All issues
Volume 47, Issue 1
Displaying 1-23 of 23 articles from this issue
- |<
- <
- 1
- >
- >|
-
III. The relation between deterioration and deviation of individual grain moisture in mass stored rough riceKazuhisa KATO, Shinzo YAMAZAKI1978 Volume 47 Issue 1 Pages 1-5
Published: March 30, 1978
Released on J-STAGE: February 22, 2011
JOURNAL FREE ACCESS1. The moisture content of individual paddy on the matured panicles had a wide distribution from 15% to 29%. In the panicles from a sunny environment, the moisture content had a parallel relation with the stage of maturity; in the rainy environment, the hanging grains on standing plants had high moisture content. The frequency of moisture class differed with weather conditions (Fig.1. 2).
2. When the fresh rough rice was dried by heated air, the high moisture grains were dried rapidly, and the mean moisture content decreased in relation to narrowing of its distribution. The different moisture of paddy was equilibrated rapidly in the initial period, and slowly in the later period during storage, but they had unequal moisture among individual grains after 10 days (Fig.3. 4).
3. The relation between the individual grain moisture and its term until deterioration was only a few days at above 23%, the grains of 19%-23% were deteriorated after 15 days, and the moisture content of grains which changed to spot or opaque within 2 months was above 19% (Table 2).
4. The humidity around the grains equalized with the high moisture of the paddy swiftly; the paddy of 19.3% mean moisture content was equalized at 90% of relative humidity (RH), of 20% at 93% of RH, of 22.3% at 97% of RH, of 24.7% and of 30% was saturated humidity (Fig.5).
5. The moisture content of paddy which prevented deterioration in the temporary storage was less than 19%. As the newly threshed paddy has a wide deviation in individual grain moisture, if the mean moisture content is as little as 19%, the storage of paddy which narrows the deviation by forced heated air is preferable.View full abstractDownload PDF (980K) -
Tetsuo SATAKE, Shouichi YOSHIDA1978 Volume 47 Issue 1 Pages 6-17
Published: March 30, 1978
Released on J-STAGE: February 22, 2011
JOURNAL FREE ACCESSResponse of three typical varieties to high temperature at different stages of growth and on flowering day was studied in naturally lighted rooms of phytotron.
Spikelet sterility was induced by high temperature largely on flowering day. Within the flowering day, high temperature during anthesis time was the most detrimental to spikelet fertility, high temperature right before anthesis being the second most. High temperature after anthesis had little influence on spikelet fertility; when spikelets were exposed to high temperature one hour after anthesis, their fertility was normal. The major causes of high temperature-induced sterility were attributed to disturb pollen shedding and decreased viability of pollen grains, resulting in decreased number of germinated pollen grains on a stigma. The ability of pistil to be fertilized appeared to remain unaffected by high temperature up to 41°C. When spikelets were exposed to high temperature for 8 hours a day, the critical temperature to induce 20% sterility was 36.5°C for N22, heat tolerant, and 32°C for BKN6624, heat susceptible. At 38°C, the critical duration to induce 20% sterility was 4 hours for N22 and 2 hours for BKN6624. At 41°C, 2 hour treatment induced about 90% sterility in all the three varieties. Dihiscence characteristic of anther that allows good pollen shedding and early morning anthesis that avoids high temperature were considered two important characteristics for heat tolerance of rice varieties at flowering.View full abstractDownload PDF (4525K) -
Shin-ichi SAWADA1978 Volume 47 Issue 1 Pages 18-24
Published: March 30, 1978
Released on J-STAGE: February 22, 2011
JOURNAL FREE ACCESSLeaves were sampled at intervals from early morning to evening from wheat seedlings grown in different seasons, and their photosynthetic activities were determined under the constant and normal measurement conditions. In summer, the photosynthetic activity was continuously depressed from the early morning to midday, and reached less than half that obtained early in the morning. In the afternoon the depressed activity slightly recovered. In the plants grown in spring, autumn and winter, the photosynthetic activity kept constant levels all day, and the midday depression observed in summer was not recognized.
The midday depression of photosynthesis in summer was not observed when the plants were defoliated on the day before the measurement of photosynthesis, leaving only the second leaves. The cause of the depression could be ascribed neither to the stomatal closure, water deficiency nor accumulation of sugars in leaves.
The author owes his thanks to Prof. Y. MURATA, Faculty of Agriculture, University of Tokyo, for going through manuscript, and to late M.S. I. FURUHATA for his technical assistance.View full abstractDownload PDF (1038K) -
III. Physiological properties of dormant Bupleurum falcatum seedsYoshie MOMONOKI, Yasuo OTA, Tadao HASEGAWA, Takeshi TANABE, Toyohiko K ...1978 Volume 47 Issue 1 Pages 25-30
Published: March 30, 1978
Released on J-STAGE: February 22, 2011
JOURNAL FREE ACCESSThis investigation was conducted to make clear the physiological properties of dormant Bupleurum falcatum seeds with an emphasis upon the metabolism of respiration. The results obtained are as follows;
1. The rate of water absorption in dormant and non-dormant Bupleurum falcatum seeds showed the same tendency, however at 15°C the absorption rate in dormant seeds was rather higher than non-dormant ones. It seems possible, therefore, that the mechanism of dormancy in Bupleurum falcatum seeds was not due to water absorption in seeds.
