1. Up to the present time many authors have argued about correlation coeffisients in paddy rice such as the correlation coefficients between the stem length and yield per tan, or between number of heads and yield per tan. Or they have argued about the correlation coefficients between mean tempurature and yield, or between hours of sun shine and yield. But they all did not make clear the condition of the case in which the correelation coefficients exist. 2. The author explained in his investigations about“the yielding efficiency of Japanese rice varieties"that the same correlation coefficients between the stem length and yield per tan differs very much by the case in which the correlation are calculated. The correlations between stem length and yield per tan in the yearly case -- calculated by the yearly correlations are independent, and in the local case -- calculated by the local correlations are postive, and in the varietal case -- calculated by the varietal correlations are negative. And the same correlations between stem length and yield per tan by the same variety Norin No.1 under the yearly and local correlations are positive. 3. the correlation cofficients between number of heads and yield per tan in the yearly case, local case, varietal case, and the yearly and local case by the same variety are also positive. 4. The correlation coefficients between heading dates and yield per tan in the yearly case -- that is the correlations calculated when the years may change -- are negative, that is under the circumstance of the whole country the year when the heading dates are early the yields are high, the years when the heading dates are late the yields are low. There is no correlation between heading dates and yield per tan in the local case. That is, there is no difference on the yield where the heading dates are early or late. The correlation between heading dates and yield per tan in the varietal case is positive. That is the early varieties are of rmaller yields and the late varieties are of bigger yield. 5. It is very important to make clear the idea of the case in which the correlation coefficients are calculated to estimate the future yield of the year. Up to the present time some Japanese agriculturists calculated the correlation coefficients of yield per tan and stem base weight, or those between the numbers of panicles and yield per tan to estimate teh yield. But those attempts often include some misuuderstanding caused by the obscure conceptions about the case of correlation. 6. By investigations hitherto made the correlation coefficient between the stem base weight and yield per tan and the correlation coefficient between the numbers of panicles and yield per tan in the case of year are not yet made clear. The author considers that the correlation coefficients should be proved under the condition of the same year and the same local conditions. The correlations are calculated in the local case, in the yearly case and in the varietal case, these are different with each other.

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On the present experiment by the windtunnel method the writer investigated, using various model fences, the breaking effects when many windbreaks were set in lavers and when the windbreaks which had a great deal of openings at the lower part as the row planting of pine tree was helped by the hedge of a dwarf plant. The results obtained were as follows: 1. When the fences which have openings and have no vortex region on the leeward are set in layers, the more the fences are used in layers, the more effective they are. On the country when the fences which have few openings and have some vortex regions on the leeward are used in layers, its breaking effect don't almost increase. 2. To help the windbreak which have a great of openings on lower part, it is desirable that the location of hedge comes near the main windbreak, though there are no difference on the leeward and on the windward.

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On the present experiment the authors invetigated the micro-meteorological condition in the field used bamboos as a protection against the frost. The results were as follows: The field used the bamboos against the frost was generalli higher in temerature in the night than the open field and lower in the daytime. The evaporation from the surface of earth was less. The wind velocity control was very small, but the air turbulwnce was more intensive. This air turbulence contributes to the raise of temperature including the effect of the cover of bamboo on the radiation from the earth.

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1. In the practise of estimating yield of rice crop, the blasted grains being included in the number of the paddy ones, it is very difficult to discriminate them. The author traced experimentally the process where some of the mature grains drop out through the grain fan and huller. 2. The rate of remaining after hulling was in proportion to the fertilization rate of then. The fertilization rate held a certain parallel connection with the blasting rate, and in many cases, blasted grains were found to drop, being confused with the empty husks, into the second box of the grain fan. The remaining rate of kernels, as the fertilization rate showed large variations both being strongly affected by weather conditions of the year and to certain extent by the plant variety. The number of kernels per unit volume, however, gave but smaller varietion, being characteristic of the variety. 3. The author discussed on the usage of a synthetic coefficient applciable to the number of grains per 1.8L, in yield estimation of rice, and concluded that considerations from the viewpoint of crop-sciense should be necessary for estimation of fertilization rate and the number of kernels per unit volume as “operators"in practise of rice yield estimation.

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Founded upon the fact that the condition of paddy grains is controlled by the fertilizing rate, a table has been made, where the applicable coffecient of kernels per 1.8L, is “a function" and the fertilizing rate, that is the remaining rate of kernels, is a variable. The table construction is as following. The relation of fertilizing rate with the remaining rate of kernels, r=0.6680, y=19.78+0.8059x, σ=4.5%(Fig.1) Its relation with the applicable numbrt of grains r=0.9759 y=148.6-1.4907x, σ=4.35%(Fig.2)

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1. The oxidizing power of roots of various plants was studied under paddy field conditions. 2. In general, the highest oxdizing power was observed in Gramineae and Compositae; Somewhat lower in Leguminaceae; and lowest in Grusiferae, Cucurbitaceae, Solanaceae, and vegetable crops. 3. The roots which stained distinctly in α-naphtylamine solution, had the highest oxidizing power in paddy field conditions.

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1. The root injury of soy-bean sown under paddy field conditions was observed. 2. When soy-bean was planted alone, the root was serverely injured and it could not generally survive. When it was planted with paddy rice, the root injury was slight. 3. It is presumed that when the two were planted in the same paddy field, the respiration of soy-bean root benefited from the high oxidizing power of paddy rice root.

