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Volume 69, Issue 1
Displaying 1-18 of 18 articles from this issue
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Eizo MAEDA2000 Volume 69 Issue 1 Pages 1-11
Published: March 05, 2000
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESS -
Takeshi IKEDA2000 Volume 69 Issue 1 Pages 12-19
Published: March 05, 2000
Released on J-STAGE: February 14, 2008
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Hiroyuki TSUJI, Hiroyuki YAMAMOTO, Kazuyuki MATSUO, Kazuei USUKI2000 Volume 69 Issue 1 Pages 20-23
Published: March 05, 2000
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSThe effect of non tillage on drought injury of upland rice was studied in Andosol upland fields. In 1988, 1990, and 1992, upland rice (cv. Toyohatamochi) was grown on nontilled and tillaged upland fields. In 1990 and 1992, because of little rain in the summer, drought injury caused a yield reduction in upland rice. But damages were not so serious in nontilled cropping. In nontilled plots, the onset of heading was earlier, and surface soil was dried slower than in the tillaged plots in the summer. In the heading stage, dry matter of top and root length density in the nontilled plot is more than in the tillaged plot. We supposed that the period of drought stress on upland rice was shorter in the nontilled plot before heading compared with the tillaged plot, since the soil water was retained more.View full abstractDownload PDF (655K) -
Hideki SUGIMOTO, Masanobu KURONO, Keiko TAKANO, Yasushi KHONO, Tooru S ...2000 Volume 69 Issue 1 Pages 24-30
Published: March 05, 2000
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSSummer buckwheat (Fagopyrum esculentum Moench. cv. Kitawasesoba, summer ecotype) was cultivated from April to June in 1998 in the drained paddy fields of two experimental sites:Hojo city, in the plain area facing the Inland Sea of Japan (Setonaikai), and Honjo village, in the intermediate mountainous area of Kyushu. Two types of experimental fields were prepared on both sites:a field left fallow during winter (fallow plot) and that on which Chinese milk vetch (Astragalus sinicus L.) was cultivated in winter as green manure (Chinese milk vetch plot). In 1997, a Chinese milk vetch plot was also provided in Hojo city. Because the precipitation during summer buckwheat cultivation in 1997 was low, grain yield exceeded 250 g / m2. Because of abundant rainfall around seeding time, however, the establishment percentage was very low and plant growth was markedly poor in 1998. The depression of the establishment of seedings and growth were severer in the fallow plot than in the Chinese milk vetch plot. Grain yield in the fallow plot was nearly zero, while it was 112g / m2 (47% of 1997) in the Chinese milk vetch plot. In Honjo village, the amount of rainfall during the period from flowering to maturing in 1998 was 2.76 times greater than in a normal year. Subsequently, because of the decreased number of grains per plant, grain yields in both plots showed low levels, such as 219g / m2 in the Chinese milk vetch plot and 143g / m2 in the fallow plot. As mentioned, the depression in grain yield caused by excessive soil moisture around seeding time or after flowering period was demonstrated to be severer in the fallow plot that in the Chinese milk vetch plot. These results suggest that Chinese milk vetch as green manure is useful for summer buckwheat cultivation and that excess moisture injury to summer buckwheat is considered to be reduced by the use of Chinese milk vetch.View full abstractDownload PDF (1046K) -
Shoji NAKAGAWA, Yuriko TAMURA, Yoshimaru OGATA2000 Volume 69 Issue 1 Pages 31-37
Published: March 05, 2000
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSFrom 1994 through 1996, qualities of rice grains cultivated under organic and conventional farming systems have been compared at 13 different locations in Japan with respect to their appearances, indices of the eating quality, mineral content, and shelf life. At each location, the organically managed paddy and conventionally managed paddy were adjacent to each other and managed by almost the same famers. The results of the paired t-tests showed that statistically significant differences in qualities of organic and conventional rice grains were found in 1994 (n=13), 1996 (n=13), and a total of three years (n=39). The organically grown rice had higher Mg / (K·N), zinc content, and embryo activity during storage and lower imperfect rice kernel ratio, nitrogen content, potassium content, and calcium content than the conventionally grown rice. Among these indices, the lower nitrogen content, higher Mg / K·N), lower potassium content, and higher zinc content of the organically grown rice could be explained because of the lower nitrogen application in organic farming systems than in conventional farming systems. Furthermore, it was found that the organic paddies contained higher available silica than the conventional paddies did statistically, at significant levels at all the locations. This may contribute to the inhibition of nitrogen accumulation in organic rice grains.View full abstractDownload PDF (1050K) -