2. In the case of dormant seeds, the absorption of oxyge in dry seeds was high as compared with those non-dormant ones, at the same time the respiratory quotient was lower in dormant seeds.
It may be suggested that the seed coats act as an absorbing layer of oxygen and thereby help to maintain low oxygen tension within the seeds, thus inhibiting germination.
On the other hand, the respiratory rate of germinated Bupleurum falcatum seeds was much higher than non-germinated ones, while the respiratory quotient in non-germinated seeds was lower than germinated ones.
3. Under low oxygen tension, non-dormant seeds usually produced more amount of ethyl alcohol than dormant seeds.
While the formation of ethyl alcohol in non-dormant seeds under high oxygen tension was lower than it dormant seeds.
From the facts, it might be possible to consider that non-dormant Bupleurum falcatum seeds had the control of respiratory pathway under both aerobic and anaerobic conditions.
4. The absorption of oxygen by dormant seeds soaked in water was much higher than that of non-dormant ones.
5. The germination of dormant Bupleurum falcatum seeds was stimulated with hydrogen peroxide treated at the concentration of 0.3 percent, and the hydrogen peroxide treated seeds showed respiratory rate same to the germinated ones.View full abstractDownload PDF (1025K) -
I. The effects of root cutting treatments on the early growth of rice seedlings after transplantingYoshinori YAMAMOTO, Kazumi MAEDA, Kisaburo HAYASHI1978 Volume 47 Issue 1 Pages 31-38
Published: March 30, 1978
Released on J-STAGE: February 22, 2011
JOURNAL FREE ACCESSThis study was undertaken to clarify the effects of root cutting. Plots and experi mental procedures were shown in Table 1. Top and root growth observed during 4 weeks after treatments were summarized as follows:
1) Immediately after transplanting, leaf wilting was not observed in C-, 5 cm-and 3 cm-plot, but leaves were wilted in 1 cmplot and especially wilted in 0 cm-plot. And in these plots, leaf wilting recovered following the appearance of new roots about 3 days after transplanting, with slight death of the leaves (Fig.1). However, develop ment of tillers during the 1st week was very suppressed in all plots, whether the leaves were wilted or not (Fig.3B).
2) There were no significant differences in topand root growth between C-plot and 5 cm-plot or between C-plot and 3 cm-plot, except total leaf area and dry weight during the 1st to 2nd week after transplanting (Figs. 3 and 5). Moreover, it was note-worthy that 5 cm- and 3 cm-plot were superior compared with C-plot in plant height, root number and dry weight of top and root at the 4th week after transplanting (Table 2).
3) In 1 cm- and 0 cm-plot, the increase of tillers during the 2nd week after trans planting was fewer than C-plot. And so, top androot growth of these plots were signi ficantly inferior to C-plot over 4 weeks after transplanting (Figs. 3 and 5). Further, in comparison with the 1 cm-plot and 0 cm-plot, the plants in 1 cm-plot showed signi ficantly greater growth than the plants in 0 cm-plot. This indicates that the short remainnings of roots on the seedling at transplanting-time are very effective for the recovery from the transplanting injury.
4) During the 1st week after transplanting, dry matter distribution ratio to root was higher than any other time in all plots, and besides, higher in order of the strength of root cutting treatments (Fig.6). But, following the development of tillers, the ratios to leaf blade and/or leaf sheath and to stem increased. And so, the distribution ratio of dry matter to root decreased and the difference between treatments became little. As such a pattern of the distributions, percentages of each organ to whole plant and top/root ratio in dry weight was nearly equal in all plots at the 4th week after transplanting (Figs. 7 and 8).
5) From the above-mentioned results, it may be suggested that transplanting injury, mainly due to root cutting, will not occur if the seedlings have 3 cm or more roots in length.View full abstractDownload PDF (1417K) -
II. The effects of root cutting treatments on the contents of organic constituents and growth rate of the rice seedlings after transplantingYoshinori YAMAMOTO, Kazumi MAEDA, Kisaburo HAYASHI1978 Volume 47 Issue 1 Pages 39-47
Published: March 30, 1978
Released on J-STAGE: February 22, 2011
JOURNAL FREE ACCESSDried materials obtained in the experiment reported previously were used for analysis of nitrogen and total carbohydrate to see the effects of root cutting treatments on the contents of organic constituents of the rice seedlings after transplanting. And discussed the relationships between the organic constituents changes and the growth rate in the seedlings. The results obtained were summarizedas follows:
1) In the 1 cm- and 0 cm-plot, leaves wilted immediately after transplanting, but their water contents recovered to near the same content as in C-plot at the 1st week after transplanting (Table 1).