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1. The O₂ consumption so each day due to the respiration of the rice roots, grown is. 2. The O₂ sonsumption was increased rapidly since the beginning of panicle differentiation or culm elongation, attaining its maximum at the beginning of heading, and decreased gradually thereafter. 3. The rate of respiration of rice roots varied parallel with the temperatures of the solution; even at the booting or heading stage it dropped suddenly at lower temperaures. 4. As almost all the oxygen in the cultural solution was exhausted during a daytime or a day, the theory that the oxygen transports from the aerial parts of the plant to the roots might be supported.

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The summary of the influences on the yield of paddy rice caused by the earthquake is as follwos. 1. Considerating the damage to the cultivated fields, and the irrigation and drainage arrangement, the paddy-fields are classified into Kyoshitzuden, Taisiden, Kanbatzuden. In the zone of Shitzden, the falling of the ground brought on the badly-drained fields. and the more powerful its degree was, the worse was the rice yield. In the zone of dry-rice-fields and the end parts of irrigated, there were found a lot of cracks and waved fields. Except a few areas damaged too much, they were almost restored to the normal condition. 2. In the early-rice zone based on one-crop farming in Shitzuden, the degrees of the crop reduction were less than of the middle and late rice zone based on two-crop farming in the dry-rice-fields. This was closely connected with the relation between the time of the rice transplantation and of the outbreak of the Fukui earthquake. In the zones met with the earthquake in 3 or 5 days after the rice transplantation, the crop reduction was extraordinary. Compared with the former, in the zones where the rice transplantatinon was done after the earthquake, the damages to the crop were much greater. 3. With the regards to the damages arising from the difference of the time of repeness, the early rice ws badly damaged, for the overflood occurred before or after heading. And in the zones suffered from drought, the middle and late rices were badly damaged. 4. As 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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1.This experiment was made to clear the effect of soil moisture upon the development of tillering rimordium and tillering but in rice seedlings. 2. The percentage of soil moisture used were four, 50-60%, 70-80%, 90-100% of the water capacity in the soil and flooded condition. 3. In the first tillering primordium and tillering primodium and tillering bud, the dffects of soil misture on their developments was not observed too much among the separate plots in field-condition, however, their developments in flooded plot was remarkably inferior to comparison with the separate plots in field-condition. 4. In the second tillering primordium and eillering bud, their developments in the first-stage of growing were best at 70-80% plot and were bad at flooded plot, but as the growth progresses they result in best developments at flooded plot, that is, according to increase of soil moisture the tendency of improved growth was observed clearly. 5. On the 3rd, 4th, 5th, 6th, etc, of tillering primordium and tillering bud, with increasing of soil moisture they result in best developments.

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1.The author had observed the development of crown roots of seedlings by using five varieties of rice, which especially it centered at the 2nd-node and the 3rd-node. 2. In the cotyledonaly node, the origin of the crown root was formed from five places that faced each other to the phloem which existed to the outside of the vascular bundle. 3. When it was manages by the α-Nathtalen acetic acid, in the cotyledonary node the origin of six crown roots was formed in it, but it was increase of on origin in the fixed position which faced each other in the central vascular bundle on the side of the seminal root.

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The oilpaper-covering nursery-bed of paddy rice is thought to be one of the most important new technics of rice culture in the cold districts of Japan. In this experiment 21 varities of rice were used to know the varietal differences induced by oilpaper-covering in the nursery stage. The plants from oilpaper-covering bed increased the number of stalks in all varieties, and this tend ency was so great in few-stalks varieties, that the varietal difference in stalks-number was disappeared. The heading date was more accelerated in medium and late-ripe varieties, but the yield was not decreased.

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Following tests were made in order to study the effects of restriction or encouragement of nutrient locomotion into kernels on the occurrence of white core (Shimpaku), milk-white grain (Nyuhaku-mai) and white belly (Haraziro) in rice plant: 1) The boot-leaf or upper half of a panicle was cut off at various stages after heading. 2) Rice plants were kept under darkness for 4 days at various stages after heading. The results were summarized as follows: 1. White core: The first test had no effect on the occurrence of white core. But, in the second test, white cores were numerously found in the panicles which had been under darkness at 5 to 14 days sfte heading.(Fig.2) Rice kernels began to become translucent from the core at 7 or 8 days after flowering under normal condition. By checking the nutrient locomotion into kernels for a few days at that time, letting the core of kernel remain as opaque, and letting the outer part of kernel become translucent, the karnel would become recognized as white core. 2. Milk-white grain: In the sdcond test, milk-white grains occurred numerously in the panicles treated at 10 to 15 days after heading.(Fig.2) The opaque part of the milk-white grain was a little outer than the white core. 3. White belly: In the first test, white bellys increased remarkably by cutting off the leaf at 10 to 15 days after heading(Fig.5.D), and decreased by cutting off upper half of panicle at heading time(E), or cutting off the leaf at heading time and upper half of panicle at 10 to 15 days afte heading(C). In the second test, white bellys occurred numerously in the panicles treated at 19 to 24 days after heading.(Fig.2)

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Rice seedlings soaked in naphthalene acetic acid solution before transplanting retarded the growth of roots for 1 or 2kays, but hastened it after afew days. The seedlings sprayed with the same solution on the seed bed at 2 or 3 days before transplanting produced a greater number of roots without delay after transplanting and became full of vitality sooner than the seedlings not treated. these effects were diminished gradually under the favorable condition, but caused a quicker production of tillers, a faster heading, and a better fruiting under such an unfavorable condition as would retard the growth of plants.

