The efficiency in tuberization of corm and cormlet, and the accumulation of dry matter to underground parts, were investigated using seed-corms from 1st, 2nd or 3rd years which are used as the seed-corms in the cultivation of konjak plants. Results obtained are as follows : 1. The weight of whole plant or corm plus cormlet was high under large seed-corm and the partition of dry matter to underground organ (corm plus cormlet) was no discernible variation between the age and weight of seed-corms. The percentage of dry weight in each organ to total dry weight of corms obtained from the 1st year crop became slightly smaller values than those obtained from the 2nd and 3rd years, and there was an inverse relationship among cormlets weight. As for the shoot dry weight, the percentage of leaflets decreased with increasing the age or weight of seed-corms, but non-photosynthetic organs increased (Figs. 1 and 2). 2. As to the corm tuberization based on fresh weight, there was a close positive correlation between seed-corm weight and leaf area. Further, seed-corm weight negatively correlated with the ratio of leaf area/seed-corm weight. The ratio of corm or corm plus cormlet weight per seed-corm weight increased with ageing of seed-corms. However, the negative correlation was found between leaf area/seed-corm weight and corm weight/leaf area ratio (Fig. 1). 3. The corm tuberization based on dry weight was similar to that based on fresh weight. However, there was a large difference between the percentage of dry matter and the age of seed-corms. The difference in leaf area/seed-corm weight ratios among the age of seed-corms was smaller than fresh weight base. Corm/seed-corm weight ratio slightly increased with increasing the age of seed-corm, however, cormlet/seed-corm weight ratio decreased. Corm plus cormlet/seed-corm weight ratio was high under small or young seed-corms (Table 1 and Fig. 4). 4. The ratios of corm, corm plus cormlet, and whole plant weight/leaf area increased with the ageing of seed-corms and specific leaf weight, soluble protein and chrollophyll contents also increased. These values were much higher in the crops in 3rd years than in 1st years. It was suggested that there was a close relationship between photosynthetic rate and age of seed-corm in konjak plant (Fig. 5 and Table 3).

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The following methods were used for obtaining the relation between rice yield and photosynthetically active solar radiation during seed ripening stage, in different areas in Japan. The yield was prefectural average yield, and the seed ripening stage was the period from average heading time to average harvesting time in each prefecture. Photosynthetically active solar radiation was cited from the data measured by the Group I-1 in the Green Energy Project of the Ministry of Agriculture, Forestry and Fisheries. Among these more than 20 measurement sites, 12 in 1979 and 11 in 1980 were selected on the basis of the availability of the data during the seed ripening stage and of normal crop situation index (91-109)(Tables 1 and 2). The accumulated photosynthetically active solar radiation during seed ripening stage was calculated by the summation of photosynthetically active radiation on every day at each measurement site, for the seed ripening stage in each prefecture in which each site locates (Table 2). Figs. 1 to 3 show the correlation between the rice yield and the photosynthetically active solar radiation during the seed ripening stage, for combined and individual data in 1979 and 1980, respectively. The correlations were significant at 0.1, 1 and 0.1 percent level, respectively. On the other hand, no correlation was found between the yield and average temperature during the ripening stage (Fig. 4). In other words, it was shown that rice yield was proportional to the photosynthetically active solar radiation during seed ripening period. This conclusion should be noted to have several conditions which were discussed in this paper : For example, there is no big difference among farmers in different prefectures in Japan for the level of rice cultivation techniques. The implications of this conclusion, however, is rather wide and important. As an example of these implications, the so-called "heat tolerance" problem in the southwestern region in Japan was discussed.

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Approaches and instrumentation are needed to collect data nondestructively that relate to the biomass, yield, and nutritious status of crop and plant communities. One approach is to relate spectral measurements on the plant canopies to their agronomic characteristics. But a spectroradiometer for scanning in the visible (400-700 nm) and near-infrared (750-2500 nm) wavelength intervals continuously in the outdoor is not available in Japan. Therefore, we designed, produced, and tested a semi-portable, computerized system for field use. In this paper we report on its design and present sample data. The instrument was a double beam system capable of measuring the reflectance from the canopy and skylight intensity simultaneously at the same wavelength over the interval 400-2200 nm (Figs. 1, 2 and 5). The scanning speed of the grating monochromator is 100 nm/min. A desktop computer (HP-9835) and changeable software control the calibration unit (standard white board), monochromator driver and A/D converters. The collected data are caluculated by the computer and saved on digital casette tape. A photomultiplier (400-900 nm) and a PbS photo-cell (900-2200 nm) are the detectors used. The field-of-view response is shown in Fig. 3, while changes in reflectance of a Kodak grey card with time of day at two wavelengths are shown in Fig. 8. Examples of crop canopy spectral profiles are presented in Fig. 6 and 7. Their patterns are similar to those in the literature for plant canopies.