Yuji MATSUE, Yosuke UCHIMURA, Hirokazu SATO2000 Volume 69 Issue 1 Pages 38-42
Published: March 05, 2000
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSThe growth habits and paroductivity of stored (5°C, 40% relative humidity) rice seeds with a 90% or higher germination percentage were examined in comparison with those of newly harvested seeds (new seeds), and the cultivars of stored seeds were identified by the random amplified polymorphic DNA (RAPD) method. There was no difference in the characters of the seedlings between the new seeds and the seeds stored for 6∼16 years. On the other hand, there was a positive correlation between the 1000-unhulled grain weight, which varied with the harvest year, and dry weight of the seedings. Among the stored seeds and new seed, no significant differences were observed in the mean heading date, culm and ear lengths, the number of spikelets per panicle and the number of ears per hill. The yield components, grain yield and inspection-grade of the stored (6∼7 or 9∼16 years) seeds were not significantly different to those of the new seeds. An RAPD analysis showed that the band pattern of stored seeds accurately corresponds to that of new seed in each cultivar. We concluded that stored rice seeds with a germination percentage of higher than 90% are practically useful, showing normal growth habits and productivity.View full abstractDownload PDF (874K) -
Hisashi TANNO, Hitoshi KIUCHI, Yuji HIRAYAMA, Harumi KIKUCHI2000 Volume 69 Issue 1 Pages 43-48
Published: March 05, 2000
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSWe report a simple method devised for testing the cool weather tolerance at the flowering stage in rice. In small square pots, 15 cm in length, 5 cm in width and 10 cm in height, eight plants having only the main culms were cultivated. The temperature was constantly kept at 17.5°C for 15 days in an air conditioned room with 50% shading. The tolerance to cool weather damage was estimated from the fertility percentage of panicles which headed at the day when the low temperature treatment was started. At least 10 panicles (3∼4 pots) were needed to classify the varieties into 7 ranks, from extremely high tolerance to extremely vulnerable, with statistical errors of ±0.8 rank. In this method, the treatment starting at the heading day caused the lowest fertility percentage in almost all varieties. Therefore, fertility percentage could be determined using fewer panicles compared with the 8-day treatment at 15°C. There was a significant positive correlation (r=0.808**, n=14) between the results obtained by this method in different years. The results obtained by this method showed significant positive correlations with those obtained by the 8-day treatment method at 15°C and 6-day treatment method at 12°C (r=0.750** and 0.802**, respectively, n=14). Although the plants examined by this method were very small, there was a significant positive correlation (r=0.922**, n=8) between the results obtained using these small plants and the plants cultivated in a 1 / 5000a pot, which were similar in size to those in the paddy field.View full abstractDownload PDF (1005K) -
Hisao EGUCHI, Shinji SHIMADA2000 Volume 69 Issue 1 Pages 49-53
Published: March 05, 2000
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSEarly maturing which enables harvesting before the rainy season is a desirable trait for wheat, in Japan. The objective of this study was to assess the length of developmental phases in 6 wheat cultivars which were sown in a field at 20 planting date-year combinations. The time at each developmental stage varied with the cultivar, planting date, and year. The variation was larger in early stages (e.g., double ridge) and smaller in late stages (e.g., maturity). After the double ridge stage, the lengths of each developmental phase was negatively correlated with the time of the beginning of the phase. These negative correlations indicate that hastening of planting date and double ridge stage does not result in earlier maturity. These correlations also make it difficult to screen for the developmental phase lengths in the field condition. The length of each developmental phases was always negatively correlated with the mean temperature, but, we could not confirm which climatic factor directly influenced the phase length, because there were high correlations between the factors. Additional experiments were conducted under controlled environments (phytotron) to screen for the cultivars with shorter heading-to-maturity phase lengths. T. spelta cultivars (e.g., 'Khapli' and ' France-62') had significantly shorter anthesis-to-maturity phase length than the control cultivar 'Shirasagi-komugi'. T. compactum cultivars had a shorter heading-to-anthesis phase length than the control cultivar, but the length from flag-leaf expansion to anthesis did not differ significantly among cultivars.View full abstractDownload PDF (743K) -
