From the experimental results, it is evident within the seeding date in this experiment that the height and the haulm yield of March 10 seeding-made in at the max. in Shanghai district. Seeding was not done before March 10 in this experiment, therefore it is not easy to make sure of the results originated from the seeding at the end of Feb. or March 1. However, from the result made under such seeding date as previously in 1942 it is evident that seeding to germination takes longer because of lower temperature and then is not uniform in germination or in growth. Since when cultivating flax by making use of the paddy field open for rice-planting, the seediug dace on about March 10 seems to be right in Shanghai district. Of seeding made after March 20, may conclude that the height-extent be likely not to be enough and the yield seems not to be adequate. In case cultivating flax in the paddy rice field, the stem grows shorter (not well advanced in growth), the yield less in Shanghai district than other fields. But from the viewpoint of fiber production, to make use of thc empty space open for rice-planting, which had not been, conceivable by the time, and yet capable of yielding pretty well, ought to be remarkable. It is unavoidable in this district that the quality bacomes worse through changeable temperature than other flax-fields as Germany, France, Belgium or etc. But, those in Shanghai district, as compared with Hokkaido's, Manchuria's, show not so many differences in those fibrous tissues; which are, for instance, the total number of fibrous cells per on bundle or the diameter of fibrous cell or the thickness of fibrous cell wall, etc. That the amount of fibrous bundle of flax grown in Shanghai district is extremely numerous than of Hokkaido or Manchuria-grown, is quite favorable. But, as regards to this cause for it, we must look to the future study.

View full abstract

1. In the paddy ficld of sandy soil, where "Akiochi" is inevitable, but only the equipment of drainage is vely good, was made the experimental research on the effect of "Kyakudo" 2. The soil used for "Kyakudo" was clay loamy soil, and the valume applied was 33, 750 kg. (9, OOO "Kan") per 990m² (1 Tan") the grade increasing 1.5∼1.8cm (5-6 "Bu") on the height of the surface of mould. 3. The varieties of rice used were "Norin No.8" (the type of heavy ear) and "Senbon Asahi" (the type of numerous ear), and observing, the growth condisions and harvest, as popularly recognized, it was recognized that the former was more fitted than the latter in the "Akioci" region, and also about the effect of "Kyakudo" the former was more remarkable than the latter. 4. By "Kyakudo" of clay loamy soil to the sandy soil, the growth conditions of paddy rice, in the growth of length and increase of tillers, was very good, and incseased percentage of available tillers and hulling, finally increased the production power of paddy rice, given the effect of markedincrease of harvest.

View full abstract

1. In the paddy field of sandy soil, that "Akiochi" is inevitable, but only the equipment of drainage is very good, was made the experimental research on the effects of the treatment of the growth accerate substances up on the roots of rice seedlings. 2. The growth accerate substances used for this research were Heteroxin, Naphthalene Acetic Acid, each manufactured at "Sankyo", and "Koa plant Hormone" (Alfa), manufactured at Koa Phisico and Chemistry Laboratory, and their concentrations used were respectively 0.01% and 0.005% in Heteroxin, 0.005% and 0.001% in Naphthalene Acetic Acid and Alfa. And the hours of treatment were ench 3 hours. 3. The vaiieties of rice used were Norin "No.8" and "Senbon Asahi", Thbe experimental results appeared on the investigatins of the growth and harvest showed the effect, by the treatment of the growth accerate substances, Namely, the divisions of treatment promoted the growth of the length, lifted per cent of available tillers, increased one ear weight, because of them increased the harvest, and it was recognized that the effects of the growth accerate substance were remarkeble great more in "Norin No.8" than in "Senbon asahi". 4. In paddy field of sandy soil, the effects of the treatment of the growth accerate substances on the seedlings of rice were believed to be the usefull technics of cultivation as one method of the removal of "Akioch".

View full abstract

Ten varieties of wheat were sown in 1939 and five in 1940, by two methods. In the first method, each variety was sown in a seperate lot; in the second one, they were sown in a mixture in much the same condition the authors obtainod as the plant stand in the early generations of hybrid where various genotypes were mixed. Several important characters in young and adult stages were investigated by the two methods. The result showed that difference in means and deviations for each variety was found due to the difference of methods, for instace, as is shown in Table l. It was proved by Student method that the difference was significant in the means but insinificant in the deviations. This fact indicates that the competition caused by planting in a mixture is prominent not flactuately but quantitatively. The competition varies by the characters as shown in the competition-values in Table 2, the order of which is as follows; heading time < culm height < weight per plant. It appeared already in the young strge (See Table 3), but the competition in this stage is not always consistent with the one in the adult stage as the signs of the competition-values reverse by varieties between the two strges. It has been pointed out by Clement et al (1929) aud other investigatons that the competition is caused by various environmental factors. Plants having different genotypes should naturally show morphological difference in their young stage they planted in a mixture, and from these difference the unbalance in aerial and edaphic occupations will be caused among the plants as they grow, therefore factors concerning the growth act good on some plants and badlly on the others. Through these behaviors genotypical forms will be warped, in other words, competition appears. The most remarkable characteristics in young stage of wheat is the recumbence or the types of young plant. In Table 3 and 4, close relations are shown between the types of youns plants and the oompetition. Growth of the erect types was good but that of the prostrate types was poor, when they were planted together. As a rule, competition was more remarkable in thick planting than in thin one, and injurious influenee of the trasplanting upon the competition varied by chracters, as shown in Table 5. The more remerkable is the competition, the more difficult is the selection in breeding tech nically; therefore in the early generation of wheat hybrids it is more advantageous to adopt the characters and cultural methods in which the competitions are less remarkable, such as heading time and culm height in the fomer and thin planting in the latter.

View full abstract

In Kanto district we can find light volcanic ash soii scope with poor land, low temperature and dry climate. Especially, in such soil scope, freezing layer, which does not melt whole day, is made up under the condition that mean temperature is below than 2°C. On this land, wheat and barley are not so grown. In ease when the roots of wheat and barley cannot go through the freezing layer, the plant is tend to be injured from drgught and cold. As the characteristics of the varieties fit to the land, good growth in earley period is required. The root system of the wheat and barley which is planted later, can not go down under the ground, and so is likely to be damaged, Consequently, in selection of variety as well as in cultivation method, it is important to take care in the earley period of the plant.

View full abstract

1. Effects of the straw or compost mulching of rice field being managed as following ways on the growth of weeds and rice yield were investigated. 1). Rice being directry seeded on the ridge ef wheat. (Bakkan Unetate Jikimaki) 2). Rice being directry seeded on flat wheat field. (Bakkan Hiraune Jikimaki) 3). Rice being transplanted on the ridge. (Unetate Ishoku) 4). Riee beihg transplanted in row on the ordinary field. (Namikiue) 2. When 37.5k.g. of wheat straw per are were applied only on the ridges of rice field (1&3), the quantity of weeds reduced to 1/4∼1/5 as compared with unweeded plot, and the rice yield were increaced 5∼9% more than that of commonly weeded. Appliation of compost at the rate of 75∼82.5k.g. also decreased the weeds to 1/2∼1/4, but 3∼7% of the rice yield decreased. 3. 37.5k.g. of wheat straw or 75k.g. of compost per are were applied all over the paddy field (2&anp;4), but they had little effects, which may be due to the soil surface being incompletely coverd in these cases.

