Japanese Journal of Crop Science
Online ISSN : 1349-0990
Print ISSN : 0011-1848
ISSN-L : 0011-1848
Volume 82, Issue 1
Displaying 1-15 of 15 articles from this issue
Regular Paper
Agronomy
  • Takayuki Suzuki, Hideaki Iwahori, Katsuki Adachi, Tooru Kobayashi
    2013 Volume 82 Issue 1 Pages 1-10
    Published: 2013
    Released on J-STAGE: January 31, 2013
    JOURNAL FREE ACCESS
    Three cropping types in sweet potato, namely, planting in April and growing with transparent polyethylene mulch, planting in May and growing with black polyethylene mulch, and planting in June and growing without mulch, were compared. The root-knot nematode density at the planting of sweet potato and the root-knot nematode injury in sweet potato were reduced by the late cropping. Then, the influences of the mulch material on the injury were examined in the same cropping season and the same nematode density. Nematode injury in sweet potato was reduced by growing with white and black double-layered polyethylene mulch and by growing without mulch as compared with the growing with transparent polyethylene mulch and with black polyethylene mulch. This suggested that the soil temperature influenced nematode injury. The cropping season of radish influenced the nematode injury in radish. However, preceding radish cropping and its season had little influence on the nematode density before succeeding sweet potato cropping and on the nematode injury in sweet potato.
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  • Makoto Hattori, Yoshifumi Nagumo, Toru Sato, Yoichi Fujita, Yasuhiro H ...
    2013 Volume 82 Issue 1 Pages 11-17
    Published: 2013
    Released on J-STAGE: January 31, 2013
    JOURNAL FREE ACCESS
    Recently, soybean yields in Niigata Prefecture have been subjected to wide annual fluctuation, and both the seed yield and quality have decreased in the last decade. This trend was confirmed based on the soybean yield statistics in Niigata Prefecture. We investigated the relationship between soybean seed yield and cropping system, and the effects of nitrogen fertility in soil and climatic factors on the yield. The yield decreased dramatically in the fields where soybean cropping continued for over four years. The recent decline in soybean yield was attributed to the decrease in pod number and seed weight. Compared with a continuous paddy field, a long-term paddy-upland rotation field had less available soil nitrogen during the soybean-growing period, especially from the beginning of the bloom (R1) stage onward. The low level of available nitrogen in the soil of long-term rotated fields was suggested to reduce pod number and seed growth. It was also suggested that on increasing amount of solar irradiation increased the pod number in early August, from the beginning-bloom to beginning-pod (R1-3) stages, and that, the heavy rains in mid-August, during the full-pod to beginning-seed filling (R4-5) stages, caused a short-term wet damage, which triggered a decline in nodule activity along with premature pod fall.
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  • Youichi Ohdaira, Ryouji Sasaki, Hiroyuki Takeda
    2013 Volume 82 Issue 1 Pages 18-27
    Published: 2013
    Released on J-STAGE: January 31, 2013
    JOURNAL FREE ACCESS
    The essential points for controlling the digestible protein content (DP) of rice grain at low levels in seed-protein mutant rice cultivars (SPMR) were investigated. A low-glutelin cultivar ‘LGCsoft’, a 26-kDa globulin-deficient low-glutelin cultivar ‘LGC-Jun’, and a normal-type cultivar ‘Nihonmasari’, were cultivated for 8–9 cropping seasons over a period of 4 years. Factors affecting seed protein composition and protein content in rice grain were analyzed. DP was affected by both the total protein content (TP) and the ratio of DP to TP in all cultivars. However, the effect of DP/TP on DP was greater in ‘LGCsoft’ and ‘LGC-Jun’ than in ‘Nihonmasari’. A positive correlation between DP/TP and air temperature from 0 to 15 days after heading was observed in all cultivars. The highest correlation coefficient was observed from 0 to 10 days after heading in ‘LGCsoft’ and ‘LGC-Jun’, which was slightly earlier than in ‘Nihonmasari’. Therefore, it is important to adjust the planting season to avoid high temperatures during the early ripening period for the cultivation of SPMR. TP affected DP more than DP/TP not only in ‘Nihonmasari’ but also in SPMR. A positive correlation was observed between TP and the nitrogen content of shoots at the heading stage, and a negative correlation was observed between TP and the percentage of ripened grains. These results indicate that shoot nitrogen status and percentage of ripened grains should be taken into account in planting and cultivation management plans.