Youli YAO, Yoshinori YAMAMOTO, Youji NITTA, Yulong WANG, Hua WU, Tetsu ...2000 Volume 69 Issue 1 Pages 54-60
Published: March 05, 2000
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSBy categorizing the water selected ripened paddy grains into groups with different specific gravity, we observed several characteristics of the paddy grain and brown rice in four cultivars. It was found that the grains of cultivars with heavier grain were intensively distributed in higher specific gravity, whereas those of cultivar with lighter grain were sparsely distributed around lower specific gravity. The coefficient of variation (CV) of the character in brown rice was always higher than that of the respective character in paddy grain. These results suggested that after the size of the hull was determined at flowering, the brown rice still had a wider variation. The brown rice volume was primarily determined by its thickness, and the influences of its length and width varied among cultivars. With the increases of brown rice volume, all characters of the paddy grain volume, the specific gravity of paddy grain, the paddy grain weight, and the brown rice-paddy grain ratio increased. These were found to be consistent in the four cultivars. The hull weight and the paddy grain weight showed positive correlation in two cultivars, but not in the others. It was concluded that the specific gravity closely related with the paddy grain weight, which was mainly determined by its brown rice volume. The brown rice volume was primarily subject to its thickness. The hull's role in regulating the growth of brown rice might be different among cultivars.View full abstractDownload PDF (969K) -
Youji NITTA, Youli YAO, Yoshinori YAMAMOTO, Tetsushi YOSHIDA, Toshiaki ...2000 Volume 69 Issue 1 Pages 61-68
Published: March 05, 2000
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSVarietal differences in the number and cross area of large vascular bundles (LVs) at the neck internode were investigated in 18 rice cultivars. There were two kinds of LVs in Chinese japonica (CJ), Japonica-indica hybrid (JI), Tall indica(TI) and Semidwarf indica (SDI) types, i.e. the large (L1) and the small (L2) bundles. The number of L2 varied with the cultivar group. The total number of LVs was in the decreasing order of SDI>TI>JI>CJ>JP (Japonica panicle weight type) >JN (Japonica panicle number type). The ratio of the number of LVs to the number of primary rachis branches (V / R ratio) was nearly 1.0 in JP and JN. However, the V / R ratios in JI, TI and SDI were higher than 1.0 because the number of L2 was added. Total or phloem areas of L1 were larger in T1 and SDI than in JP and JN. The whole area of LVs and phloem areas were in the decreasing order of SDI>TI, JI>CJ>JP>JN because of the difference in the numbers of L2. The whole area of LVs and phloem areas of JP (cv. Koganemasari) and SDI (cv. Gui zhao 2) were increased by the increment of N application at the panicle formation stage. The increment of the area of LVs and the running of L2 at the neck internode are considered to be important indicators jto strengthen the transportation system of assimilates by breeding.View full abstractDownload PDF (1363K) -
Toshihiro MOCHIZUKI, Uyuki TAKAHASHI, Satoshi SHIMAMURA, Masataka FUKU ...2000 Volume 69 Issue 1 Pages 69-73
Published: March 05, 2000
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSThe secondary aerenchyma formation in hypocotyl just below the soil surface was investigated by using the young seedings of wild soybean and six summer leguminous crops grown under upland and excessive moisture conditions for 14 days. Under the upland conditions, secondary aerenchyma was scarcely observed in any species. Under the excessive moisture conditions, however, there was an interspecific difference in the secondary aerenchyma formation. The area of secondary aerenchyma per transverse section of hypocotyl under the excessive moisture conditions was largest in soybean 'Asoaogari' (9.77mm2), followed by soybean 'Akisengoku' (7.80mm2), wild soybean 'D5' (4.37mm2), cowpea 'Sanjyakusasage' (2.63mm2), mung bean 'Bundomame' (1.97mm2) and mung bean 'Acc. 7703' (1.52mm2), those in the other crops were less than 1 mm2. The ratio of secondary aerenchyma area to stele area was largest in wild soybean, followed by soybeans, suggesting that the ability of secondary aerenchyma formation in soybean was almost equivalent to that in wild soybean. Since a significant positive correlation at the 1% level was found between dry weight ratio (the ratio of dry weight of the aerial part under the excessive moisture conditions to that under the upland conditions) and the area of secondary aerenchyma under the excessive moisture conditions (r=0.738), it is suggested that the ability of secondary aerenchyma formation is related to the wet endurance in leguminous crops.View full abstractDownload PDF (1731K) -