View full abstract

1. It was attempted for the control of weeds that dusting of CaCN₃ at the rate of 5.63k.g. per are all over the paddy field well prepared were made 5 days before the rice trans-planting into it. This proved to be effbctive for this porpos, the quantity of weed beeing reduced to one quarter of that of unweeded plot. More than 10% of the rice yield of that plot, nevertheless, was decreased as compared with that of the oridinary managed plot, the reason of which may be due to the unrationality of the apilication of CaCN₃ as the manure. 2. Application of CaON₃ at the rate of 2.81∼5.63 k.g. per are between rows of rice plants in the middle of late ef July was effective for the control of weed. The rice plants were, however injured at the same time, and the yield was consequently decreased about 20% as compared with the contro1, so this method is not practicable. Here, it may bc noted that the rice yield are sometimes increased by the application of CaCN₃ at the rate of 1.88k.g. per are with a caution not to fall on the leaves of rice. 3. Weeds of rice field were also killed by the 2% solution of H₂SO₄ or 20% solution of FeSO₄ 7H₂O, but the rice yield were decreased 5∼lO% by these spraying.

View full abstract

This paper gives the results of nursery experiments performed with Jerusalem artichoke seedlings. A small number of seeds were obtained at natural condition or glasshouse in Kyushu. The seeds were sown in the sand soil bed of glasshouse, and seedlings were transplanted in the field. All seedlings producted tubers, and the variability of weight, number and stolon length of tuber was very wide. It might be possible to breed Jerusalem artichokes from seedling at natural condition in Kyushu.

View full abstract

1. Generally speaking, existence or non-existence of a scutellar bundle in mesoctyl of cereals will not accord with the place of the botanical classification strictly, but elongation of mesccotyl possessing a scutellar bundle besides common strand may be not so striking. So there may be some relation between mesocotyl elongation and its structure. 2. Occurrence of highly numbered strand of coleoptile may be regarded as a principle all over cereals, and this may be favorable to a single nature theory of coleoptile. 3. Number of protoxylem of seminal root may be definite with each crop. But number of protoxylem of seminal root of individual having extra strand in coleoptile will not necessarily be larger than having common strand only. So there may be no correlation between coleoptile and seminal root relating to strand number in each variety of every crop.

View full abstract

Many vatieties of rice introduced considerably long years ago into Japan, were cultivated under uniform conditions on paddy field of the Mie Agricultural College in 1947 and experiment was taken in thermostat controlled at 15°C and 30°C in January in 1948. Results are as follows. (1)In 30°C-test, germination percentage and speed of all varieties except two originated in India, are very good and there are no difference within varieties and localities originated. So it is clear that seeds used are very good. Cause of bad germiination of two varieties from India are yet unknown. (2) In 15°C-test, varieties having round-shaped kernels (so-called Japonica) are better in germination percentage than those having long-shaped kenels (so-called Indica). Among the former, Japanese water rice, Japanese hill rice and Korean varieties are the best. Among the latter, Indian varieties are the worst. But mean germination speed of Japanese hill rice and Korean varieties are more rapid than Japanese water rice varieties. (3) As the results of the present observation, it will be probably said that difference of germination under lower temperature may be based rather on ecological difference due to localities than on each varietal difference. Also it may be said that the germinating capacity under lower temperature will not disappear in many years since importation to other country and that it will be considered as a fixed race character.

View full abstract

1) This is a result of mathematicai discussion for growth curve of potato plant in 1946 and 1947. 2) The growth curves of the p1ant height and the body weight are represented in Expression logy/(A-y)=k(x-x₁) (Robertson's automono-molecular curve) and Exprcssion y=b-ax². The former represent the growth process which is from sprouting to the most growth stage, the later the withering process. 3) The increase curve of the average weight per one plant is represented more moderate in ret linear Expression than in Robertson's Expression.4) Tuber swelling is commenced at stage of changing point of (dy)/(dx) in Robertson's Expression. 5) There is a difference of time, about 20 days, between the most growth stage and the last stage of tuber swelling.

View full abstract

The writer has already indicated that the Japanese barley varieties are classified into four main ear-types, and also that these ear-types differ each other as to various quantitative characters of young and adult pIants. This paper dealt with the results on their genetical behaviors in the hybrids. 1. It was proved that two pairs of independently inherited genes, Uz-uz and L-1, were chiefly concerned with the determination of these ear-types. 2. As expected from the previous studies, marked differences in the coleoptile and culm lengths as weIl as in the lengths of ear and rachis-internode were recognized among the F₂ phenotypes with diffaent combination of Uz, uz and L, 1 genes. These phenomena were here explained as the pleiotropisms of these genes. 3. The quantitative effects of the "dominant" genes, Uz and L, over the "recessive", uz and l proved to be somewhat incomplete, although the degree of incompletion was unnoticedly slight. 4. It was pointed out that the "coleoptile method" would serve to facilitate the breeding procedure of Japanese barley improvement, because some important characters of adult plants, such as ear-types, culm length, geographical adaptability and etc. could be predicted by the coleoptile length in their sdedling stages.

View full abstract

I will state here on the yearly total correlation coefficient between each yielding factor of rice varieties, and correlation coefficient between climatic factors and yielding factors about all districts of Japan. These correlation coefficients are calculated on every prefecture of Japon of heading period, length of stems, numbers of stems and yield of grain per tan of rice varieties test of agricultural experiment station of every prefecture and yield of grain per tan of prefecture statistics. And I calculated the yearly correlation coefficient between climatic conditons such as mean temperature from. April to October, mean temperature of guly, the sunshine hours from April to October, and the volumes of rainfall from April to October, and heading period, length of stems, numbers of stems, prefecture and yield of grain per tan of rice variety test of agricultural experiment station of every prefecture and the yield of grain per tan of the prefecture statistics. From such correlation coefficients calculatcd on every prefecture I calculated the correlation coefficient of all district of Japan such as Tohoku, Hokuriku, Kanto, Tyubu, Kinki & Tokai, Sanin, Sanyo, Shikoku and Kyushu districts. The correlation coefficients are as follows, look at the table I. And I celebrate the results graphically, look at the Graphs.