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On the agricultural administration, cultivation in the transplantation of upland rice is considerably prevailing, but its ground study is seemed to be neglected.In the first study, we investigated the differences on the growth of upland rice in transplanting cultivation and direct sowing. We parted the test in the pot and on the dield, varied the date of the seedling and transplanting and combined them. In the result obtained; in series of transplantation, length of plant is long, stem number is few, period of ear is shortened, length of culm, length and weight of ear is dominant. Especially the percentage of fertility in series of transplantation is larger from 4.5 to 6.8percent than in series of direct sowing.

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1. The relation between the stage of growth and drought injury in wheat plants as well as in naked barley plants respectively was investigated. In the experiment, drought conditions were performed artficially by keeping the soil moisture at 35% of its water capacity for 30 days, the treatment being given in every experimental plot at the period differing by 20 days with each other. 2. The results showed that harmful effects of drought on plant growth and yield were most t remarkable when it occurred at the stages where ears reached to full development and began to emerge, while they were least or not recognizable when given or early stage of growth.

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1. The experiment was carried out to make clear the differences of resistance to pottassium defficiency on nine wheat varieties by split plot design with four blocks. The results obtained were as follows: a) Height and leaf-width decreased, but the proportion of height and leaf-width didn't change. b) There were differences between varieties and treatments, but the interaction was recognized only in the head-numbers. c) The resistance orders were as follows: North No.16-NOo.69, 70, 26, Fukokuibaraki No.1, Norin No.50, 9, 44-Shirasayaibaraki No.1. d) Head numbers type was weak resistant to potassium defficiency, while head-weight type hrs strong one.

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1. In this study, the author have investigated the relation between the distance of cultivation and frequency of natural crossing of a variety of naked barley in Jpan, namely var. violaceum Keck. with the varieties of naked barley in Jpan, namely Akashinriki and Osakayakko No.52 at Settu Experimental Farm, Kyoto University. 2. The iodine reaction, which is based on the phenomenon of xenia between waxy and nonwaxy characters, on the starch of endosperms of waxy barley, was used as the determination of natural crossing. 3. The percentage of natural crossing in the variety of naked barley in Jpan was lower than that of wheat, and it was 0.061% in the case of mixed cultivation. The phenomenon of natural crossing was not noticed in the case of alternative cultivation, which was over four feet apart between rows in the field.

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In the winter of 1948-49, wheat plants(Var.Norin No.50) were cultivated under the conditions of filling sand(3, 5, 10, 15 and 20cm thick) and removing soil(till the depth of 2 and 5cm) at different stages. Morphological modifications of wheat were following: (1) The number of tillers of sand filling plots decreased as compared with the untreated plots, and the length of plants of the former became longer than the latter. (2) On the contrary, the number of tillers under plots of soil removing increased sufficiently, and the length of plants became shorter and stunted.

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1) By the peeling the chemical variation of Danshaku at the germination period was affected a little in the glucose, and very much in the sucrose and starch compared with the control plots. The highest of white potato stem, nineteen days after planting of the peeled plots was four times longer compared with the control plots. 2) By the peeling the chemical reaction of carbohydrate of the Benimaru at the germination period was affected a little in sucrose and much in glucose and starch compared with the control plots, The growth of stem of the peeled white potato was six times greater compared with the control plots. 3) Under the standard condition the chemical variation of carbohydrate did not deffer so much between Danshaku and Benimaru. 4) By the peeling the chemical reaction of carbohydrate was affected a little in Sucrose of Danshaku and Benimaru, however much affected in glucose and starch of Benimaru. The growth of stems of Benimaru was 3.5times greater of Danshaku. In general, the germination was promoted and chemical variation of carbohydrate was remarkably noticed by the peeling. It is conceivable that in the short period of germination the decomposition of starch was especially distinctive and glucose ahd sucrose were naturally increased.

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1. This experiment has been carried out on the development of seeds in the pod of the peanut. 2. Both the average number of the ovules in the ovary and the retio between the two-ovule and the three-ovule pods have been seemed almost invariable and fixed in each variety and neither were influenced by the efflorescence time on the same stock. 3. The growth of the abnormal seeds in the incipient stage of seed growth sddmed to vary in each variety. Valencea variety has been found most subject to such growth. But such a thing has not been founded in any variety in the desinent stage of growth. 4.The abnormal growth in the incipient stage of the three-and four-seeded pods in Valencia variety plants has been found most frequently at the basal position in the pod, while the abnormal growth in the desinent stage has been found mostly at the tip position of the pod. 5. It may be said with Valencia variety that the more numerously the seeds are contained in a single pod, the more frequently, though not in a marked degree, was the unusual growth in the incipient stage. But such growth was not found with the two-seeded pods. 6. The microscopic obsevations of the abnomal seeds in the incipient stage seemed to reveal that at least the fertilization was acomplished on most of them, but, they soon stopped theirgr owth and finally turned into degeneration.

