A series of experiments was conducted on the direct sown rice plant cultivated under upland condition in early, ordinary and late seasons, respectively, by varying the nitrogen application amount as basic manure as well as the seeding density. Amount of nitrogen applied in three plots was 0.3 kg/a, 0.6 kg/a and zero, respectively. Number of grains sown in each plot which was divided into four was 200, 400, 600 and 800 per m² respectively. In the case of ordinary cultivation another pot was laid out in which dicyandiamide was added to nitrogen. Observations were continued up to the 4th leaf stage on the nitrogen content of soil and the growth of rice plant. Results obtained are as follows. 1. In any growing season, the nitrogen content of soil depended on the amount of nitrogen applied, but the loss of nitrogen applied as basic fertilizer was quite heavy due to nitrification. 2. Nearly total disappearance of the 0.3 kg/a basic nitrogen manure occurred in the 1st to 2nd leaf stage with the early season rice plant, in the 2nd to 3rd leaf stage with the ordinary season and in the 3rd leaf stage with the late season. 3. Nitrification was checked by addition of dicyandiamide to ammomium sufate, which re resulted in a remarkable effect on the growth of rice plant. 4. Growth of the rice plant improved in proportion to the amount of nitrogen applied in basic dressing but there is little difference in growth between the non-nitrogen and 0.3 kg/a plots, while a big difference between the 0.3 kg/a and 0.6 kg/a plots. Dry matter weight of individual plants decreased as the seeding density increased, and the same tendency was found with the nitrogen content of rice plant.

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Productivity of early, ordinarily and late sown rice plants cultivated under upland condition was compared with that of early and ordinarily sown ones grown under water-logged condition. 1. Possibility of productivity increase was shown only by the early grown rice plant under upland condition and in this case a vigorous growth in the early stage leading to the enlargement of the leaf area is considered to be a major factor of the yield increase. 2. Increase of the seeding density and amount of nitrogen fertilizer resulted in a little increase in productivity in the case of direct sowing under upland condition while in a slight decrease in the case of direct sowing under water-logged condition. 3. For the late cultivation, it is the most important to prevent the cool weather damage by making heading occur within a certain time limit and also the increase of the number of panicles per area depending upon the main stem is helpful for yield increase. 4. In the case of the late sowing (on August 1, 1963) of Eiko, an extremely early variety, at the rate of 600 grains per m², a yield of 34.6 kg/a of brown rice was obtained.

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This experiment was conducted on the direct sown short-period rice plant cultivated under upland condition in different seasons (early, ordinary and late), to know from the viewpoint of dry-mater production the effect of the upland period growth on the growth and yield after the water-logged period. 1. The rate of dry-matter increase per field area in the water-logged period through the early ear-forming stage was almost completely determined by the leaf weight index, and the higher the leaf weight index in the water-logged period, the higher the leaf weight index and the dry-matter increase rate in the above mentioned period. 2. In the period from early ear-forming stage through heading stage, the effect of the leaf weight index on the dry-matter increase rate was smaller than in the previous period in the case of early season cultivation while completely lost in the cases of ordinary and late cultivation. The effect of the net assimilation rate on the dry matter increase rate was not found either. There was a high positive correlation recognized in the leaf weight index between the water-logged period and the above mentioned late growth period. 3. In both periods mentioned above, the increase of the leaf weight index led to a decrease in the net assimilation rate. Since the relative growth rate was almost entirely governed by the net assimilation rate, difference in the top dry weight in the water-logged period decreased along with the advance of growth but did not disappear totally. 4. In the ripening stage there was no correlation found between the leaf weight index and net assimilation rate while they each had a positive relation with the dry-matter increase rate. Also the higher the leaf weight index in the water-logged period, the higher the leaf weight index and the dry-matter increase rate in the ripening stage. 5. It has been recognized that the dry-matter increase rate of the panicle in the ripening stage is largely determined by that of the top part in the same stage and the increase of the leaf weight index in the early growth stage is closely related to the high yield.

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The present work was planned to obtain further information as to the effect of salinity on rice plants, particularly from the view point of osmotic adaptability of rice plants to saline solution, using a variety "Eiko" as material. The plants were grown in culture soltion in a green house for about 3 weeks. Then they were subjected to hypertonic solutions containing 0.1, 0.2, and 0.3 M sodium choride, respectively. The osmotic pressures of plant saps obtained from rice plants and of culture solutions were measured by cryoscopic method. The amount of choride in expressed saps of rice plants was determined by Volhard's method. When the rice plants were treated with saline solution, the rolling of leaves and the browning of leaf-tips were recognized. At the same time the water contents in salt-treated rice plants decreased remarkably. On the other hand, the increase of the amounts of chloride in the experessed sap of rice plants treated with saline solution was recognized. Simultaneously this increase caused in turn the increase of osmotic pressure of rice plants. It seems quite clear from these facts, therefore, that the rice plants have high adility to adjust their osmotic pressures according to that of the surrounding solution. When the experimental plants were transferred from the saline solution to basic solution, the water and chloride contents and osmotic pressure of the expressed sap recovered to each original level which was observed in the basic nutrient solution, whithin a limit of saline concentrations used.