View full abstract

Barley's sterility "Schartigkeit" was recogmzed in the south-west district of Japan, especially in all prefectures in Kyushu in 1946. The sterility was noted in various varieties of barley, in partial or general on their head, especially in "Golden melon" most remarkably. At the farm of the Miyazaki Agricultural Experiment Station, "Golden melon" and others were sterilized perfectly and did not obtained any grain. This phenomena were regarded so important upon the agronomic practices and breeding experiments, that some investigations were performed at the farms of Kyushu Branch of Agricultural Experiment Station and of the all prefectures in Kyushu and others. The summary of the investigations is as follows: (1) The most unusual conditions in the climate during the barley growth period are that the temperature rised suddenly from the end of January on wards, and the amount of percipitation was great from the end of Februaly to the early day of May. (2) The culm was very shorter in all varieties of wheat and barley in the year than in the ordinary ones. Especially the varieties or the culms, in which plentiful sterile florets were recogoized did not ear, and these plants resembled to the "Sitzenbleiben" in late seeded barley of winter type. (3) The glume of the sterile floret was normal in form, but the development of male and female organs were somewhat imperfect. And especially the forms of the anther and of the pollen grain were abnormal, but malformed or organless plant was not found. (4) The tendency of cleistogamy was very remarkable in the year, and it is noticeable that on some varieties or culms late-eared, the fertilization was completed several days earlier than the earing date. (5) The distinction of this sterility may be seen easier on the two-rowed barley than on the others, but no relation was recognized between the forms of ear (two, four, or six rowed) and the such sterility. (6) Such sterility was found abundantly in the winter type varieties and less in the spring types. And in the same variety, sterility were found less in the earlier seeded plants than in the later seeded ones. (7) The correlation between the sterility and the date of earing has not been recognized, but the sterility was somewhat more notable in the later earing plants than in the earlier earing ones. (8) On the same variety, the sterility was found more remarkably in the warm region than in the cold one in the south-western Japan, viz., the warmer condition is the profitable for the outbreak of the phenomena. (9) Negative correlation was recognized between the sterilty and the earing degree, viz. the sterility is of high per cent in such plants, as the internode under the ear does not elongate so as the ear appears upon the sheath of the uppermost leaf. (10) The sterility was found not only in barley but also in rye and oats, and less in oats but abundant in rye. The sterility was also found in the rye grown in the glasshouse as about the same degree as in the open field under natural conditions.

View full abstract

We investigated the growth and yield of 4 wheat varieties in different kind of soil, - One was soil (pH. 4.2) without lime and barnyard manure and had been given 50 Kg. of ammonium sulphate, 52 kg. calcium superphosphate and 18 kg. potassiumsulphate per 10 are every year since 1936, and the other (pH. 5.8) was the control, which had been given 6O kg. of lime per 10 are every year beside three kinds of fortilizer. In the early stage of growth, the seminal roots find much difficulty in going into the acidified soil, so they come up to surface to a degtee when the soil is frozen, but this phenomenon is scarcely caused in "HIRAKIKONUGI" variety. The decrease of the height of plant and the number of stem in the acidified soil is not remarkable in the early stage of growth, but conspicuous after the middie stage. This hindrance is least to "HIRAKIKOMUGI". As for the growth of root, in the acidified soil, the decrease of number and weight is not great in the early stage of growth, but it seems that their sideroots do not come out. In the middle stage, the growth extremely hindered and the ratio of root weight to that of control at the latter part of March is 36% in "HIRAKIKOMUGl", 17% in "AKABOZU", 16% in "KOMPIRA" and 12% in "WASEKOMUGI". the root-system at the last stage of growth in acidified soil. As to the yield, that of acidified soil is much less and the ratio of the weight of grains produced per unit area to that of control is 26% in "HIRAKIKOMUGI", 5% in "AKABOZU", 13% in "KOMPIRA", and the harvest of "WASEKOMUGI" is almast nothing.

View full abstract

(1) The pollen grains of a tobacco variety-yellow orinoco-were tested about the longevity on their fertilizing power as well as the decreasing their vitality, by means of pollination test on the pistils. The pollen grains tested were previously stored under different conditions, in detail, some of them were set under ordinal room condition, keeping in Petri-dishes (wet condition), and others under absolutely dry condition, keeping in a CaCl₂ desiccator (dry condition). (2) For the longer hours the pollen grains were stored, the smaller capsules were obtained by these pollen grains, and less number of seed was counted in each capsule. Practically, it may be said that the maximum duration of the fertilizing power of the tobacco pollen is 40 days under the "Wet condition", and 180 days under the "Dry condition". Moreover, in the case of smearing with the stored pollen, which had passed the periods above mentioned, the ovaries developed often into seed-less fruits. (3) The stored pollen was sown on the artificial medium (10% water solutiqn of cane sugar), and compared their germinating percentage with the fertilzing power. (4) As it is well known, the germinating percentage decreased as the pollen became older, and the ferilizing percentage also decreased in the same manner. But there were sorne differences observed between these two caases. Namely, the decrease of the former was rapid than that of the latter. In other words, the pollen which could fertilize the egg was often un-able to germinate on the media. (5) It is sometimes reported that the pollen, stored under dry condition, germinates better in the case of pretreatment keeping them in a moist chamber for a short time, than in the ordinal case of setting them directly upon the medium. In this study, the author hold the dry stored pollen grains in a moist chamber for 30 minutes to make them absorb the moisture, and set them on the media as well as on the pistils. The germinating percentage on the media increased by means of this pretreatment, but the pollen which passed the practical storing period or the dead pollen could not germinate even if such treatment, above mentioned, was made. In the case of the pollination was made upon the pistil, the effect on this pretreatment can be observed neither on the fertilizing percentage nor on the longevity of fergilizing power. (6) The relation between the length of storing of pollen and the nature of the offspring was studied. The size of the seed obtained by the stored pollen was various. Generally, they were smaller and lighter than the normal seed obtained by the fresh pollen, showing to be only two third the weight of the ordinal seed. (7) As the storing of the pollen used became longer, the vital force of the seed obtained by these pollen become smaller. Namely, it was observed that the germinating power and the germinating percentage become lower (8) In the nursery, various malformations were observed, when the seeds obtained by stored pollen were sown. These abnormality recovered gradually, but in the case of very old pollen used, the abnormality rather increased as the plants grew. mentioned, the ovaries developed often into seed-less fruits. (3) The stored pollen was sown on the artificial medium (10% water solutiqn of cane sugar), and compared their germinating percentage with the fertilzing power. (4) As it is well known, the germinating percentage decreased as the pollen became older, and the ferilizing percentage also decreased in the same manner. But there were sorne differences observed between these two caases. Namely, the decrease of the former was rapid than that of the latter. In other words, the pollen which could fertilize the egg was often un-able to germinate on the media. [the rest omitted]

View full abstract

The result of investigation is summarizee as follows; 1. The "strairght head" occurred when the soil was not dried so extremely and consequent]y plants showed no wilting and no remarkable injury as to vegetative growth. 2. The "straight head" occurred when the plants were exposed to drought at such three stages in the process of rice panicle development namely stage of differentiation of flower primordia, stage of differentiation of flovver primordia, stagl of reduction division of germ cell and also stage of heading and flowering. 3. The "straight head" occurred seriously at where the soil shows high manuring effect by drying or at where the soil is deficient in activated iron. 4. The occurrence of "straight head" was inhibited by suppling water during the period from 19 days to 12 days previous to heading and was promoted by irrigation before or after that period. 5. It was assumed that the extreme sterility occurs when the panicle or flower are able to continue their development, without ceasing, under drought condition and simultaneously there is temporal unbalance of water relation in the plant which happens during the short duration of noontime of every day resulting from acceralated transpiration at that time.