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1) In this study, Intended to clear the effect of ground water level upon the growth of rape plant. 2) In this experiment, I made the ground water level of each plots as follows; 9cm, 15cm, 21cm, under the surface of ridge and the control. 3) In productivity and various characters those seem to be the factors of productivity, there were remarkable differences between 9cm plot and the other plots, but among 15cm plot, 21cm plot, and the contorol plot, there is no difference. 4.) By the root-system in the control plot, the roots of rape lie very densely in the part from surface of ridge to 15cm under, and there are few in deeper part. 5) Judging from the root-system, it will be fact that in 9cm plot, all of the roots are in the condition of flooding, but in the other plots a great part of roots are saved from the condidtion of flooding. It is seems that this condition of roots is the fundamental cause of the difference between 9cm plot and the other plots.

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In order to clarify the mechanism of spring growinfhabitof rape (Brassica napus L.), the experiments on the following three subjects concerning plants'response to defferent temperature and day length were conducted. a. Relation among grede of spring nature, temperature sensibility and illumination sensibility of rape varieties. b. Relation between vernalization and grade of spring nature of rape. c. Organization of bolting acceleration. The followings are the gist of experiments. (1) There exists a close relation between the grade of spring nature and tempereture sensibility of rape varieties and the higher the grade of spring nature, the higher the temperature sensibility. There is almost no illumination sensibility in rape and its bolting and flowering are accelerated to only a little degree by long day treatment and there is no relation between illumination sensibility and the grade of spring nature. (2) Therefore it is concluded that the difference of grade of spring nature fo rape varieties results from the different sensibility to temperature. This is entirely defferent from the nature of wheat and barley family, the grade of spring nature of which results from both sensibility to temperature and illumination. (3) As the grade of spring nature goes up, that is, temperature sinsibility goes up, there is less need for lower temperature for bolting and flowering fo rape. This is, bolting of those varieties, having higher grade of spring nature, can be accelerated by shorter period exposure to low temperature than the varieties, having lower grade of the nature. The higher the grade of spring nature, the greater the bolting acceleration. This is due to the fact taht the varieties having higher grade of spring nature have their fall growing habit eliminated more completely. (4) In case rape is grown on the ordinary field and transported to the green-house, bolting and flowering are accelerated as the period of exposure to the natural lower temperature, due to the delay of transport to the green-house, becomes longer, and its accelration speed reaches peak at a certain period and then slows down. The peak period is the time when differentiation of flower bud initial begins and the varieties having higher grade of spring nature begins defferentiation at earlier period. (5) The fact that bolting and flowering are accelerated by lower tempereture is based on the reason that the lower temperature is an important element in the transitional period from vegetation to reproduction. But once the plant goes into reproduction period and starts differentiation of flower bud, lower temperature takes controling action and delays plant growth. Higher tempereture speeds up plant growth. (6) The number of leaves on thd main stem, which grow with the acceleration of bolting and flowering increase by lower temperature and make little change by day length. This trend is remarkably different from the wheat and barley family, the number of leaves on the main stem of which reduces with the acceleration of earing in the every case of higher or lower temperature treatment, long day or short day treatment, etc. (7) In case of chilling the sprouted seeds, the varieties having higher grade of spring nature have greater acceleration of bolting and higher decreasing per cent. of number of leaves on the main stem. But it is presumed that if the chilling period is extended, varieties having lower grade of spring nature like wheat and barley family, will have greater bolting acceleration and higher decreasing per cent. of number of leaves on the main stem. That is, threr is a lag in the grade of spring nature between rape and wheat or barley family.

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(1) In this report, I studied on the various characters of many varieties of the sesames, in order to find the most suitable variety in Tokai district. (2) The sesames need about 100 days for ripening, and 10 days for germination, and their growth are slow until about one month afte gemination, but after then it becomes very rapidly and then slower again according as the ripening comes near. (3) They have indefinite inflorescence, threr are not so much differences in the flowering date between each variety, but in the ripening date there are remarkable differences, and some varieties ripe earlier about one week than the others. (4) The shape and size of leaves depend on variety. The leaves on the central part of a stem are larger than the leaves on the other parts of a same stem and also have large incision. (5) The type of plant are various. Some varieties have many branches, but the other have fewer or none of those branches. (6) Some varieties have one capsule (pod) on one node, some have two or three capsules and the length of inter-node is irregular. The numver of chamber in one capsule is four in some varieties and six or eight in the otheres and some times from four to eight on the same stem. It seems that there is a tendency that the variety having many chambers in one capsule is more productive. (7) According to this study, we can perhaps classify the sesames by the colour of its grain as follows: white sesame, yelow sesame, brown sesame, black sesame, each of them have many defferent characters.

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Expecting that the root pressure of sugar cane may have some relation to its drought resistance, the experiments presented here were carried out by measuring the degree of the root pressure and the root pressure-holding power of young seedlings of some sugar cane varieties. The results obtained are as follows: 1. When the water content was enough in the soil the strength of the root pressure was nearly corresponding to the root development (dry matter weight of root), but had no close relation to the drought resistance. 2. Difference of the root pressure-holding power of sugar cane varieties, during the water content in the soil being very poor by stopping irrigation, had pretty conspicuous relation to the drought resistance of varieties. That is, the seedlings which showed high root pressure-holding power approximately belonged to drought resistant variety. 3. Difference of the root pressure-holding power had no conspicuous relation to the root development. It seems that threr will be other factors which affect more on the root pressure-holding power than the root development.