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A study on the relationships between canopy architecture and yield of rice sown directly requires experimentation with population density of different magnitude and basal nitrogen levels. A lowland rice cultivar, Yamabiko, was sown directly in a square design at five population density levels (1600, 400, 100, 25 and 6.25 plant/m² at seedling stage) having two nitrogen levels as basal dressing (0 kg-N/10a : 0-N plot and 10 kg-N/10a : 10-N plot) on a well-drained paddy field in 1972. Each plot was replicated three times. Plants were grown on available soil moisture for one month. Thereafter, field was flooded with irrigation water which was kept stagnant in the field till dowgh-ripe stage. The leaf stratified structure of each plot was evaluated on the basis of F₁ and F₂ scores obtained by the multivariate analysis method as described in part I¹⁴⁾. The relationship between the leaf stratified structure and yield was analysed and the results were compared with those of a rice community of transplanting culture reported in two previous papers^{14, 15)} in order to find the characteristics of the structure of this rice community sown directly. The results are as follows : 1. The relationship between F₁ or F₂ score and the leaf stratified structure and the seasonal trend of leaf stratified structure were virtually the same as those of two previous papers (Tables 1 and 2 ; Figs. 1, 2 and 3). 2. The yield (winnowed paddy) was maximum at 400 plant/m² density level both in 0-N and 10-N plots and the yield of 10-N plot was about 19% higher than that of 0-N plot (Table 3). 3. The leaf stratified structure and top dry weight appeared to be independent of each other. 4. Positive correlation between yield and top dry weight at each growth stage was found in 0-N and 10-N plots. The correlation was higher at later stage of plant growth, and it was always higher in 0-N plot than in 10-N plot (Table 4). 5. The correlation between yield and F₁ or F₂ score was high and positive at the young panicle formation stage only in 0-N plot and at all stages except active-tillering in 10-N plot (Table 5). This trend was similar to that reported in part I, presumably due to the similarity of the weather between these experiments. 6. The relative strength of correlation between yield and F₁ or F₂ score compared with correlation between yield and top dry weight (see part II¹⁵⁾) was greater in the communities with larger leaf area index (LAI), which include 10-N plot or later stage of plant growth. By contrast, in the communities with smaller LAI, the relative strength was small. The smaller the LAI was, the higher was the change of this relative value (Figs. 4 and 5). 7. The comparison of the leaf stratified structure of a rice community sown directly with that of a transplanted community¹⁵⁾ shows that the former structure had a tendency to have a high leaf weight percentage (see part I for the definition) in the lower stratum at the active-tillering stage and in the upper stratum after the young panicle formation stage (Fig. 6). The results of No. 1, 3, 5 and 6 are the same as those of two previous papers^{14, 15)}. It is therefore suggested that the relationship between the leaf stratified structure and yield of rice is little influenced by the differences in cultural methods as well as the yearly variations in the environmental conditions. It was observed that F₁ and F₂ factors maintained their individual characteristics in the three experiments. Thus, it is concluded that the statistical method used in the series of this study is very useful for analysing canopy architecture of rice community and for investigating the yielding ability of rice from the viewpoint of canopy architecture.

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日本稲, インド稲およびインド稲半矮性二十数品種を供試し, ライシメーター法によって収穫期乾物重に対する分げつ期から収穫期までの積算水消費量を検討した. 地上部乾物重当たりの水消費量には明らかな品種間差異が認められ, インド稲, インド稲半矮性, 日本稲の順に小さくなった(Table 3). 次に, 日本稲およびインド稲4品種を選び, ポット水耕法により分げつ期と穂ばらみ期に2週間の乾物増加量と水消費量を測定し, 要水量を算出した. インド稲の要水量は日本稲と比較して明らかに大きく, その差異は水消費量に起因していた(Table 4). 上記の結果を確認するため, ポロメーター法により葉身の蒸散抵抗の品種間差異を検討した. インド稲, インド稲半矮性の蒸散抵抗は日本稲の約半分であり, 単位葉面積当り蒸散速度が高いことが確認された(Fig. 1, Table 5). 以上の結果は, 日本稲とインド稲が水分代謝の上で生理的または形態的に異なる機構を有することを示唆するものである.