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This experiment was carried out to investigate the changes of carbohydrates and nitrogenous compounds in kernel after flowering and the relation between the changes of these compounds and baking quality was discussed. Varieties used were soft wheat (Shinchunaga) and hard wheat (Norin No. 75). Dry weight of 100 kernels was maximum on the 33rd day after flowering and then decreased. Moisture percentage of kernel decreased with kernel development. But the moisture percentage of kernel of hard wheat (Norin No. 75) was almost always lower than that of soft wheat (Shin-chunaga). Carbohydrates were accumulated rapidly in kernel as a form of non-reducing sugar during the first 9 days after flowering. But, the content of sugars decreased rapidly after the 9th day when rapid increase of starch began. And the content of sugars increased for a short time since the 24th day after flowering. The content of insoluble protein-N in kernel increased rapidly until the 30th day after flowering. Then it remained nearly constant. The content of soluble protein-N and residual-N (probably polypeptides) increased rapidly after the 30th day after flowering. The rate of accumulation of insoluble protein-N in kernel of hard wheat (Norin No. 75) was faster than that of soft wheat (Shinchunaga), and the increase of content of the soluble protein-N in hard wheat (Norin No. 75) began from earlier stage than soft wheat (Shinchunaga). Considered from the results of dry weight of 100 kernels, the content of carbohydrates and of nitrogenous compounds, it may be concluded that the optimum time of harvest to obtain higher yield and better quality is about the 30th to 33rd day after flowering, or about the 37th to 40th day after heading.

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In the previous paper Tanaka, one of the writers, reported the developing process of the lateral roots growing from the main root in the leguminous crop plants, which according to its developing condition could be classified into three types, namely alfalfa, vetch and intermediate types. In this report the main roots of crops belonging to those three types were anatomically observed and compared with each other. 1. In alfalfa type, initials of lateral roots are formed adjoining each other, and also appear at varying times (Fig. 1, B-I∼VI, C). Consequently, the formation of meristems for rooting was recognized on the main root (Fig. 2, D-I, II). 2. The development of the medullary ray of the root differ with the crop and type (Fig. 3, E-I∼V), and is considered to have a close relation with the development of lateral roots. 3. It was also recognized that the secondary thickening growth of the root also differs with the crop and type (Fig. 4). Generally, the alfalfa type showed a tendency to grow more in thickness than the vetch type.

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In the previous paper, it was recognized that intimate correlations, positive or negative, were found among factors concerning photosynthetic activity, such as potassium per cent, nitrogen per cent., respiratory rate and carbohydrate content in the leaf, but it was not blear that which one of these factors showed a true correlation with photosynthetic activity. Therefore, the present study has been attempt to elucidate the factors showing a true correlation with that. Various experiments shown in table 2 and table 4 were carried out and photosynthetic rate, three major nutrient elements content and carbohydrate content in the leaf were determined. 1) Partial correlation coefficients were calculated between the factors and photosynthetic rate. A high significant partial correlation was found only between carbohydrate content and photosynthetic rate, all the other correlations proving insignificant. 2) In order to evaluate the influence of carbohydrate accumulation on photosynthetic rate, the diurnal changes of both photosynthesis and carbohydrate content in the leaf were observed. The photosynthetic rate showed no marked diurnal fluctuation through morning to afternoon, while the carbonhydrate content showed higher values in the afternoon than in the morning. It is considered from this that carbohydrates accumulation does not exert, at least, direct inhibitory influence upon photosynthetic rate. On the other hand, in cases such as plants were cultured under differential nutrient conditions or at different growth stages, those leaves highly active in their photosynthesis were shown to be low in carbohydrate content, and those less active leaves were shown to be high in carbohydrate content. From these it was considered that the velocity of removing photosynthates from leaves might be more important factor for photosynthesis rather than carbohydrate accumulation itself. 3) The growth of tuber which is the largest acceptor (sink) of the photosynthates in the sweet potato plant at later growth stage, was inhibited by exposing tubers to light. The treated plant was depressed in the photosynthetic rate and increased in starch content of leaves owing, presumably, to the restricted translocation of photosynthates from leaves. Farthermore, in another experiment, there was a parallel relation found between the net assimilation rate and the dry-weight increase of tubers. 4) All the above mentioned results suggest the following hypothesis : since the accumulation of photosynthates in the leaf does not bring any great change in the diurnal course of photosynthesis of sweet potato leaves, it is not accumulation of photosynthates in the leaf but the rate of movement of photosynthates from leaf (source) that is essential in controlling photosynthetic rate from inside. According to this hypothesis, to promote the growth of tuber means to increase the rate of translocation of photosynthates from leaves, and this, in turn, will give an accelerating influence to photosynthetic activity. Thus, the fact that potassium content in the leaf had a very intimate correlation with photosynthetic rate can be explained primarily by the nutritional effect of potassium for promoting the tuber growth.