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Some ecological characters of yield of sorgo were examined and it was found that the joint-to-joint analysis is recommended as a method for ecological studies in this crop just as in sugar cane. The results obtained in this experiment are summarized as follows: 1. April (early) planting may be recommendable for twice-reaping system when sorgo is used as a forage crop, though it is not suitable for grain sorgo because it may be seriously damaged by birds. A moderate planting season for using it as both green and grain sorgo seemed to be in June (late planting), when the advance of the date of heading may be brought about. 2. Varieties suitable for early planting may surely be distinguished from those for late planting by deciding the relative position of the heaviest internode which is determined by joint-to-joint analysis of the stem; the variety whose heaviest internode locates at a low positoin in a standing stem is adapted for early planting, and the one with the heaviest node at a high position for late planting. 3. Rind harness is remarkably high at the lowest intermode and it gradually decreases upwards along the stem. 4. An even transition of brix throughout the successive internodes from the base to the top can be observed at flowering time, but later, brix begins to increase, as grains mature, in the middle and uper portions of the stem, leaving brix in the lower portion almost as it is. The course of maturing as mentioned above may greatly be affected by yield of grains and mechanical damages in green leaves. The maximum mean brix is expected at full maturing stage of grains, and the persistence of high brix varies with either variety or planting season. 5. Windbreakage of the stem caused by stem borers, deterioration of the content of internode tissue and damages in grains by birds all vary widely with the plant variety as well as season.

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The author has studied on the leaf length and yield of soiling of pearl-millet. 2. Pearl-millet is advantageous forage plant for soiling as its growth and regrowth are vigorous, namely, the leaf length reaches 1m in one month. 3. Pearl-millet for soiling may plant 30cm apart in 40cm row and 3 plants for one stock. 4. Soiling method cutting 2cm above the ground is better than that of 4cm. 5. Soiling average yield is about 70-100kg per 1/100 tan. 6. The yield from old seedling plot is greater than that of younger one.

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The author has studied on the seed production of the pearl-millet. 2. When the pearl-millet is planted at the end of July, the seed is produced after 3 months. 3. Hull seed weight per 1 tan is 700kg. The period from transplanting till seed production is short and seed yield is good and managing is easy, so it is favourable forage plant. 4. The ear size of the early ripening plants is greater and longer than that of the late ones. 5. The latest time of soiling for the purpose of seed production on soiling field When the seed is produced is early September. 6. Weight of unhulled seed one Sho (1.8L) is commonly 320-450g and per one ear is 6.0-18.0g.

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This paper gives the results of the physiological investigations on germination of the Japanese barnyard millet as a weed in rice field. The germination of this weed is irregular, slow and extend over long period. Some seed of the plant have germinated on 8th day after flowering. Afterripening of it will be completed in about 45-days. In normal storage of it, that is, natural drying and storage in desicator, ability of the germination was manitained for 2-3years. But hulled seed will quickly lose this ability in 2-3months. The greater specific gravity of the seeds increased the percentage of germination. Solutions of salts which were used in this experiments did not control the germination, expect K₂CrO₄ and K₂Cr₂O₇. This seeds have not distinctively both light-germination or dark gemination habit. The optimum temperature of germination is from 30°C to 40°C and 10°C is too low for germination of the plant. Inconstant temperature was dffective as well as the seeds of other weeds. Germination of unhulled seeds was accelerated by sulphauric acid, physical and hulling treatments. Soil-coverings of 0.5 and 1cm have no dffect on the germination of the seeds, 3 and 5cm distinctly but those of over 7cm completely prohibited the germination of the seeds.

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1. This paper gives a results of investigation on the propagating ways of this weed. 2. Number of seed setting plants in a paper-bag were 116, and sterilized plants were 128. But the self-fertilization of this plant must be studied by the classification of these types. 3. In low-land rice-fields, after harvest of rice crops, the average number of falling seeds of the were was 234.4 per 30cm squares of field surface and in the another case it was 117.2, but the percentage of germination was 14.51. We have obtained a few seedlings of the plant out of seeds from a block 20×21×20cm of area of low land field soil. 4. In chaffs which were 640.2g in the weight, we have found 568 of this weed seeds. In straws and seeds of rice some seeds of the weed were found. 5. We have not obtained the seeds which had veen brought into low-land rice-field with irrigating water. 6. This weed seeds have been buried in stable manure, the temperature of which was ranged from 58°C to 48°C, and they did not germinate in a month. But 10 seedlings of the plant have grown from immatured stable manure of about 200gr in the weight. 7. We have collected the seeds which have been passed through the digestive organ of hens, and 7 per cent of the germinated seeds. 8. The seeds were buried in soil for 6 to 15 months and some of them have maintained the activity.

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With the purpose of supplying oxygen artificially to the plant which is suffering from poor soil aeration, the author exzamined several kinds of known inorganic peroxides which can release oxygen gradually whenever it comes in contact with excessive water in the soil and which is harmful neither to the plant nor to the soil properties. Among the compounds examined, calcium peroxide, CaO₂, was found to be most promising. Therefore, the author carried out the following experiments. (1) Release of oxygen from CaO₂ in the water. 1gram of CaO₂ and CaO₂ mixed with the soil were placed in the water and the amount of gas released from CaO₂ was measured for two months(Fig.1). It was proved that CaO₂ releases oxygen very slowly even in the water. (2) Effect of CaO₂ on the germination and on the growth of rice and barley plants. Under various conditions of seed-bed, i.e., temperature, amonut of CaO₂ used, depth of soil where seeds were placed, or the depth of the flooding water over the seed-bed were varied, CaO₂was distinctive in promoting the germination and also the growth (Tables 1, 2, and 3).