2) At the 1st week after transplanting, nitrogen concentrations of the top organs decreased in all plots. However, total carbohydrate concentrations of each organ, particularly in leaf sheath and stem increased, except 0 cm-plot (Fig.1). But, in general, there was no definite tendency in the effects caused by treatments during 2 weeks after transplanting. And, the concentrations of both constituents of each organ in 5 cm-and 3 cm-plot changed to near the same values as in C-plot, thereafter. On the other hand, in 1 cm- and especially in 0 cm-plot, nitrogen concentration, in particularly protein-N, was higher and total carbohydrate was lower than those in C-plot, because of nitrogen absorption rate increased linearly in these plots (Fig.3).
3) Total nitrogen and carbohydrate accumulation of each organ changed in parallel with dry matter production in all plots (Fig.2). But, nitrogen accumulation rates in 1 cm- and 0 cm-plot were higher than dry matter production rate since the 2nd week after transplanting, compared with C-plot. Therefore, C/N ratio of whole plant became in order of C≅5 cm≅3 cm > 1 cm >0 cm-plot (Fig.4). These results indicate that the plants in 0 cm- and 1 cm-plot are physiologically more active than the ones in other plots after taking roots.
4) RGR during the 1st week after transplanting was lower in order of the strength of root cutting treatments, mainly due to the difference of NAR by the degree of leaf wilting (Fig.5). However, it was noteworthy that RGRs in 5 cm- and 3 cm-plot changed near the same values as C-plot, on the other hand, RGRs in 1 cm- and 0 cm-plot were higher than those in other plots since the 3rd week after transplanting. It was suggested that these results were brought by the differences in NAR and RLGR but not in LAR, due to the difference of nitrogen concentration in the whole plant. And RGR showed close correlations with NAR and RLGR (Fig.6).
5) From the above- mentioned results, it was concluded that there was no dif ference between the normal seedlings and the ones having 3 cm or more roots in length, because both were almost the same in contents of organic constituents and RGR during 4 weeks after transplanting.View full abstractDownload PDF (1623K) -
II. Comparison of early growth of cropsKatsuyoshi NOGUCHI, Kanenori NAKAYAMA1978 Volume 47 Issue 1 Pages 48-55
Published: March 30, 1978
Released on J-STAGE: February 22, 2011
JOURNAL FREE ACCESSThe experiments reported here were designed to compare early growth on 4 species. of crops and 5 species of weeds typically in the Kanto plain. The experiments were conducted by changing the seeding time from April to July in 1971-72 years.
1. The plant height or main stem length on 30 days after seeding was the largest in corn, medium in upland rice and soybean. These were superior to weeds at the condition of the average of daily mean air temperature 13-25°C. Peanut was the smallest of crops, was equal to large crab-grass (Digitaria adscendens HENR.) at the condition of about 20°C, and was inferior to large crab-grass, common purslane (Portulaca oleracea L.) and Chufa (Cyperus microiria STEUD.) at the condition of about 25°C. The amount of extension of each plants was larger at high temperature condition, and the rate of extension by rising up the temperature was nearly equal in crops and the rate of weeds except Polygonum nodosum PERS. was larger than that of crops.
2. The top dry weight on 30 days after seeding was the largest in peanut, medium in corn and soybean. These were suprior to weeds at the condition of 13-25°C. Upland rice was the smallest of crops, was inferior to Polygonum nodosum PERS. at the condition of about 20°C, and inferior to Polygonum nodosum PERS., common purslane and large crab-grass at about 25°C. The amount of top dry weight was larger at high temperature condition, and the rate of increase in top dry weight of weeds by rising up the temperature was larger than that of crops. The high positive correlation between the top dry weight on 30 days after seeding and seed weight was observed.
3. The amount of increase in top dry weight of crops during 30 to 50 days after seeding was the largest in corn, medium in soybean and peanut, the smallest in upland rice. That of weeds was the largest in Polygonum nodosum PERS. which was superior to soybean, peanut and upland rice, besides superior to corn under about 22°C. That of large crabgrass, common lamb∋s-quarters (Chenopodium album L.) and common purslane was medium, but these were superior to that of upland rice. That of Chufa was the smallest of plants. The amount of increase in top dry weight was larger at high temperature condition, and the rate of increase by rising up the temperature was large in Chufa and large crabgrass.
4. As mentioned above, though growth of weeds from seeding to 30-40 days after seeding was inferior to crops, that of weeds from 30-40 days to 50 days after seeding was large, and competitive capasity to crops was extreamly elevated, especially at the condition of above 18-20°C. So, the weed control in early time is necessary, especially at higher temperature.View full abstractDownload PDF (1370K) -
III. Effect of shade on growth of weedsKatsuyoshi NOGUCHI, Kanenori NAKAYAMA1978 Volume 47 Issue 1 Pages 56-62
Published: March 30, 1978
Released on J-STAGE: February 22, 2011
JOURNAL FREE ACCESSEffect of shade on growth of weeds was examined in 1973 and 1974. The weeds used in this experiment were large crab-grass (Digitaria adscendens HENR.), Chufa (Cyperus microiria STEUD.), common lamb's quarters (Chenopodium album L.), Polygonum nodosum PERS. and common purslane (Portulaca oleracea L.). Upland rice was used for reference.