Takeaki TAGAWA, Kenji HIRAO, Fumitake KUBOTA2000 Volume 69 Issue 1 Pages 74-79
Published: March 05, 2000
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSSpecific characteristics in the photosynthetic response to nitrogen application were compare between Oryza glaberrima Stend. strains introduced from West Africa and O. sativa L. strains including japonica, javanica, indica and japonica-indica types. These plants were grown in solution culture with different nitrogen concentrations. Chlorophyll content in leaf, the maximum quantum yield (Fv / Fm) in photosystem II and total Rubisco activity showed no significant inter-specific difference. However, O. glaberrima strains represented significantly high nitrogen utilization efficiency (CO2 exchange rate / nitrogen content in unit leaf area), high stomatal and mesophyll conductances in leaves with low nitrogen content, and high photosynthetic efficiency per unit Rubisco activity (CO2 exchange rate / total Rubisco activity). These findings suggest that the in vivo activation level of Rubisco is higher in O. glaberrima strains than in O. sativa strains. The high nitrogen utilization efficiency detected here is unique to O. glaberrima, and is considered to be an advantageous genetic character in photosynthesis. The introduction of such a character into O. sativa is regarded as a step toward the genetic improvement of leaf phtosynthetic ability of this species grown in a nitrogen-input saved condition.View full abstractDownload PDF (900K) -
Shigenori MORITA, Miwa OKAMOTO, Jun ABE, Junko YAMAGISHI2000 Volume 69 Issue 1 Pages 80-85
Published: March 05, 2000
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSBleeding rate could be an effective index for the physiological activity of a whole root system in field-grown crops, because it is based on active water absorption caused by root pressure. We examined the bleeding rate of field-grown maize with reference to root system development. The bleeding rate decreased rapidly just after detopping, which suggested negative effects of shoot removal on bleeding in maize. The bleeding rate of different plants at every hour showed that it has a diurnal change pattern with the maximum value occurring at around 8 a.m. Then we examined the bleeding rate early in the morning with reference to shoot growth. It increased with shoot growth and root development to reach the maximum value at around tasselling and decreased thereafter. The number and diameter of nodal roots emerging acropetally along the stem were increasing until tasselling. Therefore significant positive correlations were evident between the bleeding rate and the root morphological traits, such as total number, diameter, and cross area of nodal roots of a whole root system until tasseling, although these relationships were not clear afterwards. Physiological activity per unit root mass was estimated on the assumption that bleeding rate is a product of root morphology and its physiological activity. The physiological activity per unit root mass increased in the former half of the growing period, then decreased, possibly because of the relative relationship between the formation of new roots and the senescense of existing roots.View full abstractDownload PDF (894K) -
Naoko FUKUTA, Tomoyuki YUKAWA, Osamu MATSUMURA2000 Volume 69 Issue 1 Pages 86-91
Published: March 05, 2000
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSThe varietal differences in the contents of mineral nutrients in leaves under snow cover was examined in relation to the morphological characteristics of shoots in 16 varieties of broad beans. By snow coverage, the necrotized leaf area of the plant was increased and the contents of K, Ca and Mg in the leaves were decreased. The decrease in the mineral nutrient contents and the increase in necrotized leaf area by snow coverage were less in the snow-tolerant varieties than in vulnerable varieties, implying that mineral nutrients do not leach out easily in the tolerant varieties. Therefore, the wax content related to wettability and the number of wounds on the leaf surface which promote leaching out of mineral nutrients were measured. The tolerant varieties did not contain much wax on the leaf surface, but had a smaller number of wounds, which were caused by graupel fall with strong wind before snow covering, than the vulnerable varieties. Furthermore, in tolerant varieties, the plant height, internode and petiole were short, and total leaf area, leaf area touching on ground and intercellular space of the leaves were small. These morphological characteristics showed a close relationship with the number of wounds. These results suggest that the tolerant variety does not leach out a large amount of mineral nutrients under snow through avoidance of wounding, and that the morphological characteristics of broad bean affect snow tolerant.View full abstractDownload PDF (1053K) -