View full abstract

As the materials for experiments were taken (a) 44 representative native varieties, (b) 40 improved varieties in Japan, (c) 10 varieties in Manchuria or Formosa, and (d) 60 of foreign varieties. These samples were grown at the same farm of the late Kyushu Wheat Breediag Station. From the experimental results, 'the varieties which are superior on the baking quality in their native (cold) land, also showed a high quality growing in the warm region, especially the spring varieties in the cold region are better than the others. But it shows a tendency inferioring on the quality when the maturing process were hastened abnormally by the deficiency of the water supply and etc. A study was made also on the interrelation of baking quality and certain physical and chemical properties of grain and flour with these many varieties.

View full abstract

The occurence of sterile sprkelets as an injury by low temperature due to late seeding and transplanting is insignificant in a year like 1943 when abundant sunshine and high temperature prevailed during the whole growing period, and consequently no inter-varietal difference sbows itself, but in a year like 1942 when the climatic conditions during the growing period were unfavorable with frequent visits of abnormal low temperature at the stage of ear formation and flowering, the per-centage of sterile spikelets increases and inter-varietal differences show themselves somwhat notably. This manifestation of inter-varietal differences in injury to fertilization is chiefly sttributable to the differences in the varietal resistability to low temperature and the degree of decline of the physiological function due to late seeding and transplanting, chance concurrences of the stage of formation of generative cells or the stage of flowering and pollination with abnormal low ternperature, and other relations. By inquiring into such relations, we classified the insensibilities to cold of the varieties used in our experiment. In late seeding and transplanting, inter-varietal differences arise in the injury to fructification due to low temperature, but it is difficult to detect therefrom differences in the resistability to low temperature or in the insensibility to cold of a variety. Inter-varietal differences in the degree of reduction of the number of days from seeding to earing attendant upon late seeding and transplanting is thought to be accompanied with differences in the degree of decline of the physiological function, and therefore is, in this sense, related to the injury by low temperature. Inter-varietal differences in the delay of earing exercise an influence upon the degree of injury by low temperature by causing more or less chances of meeting with an unseasonable low temperature at the stage of ear formation or flowering. Decrease in the number of ears per hill (individual) is, in ordinary cases, not due to injuty dy low temperature. The total number of spikelets per ear generally shows little cbange, and inter-varietal differences in the rate of its decrease are hard to detect. Aa a method of determining the insensibility of a paddy rice variety to cold, late seeding and tra splanting has the advantage that a number of materials can be used in experiment at the same time, but this method can be employed only in cold regions, and that in a year when unseasonable low temperatures attack during the specific growing period. Moriover, it involves much labor and trouble in the conduct of an experiment and judgement of its results, and therefore cannot be considered as appropriate for general purposes. we have also made a classification of the insensibilities to disease of the varieties used in our experiment on the basis of the per-centages of ears affected by blast as the result of late seeding and transplanting, and we can infer that different genetic factors take part in the insensibilities of a paddy rice variety to cold and to disease.the differences in the varietal resistability to low temperature and the degree of decline of the physiological function due to late seeding and transplanting, chance concurrences of the stage of formation of generative cells or the stage of flowering and pollination with abnormal low ternperature, and other relations. By inquiring into such relations, we classified the insensibilities to cold of the varieties used in our experiment. In late seeding and transplanting, inter-varietal differences arise in the injury to fructification due to low temperature, but it is difficult to detect therefrom differences in the resistability to low temperature or in the insensibility to cold of a variety. Inter-varietal differences in the degree of reduction of the number of days from seeding to earing attendant upon late seeding and transplanting is thought to be accompanied with differences in the degree of d

View full abstract

This study is preceded by making clear of the formation-process of fat and protein involved in the seed which is an object for tne production, to establish firmly the theory of peanut-cultivation. The results of experiments summarized are as follows: 1. The size of the pod on the 35th day after flowering, and the sizs of the seed on the 42nd after are to be almost at their max. 2. The raw-weight of the pod is to become its max. on the 35th day after flowering and is afterwards likely to decrease, but the raw and dry-weight of the seed keep to increase up to the 84th day gradually. The dry-weight of the pod is to continue to increase up to about 70th day gradually and is afterwards to decrease a bit. 3. Fat involved in the seed is to become its max. nearly on the 77th day after and the Iodine value is to show its greatest on the same day after. 4. Protein is te be its max. on the 77th day after flowering and afterwards decreases a bit. 5. Ashes are abundant in the pod during the beginning of growth, ashes in the pod is afterwards to keep to decrease and become constant on the 77th day after. Ashes in the seed are tobecome nearly constant on the 70th day after.

View full abstract

(1) Adaptability of rice seedling raised in various nursery conditions to the degrees of nitrogen fertility of the paddy field was studied. The kind of nitrogen fertilizer management of the field to which the seedlings of various makings were transplanted and grown up to maturity were AB (N, basic and top-dressed), Ab (N, basic only). aB (N, top-dressed only) and ab(N, no applicaeion). (2) The seedling grown up sparsely in the nursery (I). was large when transplanted, containing more total nitroten (N) and carbohydate (C) as compairing with the small seedling grown on the densely sown bed (III). The plant from such large seedling could absorb large amount of N in its early stage of growth, but the increment of N percentage in that stage proceeded more slowly in the plant than in plant from the sman seedling above mention. At the late stage of the vegetative growth, the plant from large seedling showed, after all, a higher percentage of N content than the plant from the small seedling, and the former shoot the ear earlier than the latter. The yield records of two years experiments showed that the large seedling resulted frorn sparsely sowing was more suitable to the basic-dressed field than the top-drssed one, while, the small seedling produced by thick sowing grew up better when the field was top-dressed. (3) The seedling of early sown and left over time in the nursery ('matured seedling') (lV) was, when transplanted, rather deficient in N as compared with C content, while the seedling of lately sown and kept at nursery for comparatively short period ('young seedling') (VI) was rich in N, comparing with C. The matured seedling maintained its lower N percentage for a time after transplanting, aspecially so in the field receiving no basic application of N. In the later stage of growth, the N absorbing power of such plant seemed to be smaller than the plant from young seedling. In warm year (1946), or on N rich fields, the N absorbed by the matured seedling showed higher efficiency for grain production than that absorbed by the young seedling. In cool year(1945), or on N deficient fields, however, the young seedling, absorbing larger arnount of N, showed higher efficiency of N than the matured seedling in producing grain. (4) The seedling grown up under limited light intensity (VIII) had smaller amount of N and C, and its C-N ratio was lower than that found in the seedling grown under full light intensity (VII). In 1946 the shaded seedling behaved in the field more like the small seedling, and in 1945 rather like the young seedling. The seedling raised on non-irrigated nursery (IX) had larger amount of N and C, and its C-N ratio was lower at the transplanting stage. Moreover, after transplanting N content in unit dry matter of such plant increased more distinctly that of the plant nursed on full irrigated bed (VII). In 1946 the non-irrigated seedling behaved chiefly as the large seedling, and in 1945 it behaved as the young seedling. (5) The authers conclude that the amount and percentages of N and C, and the ratio of the both elements at the transplanting stage are very important seedling characteristics affecting the suitability of the seedling to a certain condition of soil fertility or the N fertilizing management. more total nitroten (N) and carbohydate (C) as compairing with the small seedling grown on the densely sown bed (III). The plant from such large seedling could absorb large amount of N in its early stage of growth, but the increment of N percentage in that stage proceeded more slowly in the plant than in plant from the sman seedling above mention. At the late stage of the vegetative growth, the plant from large seedling showed, after all, a higher percentage of N content than the plant from the small seedling, and the former shoot the ear earlier than the latter. The yield records of two years experiments showed that the large seedling resulted frorn sparsely sowing was more suitable to the basic-dressed field than