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The morphological structure of the surface of leaves and stems of Atriplex nummularia, grown in a culture solution with or without 2% sodium chloride, was observed under optical as well as cryo-scanning electron microscopy. Both upper and lower surfaces of leaves were covered with 2-3 layers of densely grown vesiculated hairs (Figs. 1, 2, 3). The vesiculated hairs consisted of bladder cells (100 to 200μm in diameter) and stalk cells connected with the epidermis (Fig. 9). The bladder cells were covered with waxy bloom (Fig. 4). The stem surface was also covered with vesiculated hairs (Figs. 8, 10). The vesiculated hairs and the lamina were separated, and sodium and potassium contents of each fraction were analysed. When sodium chloride was added to the culture solution, the sodium content markedly increased in the vesiculated hairs unlike in the lamina (Table 1 ). Ion contents of the bladder cell and of various cells of the lamina were determined by using x-ray micro-probe under scanning electron microscope. The peaks corresponding to sodium and chlorine were observed on the surface, in the cytoplasm, and in the vacuole of the bladder cell. On the other hand, the small peaks correspondinng to potassium and chlorine were observed in the epidermal cell, mesophyll cell and bundle sheath cell (Figs. 11, 12). Crystals of sodium chloride could be seen in the internal part of collapsed bladder cells (Figs. 5, 6, 7, 11). Based on these observations it is suggested that A. nummularia, which was grown in a culture solution with 2% of sodium chloride, can remove the chloride from the lamina of plants which absorbed the ions through roots and conducting tissue, by the repetition of the following cycle ; (1) transport of sodium and chlorine from the lamina to the bladder cells and accumulation of sodium and chlorine in these cells, (2) collapse of the bladder cells containing crystals of sodium chloride and (3) liberation of the crystals from the collapsed bladder cells. It is postulated that sodium chloride can be excreted from the surface of the stem by the same mechanism since similar vesiculated hairs were observed on the surface of the stem.

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The object of this report is to clarify the dry-matter accumulation habits during the early vegetative growth period and to investigate the effect of the early growth on yield and quality of maize for whole-plant silage in the north-marginal area in Japan (where accumulated temperature from May to September is 2200°C.). Experiments were conducted for 6 years (1978∼'83), based on the same design. Wase-homare (an eary hybrid) was planted on three dates from mid-May to early-June in 1978∼'82 and late-May in 1983. The dry-matter weight in each organ was measured at the 4th-, 7th-, and 11th-leaf fully developed stages, and dry-matter yields were measured at harvesting date. The results obtained were as follows : 1. Root dry weight growth rate in each growth period from emergence to the 11th-leaf stage showed highly positive correlations with leaf expansion rate and top growth rate (TGR)(Table 1). 2. TGR during the period from emergence to the 4th-leaf stage showed highly positive correlations with daily maximum temperature and sunshine hours, but was not correlated with solar radiation (Table 2). 3. TGR in each growth period from emergence to the 7th-leaf stage showed a highly positive correlation with LAI. TGR during the period from the 7th-leaf stage to the 11th-leaf stage showed highly positive correlations with both of LAI and NAR (Table 3). 4. TGR during the period from emergence to the 4th-leaf stage showed highly positive correlations with ear DM yield, total DM yield and percentage of dry-matter in whole-crop, but was not correlated with stover DM yield (Fig. 4). 5. Thus it was concluded that the early growth is of great significance on the growth and development of ears which are essential for stable and high yield, and high quality of maize for whole-plant silage under severe conditions in the north-marginal area.

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Excluding species of the subfamily Bambusoideae which are all C₃ species, identification of C₃ and C₄ species of the grass family in Japan was carried out, then geographical distribution of C₃ and C₄ species in Japan with special reference to climatic conditions was investigated. Obtained results are as follows : 1) Since the CO₂ compensation point is closely related to the "Leaf Anatomy" and no exceptional relationships were observed in this study. Tested species were accepted as C₃ or C₄, depending on the tested results, regardless of whether the distinction was made on the basis of CO₂ compensation point, "Leaf Anatomy". We also classified untested species as C₃ or C₄, where possible, on the basis of their taxonomic affinities. 2) The species belonging to the subfamily Oryzoideae, Arundinoideae, Festucoideae are all C₃ species, and to the Eragrostodeae are all C₄ species. Most of the species belonging to the subfamily Panicoideae are C₄ species, but it is noted that the exceptional C₃ species are also contained in the genus Isachne and Coelachne of the tribe Isachneae, the genus Panicum, Sacciolepis and Opismenus of the tribe Paniceae. 3) High correlations exists between geographical distribution of percent C₄ expressed as percentage of C₄ species in the total grass flora and climatic conditions, especially yearly mean temperature conditions. 4) Increase in percent C₄ of the grass family with latitudinal descend in Japan depends chiefly on increase in species of the subfamily Panicoideae and decrease in species of the subfamily Festucoideae. On the other hand, no remarkable changes in species of the subfamily Oryzoideae, Arundinodeae and Eragrostoideae were found. 5) In the subfamily Festucodeae, it was found that perennial species increased and annual species decreased with latitudinal ascend, at the same time, in the subfamily Panicodeae, perennial species decreased and annual species increased with latitudinal ascend. It is most likely that the life-form of plant is related to the ecological distribution of the grass family.