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The author investigated the relations between annual rice yields per unit area in Aomori Prefecture and monthly means of air temperatures of summer season recorded at Aomori Meteorological Observatory for sixty four years from 1866 to 1949, and came to a conclusion that the bad harvests, which gave values of actual yield 1_c<75, in percentage of the mormal yields, the latters being estimated theoretically for the corresponding year, should more naturally be considered as to form another distribution apart from the ordinary harvests which gave values 1_c=±25 forming a normal distribution. The aspects discussed are as follows: (1) Of all the correlation Coefficients computed between temperatures and yields, that of the highest value(r=-0.755)was found between 1_c and the mean temperature for three months from June to August, while the next (r=+0.743) was that between 1_c ane the mean temperatures for five months from May to September. (2) The lines of regression of 1_c on temperature were found to be devided into two parts giving critical points at 1_c=75, where the corresponding three months' mean temperature was 18.95°C and the five month' mean was 17.25°C (Fig.5) (3) The rate of yield reduction per unit temperature depression proved larger for temperatures below the critical point than for those above it, and consequently bad harvests being due to temperatures below that point should naturally fall out of the range of the normal distribution formed by ordinary harvests concurrent with temperatures above it.

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From the experimental studies on the injurious effect of sulphur dioxide upon the rice cultivation, it was ascertained that SO₂ affects strongly on the pollen and ovary. The pollen and the matured grain show the marked fall of fertilities when the plant is fumigated at flowering and boot stage.

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The carbohydrate and N-compound of the fifth-growth of potato-tubers found in “Kannnanshiro"were analyzed by the authors. 2. The accumulation of starch and total N in the new sprout tissue increased gradually fact above-mentioned was observed. 3. From the result above-mentioned, it is clear that the cause of such a high order growth of potato-tubers is just the same as that of the secondary growth.

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This investigation has been carried on in the Tsunekichi ADACHI's experimental farm at Shibetsu-cho in Hokkaido, to know the effects of the previous crops, on upland fields to which paddy field were after transfered, upon rice crops. In the first year after transfering the upland field to the paddy field again, the weight of plants, number of available tillers and total weight of panicles indicated marked increase compared with those of the crop on permanent paddy fields. But in the second year no defferences were found, and in a plot (e) the available tillers being rather reduced in its number. As a previous crop of rice plant, the clover was superior to any other crop to increase the yield of rice plants in 6 years rotation of rice-rice-oats(mixed with clover)-clover-clover.

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1) The length of each of all leaf-blaeds and-sheaths internodes of the main-stem, were measured on 9 rice plants sampled every other day since transplanting, intending to know the elongation process of each leaf and internode and further to make clear the interrelations between them. 2) The rate of elongation of each leaf and internode was very slow during the time from its differentiation till it reached 1.0cm and 3-5mm in length respectively, taking about half a month by that time, and another half a month thereafter till elongation ceased.(Fig.3, 4) 3) The elongation curves of leaves and internodes were so-called “S-curves", the former being composed of 2 S-curves which represented the elongation of blade and sheath of a leaf respectively.(Fig.1, 4) 4) When the blade of the 10th leaf, for instance, began its rapid growty, the 9th leaf-blade and the 8th leaf-sheath projected together--always the former was a little longer --above the top of the 7th leaf-sheath. When the blade of the 10th leaf attainde its full size, its sheath still continuing go grow, the internode below its base might be 2 or 3mm long. All internodes, which were due to grow long, did so after the leaves borne at their respective upper ends had ceased to do so.(Fig.4) 5) As the locus went up, the leaves beared blades successively larger and attainde its maximum in the 3rd (Norin No.17) or 4th(Norin No.8) leaf from the boot leaf, the blade of which was shorter and broadest than that of its predecessors.(Fig.2)

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1. There is a close relation between the development of germinative power of immature seeds and their kernel development which depends upon the location on the panicle. 2. In regard to the dried hulled kernel, the superior kernels on the panicle obtain the germinative power from the 7th to the 9th day after flowering, whereas the inferior kernels from the 9th to the 12th day. The rice embryo obtains the geminative power when its morphological development is completed.(Fig.2) 3. In regard to the dried unhulled grain, the superior grains on the panicle obtain the germinative power in 9-15 days and the inferior grains in 15-30 days after flowering. The unhulled grain requires some farther development of kernel to germinate than the hulled kernel, because the small seedling must emerge out of the hull which may be broken by the expansion of kernel and the mechanical power of seedling.(fig.3, 4) 4. concerning to the fresh unhulled grain, the superior grains awake from dormancy and obtain the germinative power in 22-35 days, and the inferior grains in 30-50 days after flowering.(Fig.5, 6)

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In this investigation the coefficients of germination are used to discuss the comparative speriority of germination at each temperature. The coefficients of germination are calculated by dividing the percentages of germination by the mean numbers of days of germination and they are indicated in the following table. [table] Accoding to this investigation the minimum, optimum and maximum temperatures for the germination of maize seeds are as follows. Minimum 6-8°C Optimum 34-38°C Maximum 44-48°C

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1. The increase of the depth of sowing showed the decrease of the ratio of emergence to the amount of seeds sown and the degree of the decreasing was larger in barley than wheat. 2. The deep sowing mede the periods of the emergence of the leaves later. 3. The deep sowing made the length of the leaves and leaf sheaths longer, but these results owed to elongtion of the subcrown internodes, the actual lengths of the leaves being reduced. 4. The deep sowing gave remarkable restraint against tillering at lower nodes. 5. In case of the deep sowing over 5cm, it was found that the subcrown internode developed and the crown came up to the depth of 2-6cm.