1. Plant height of large crab-grass and Chufa increased at 75 and 84% shade condition, but was extremely inhibited at 93% shade compared with the no shade control. Main stem length of common lamb's quarters and P. nodosum PERS. was equal to the control at 75% shade, but was inhibited at 84% shade. That of common purslane was inhibited at 75% shade.
2. The tillers or branches of each plants decreased in number at all shade conditions. The effect of shade was not serious to common lamb's quarters, intermediate to large crab-grass and P. nodosum PERS., and serious to common purslane and Chufa. Very few tillers or branches of each plants were produced at 93% shade.
3. Top dry weight of each plants decreased at all shade conditions. This decrease was the most remarkable in common purslane and Chufa which were under 10% dry weight at 84% shade compared with the control, and P. nodosum PERS. was under 20% at same conditions. The effect of shade to large crab-grass, common lamb's quarters and upland rice was relatively small, and these plants were approximately 30% dry weight at 84% shade. At 93% shade, top dry weight of each plants was less than 2% compared with the control.
4. The period of heading, flowering and ripering was delayed generally at all shade conditions. The effect of shade was not serious to large crab-grass and P. nodosum PERS., but serious to another plants, especially to common purslane at growing period shade.
5. These results suggest that the amount of shade required to diminish greatly growth of common purslane and Chufa is more than 80%, that of P. nodosum PERS. is 80-90%, and that of large crab-grass and common lamb's quarters is more than 90%.View full abstractDownload PDF (1146K) -
III. Changes with growth in photosynthetic capacity and respiratory capacity of wheat standSeikichi KOH, Atsuhiko KUMURA, Yoshio MURATA1978 Volume 47 Issue 1 Pages 63-68
Published: March 30, 1978
Released on J-STAGE: February 22, 2011
JOURNAL FREE ACCESSUsing the data on diurnal changes of CO2 exchange and environmental factors obtained at each stage of growth in two experiments of 1969-70 and 1971-72, the authors investigated the developmental changes in photosynthetic capacity and respiratory capacity of wheat stand and their related factors. The results obtained are summarized as follows:
1. In both experiments, photosynthetic capacity of wheat stand (rate of net CO2 uptake per unit land area at the radiation level of 0.6 ly min-1 and at comparatively favourable temperatures) gradually increased in winter and then rapidly attained the maximum value (ca. 5 g CO2 m-2 hr-1) at flowering, and thereafter decreased rapidly (Fig.2).
2. The time trend in photosynthetic capacity was closely related with that of LAI throughout the whole growth period in the two experiments (Fig.2).
3. From the investigation of LAI-photosynthetic capacity curve, which was drawn from the data obtained at various times of growth, it was shown that photo synthetic capacity increased with increasing LAI in its range up to 4-5. Above this range of LAI, photosynthetic capacity did not seem to increase with increasing LAI (Fig.3).
4. According to two comparisons, namely, one between photosynthetic capacity of stand before and after heading, and the other between apparent photosynthetic rate of stand before and after ear removal, wheat ears contributed to the photosynthetic capacity of stand by 10-20% (Fig.3, 4).
5. The respiratory capacity of stand (rate of CO2 release per unit land area at 10°Ctemperature) increased with growth and attained the maximum value (ca. 0.4 g CO2 m-2 hr-1, 1969-70; ca. 0.3 g CO2 m-2 hr-1, 1971-72) at flowering or a little earlier, and thereafter decreased rapidly (Fig.2).
6. The respiratory activity of plant (rate of CO2 release per unit plant dry weight under 10°C temperature) remained relatively low and constant during winter. Then, the activity began to increase at the middle of February and attained the maximum value at the beginning or middle of March when the stand just started to grow vigorously, decreasing thereafter with the progress of growth (Fig.5).
7. In the former half of the growth period, the change with growth in respiratory capacity of stand was mainly attributed to that in total plant dry weight per unit land area, and in the latter half, to that in respiratory activity of plant (Fig.2, 5).View full abstractDownload PDF (1009K) -
IV. After-effects of low night temperature on daytime photosynthesis examined under controlled conditionsSeikichi KOH, Atsuhiko KUMURA, Yoshio MURATA1978 Volume 47 Issue 1 Pages 69-74
Published: March 30, 1978
Released on J-STAGE: February 22, 2011
JOURNAL FREE ACCESSAfter-effects of low night temperature on photosynthesis in the following daytime were examined under controlled conditions. The results obtained are summarized as follows:
1. Night temperature affected two aspects in daytime photosynthesis; one was the time required for photosynthesis to attain a plateau after the beginning of illumination and the other was the height of this plateau. Low night temperature lengthened the time and also lowered the plateau.
2. The above mentioned after-effects of low night temperature were most remarkable in case both air and soil temperatures were low.