View full abstract

I had reported the effcct of bark powder of camphor tree on the growth of the crops, and after ward I conducted the same experiments on rice plant, upland rice, barley, wheat and potatoes. The result on the germination and the field experiment on potatoes are as follows. I Germinating cxperiment One section (withont powder) and the other (with powder) Were 100 percent in germination percentage. In the germinating energy, the top was the best and the middie and the base followed in order. In comparing the standard with the other, I could not find any difference between them But the middle and the base buds of the latter were superior to the standard. ll Field experiments I conducted the experiments dividing 3 section. A section (put the powder on cut surface). C section (mixed the powder in the soil) and. B section (without the powder). A and C sections were better than B section in harvest at the rate of from 23-38 percent. ln the beginning there were some tendency of retarding in A and D section, but at the end I found the one with the powder mixed in soil was the best in harvest.

View full abstract

About 2000 varieties of cultivated rice collected in the rice growing countries in the world, records of shooting date were taken at the Experimental Farm of the Kyushu University in Fukuoka, Japan. They were sawn late May, transplanted early July and reared under customary management. The results were compiled in table 1, 2 and 3. In table 1, 1938-1942, wide variations were found, the earliest July 20th and the latest Sep. 24th. They were classed into 5 groups very early, early, intermediate, late, very late. Varieties belonging to the very early group were found in Hokkaido, Manchuria, North China, U.S.S.R. that is, in the so-called high latitude districts and the very late ones appeared in Japan p-roper, central and south China Phillippine, and U.S.A. Many sarnples collected in the tropical and subtropical regions could not shoot or ripe under such climatological condition as in Fukuoka and died out as shown in table 2. In table 3 the fact is presented that late variety group completes their shooting behavior during vety short perid, while the other groups need longer time. The former is the fittest ecological type in the experimental farm condition.

View full abstract

It was apparent that change of the temperature from 12-13°C to 30°C promoted the microsporogenesis and development of the pollen of rice-plant at the reduction division stage, when this high temperature was kept for a long time.

View full abstract

1. Cytological studies on tbe sterility of rice plants irrigated with cool water have been conductcd in Kamikawa Rice Breeding Inttitute of Hokkaido Agricultural Experiment Station during these two years in order to make clear the cause of their sterilities. 2. Sterilities were far more higher in the treated plants than those in normai conditions, and abnormalities found to occur in their pollen formation were to follow: 3. The rate of microsporogenetic development was significantly retarded in the treated plants which possibly being the cause effecting in inmature pollen at the anthesis. 4. Various abnormalities in the behavior of pollen mother-cells were also found. i. e. asynapsis, lagging and non-orientation of dividing chromosomes, failure of meiotic cytokinesis, and the abnormal hypertropy of tapetal cells. 5. Such abnormalities appeared to be of the same nature to those occuring under low air-temperatures as having been detdcted in our laboratory.

View full abstract

For linkage analysis of genes especially of quantitative characters, a new possible method is suggested. This may be called "One chromosome-method", and consists of crossing of two varieties, successive backcrossing to one parent and selfing, leading to a formation of a recovered line with one pair of chromosomes from the non-recurrent parent and all the other pairs of chromosomes from the recurrent parent. If we cross these plants to the recurrent parent and self the F₁ plants, the coming F₂ plants may separate into three groups: one homozygous sirnilar to the recurrent parent, one heterozygous similar to F₁ and one homozygous similar to the recovered line in a ratio of 1:2:1. Precise comparison of the two homozygous groups may reveal the linkage relations of genes locating on the specific chromosome pair. This analysis may especiauy be avaiiable to animals in which crossing-over does not occur in the heterogametic sex.

View full abstract

Study carried into effect at the land newly laid out, in past two years. Symptoms appear on winter wheat plant are presented as follows. 1. Effect on plant as a whole. Growth is slow and plant are dwarfed at maturity. Tillerings fewer than normal. Leaves are slender and sharp, and turn dark purple in color in all airial parts. 2. Effect on root. Poor developement of roots. Fewer numbers than normal, and roots have reduced amount of root-hair.

View full abstract

1. The results here report are of 5 years experiments (1943-1947) in which α-naphthalen acetic acid and heteroauxion were applied to rice plants as growth substance. 2. The plants grown from the seeds treated by 0.05, 0.025% of solution of growth hormone 24 hours are indicated some positive effect on the growth in 1943, as well as the plants sprayed over by the solution of growth substances. 3. It has been confirmed that the treatment of seed and growing rice plants with the solution of growth substances at the concentration named, no significant inereases in the yield of rice plants have been obtaiained.

View full abstract

1. The effect of growth substances upon the growth or potato plants were examined these few years. The results of 3 years (1945-1947) were reported here. 2. The seed pieces of potato were treated by 0.01, 0.005, 0.002 and 0.001% solution of α-naphthalene acetic acid and heteroauxion 0.5, 1, 3 and 24 hours. 3. In general, no significant effect in tuber production of potato tubers have been obtained as indicated the positive and negative reports to growth sutbstance treatment.

View full abstract

Die gegenwartigen Reisarten entwickelten am haufigsten in ost-sudlichen Gebieten Asiens aus den direkten Vorfahren des kultivierten Reis, d.h. Oryza sativa spontanea. Weiter bemerken wir unter indo-chinesischen Reisarten die verschiedesten Typen. So liegt die Vermutung nahe, dass Indo-China als der Ort der Entstehung des Reisbaues. Die Urvolker, die den Wildreis am ersten zur Kultivierung gebracht hatten, gehohren aus archaologischen Grunden dem austroasiatischen Sprachstamm, z.B. Kolarien und Mon-Khmer. Der Reisbau wurde durch obige Volker im Beginn des neulithischen Alters angefangen. Der Bergreis geht dem Wasserreis etwas fruther im gebirgigen Land voraus.