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Much of the success in growing wheat plants depend upon preparing the kind of seed bed which will give the plant good start, seeding correctly, and cultivating the crop which need it after coming up. While in the warmer districts in this country, there is no timme to practice a correct preparation of seed bed, in order to short the time after the harvest of preceding rice crops, so that the start of tillering is evidently later than that of cooler districts. In order to determine what effects the small ridge of soil had on wheat plants, we heaped up the soil at the north side of the seeding stripe at the time of soil preparation. In the early stage of growth, the number of tillers of wheat plants in the plot mentioned above was larger than that of control one, as shown in the figure. While in the later stage of growth, the number of tillers in the former plot became less than the latter. This difference in number of tillers in adult stage, was induced by the depth of crown of seedlings under the soil surface, which has been deeper in the case of protected plants, than the control one, owing to gradual collapse of soil ridge by wind and rain.

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Wheat seedlings were trampled three times during nursery bed, as similar to those carried on in farm practice (B. in figure); or mulched on the seedlings directly with straw mat every night, for the purpose of accelerating the tillers and the stout growth of the seedlings before transplantation (C. in figure). The result turned out according to the author's expectation, as shown in the figure.

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(1) We experimented on the absorption of water and germination of rice seeds in varying concentrations of sodium chloride. (2) The absorption of water increased rapidly during first 18 hours and then relaxed comparatively. (3) The increase of absorption of water was the highest in the plot of 0% of NaCl concentrarion(27%) and was the lowest in the plot of 3.0% (20%). (4) Relation between absorption of water and germination; the germination was aomost normal in the case between 0% and 0.6% (Absorption was more than 24%) and was not found in the case between 1.4% and 3.0%(Absorption was lower than 23%) (5) The quantity of NaCl contented in the seeds was the least in the plot of 0.06%(0.02% NaCl), increased in proportion to the noncentration of NaCl, and was the most in the plot of 3.0% (0.5%).

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In order to investigate the formative effects of 2.4-D on the rice plant, the subject being of specila importance among our agronomical research items, the author carried out experiments with a paddy rice variety, Norin No. 1. As the results 2.4-D when sprayed to the soil either during the nursery stage of growth or whithin the definite period after transplanting the seedlings, was found to induce many characteristic effects on the plant, the principal aspects being as follows: 1. Roll leaf. As shown Figure 1. the leaves on the plants affected were deformed into cylindrical shapes, and in such leaves, as shown in Table 1, the number of the middle-sized vascular bundles was slightly smaller than that in normal plants and that of the inferior ones was remarkably reduced to about 1/3 of the normal value. 2. Abnormal cell-division in the culm-base tissues. Remarkable fanwise tillering of shoots was observed on the plants sprayed with 2.4-D under unfavaravble conditions, the phenomenon being supposed to be partly due to the abnormal cell division in the culm base tissues as shown in Figure 10. 3. Stumpy root. The stumpy roots on the plants affected as shown in Figure 12 were distinguished from the mormal roots by the difference in the thickness of epidermis as well as by indistinctness of the confines between coetex and central cylinder.

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Rice plants on the so-called fall droppen paddy field show low yielding efficiency. This experiments were done in three different plots, that is, normal paddy field: Ninomiya, semi fall droppen field: Tomioka, and the heavy fall droppen field: Idoori, Growth rate, increase of fresh and dry matter in unit area, and nitrogen %, total sugar% and crude ash% in plant samples of eyery plot were examined. It is recognized that the fall droppen phenomena in rice plants arise not only from earing stage, but from early vegetative stage in paddy field. The fall droppen phenomena is not peculiar, but it is due to the nutritious deficiency of the plant on the habitat

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This paper is the experimental report on the influences upon the per-nut of the change of the soil temperature by mulching method. Treatment plots are black paper mulching plot, wheat straw mulching plot and control. 1. As to the soil temperature, it is high in the black paper mulching plot, ordinary in the control and low in the wheat straw mulching plot. 2. As to the soil moisture, it is high in the wheat straw mulching plot, ordinary in the black paper mulching plot, and low in the control. 3. As to the growth of pea-nut plants, the length of stems and branches and the number of branches. are best in the wheat straw mulching plot, and worst in the black paper mulching plot. 4. The blossoms in the black paper mulching plot are comparatively numerous in early period and the blossoms in the wheat straw mulching plot are numerous in late period. 5. The comparatively good pea-nuts were found in the black paper plot. 6. The weight of pea-nut plants, without seeds is heavy in the wheat straw plot and light in the black paper plot.