3. Low air temperature alone also brought about the two kinds of after-effects.
4. Low soil temperature alone did not seem to bring about the after-effects. However, in case it combined with low air temperature, it strengthened the effect of low air temperature on the time required for photosynthesis to attain a plateau.View full abstractDownload PDF (1021K) -
V. The mechanism involved in an after-effect of low night temperatureSeikichi KOH, Atsuhiko KUMURA, Yoshio MURATA1978 Volume 47 Issue 1 Pages 75-81
Published: March 30, 1978
Released on J-STAGE: February 22, 2011
JOURNAL FREE ACCESSUsing potted wheat seedlings, the authors attempted to determine the mechanism of depression in apparent photosynthesis brought about as an after-effect of low night temperature. From the results obtained it was inferred: that the depression of apparent photosynthesis brought about as an after-effect of low night temperature is attributable not to the acceleration of photorespiration, but to the depression of photosynthesis itself, that the photosynthetic depression mentioned above is caused by both decreases in the stomatal aperture and the photosynthetic activity within mesophyll cells, and that the decrease in the photosynthetic activity within mesophyll cells is caused, at least in part, by a decrease in the activity of light reaction. However, the decrease in the photosynthetic activity was not always associated with a decrease in the activity of dark reaction.View full abstractDownload PDF (1240K) -
I. The relationship between photosynthesis and transpiration in corn leafTomoshiro TAKEDA, Hideki SUGIMOTO, Waichi AGATA1978 Volume 47 Issue 1 Pages 82-89
Published: March 30, 1978
Released on J-STAGE: February 22, 2011
JOURNAL FREE ACCESSIn order to clarify the relationship between photosynthesis and transpiration in corn leaf, the responses of photosynthetic rate, transpiration rate and water vapour transfer coefficient (D) to light intensity, leaf-air vapour pressure difference (leaf-air VPD) and leaf water content were measured by means of the chamber method. The assimilation chamber was designed to be controllable independently environmental factors such as light intensity, temperature, humidity and wind speed. The results obtained were summarized as follows;
1. The responses of photosynthesis, transpiration and D to light intensity were shown almost the same pattern when leaf temperature, leaf-air VPD and wind speed were maintained constant (Fig.3).
2. When only leaf-air VPD was changed under constant conditions of other factors, the relationship between photosynthesis and transpiration showed two types, namely negative and no correlations (Fig.5).
3. When only leaf water content was changed by means of detaching leaf blade from plant under constant environmental condition, the responses of photosynthesis, transpiration and D to leaf water content were shown almost the same trend (Fig.7).
4. Through analysing the results shown in 1, 2, 3 the relationships between photosynthesis and transpiration were summarized as follows; (1) When transpiration was directly proportional to D, it was positively correlated with photosynthesis. (2) When transpiration was inversely proportional to D, it was negatively correlated with photosynthesis. (3) And when transpiration had no relation to D, it had no correlation with photosynthesis (Fig.9).
5. From the results mentioned above, it was concluded that photosynthesis was rather affected directly by D than transpiration (Fig.10).View full abstractDownload PDF (1267K) -
II. The effects of air temperature and solar radiation on the dry matter production of some cropsNguyen Quoc VONG, Yoshio MURATA1978 Volume 47 Issue 1 Pages 90-100
Published: March 30, 1978
Released on J-STAGE: February 22, 2011
JOURNAL FREE ACCESSIn order to make clear the effects of temperature and solar radiation on relative growth rate, RGR, net assimilation rate, NAR, leaf area ratio, LAR, and other growth parameters as well as on differences in the pattern of dry matter production among species, 6 experiments were carried out, using the seedlings of 9 species including C3 winter crops, C3 summer crops and C4 crop species. Main results obtained are as follows:
1) There was clear difference in RGR exhibited among species and groups under the condition of high temperature and strong solar radiation. In the case of low temperature and weak solar radiation, however, difference was not so clear.
2) As a result of examination regarding the cause for the difference in RGR carried out by dividing it into two components, NAR and LAR, it has been revealed out that there is a clear difference among species and groups in NAR under the condition of high temperature and strong solar radiation, but that under the condition of low temperature and weak solar radiation, difference in NAR among species and groups is not clear.
From multiple regression analysis, evidence has been obtained that contribution of temperature and solar radiation to NAR is very high, more than 86%, in all the 3 groups.
3) Further, it has been made clear that LAR, one of the factors composing RGR, tends to be negatively affected, as a net result by the two climatic factors in the C3 winter crops, while there is no such effect recognizable in the C4 species, with intermediate response in the C3 summer crops. Besides these, by the examination on SLA and LWR which compose LAR, it has been concluded that the change in LAR was affected through both SLA and LWR.
4) Net assimilation rate is closely related with RGR in all the 9 crop species. The regression line, however, differs from C3 to C4 species. This difference is due mainly to the difference in LAR of the two groups.