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A lot of experimental results indicates that an abundant application of potassium to the sweet potato leads to an increased tuber yield, though it is less effective to the growth of top. Potassium contained in the leaf of sweet potato is quite effective for maintaining photosynthetic activity, thereby contributing to increase the dry weight of the plant. However, it is unknown why potassium promotes the growth of tubers. Therefore, experiments were carried out by gravel culture or by field culture to acquire the information concerning the relationship between potassium and growth of tubers. The sweet potato plants cultured with various cultural solutions showed an intimate relationship between their tuber weight and K₂O/N ratio in the tuber. A high K₂O/N ratio in the tuber was combined both with a low ratio of water soluble nitrogen to total nitrogen content and with a low total nitrogen concentration in fresh tuber, this in turn, showing an intimate negative correlation with the net assimilation rate (Fig. 4). Also, to increase the potassium/nitrogen ratio in dosage of fertilizer gave a favorable influence upon both the increment of tuber weight and net assimilation rate. In the field experiments where much potassium applied, the effects of potassium were recognized in bigger tuber weight, higher, net assimilation rate and increased water content in tubers. Above mentioned results suggest that potassium participates in either the protein metabolism, or the hydration of tuber tissue or both, which are the most fundamental processes included in the growth of tuber in some way. It is, therefore, highly possible that the promotion of tuber growth by potassium may result in the promotion of photosynthetic activity through the accelerated translocation of photosynthates from leaves to tubers.

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Japonica, Indica and Java rice varieties as well as barnyardgrasses ("Tainubie" : Echinochloa crus-galli Beauv. var. oryzicola Ohwi and "Keinubie" : Echinochloa crus-galli Beauv. var. caudata Kitagawa) were tested as soiling crops under both lowland and upland conditions, but Japonica upland varieties were tested singly under upland condition. The upland condition was rather swampy by the leaking water from the adjacent paddy field. The results were as follows (Fig. 1 and 2). The total yield of three clippings was slightly more under lowland condition than upland condition except "Tainubie". The order of the yield among species was almost the same under lowland and upland conditions. Namely, " Keinubie "ranked the first, "Tainubie", "Tetep" (Indica) and "Danahara" (Java) came to the second, "CO 13" (Indica) and "Nepby" (Java) came to the third almost the same yield as "Shioji" and "Tsurugiba" (Japonica) and upland varieties (Japonica) came to the last. As for the yield of each clipping under lowland condition, "Keinubie" was the top and "Tainubie" was the last at the first clipping, "Keinubie" and "Tainubie" were superior than the others at the second clipping and there were not so remarkable differences among species at the third clipping. Under upland condition, "Keinubie" was the top and there was little difference among others at the first clipping, "Tainubie" was the highest and upland rice was the lowest at the second clipping, and barnyardgrasses and paddy rice were higher than upland rice at the third clipping. More difference was seen between the yield of each clipping in "Tainubie" than in other species. Nitrogen content of rice plant was higher than barnyardgrasses and under upland condition all species showed a higher nitrogen content than under lowland condition. Cosequently the yield of crude protein was almost the same between barnyardgrass and rice although the former gave a higher fresh or dry yield than rice. All the species gave a higher yield of crude protein under upland condition than under lowland condition. Cows seemed to prefer barnyardgrass to rice plant depending, perhaps, partly on the former's lower silica content than the latter, but rice plant was also proved to be a good roughage by the digest test using sheep. From these results it can be said that ride and barnyardgrass are suitable as roughages to be cultured on an in drained or swampy land, and that, among the varieties used in this experiment, "Keinubie", "Tetep" and "Danahara" are considered to be most appropriate.