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Extreme sterillity so-called "straight head"of rice often occurs in farmers fields under dry weather in Japan. This straight head seems to be a sort of drought damages, though the mechanism of its occurrences is still unknown. In order to find out the mechanism of the occurrence and to establish the preventive culture method against it, the writer has conducted a series of experiments from several years ago. According to the results already obtained in these experiments the occurrence of straight head appeared to be closely related to the following two soil properties; the manuring effect of soil by drying and the amount of active iron in soil. Therefore in the present experiment these two soil properties and other physical soil properties were measured with many kinds of soils obtained from various districts where the straight head often occurs or not. Results of the experimene are as follows:-- (1) Close relationship was not found between the occurrence of straight head and the following two soil properies; the content ot sand or clay and the water holding capacity. (2) The soil of the fields where straight head often occurs showed either high manuring effect of soil drying or deficiency or active iron. And if A denotes the value of the manuring effect of soil drying as experessed by the ammonium nitrogen in mgr per 100gr dry soil and B denotes the amounts of active iron expressed by free Fe₂O₃ in mgr per 1gr dry soil, close relationship was found between the occurrence of straight head and the value of A/√B of the soil. In general, the value of where the straght head often occurs was greater than 5 and that of the soil A/√B of the soil where the straight head often occurs greater than 5 and that of the soil where the straighr head never occurs was less than 3. (3) The fact that straight head often occurs where the soil is rich in humus or in the fields under stagnant water all the year round and it seldom occurs in the ordinary well drained fields or in the field used to be exposed to drought condition seems to be responsible for the fact that the former fields show higher manuring effect of soil by drying than the latter. (4) From these results, both the manuring effect of soil drying and the amount of active iron in soil are considered to be essential among factors which determine whether straight head actually occurs or not under drought condition.

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In the previous work the increse of the susceptibility of rice to Helminthosporium disease caused by hydrogen sulphide added to culture solution was assumed to be referred to the retardation activity of roots for some nutrients due to the root injury by hydrogen sulphide. Then, in order to ascertain more exactly such an unfavorable effect of hydrogen sulphide on nutrients absorption, a solution culture experiment has been carried out, in which nutrients uptake by rice growing with or without hydrogen sulphide is examined. In this experiment the absorption rate as expressed by the quantities of nutrients absorbed per unit dry weight of a plant during a definite interval, was calculated by the analysis of the culture solution, and also the percentage cotents of each nutrient in stems and leaves of adult plant were determined. The results of the experiment are summarized as follows:-- (1) The absorption of some nutrients as well as water was considerably decreased by the addition of hydrogen sulphide to culture solution. Especially the absorption of potassium and silica was remarkablly inhibited. The uptake inhibition of nutrients and water was in the order K₂O>SiO₂>NH₃-N>MnO>H₂O>CaO. While the uptake of phosphorus was not retarded at all. (2) percentage contents of silica, potassium, manganese and calcium in stems san leaves were decreased by the addition of hydrogen sulphide. (3) The ratio of silica to nitrogen (SiO₂/N) and that of potassium to nitrogen (K₂O/N) which were appreciated to heve close relationship to the susceptibility were determined based on the amount of these nutrients absorbed during a definite interval or also on the percentage bontents of these nutrients in leaves and stens. And it was found that these ratios were considerably diminished by the addition of hydrogen sulphide. (4) From the analytical data of leaves and stems it is suggested that the translocation of calcium and phosphorus may be inhibited by the addition of hydrogen sulphide. (5) From these facts ahd other experimental results already reported, the increase of the susceptibility of rice to the disease which is due to hydrogen sulphide seems to be mainly attributed to the retardation of absorption of some nutrients, especially of potassium, silica and manganese.

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A study for controling weeds in paddy fields was made using 2.4.5-T, which was synthesized from the isomer except γ contained in the insecticide BHC. For practical use 60-70g of 2.4.5-T should be applied per tan(990m²)at about three weeks after transplantation. It is requested however to cultivate the sore and weed instrumentally twice and moreover to draw off by hand the Japanese barnyard millet (Panicum Crusgalli L, var, submuticum MEY.) prior to the application of 2.4.5-T. The controling effect given in the plots treated with 2.4.5-T we are less than that in of thet treated with 2.4-D.

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The effect of the three menthods of weed control and their influence on the growth and yield of upland rice was investigated in 1950. The results obtained were as follows: 1. The effect of harrowing by spring-tooth harrow and soil sprinkling among tillers on weed control was conspicuous, but that of double deep culture ploughing was not apparent. 2. The yield of upland rice was not influenced by deep ploughing, harrowing, and sprinkling soil among tilleres twotimes (on July 8th and 28th, but increased by sprinkling soil three times (on July 3rd, 18th, and August 1st). 3. There facts suggest that the effect of sprinkling soil on the yield of upland rice differ by the developing stage of crop when sprinkling soil is perfomed. Harrowing by the spring-tooth harrow and sprinkling soil among tillers will reduce the weeding labour in upland rice cultivation.

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We experimented the effect of different concentrations of heavy water on the germination and growth of harley. Exp. 1. In each of seven perti dishes we placed a sheet of blotting paper having been immersed in the solution which had different concentration of heavy water in distilled water, namely 0/000, 1/000, 1/2000, 1/3000, 1/4000, 1/5000, 1/10000, respectively and barley seeds were sowed on the paper. Exp. 2. (method) Seven glasses were filled with sand, and the sand in each glass was saturated with the same solutions as mentioned in the exp. 1 respectively. Barley seeds were sowed on the sand and each glass was covered by a glass plate to prevent evaporation from the surface of the sand. Exp.3. (method) This time, germinationg barley seeds were planted in the holes of the corks set in the seven bottles which contained the different concentrations of heavy water diluted with KNOP's solution instead of using distilled water. Conclution: As to the germination percentage' of seads, we found that the concentration of 1/4000 was greater than the others and the control shwed superiority over the 1/1000and 1/10000. In KNOP's solution, plants of the 1/1000and 1/10000 concentrations heavy water plots and the control showed longer growth in the top length than that of the 1/4000, while the 1/4000 resulted the longest in the root length of all.

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