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  • Akihiro Ohsumi, Hironori Heinai, Osamu Matsumura
    2013 Volume 82 Issue 1 Pages 28-33
    Published: 2013
    Released on J-STAGE: January 31, 2013
    JOURNAL FREE ACCESS
    Basal dressing with lime nitrogen can inhibit the occurrence of rice false smut. However, how it affects rice yield and appearance quality has not been fully revealed. We compared the yield and grain appearence quality of Koshihikari that received basal dressing of lime nitrogen (LN) with those that received split application of ammonium sulphate (CTL) in 2010 and 2011. Total amounts of nitrogen were 4 g m-2 in both LN and CTL. We investigated the uptake of 15N labelled fertilizer of lime nitrogen, and proved that rice continued to absorb lime nitrogen until the panicle formation stage. The recovery rate of lime nitrogen given as basal dressing was estimated to be 9.1-17% at full heading stage. Ripening ratios were significantly lower in LN than in CTL in both years. The rice appearance quality in LN was inferior to that in CTL in 2011, a year with small biomass production in the ripening period due to low irradiance. The low ripening ratio and poor grain appearance quality were associated with less nitrogen absorption after panicle formation. These results indicate that additional nitrogen application to improve the plant nitrogen status at heading is required for LN to have biomass production and grain appearance quality equivalent to CTL.
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  • Toru Sato, Satoshi Azuma
    2013 Volume 82 Issue 1 Pages 34-41
    Published: 2013
    Released on J-STAGE: January 31, 2013
    JOURNAL FREE ACCESS
    Yield characteristics of iron-coated and direct-seeded rice in a submerged paddy field were evaluated using different seeding methods and water management after seeding in comparison with those with calcium peroxide-coated seeds in the Hokuriku region. Seeding methods were stripe seeding (57 and 30 seedlings/m2) and hill seeding (17 cm and 24 cm between hills). Water managements were flooding and drainage in the early growth stage. Yield in iron-coated direct-seeding was slightly lower than that in calcium peroxide-coated direct-seeding. Yield in iron-coated direct-seeding with hill seeding (17 cm between hills) was the highest among the iron-coated direct-seeding plots, and there were no significant differences in yield between calcium peroxide-coated and iron-coated direct-seeding. This is probably because the light intercepting structure was better, and dry matter production after heading was larger in the hill seeding than in the stripe seeding. The effect of water management on yield was larger in the drainage plot than in the flooded plot. Probably because resistance to logging was higher in the drainage plot resulting in less lodging and high yielding. These results indicate that hill seeding (17 cm between hills) and drainage after seeding are important for reducing lodging and increasing yield in iron-coated direct-seeding.
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Quality and Processing
  • Kenji Nagata, Ryouji Sasaki, Youichi Ohdaira
    2013 Volume 82 Issue 1 Pages 42-48
    Published: 2013
    Released on J-STAGE: January 31, 2013
    JOURNAL FREE ACCESS
    Twenty cultivars were grown in paddy fields seven times from 2008 to 2010. The percentage of cracked grains was positively correlated with the temperature during the early stage of grain filling. Among the cultivars used, Futaba, Yamahikari and Fujisaka 5 showed high percentages of cracked grains. Cultivars Hananomai, Hanaechizen, Nikomaru and Himenomai showed high percentages of grain cracking when the temperature during grain filling was high although cracks were scarcely formed when it was low. On the other hand, Chinese cultivar Yan Xuang 203 showed stably lower percentages of cracked grains under higher temperature conditions. In the pot experiments conducted in 2009, the temperature conditions after the heading stage were identical for all cultivars and high temperature treatment was given during the early stage of grain filling. In this experiment, the percentage of cracked grains was significantly lower in Yan Xuang 203 than in the other cultivars. We concluded that Yan Xuang 203 is highly resistant to grain crack formation even when the air temperature during the grain filling stage is high.
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  • Kouji Nakamichi, Nana Ashikaga, Masatomo Kurushima, Mikako Sato, Yasuh ...