5) There is an evidence for the existence of a close relationship in the C3 winter species between SLA and NAR, suggesting that in this group the climatic response and species difference in RGR may be exerted through the effect of SLA on NAR.View full abstractDownload PDF (1654K) -
Shin-ichiro KAWATA, Shigenori MORITA, Koou YAMAZAKI1978 Volume 47 Issue 1 Pages 101-110
Published: March 30, 1978
Released on J-STAGE: February 22, 2011
JOURNAL FREE ACCESSIt is known that in the stele of the rice crown root, there are three kinds of vessels-late metaxylem vessels (MXVII), early metaxylem vessels (MXVI) and protoxylem vessels (PX) -as well as two kinds of sieve tubes, metaphloem sieve tubes (MP) and protophloem sieve tubes (PP). Our observation was carried out on the process of the differentiation of those vessels and sieve tubes at the crown root tip.
Of the vessels, the MXVII differentiate earliest from the “large cells” which con stitute the tip of the stele excluding the pericycle (Figs. 1 and 2), followed by the dif ferentiation of the MXVI and lastly the differentiation of the PX takes place. Of the sieve tubes, the differentiation of the PP follows that of the MP. Thus, in both cases, the differentiation was found to proceed centrifugally. On the whole, the differentia tion of vessels and sieve tubes proceeds from the root tip in the order MXVII, MP, MXVI, and, finally, almost at the same time, PX and PP.
The observation mentioned above suggests that there may be a very intimate corre lation between the differentiation of each vessel and that of each sieve tube; e.g., a close correlation was found between the differentiation of the MXVI and that of the PX (Fig.14). The “joining” of the two PP (such a phenomenon as that in Fig.13 D→ A) accompanied by the “shift” of the MXVII (such as that in Fig.6 A→ D) may also be an example of that correlation.
The differentiation of all vessels and sieve tubes proceeds acropetally with con tinuity. Detailed observation, however, revealed that the formative cells of vessels and sieve tubes do not always form distinct rows longitudinally (Figs. 4, 5, 6 and 13). Consequently, it can be thought that the differentiation of vessels and sieve tubes in the root proceeds under influences exerted both from the root apex and the basal part.
The PP differentiate from the “protophloem mother cell” (PPMC) (Fig.8) by the two successive oblique cell divisions (Figs. 9, 10, 11 and 12). Other kinds of vessels and sieve tubes, however, do not have cells which correspond with the PPMC.View full abstractDownload PDF (11716K) -
VI. The effects of some conditions in raising of seedlingToshihiko NISHIO, Sadakichi FUJII1978 Volume 47 Issue 1 Pages 111-117
Published: March 30, 1978
Released on J-STAGE: February 22, 2011
JOURNAL FREE ACCESSTo obtain good seedling which was capable of producing high yield and was suitable for mechanical transplanting, some experiments on raising of seedling were conducted under various nursery conditions (i.e. (1) seeding rate 90-720g/m2, (2) upland or lowland nursery bed and (3) nursery period 19-48 days).
1. Physical characteristics were influenced apparently by seeding rate. Comparing with the seedling grown under dense seeding rate, the one grown under sparse seeding rate was (1) thicker in basal section (increase in section modulus), (2) more resistant to buckling and bending (increase in buckling index), but (3) more flexible in the structure (decrease in buckling stress) of basal part. Seedling grown under sparse seeding rate also possesses well-developed basal part with short foliage, therefore (4) more resistant against to buckling and bending of whole seedling (decrease in buckling index and deflection rate).
2. Comparing with the seedling grown in lowland nursery, the one grown in upland nursery was (1) thinner in basal section (increase in section modulus), (2) more rigid in the structure of basal part (increase in buckling stress) and (3) more resistant to buckling and bending, which were due to the well-developed basal part with erect and short foliage (decrease in buckling index and deflection ratio).
3. Physical characteristics of seedling in relation to nursery period were as follows: -
With growing, the basal part of seedling became (1) thicker in section (increase in section modulus), (2) more rigid in the structure (increase in buckling stress), therefore more resistant to buckling and bending (decrease in buckling moment). (3) In early seedling stage, the resistance against to buckling and bending of whole seedling (buckling index and deflection ratio) was not so high because of the undeveloped basal part. It increased once because of the developed basal part in comparison with foliage growth, but decreased again because of foliage elongation when nursery period was too long.
4. The above mentioned results on physical characteristics were similar to the well-known informations on physiological characteristics of seedlings. It was informed that the seedling grown under sparse seeding rate or the seedling grown at upland nursery was generally healthy and capable of producing high yield under the paddy field condition after transplanting. Similarly, the seedling grown under same conditions possessed better physical characteristics which were beneficial for mechanical transplanting.View full abstractDownload PDF (1235K) -
III. Relationship between CO2 concentration and nitrogen nutrition in some C3- and C4-speciesKatsu IMAI, Yoshio MURATA1978 Volume 47 Issue 1 Pages 118-123
Published: March 30, 1978
Released on J-STAGE: February 22, 2011
JOURNAL FREE ACCESSTwo kinds of experiments were conducted to elucidate the relationship between atmospheric CO2 concentration and nitrogen nutrition on the dry matter production of crop seedlings. One was a water culture (Table 1) of rice, and the other was a soil culture of rice, Japanese millet and maize at 5 to 6-leaf stages. In the former experiment, nitrogen was applied at 5 to 40 ppm in ammonium nitrate form, and in the latter, 30 to 160 mg nitrogen per plant was applied in ammonium sulfate form. CO2 enrichment or depletion treatments (160 to 3200 ppm) were carried out in transparent plastic growth chambers placed outdoors for 8 to 10 days in June and August. The following results were obtained:
1. In rice plant (C3-species), higher CO2 concentration promoted dry matter production, and the effect was accelerated by higher nitrogen levels due mainly to increased leaf area of tillers (Tables 2, 3, 4; Fig.2). No change was caused in the response of net assimilation rate (NAR) to CO2 concentration by nitrogen levels in the soil (Fig.1).
