the germination of seeds stored in dry state was very poor compared with the seeds stored in normal condition. This was due to the dehydration of seeds in the storing period, but the duration of life of deeds was not changed. The degree of poorness of germination was larger in esculentus than in Nori-Asa. This poor germination is due mainly to the difficulty in absorbing water. The water absorbing ability was the largest in Manihot, next comes esculentus and in Nori-Asa it was the smallest. In Manihot, this ability of seeds stored in normal condition was similar to those of seeds stored in dry state, but in esculentus and Nori-Asa, the ability was larger in the seeds stored in normal condition than that in seeds stored in dry state. The cause of the phenomena was due mainly to the palisade cells as well as the light line which has certain relation with the water absorbing ability. This was proved by the germination experiments in which the seed coat was injured by the grinder or it was treated with concentrated sulphuric acid.

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Resistive varieties seemed to have shorter culms, thicker tracheas, and wider leaves in proportion to the length of the leafblade, than sensitive varieties .in the resistive varieties, the leafblade area per unit weight of water contained in the tissue, the number of stomatas per unit area, and consequently the number of stomatas per unit weight of water contained were smaller than those in sensitive varieties. When the stem which had been cut off below the top-leaf was inserted in bottle containing water and leaved in-door over night, the degree of leafrolling in resistive varieties was very slight compared with sensitive varieties.

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In the previous experiment, it was shown that the late transplanting resulted in the remarkable decrease of yields.. with the aim to analyze the reduction of yield caused by the late transplanting, we have compared the growth and yield of rice crop under two different treatment; one sown densely (18 × 18cm) and other sown sparsely (24.2 × 24.2cm) on the seed bed, both transplanted later than usual. The seedlings in sparsely sown plot produced their tillers regularly; they have more than thirty tillers already at the time of transplanting, and howed high yield. But in the other plot the tillering is inhibited; no one tiller at the time of transplanting, and showed low yield, about half of that in the usual cultme. After the seedling were transplanted, the tillering has continued to some extent in former plot, but the many new tillers appeared at the higher nodes of the stem in letter plot. The high yield obtained in the sparsely sown plot may be explained by the following five reasons: (1) Seedlings were grown for longer time under favourable condition because the seed bed was more fertile than the paddy field and also it was rsurrounded by shelter-hedge. (2) As rice plants had good enough space to grow until the time of transplanting (5thof July) they could produce many healthy tillers from the lower nodes of their stem; 30 or more tillers were growing at the time of transplanting. (3) consequently the larger number of tillers and ears were produced. (4) As tillers from the lower part of the stem appeared early, the date of heading was also early, resulting heavy grain weight. (5) As far as the result of this experiment was concerned, the rice crop sown sparsely seemed to be able to produce higher yield, even when it transplanted later than usual culture method. But this trend might not be always observed because the different result would be obtained under different weather. The low yield of densely sown plot may be explained by the following fact; (1) tillering was inhibited seriously because of the narrow space given, and after they were transplanted. Appeared the tillers from the upper part of the stem as well as the tillers of higher order. (2) The number of tillers and stems were fewer than those of other plots.(3) As the tillering was delayed, date of heading was also delayed, and the light grains were produced.

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