Yasuyuki YOSHIMURA, Fumitake KUBOTA2000 Volume 69 Issue 1 Pages 92-94
Published: March 05, 2000
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSThe transportion of water and photosynthetic products in a leaf is mainly performed through the leaf veins, and it is sufficiently predicted that the morphological characteristics of leaf vein nettings are responsible for the restriction and adjustment of photosynthesis and evapotranspiration in relation to the transporting function. We tried here to apply the lattice-crossing method based on Newman's theory to estimate easily the vein length in a leaf, using two sweet potato cultivars. The average area of leaves used here was 37.3 cm2, in which the total leaf vein length measured by curvimeter was 404.7 cm. A tracing paper on which the lattice was printed was placed on a paper in which the abaxial surface of the leaf was copied with anexpansion of 200% to 400%, and the number of crossing points of vein and lattice line was counted. The vein length could be estimated within 10% error as compared with the measured vein length. The lattice-crossing method provided a correct estimation for the vein length of sweet potato leaves.View full abstractDownload PDF (649K) -
Susumu ARIMA, Jiro HARADA, Shuichi ASANUMA, Minoru MIHARA2000 Volume 69 Issue 1 Pages 95-101
Published: March 05, 2000
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSBased on the pipe-model theory, the root growth characteristics and root nodule distribution in soybean grown in pots were analyzed, using the variety Fukuyutaka and two mutants derived from the variety Enrei, super-nodulating (En6500) and non-nodulating. Fukuyutaka plants were grown under various nitrogen levels, soil hardness, shading levels and bacillus densities, in soil. The ratio of the amount of thin roots which does not conform to the pipe model to that of thick roots which conformed to the model was nearly the same regardless of cultivation conditions. The formation of nodules began in minute radicles of 0.2-0.3 mm diameter class, and about 95% of root nodules were distributed in the thin roots of 1 mm or less. A high correlation was observed between the amount of roots and the number of root nodules in every root-diameter class. However, the big root nodules (larger than 3 mm in diameter) tended to be distributed over all root-diameter classes equally. It was suggested that the distribution of the root nodules with high nitrogen-fixing ability is closely related to the amount of the vascular bundles in each root diameter class.View full abstractDownload PDF (947K) -
Yuji MATSUE, Osamu YAMAGUCHI, Hirokazu SATO, Takahide BABA, Kouhei TAN ...2000 Volume 69 Issue 1 Pages 102-109
Published: March 05, 2000
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSThe abnormal weather did much damage to wheat and two-rowed barley in Kyushu in 1998. The crop situation index and the average yield in Fukuoka Prefecture were 50 and 168 g / m2 for wheat and 52 and 173 g / m2 for two-rowed barley, respectively, the third lowest since 1945. Furthermore, the inspection grade had deteriorated greatly because of the occurrence of damaged grain. Low yield was caused by a decrease in the number of ears and 1, 000-grain weight in response to a high air temperature and high precipitation during growing period. In wheat, the deterioration of apparent quality was caused by an increase in lodging, scab, and sprout because of high precipitation. Immature grains caused by a short ripening period also affected the quality. In two-rowed barley, low quality was due to an increase in husk under-development in response to a shortage of sunshine hours around the heading date and grain with ventral swelling because of high precipitation at the grain-filling stage. The yield and apparent quality of wheat were improved by application of the top dressing at the tillering stage, trampling and earthing under abnormally warm and wet weather.View full abstractDownload PDF (974K) -
[in Japanese]2000 Volume 69 Issue 1 Pages 110-112
Published: March 05, 2000
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSDownload PDF (605K)
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