2. Japanese millet (C4-species) was similar to rice in its response of leaf area growth to CO2 and nitrogen, but its low response of NAR to CO2 brought the lower response of dry matter growth rate (GR) to CO2 as compared with rice (Table 4; Fig.1).
3. In maize (C4-species), leaf area growth showed fairly a high response to CO2 at both nitrogen levels, but the response of NAR to CO2 was very low, causing its low response of GR to CO2. Little response of NAR to nitrogen levels was observed both in rice and Japanese millet alike (Table 4; Fig.1).
From these results, it may be concluded that the pattern of dry matter production of crop plants in their response to CO2 concentration or nitrogen nutrition does not always reflect their CO2-photosynthesis characteristics as C3-or C4-species, due principally to their differential response in leaf area growth.View full abstractDownload PDF (920K) -
XV. The effects of light intensity and TIBA on the photosynthetic capacity and nitrogen metabolism in the two contrasting varieties of soybean plantsTakashi ORITANI1978 Volume 47 Issue 1 Pages 124-132
Published: March 30, 1978
Released on J-STAGE: February 22, 2011
JOURNAL FREE ACCESSUsing two soybean varieties, Harosoy and Tosan No.89, which were contrasting in growth habit, the author examined the relationship between the photosynthetic activity of leaves and nitrogen metabolism with reference to leaf growth. The results obtained are summarized as follows:
1. Harosoy had far less leaf area than Tosan No.89. In the case of Harosoy, leaf area decreased with the reduction of light intensity under which the plants had been grown. In the case of Tosan No.89, the leaf area development was rather promoted by moderate shading.
2. Harosoy showed higher photosynthetic activity compared with Tosan No.89 when they had been grown under full natural light. However, in the case of the former variety, photosynthetic activity distinctly decreased with the reduction of light intensity during the growing period. By contrast, in Tosan No.89, shading treatment did not necessarily bring about depression of photosynthetic activity so long as it was not very severe. Such variations in photosynthetic activity with variety and light condition were associated with the parallel variations in soluble proteins and fraction-1 protein.
3. TIBA spraying resulted in depression of leaf expansion and increase of photosynthetic activity. Such a variation in photosynthetic activity was associated with the parallel variations in total-N. protein-N, soluble protein and non protein-N. The effects of TIBA as described above were especially remarkable under the conditions in which leaf expansion was large, i.e., in variety Tosan No.89 and under shading treatment.
4. From these results, it was suggested that the photosynthetic activity of leaves is regulated through protein metabolism, and this, in turn, is under the control of hormons which are concerned with leaf expansion.View full abstractDownload PDF (5638K) -
II. Utilization of short wave and photosynthetically active radiation by rice and soybean plant populationsOsamu HIROTA, Tomoshiro TAKEDA, Yuji MURATA, Michiaki KOBA1978 Volume 47 Issue 1 Pages 133-140
Published: March 30, 1978
Released on J-STAGE: February 22, 2011
JOURNAL FREE ACCESSIf we want to know the strictly meaning utilization efficiency of solar energy by crop plants, it is necessary to make clear absorption rates of photosynthetically active radiation (PhAR), because they can never convert any radiation except PhAR to the energy for their growth. Also for researching the development of solar energy utilization by crop stands, it would be useful to compare the various types of crop stands in conversional efficiencies of solar radiation. For this purpose, rice (var. Tyotama) and soybean (var. Tamanishiki) plant populations were used to study. In order to obtain the absorption rates of short wave radiation and PhAR in the stands, following items of radiant energy were measured; incident energy to the top of canopy, albdo of canopy and transmissive energy into the ground surface. On the other hand, to estimate photosynthetically fixed energy by the stands, total dry matter produced and its combustion energy were measured on successive growing period.
Results are summarized as follows:
1. Rate of energy absorption increased with leaf area index (LAI). The absorp tion rate of soybean stand was higher than rice at low LAI, but the maximum absorption rate at high LAI was not different in both stands. These values were 73% for short wave radiation and 88% for PhAR (fig. 4).
2. Combustion energy per unit dry weight of whole plant was little changed throughout growing season. Combustion energy of soybean was higher than that of rice. These averaged values were 3676 and 4165 cal/g for rice and soybean plants respectively (table 4).