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On the existence of any connection between the leaf blade and the tillering bud, studies were made by means of removal of leaf blade of different leaves or absorption of gibberellic acid (GA) through different leaves. In 1958, the leaf blade of the 4th (plot A) or the 3rd (plot B) leaf or both of them (plot C) were removed at seedling age 4. In 1959, the 5th (plot A) or the 4th (plot B) or both of them (plot C) were removed at age 5. GA was absorbed through the 4th or the 5th leaf blade at seedling age 5, in 1959. After the treatment, dry weight of plant, both growth in length and differentiation of leaves of each tillering buds were traced. The removal of leaf blade retarded the growth of each tillering bud as well as accumulation of dry weight of plant (fig. 1-fig. 4, table 3). When removed at seedling age 4 (fig. 3), the removal of the 3rd leaf or the 4th leaf or both of them caused similarly the retardation of the 2nd, 3rd and 4th tillering buds especially the 3rd and 4th ones. In the case of removal at seedling age 5, the removal of the 4th, or the 5th or both of these leaves retarded similarly the 3rd, 4th and 5th tillering buds especially the 4th and 5th ones. Moreover, the retardation in the growth of these tillering buds were nearly proportional to the inhibition in accumulation of dry matter in whole plant (table 4). That is, which tillering bud is retarded is recognized to be not due to which leaf is removed, but due to when leaf is removed. The absorption of GA through the 4th or the 5th leaf blade inhibited the growth of tillering buds. Also in this case, difference in leaf treated did not cause the difference in the situation of tillering bud inhibited (table 6). From these results, the growth of tillering bud is recognized to be not related to some particular leaf of main stem but related to all of leaves. In addition, when treated at seedling age n the n-th and (n-1)th tillering buds were affected sensitively.

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Many studies have been conducted on the problem of lodging in cereals, and in these studies many characters concerning to lodging were investigated and several techniques for determining lodging resistances have been proposed. In general, many past studies have been projected in physical property of culms, and techniques for measuring of physical properties. As culm are constituted of metabolic products, it will be necessary to have the physiological consideration on the stiffness of culms. The stiffness of culm is considerded to be the important physical character for lodging resistance of barley. The purpose of this study is to make clear the mechanism of the stiffness of culms. A brittle culm variety, Sekitorisai-No. 1, and a stiff culm variety Haganemugi (Hordeum sativum, JESSEN) were used to compare the relation between culm development and dry matter production. It was observed that the distribution ratio of dry matter to culm was higher in the stiff culm variety than in the brittle variety. The growth of culm rapidly proceeded before the heading stage, and the constitution of internodes were regarded as that the upper internodes were long and the basal ones short. The tendency was more apparent in stiff culms.

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The breaking strength and hardness of culms in barley were measured to research the physical properties of culms. Bending moment (M), bending stress (σ), and moment of inertia (I) were calculated from the breaking strength, culm diameter, and thickness of culm tissues. Consequently, the bending moment value reached the maximum in 2 weeks after the heading stage, and afterward it gradually decreased. The bending moment and hardness in Haganemugi (stiff culm variety) were apparently higher than in Sekitorisai-No. 1 (brittle culm variety), and as the reason it was considered that more sufficient growth of culms was given in the former. The hardness was unhomogeneously in each part of internodes, and it showed the lowest value at the just upper part of a node.

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Haganemugi and Sekitorisai-No. 1, 6-rowed barley varieties, were used and the effects of leaf sheath and turgor pressure on culm strength were studied. Generally, the leaf sheath efficiency for culm strength was about 10 to 70 %, and it was higher in the upper internodes than in the basal. On the other hand, the leaf sheath efficiency for culm strength of Haganemugi (stiff culm variety) was lower than that of Sekitorisai-No. 1 (brittle culm variety). The turgor pressure efficiency for culm strength was about 10 to 40 %, and it gradually decreased with the growth of culms. The efficiency value in Sekitorisai-No. 1 was higher than in Haganemugi.

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The development of culms in Sekitorisai-No. 1 brittle culm variety) and Haganemugi (stiff culm variety) was examined from the standpoint of chemical composition. Total nitrogen, protein-nitrogen, cellulose, total sugars, silica, calcium, magnesium, and potassium were quantitatively determined, the following results were obtained : the increase in total nitrogen and protein-nitrogen content was remarkable before the culm elongation stage, while the increase in cellulose was after the heading stage. On the other hand, a large amount of silica was recognized in culms of Haganemugi, and in leaf sheath of both varieties. It was considered that the amount of calcium and magnesium in culms was not closely related to the stiffness of culms. It is necessary for the stiffness of culms that amount of protein and cellulose in culms are sufficient enough for culm development and silica for silicified cell formation.

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Development in culms of Sekitorisai-No. 1 (brittle culm variety) and Haganemugi (stiff culm variety) was influenced by shading during 4 periods (culm elongation stage, heading stage, milk stage, and paste stage). The solar radiation was diminished to 50 % of non-treatment. Consequently, dry matter production was lowered and the injurious effects on the stiffness of culms were recognized in heading stage treatment. The treatment in paste stage effected slightly to culm growth, and then lodging was not observed in the fields at all. The effect of treatment were more slight in Haganemugi than that in Sekitorisai-No. 1. Generally, the bending moment was lowered by shading, and the tendency was paralleled with the progress of dry matter production.

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