    2013 Volume 82 Issue 1 Pages 49-55
    Published: 2013
    Released on J-STAGE: January 31, 2013
    JOURNAL FREE ACCESS
    The hard spring wheat cultivars “Harukirari” and “Haruyokoi” were cultivated at the Kamikawa Agricultural Experiment Station, Hokkaido, for 3 years and their grain protein content, wheat ash content, flour protein content, flour ash content, ratio of break flour to middling flour (BM), dough water absorption, gluten index, and loaf volume were evaluated. The flour sifted from “Harukirari” had lower protein and ash contents than the flour sifted from “Haruyokoi”. BM increased with the increase in the grain protein content, and was higher in “Harukirari” than in “Haruyokoi”. As the flour protein content increased, dough water absorption and loaf volume increased, while the gluten index decreased. Dough water absorption and gluten index were lower in “Harukirari” than in “Haruyokoi”, and loaf volume was larger in “Harukirari” than in “Haruyokoi”, while the flour protein content was similar. Size-exclusion high-performance liquid chromatography revealed that the extractable polymeric protein content (EPP), extractable monomeric protein content (EMP), and unextractable monomeric protein content were positively correlated with the flour protein content. EMP, which mainly consists of gliadins, increased with the increase in flour protein content. When the flour protein content was the same, EPP and EMP were higher in “Harukirari” than in “Haruyokoi”. However, the unextractable polymeric protein content was lower in “Harukirari” than in “Haruyokoi”.
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Genetic Resources and Evaluation
  • Toshikazu Morishita, Hiroyasu Yamaguchi, Konosuke Degi, Akemi Shimizu, ...
    2013 Volume 82 Issue 1 Pages 56-62
    Published: 2013
    Released on J-STAGE: January 31, 2013
    JOURNAL FREE ACCESS
    Curcumin contents (curcumin, monodemethoxycurcumin, and bis-demethoxycurcumin) and antioxidative activities of 11 strains of Curcuma longa, 6 strains of Curcuma aromatica, and 3 strains of Curcuma zedoaria were evaluated in Ibaraki Prefecture in 2004 and 2005. C. longa was classified into two groups, according to total curcumin contents, 8 strains mainly from Japan and Taiwan (C. longa I) that contained 200–700 mg/100g dry weight (DW), and 3 strains from Southeast Asia (C. longa II) that contained more than 1800 mg/100 gDW. C. aromatica had a total curcumin content of 50–100 mg/100 gDW. Two of the 3 strains of C. zedoaria, did not contain curcumins, but 1 strain contained about 1500 mg/100 gDW. There were difference in the ratios of curcumins among C. longa I, II, C. aromatica, and C. zedoaria. Although the curcumin contents and antioxidative activities of most strains were higher in 2005 than in 2004, the year-to-year correlation was significant. Consequently, despite the large year-to-year variation in curcumin contents, the order of groups was stable. Although it is impossible to estimate the curcumin contents of each strain, it is possible to classify the strains into groups.
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Modelling, Information and Environment
  • Toshikazu Suzuki, Kaori Eguchi, Takashi Ikka, Akio Morita
    2013 Volume 82 Issue 1 Pages 63-68
    Published: 2013
    Released on J-STAGE: January 31, 2013
    JOURNAL FREE ACCESS
    The starch content of tea plant was measured by the colorimetric iodine method (iodine method) after hot-water extraction. The maximum absorbance of starch extracted from tea roots was around 600 nm, and extraction with hot-water for at least 10 minutes was considered sufficient for accurate measurement. The starch content measured by the iodine method was compared with that measured by the phenol-sulfuric acid colorimetric method in which starch was extracted with perchlorate (control method). The starch content in roots and stems measured by the iodine method was closely correlated with the value obtained by the control method (r=0.98). However, in samples with a low starch content (less than 30 mg g-1), the value obtained by the iodine method was lower than that obtained by the control method. As compared with the control method, the time and cost required for analysis were reduced to 1/3 and 1/90, respectively, by the iodine method. Moreover, harmful chemicals are not used in the iodine method. It is concluded that the iodine method is an easy-to-use and safe method to accurately measure the starch content of tea plants.
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Research and Technical Note
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