View full abstract

(1) The secondary-growth of potato-tubers inducig artificially by changing the ehvironmental conditions were studies with water cultur, using "Danshaku" in 1948. (2) It is clealy evident from the results herein presented that the high temperature (40°C), light exposur, dryness and concentrated cultur solution are all causes of secondaiy-growth of potato-tubers. (3) It is suggested as the basic cause of secondary-growth may be due to some growth substance which is affecting by abnorml condition of environment.

View full abstract

In snow falling region for long period, it is often to be seen that barley is completely destroyed by parasitic disease of Sclerotium species. Barley has been regarded as one of unstable crops, and this study is worked by actual reguirment of farmers who can hardly expect the prevention of the disease by drungs. This method has been practised since 1946 for the purpose of safely cultivation by means of replanting autumn-sowing-barley in spring, that is not to place barley in the field during the winter but to make it experience the season artificially in vassels. This report is the abstract of the most practical method that has ever been investigated. 1. Fertill rich soil much water and good darining is desirable for the field. If it is newly cultivated land and of strong acidity, it should be previously moderated. 2. As forma No.4-Barley is good for this method. 3. Treatment A.) Artificial Germination Treatment: 2 kilograms seeds are stirted up three time during 11st∼12nd of Feb. with pouring water of one-third of 1 litre water in each time. Then they are kept at 12°C in warm "Kotatsu" or in compost for ten days until the testas of 3∼5% of the whole will brcak up. B.) Low Temperature Treatment: This is practised often the germination. Materials are kept at O∼2°C being stirred for 40-50 days. 4. Sowing period must be kept not to delay beyond 20th of April, the amount being 14.5∼18 litres for ten acres. Material is flooded one day befor sowing. 5. Manure: grolwthing in the early time is the most important. if leaves are few, it does not come out into ear, we, therefore, must give some amount of manure of much nitrogen content towards the middle of May succeedingly. 6. Supervision: For the complete early time supervision, it is needed to take care against birds, beasts and weeds, and to sprinkle drung for the prevention of Rust. Besides, cultivating is needed at the time of succeeding manure in the middle of May. 7. Harvest-time is 15th of July. Yield is 360 litres per ten ares on the average. Beans, buckwheat and autumn vegetable are suitable for the latter cultivation. 8. In conclusion, cultivation by vernalizational treatament is very much effective for the achievement of rotation (labour distribution, higher utilization of fields, cold-weather damlge prevention) and for the prevention of paasitic disease of Sclerotium species.

View full abstract

Catalase activity in seeds and flour of wheat varieties (16 var. of spring and winter types) was determined at the temperature, 5°∼10°, 20°and 30°C. And the thermosensitiveness of the ferment, namely the mobility of the ferment expressed by the ratio-difference between activities at lower and higher temperature. The activity at lower temperature was calculated in each variety. The results were as follows: (1) the activity, especially that at lower temperature was higher in earlier varieties than in those of later heading. (2) the thermosensitiveness of the ferment was greater in earlier varieties than in later ones. The earlier varieties (spring types) are in general more responsible to higer temperature in their growth than the later ones (winter types). Potentials e.g. the ferment in seeds of wheat varieties showed the corresponding responses to higer temperature as plants do in their growth. (3) the activity in flour was not so much correlated to the growth habit that the author found in that of seeds.

View full abstract

This paper has been reported on distribution of stomata in coleoptile and mesocotyl of several cereals as prelitninary. 1. Number of stomata and its mode of distribution both on adaxial and abaxial sides of coleoptile are different in each crop. 2. Ratios of number of stomata of abaxial side to adaxial side are different in each crop but those are especially large in rice, except some varieties. 3. Numbcr of stomata and its mode of distribution in mesoooty lare different in each crop.

View full abstract

The author presents here only the preliminary account of a series of the studies, which have been carried out on the Japanese barnyard millet, a weed on the lowland rice field, and in near future the results obtained will be made public in some detail. Wild Japanese barnyard millet (Echinochloa crus-galli) is one of the most common and noxious weeds occurring on the paddy rice field in Japan, and thus the author duly considers that the results of these investigations, revealing various specific characteristics of the plant as the weed on rice field, would have no less important bearing on the practical problems of rice culture in Japan, though they are rather of basic interest in the main. Investigation were usuahy carried through on the transplanted plants grown in the Wagner's pot, but in some occasions the direct seedage method was also applied.

View full abstract

1. "Flora" and "growing phases of crop plants" in fire-raged districts in the city of Osaka are very monotonous, having been influenced by those of pre-war. This is, according to writer's opinion, because of the fact which th "Flora" and "growing phases of crop plants" had been kept under remarkable restriction by the narrow green land, the damage of heavy smoke and methane etc. 2. In the same districts, the plant was made. In it 71 families, 192 species in high class plans aboue Fern plant were described, containing 21 families, 67 spccies known as edible plants and 7 families, 11 species as poison plants. 3. Invasion of plants to the fire-raged district was started mainly from the places left from war-disaster and in consequence the flora was rearranged by paticular kinds as Amarantaceae, Chenopodiaceae and some parts of Asteraceae which are speady in seed-spreading and are full of vigour in procreative power. 4. Sail of fire-raged districts contains slight alkali and is dry and unproductive but it has not got worse. So if taken good corn and fertilized, no obstacle would be given to cultivation of crops. 5. Only in case of Cultivation of pulse crops, it is necessary to make infection of nodule bacteria or to spread soil containing them. 6. Self-supply gardening has been deen developed actively but in general yield per unit area is very small becanse of unproductivity and dry condition of the soil as well as lack of care. 7. Concerning to the fact of having been fire-raged, crop da mage by injurious insects and diseases is little and especially so in the case of the damage by soil-living insects or soil-infectiag pathogenes. iaceae and some parts of Asteraceae which are speady in seed-spreading and are full of vigour in procreative power. 4. Sail of fire-raged districts contains slight alkali and is dry and unproductive but it has not got worse. So if taken good corn and fertilized, no obstacle would be given to cultivation of crops. 5. Only in case of Cultivation of pulse crops, it is necessary to make infection of nodule bacteria or to spread soil containing them. 6. Self-supply gardening has been deen developed actively but in general yield per unit area is very small becanse of unproductivity and dry condition of the soil as well as lack of care. 7. Concerning to the fact of having been fire-raged, crop da mage by injurious insects and diseases is little and especially so in the case of the damage by soil-living insects or soil-infectiag pathogenes.

View full abstract

The purpose of the present experiments were twofold - to analyse the action currents in in potato tubers, and to determine the relationship of the potential to cell activity at the period of sproutang. Our experiments were conducted with fall crops of Early-Rose potatoes during the spring of 1948 and 1949. The measurements were made by the use of sensitive galvanometer with zinc Zinc-sulphate electrodes induced to the skin and to the flesh of tubus. Principal results obtainod were as follows: I. The acrion current appeared generally at the end of rest period. The magnitude of both action potential and rest potential increased as the tubers began to sprout and falls off rapidly with the continuanance of the sprouting. II. The electric properties disappeared when the buds reached about 0.5cm. in length. This stage can be said "the critical period" in electrophysiological sense. III. The magnitude of action currents were more significant with pre-cooled tubers (2°C.-3°C.) This fact is full of suggestion considering that the low temperature favors the breake of dormancy. IV. The mechanical stimulation by the use of vety sharp knife increased in action potential. This procedure was found to be very successful for the potatoes production and it has been already put inte the practlce.