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In the previous paper, the authors carried out identification of C₃ and C₄ species of the grass family in Japan, then investigated the geographical distribution of them with special reference to climatic conditions. In the present paper, by means of the same method, we tried to investigate the geographical distribution of C₃ and C₄ species of the grass family occurred in Korea and Taiwan which are located at near Japan, Hainan and Java which are located at the subtropics or tropics of South East Asia. As to the distribution of C₃ and C₄ species along altitudinal gradient in Java, special analysis was carried out. Obtained results are as follows : 1) The districts concerened with the present study exclusively belong to the South East monsoon regions, especially Taiwan, Hainan and Java belong to the wet-subtropics or tropics. These districts are comparatively poor in no. of species belonging to subfamily Eragrostoideae, in contrast, abundant in that of Panicoideae. It is noted that the proportion of species of tribe Andropogoneae in subamily Panicoideae are comparatively abundant, and also it should be noted that no. of C₃ species of Panicoideae are rather abundant. 2) In general, increases in percent C₄ with latitudinal descension occurred. The latitude of Java is lower than that of Hainan. However, in spite of lower latitude, Percent C₄ of Java (66%) is lower than that of Hainan (81%). In Java, there are many high mountains (3000-4000 m), but Hainan is not so high, its only 1800 m at the highest. This fact drops percent C₄ of Java under that of Hainan. The same situation is applied to the case of comparison between Taiwan (60%, 22-25°N) and Ishigaki (70%, 24°N). 3) In Java, percent C₄ decreases markedly with ascension of altitude. This fact is caused by the increase of no. of species belonging to Festucoideae. It is considered that climatic temperature falls down with ascension of altitude, and the no. of species belonging to Festucoideae which agree with cool climatic conditions increase rapidly at higher latitude. In spite of their latitudinal sites. Java and Taiwan have so many species belonging to Festucoideae. This fact supports the above mentioned deduction.

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数種のマメ科穀実作物を異なる水分供給条件下でポットで土耕栽培し, その影響を調査した. さらに, 生育の異なる段階にあるリョクトウに萎凋処理を行い, 生育, 収量に及ぼす土壌水分欠乏の影響をとくに窒素栄養と関連させて調査した. その結果, 下記のことが明らかとなった. 1. 各種マメ科穀実作物の子実収量, 植物体乾物重, 全窒素量は土壌への水分供給が制限されるに伴って低下するが, リョクトウにおける低下度合はダイズやラッカセイなどに比べて小さかった. 2. リョクトウの子実生産効率や子実タンパク生産効率は土壌への水分供給の制限によってほとんど影響を受けないが, ラッカセイでは水分供給の制限に伴い急激に低下した. 3. リョクトウに対する萎凋処理はいずれの生育段階においても, 子実収量, 植物体乾物量, 全窒素量, 窒素固定能および生産効率に対して抑制的に働くが, その抑制度合は開花期-英形成期の処理において最も強かった. 4. 萎凋処理に伴う子実収量の低下は着莢数や莢当りの子実重の減少に基因するが, 着莢数の減少が最も主要な要因として働いていた. 5. これらの結果から, リョクトウの栽培に際し, 着莢期以前の萎凋が子実収量や生産効率を顕著に抑制するためにとくに同時期での水管理に留意すべきである.

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異なる生育段階にある上耕栽培したリョクトウ植物体に対して湛水処理を行い, 生育, 子実収量および窒素栄養に及ぼす影響を調査した. その結果, 下記のことが明らかとなった. 1. リョクトウに対する湛水処理はいずれの生育時期においても生育抑制, 植物体全窒素量の低下および子実収量の低下をまねくが, とくに開花盛期や着莢期での影響が最も大きかった. 2. 上記の時期における湛水処理に伴う子実収量の低下は主に着莢数の減少が関与し, ついで莢当りの子実重の減少が関与していた. 3. 子実生産効率および子実タンパク生産効率も上記の時期における処理において最も低かった. 4. また, 湛水処理は根粒内のレグヘモグロビンの消失と窒素固定能の失活をもたらした.

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