3. Utilizational efficiencies of radiation (Eueff), which were obtained from dividing the fixed energy into stand by incident solar energy onto canopy, were low at early growing stage. There was no difference in Eueff between rice and soybean stands. But later, Eueff increased and reached maximum, then decreased gradually. The maximum value of Eueff of the PhAR were estimated to be 4.5-5% for rice stand and 3-3.5% for soybean (fig. 6).
4. Conversional efficiencies (Eøeff), which were obtained from dividing the fixed energy in stand by solar energy absorbed into the canopy, were almost constant at early stage but decreased progressively at later for both crop stands. Eøeff of rice stand were always higher than those of soybean. The mean value of Eøeff of PhAR in early sage is 5-6% for rice stand and 3-4% for soybean (fig. 7).View full abstractDownload PDF (1207K) -
Shohei HIROSE, Kazuma NOJIMA1978 Volume 47 Issue 1 Pages 141-146
Published: March 30, 1978
Released on J-STAGE: February 22, 2011
JOURNAL FREE ACCESSOn the infection of Maize downy mildew, if it is supposed that the infected plants do not act on the other healthy plants within same hill as the contagious source, the infection rates on hill base are theoritically shown by the expansion of formula (p+q)n, where p, q and n stand for the infection rate on individual base, 1-p and number of plants per hill, respectively.
On the data obtained from the different experiment station, using the different varieties and hill spacing, the observed infection rates on hill base were compared with the expected ones calculated from the formula.
It was proved that both rates were coincident well as shown in Tables 1, 2, 3 and 4.
From these facts, it was concluded that the supposition mentioned above would hold good, namely, the disease would not be transmissible from the infected plants to the healthy plants within the same hill, or it would be very few if transmitted.
Lastly, based on the results, the effect of roguing of diseased plants was discussed from a viewpoint of Maize downy mildew control.View full abstractDownload PDF (1056K) -
I. Individual variation in the various characters of upland-cultured paddy rice in different varieties and plant densityHiroharu BANBA, Takahiro OHKUBO1978 Volume 47 Issue 1 Pages 147-154
Published: March 30, 1978
Released on J-STAGE: February 22, 2011
JOURNAL FREE ACCESSRelationships between yields and individual variation in the various characters in plant community were studied in upland-cultured paddy rice. In this experiment two varieties and three densities were adopted to cause individual variation in the various characters of upland-cultured paddy rice.
The results are as follows:
1. The coefficient of variation of the characters such as culm number, panicle number and dry weight was greater than that of plant height, culm length and ear length (Table 3).
2. The individual variation of the characters such as culm number, panicle number and dry weight could be compared with coefficient of variation, because the actual data were in conformity with the regression line between the standard deviation of the above-mentioned characters and the mean value of those. On the other hand, with the characters such as plant height, culm length and ear length it could not be compared with coefficient of variation, because the above-mentioned phenomenon was not ob served.
3. The individual variation of each character of “Myojoo”, panicle number type variety, was greater than that of “Fujiminori”, panicle weight type variety.
4. The individual variation of each character of upland-cultured paddy rice under high plant density was greater than under low plant density. Because there was severe competition among individuals under the high plant density (Table 5).
5. The individual variation of each character decreased with progress of growth stage under the low plant density, but increased under the high plant density (Fig.5).View full abstractDownload PDF (1323K) -
II. Individual variation in the various characters of upland-cultured paddy rice in different tillage method, seeding time and plant densityHiroharu BANBA, Takahiro OHKUBO1978 Volume 47 Issue 1 Pages 155-162
Published: March 30, 1978
Released on J-STAGE: February 22, 2011
JOURNAL FREE ACCESSRelationships between yields and individual variation of various characters in plant community were studied in upland-cultured paddy rice. In this experiment two tillage methods, four seeding time and two plant densities were adopted to cause individual variation in the various characters of upland-cultured paddy rice.
The results are as follows:
1. The individual variation of each character under deep tillage with heavy manure was not so different with that under normal tillage with standard manure (Table 4).
2. In the late seeding time individual variation in each characters was small as compared with early seeding time, when reproductive growth progressed well (Table 6).
3. A large individual variation in each character at early seeding time was caused by long growing period or severe competition.
4. Individual variation in each character was strongly influenced by seeding time or plant density, on the other hand, it was not influenced by tillage method or rice variety.
5. Individual variation of dry weight of upland-cultured paddy rice was not related to dry weight.View full abstractDownload PDF (1245K) -
Shigeo NISHIMURA, Eizo MAEDA1978 Volume 47 Issue 1 Pages 163-164
Published: March 30, 1978
Released on J-STAGE: February 22, 2011
JOURNAL FREE ACCESSDownload PDF (1385K) -
Ryuichi ISHII, Yoshio MURATA1978 Volume 47 Issue 1 Pages 165-188
Published: March 30, 1978
Released on J-STAGE: February 22, 2011
JOURNAL FREE ACCESSDownload PDF (4379K)
- |<
- <
- 1
- >
- >|