View full abstract

Many varieties, 136 in total, conected from Japan, Korea. China and U. S. A . were used. Seeds were sown at 6 suceeeding periods from April to September. Dates of germiuation, beginning and end of flowering, and maturity were recorded. With these data, the fouowing 3 duration were calculated ; A. Flowering days from germination to beginning of flowering, B. Flowering duration-from beginning to end of flowering, C. Growing duration-from germination to maturity By using the above 3 items (A, B, C), the classification of summer vers. autumn types of varieties were tried in respect to the following 3 ecological characteristics ; (I) The rate of shortening of the flowering days due to the delay of seeding periods calculated by assuming the mode of change of the flowering days according to the seeding periods to be 1 linear. (II) Relative length of flowering duration to flowering days, B/A. (III) Relative length of growing days to flowering days, C/A. As shown by the following table we can distinguish firstly 3 types of Summer, Intermediate and Autumn, secondarily 3 classes in Summer type (SI, SIp, SII), 2 classes in Intermediate type (MIII, MIV), and 3 classes in Autumn type (AV, AVI, AVII). [Table]

View full abstract

In this study, the author shows frequency and mode of emergence of extra strand, and relation between extra strand and stomata in coleoptile of rye crop plant as follows. 1. Frequency of occurrence of individuals having extra strand in coleoptile is 5.1%. 2. In rye, the order of emrgence of extra strand may be at random, but in rice it may be regular. 3. Row-number and shape of stomata belonging to extra strand are different in several respects from those belonging to common strand.

View full abstract

1. For the study on the cultivation of Jerusalem Archichocke, especially the fundamental study of its yield, the dispersion phases of tuber were investigated first. 2. Between the tubers and stolons, the correlation was found that the magnitude of tubers is in direct proportion to the length, depth and thickness of stolons and is in inverse proportion to the thickness of origins from which the stolons grow. 3. For instance, the means of stolons were 57.60±1.679cm in length, 13.06±0.244cm in depth, 3.21±0.045mm in thickness and the mean of origins was 4.38±0.159cm in height. 4. As for the directions of tuber development, the ratio was each 20% both in east and west, 30% in north and south. The direction of dike was north to south. 5. In spite of the negligence of Jerusalem Archichocke cultivation, it grows flourishingly, but in its harvest a great deal of labor is required. If the way of harvest be rough, it is feared that the next cultivation will be hindered by the abundant presence of those which are missed to be dug up. 6. For the investigatioa of Jerusalem Archichock yield, it is required that the way of harvest, the extent of fineness or coarseness etc. must be considered together with the yield quantity itself.

View full abstract

In wheat or barley cultivating villages in Kanto district where violent north winds are frequent in winter, the use of windbreak is badly nedded. Formerly forest plantings were used, but recently they have often been to cut down to bring land under cultivation. So Farmers in the district use a few kind of windbreaks. They are: 1. Hedges of azalea or tea plants, running from west to east with a distance of sixty feet or less, between them. 2. Stubbles of upland rice digged up and arranged in a ridge at tbe back of wheat or barley. 3. Rows of wheat or barley straw inserted into earth at a distance of 20 feet or less. The author examined the efficiency of the three above-mentioned windbreaks at Tokyo University Farm from January to March in 1948. He conducted experiments on it on windy days, using several Birum anemometers in order to know the force of wind. The Results of Experiments: As a windbreak a hedge of dwarf plants like azalea or tea plants is not at all inferior to wood planting. Too dense a windbreak as a board fence in not good, because large and strong vortex is provoked in field which is from 1.5 to 6.5 times of the fence apart from it, which is not desirable for wheat cultivation. It is desirable that a windbreak is full of crevices as a hedge of azalea or tea plants. Two other windbreaks (No. 2 and No. 3) also were very effective although they did not look so. It was because ridges of stubble of upland rice plants shelter enough wheat or barley for violent wind, and rows of wheat or barley straw inserted into earth reduced to half of the force of wind in the fields where no windbreak was erected.

View full abstract

This report is described on the negative geotropism of the lodged stems of wheat and naked barley. (1) It was observed that the lodged stems of the naked barley were recovered more rapidly than the wheat. (2) When the stem was lodged at the 2nd internode, the rising process of the 1st internode was represented by two straight lines, which was almost similar in both cereals. The angle of inclination of the 1st straight line was sharp, while the 2nd one was gentle, and there was the transition point from the 1st straight line to the 2nd one at an angle of about 40°in wheat or about 50°in naked barley. (3) The stem lodged at the lower internode was recovered to normal situation through over-bending. (4) It is obvious that the process of the negative geotropism is different by the tirne of lodging, for example, on the comparatively early lodged stem the rising grade is progressed. However, the behavior of the negative geotropism may be similar to the above mentioned results.

View full abstract

1. Castration of many ears of wheat var. Saitama No. 27 apparently in a stage of several days before flowering was carried out simultaneously by the clip method in the field, and then mature pollen of wheat var. Norin No. 26 was pollinated daily. 2. During eleven days ranging from the time a few days before flowering to the time six or seven days after flowering, fertilizing ability of the pistil was highly retained. Seeds of high vitality were produced by the daily pollination during these eleven days. 3. It was observed that fertilizing ability of the pistil decreased sharply after the twelfth day from castration and then almost disappeared on the fourteenth day from castration. 4. Immediately atter castration and on the following day the receptivity of the pistil was comparatively low while germination energy of the seed was high, but sinee the second day from castration, the receptivity of the pistil and germination energy of the seed showed the sarne tendency. 5. It is favourable in crossing operation that pollination is possible to be carried out safely at any time during these comparatively long period.

View full abstract

Unfavourable conditions for tiding over the season of dry monsoon in the regions of Kanto loam (light and coarse soils) are found to be defeated some degrees in several radish varieties by the practice of sowing in early spring.

View full abstract

Correlation between heading date or air temperature in ripening period and weight of grains were investigated, due to materials get from the experiment of weather influence for rice yield conducted by the agricultural experiment stations which lie in the Tohoku Region, studying cool weather injuries in rice. Means of cultivation in these station were much the same and all seeds examined were produced from the national experiment station "Oushikenchi". The result of the investigation are as follows. a) Rice grains in the Tohoku Region's weather condition easy to reduce its weight as delay of heading and fall of air temperature in the ripening duration. b) Mean temperature of maximum and minimum in 40 days after heading needed for the full developement of grains are about 22°C, and when the temperature goes down to below 20°C weight of grains considerably falls.

View full abstract

This report relates on the heading periods of rice varieties all over Japan proper. Every year from 1931-1940, all heading periods of rice varieties in variety tests in all perfectual agricultural experiment stations all over Japan proper are sumed up in a table, and from that the yearly fluctuations curves of heading period of rice varieties all over Japan proper are made. The numbers of rice varieties summed up in this calculation are about 4000 varieties every year The most early day of heading is July 19th. and the latest day of heading is September 25th. and the curves displays a monomodal asymmetric curves. The mode of the distribution curve of heading period is exceptionally early in 1931 and 1934, the bad year. And in the normal year the mode is at 7th-10th of September, and it coincide with the critical day for rice crop the 1st of September and the 10th of September. The mean of distribution is about 27th-3lst, Augast. And it alters about 3-4 days by the year. And it is early in the good year, and it is late in the bad year. The skewness of the curve is all negative except 1936, that is, the center of distribution is located to the right side of the curves. The heading period of Japanese rice plant is from 19th of July to 25th of September, and in normal years it is from 25th of July to 20th of September. From the point of view of all over Japan proper the late and early of heading period has negative correlation with the yield and stem length, and has positive correlation with the number of stems. As the reasons of early and late of heading period of rice the mean temperature from March to November, and the mean temperature of July, and the hours of sunshine has a negative correlations, and the volume of rain fall has a positive correlation. I am willing to continue this investigation now on. The numbers of rice varieties summed up in this calculation are about 4000 varieties every year The most early day of heading is July 19th. and the latest day of heading is September 25th. and the curves displays a monomodal asymmetric curves. The mode of the distribution curve of heading period is exceptionally early in 1931 and 1934, the bad year. And in the normal year the mode is at 7th-10th of September, and it coincide with the critical day for rice crop-the 1st of September and the 10th of September. The mean of distribution is about 27th-3lst, Augast. And it alters about 3-4 days by the year. And it is early in the good year, and it is late in the bad year. The skewness of the curve is all negative except 1936, that is, the center of distribution is located to the right side of the curves. The heading period of Japanese rice plant is from 19th of July to 25th of September, and in normal years it is from 25th of July to 20th of September. From the point of view of all over Japan proper the late and early of heading period has negative correlation with the yield and stem length, and has positive correlation with the number of stems. As the reasons of early and late of heading period of rice the mean temperature from March to November, and the mean temperature of July, and the hours of sunshine has a negative correlations, and the volume of rain fall has a positive correlation. I am willing to continue this investigation now on.

View full abstract

On the basis of the results of the experiment given in the Report Nos. I-VIII, the author made an analytical study of the resistabilities of paddy rice varieties to unseasonable low temperatures, at the same time showing the relations between them and the phenomenon of low temperature injury, and also making observations of the possibilities of breeding resistent varieties, and methods of determining the resistabilities to low temperature injury. A summary of our findings is given below. (1) The mechanism of the resistability of a paddy rice variety to unseasonable low temperature is very complex, a number of factors taking part in it, but it can be roughly divided into insensibility to cold and insensibility to the blast disease, or analyzed into the three factors of environmental adaptability, resistability to cold and resistability to the blast desease. It is thought that resistability to coid and environmental adaptbility take part in insensibility to cold, while resistability to the blast disease and environmental adaptability go into insensibility to disease. (2) The mechanism of the resistability of paddy rice to cold varies according as its organs and tissues differ during the process of its growth. The function of forming primordia of stamens and pistils, function of forming generative cells and matured pollens etc. are remarkably sensitive to injury by cold, and there exists an inter-varietal differenee in this resistability to cold. (3) The insensibility of a paddy rice variety to cold is determined by a combination of the difference in the degree of decline of the physiological function of the plant body due to low temperature and the difference in the resistability of the organs and tissues to cold, and the insensibility of a paddy rice variety to cold in its broad sense can be represented, for pnctical purposes, by the insensibility to cold at the stage of formation of generative cells. (4) The mechanism of injury by cold and that of injury by cold water in a paddy rice variety is not always identical, but generally speaking, insensibility to cold and insensibility to cold water among varieties are practically shown in a parallel relation (Ref. Table 1). The inseiasibillty of a paddy rice variety to cold water which is expressed in injury to fertilization or per-centage of decrease in the weight of refined grains due to long-term irrigation with cold watet can, from a practical point of view, be considered as showing its insensibility to cold. (5) There exists an inter-varietal difference in the degree of decline of the physiological function of the plant body due to adverse weather, i.e. in the environmental adaptability, which is thought to play an important role in the insensibilities of a paddy rice variety to cold and to disease. (6) The injury of a paddy rice variety due to unseasonable low temperatures manifests itself as the composite results in which its resistability to low temperature and cultural environments take part. We made an inquiry into this relationship, about the main varieties used in this study by comparing the resistabilities to low temperature as shown by an experimental inquiry with the injury that actually took place in unseasonable low temperature years. (7) Different genetic factors take part in the iasensibilities of a paddy rice variety to cold and to blast (Ref. Table 2), and therefore it is thought possible to breed a variety possessed of these two characters, i.e. a variety both highly adaptable to environments and highly resistant to cold and to blast. (8) Different genetic factors take part in the resistability to unseasoual low temperatures, time of maturation and yieldability of a paddy rice variety (Ref. Table 2), and it is inferred therefrom that the breeding of a variety highiy yielding and highly resistant to unseasonal low temperatures is possible. (9) As a method of determining the cold resistant variety in plant-breeding experiment, a comparative study of the per-cent

View full abstract

1. It was reported formerly by the authors, that the following changes were observed as the after effects of stamping:- a) Reduced plant height, numerous stems and leaves and deepend roots are the morphological features of the stamped plants. b) Observation on the epidermal cells and stomata of the stamped leaves showed reduction in their size and increase in the stomata frequency. And other physiological characteristics which can be seen in the xerophyte plant. c) Spikelet differentiation was delayed by the stamping at the seedling stage and the growth and development of the spike which had been differentiated before the treatment was checked. 2. Bending or harming severally enforced on the leaves or stems resulted these morphological and physiological changes. The checking effect on growth was distinct in harmed plant, and increase of stems, in bent one. 3. Plants showed more amount of transpirated loss of water caused by bleeding water from the wounds by harming or bending treatments. 4. The increased content of nitrogen, but none in the total carbohydrates, was indicated by chemieal analysis of the top parts of plant caused by stamping. Leaves gained weight per unit of ared when they were bent at the base of blade. 5. By these facts, the mechanism by which the effeets of stamping were brought suggested to be as follows:- a) Stamped leaves lose more water than usual on acoount of the bleeding from their harmed portions; and ascent of water is somewhat checked by the bending; whereupon the tops of plants fall into the condition of temporary shortage of water. Hence, the stamping turus a plant into xerophytic of its feature. b) Increase of the root number and length seen in the stamped plants is attributed to the effects of gained loss of water from the top parts which calls for more absorption of water nevertheless the treatment concurs hardened soil which restrains root growth to some extent.

View full abstract