Japanese Journal of Phytopathology
Online ISSN : 1882-0484
Print ISSN : 0031-9473
ISSN-L : 0031-9473
Search
Advanced search
OR
Browse
Search
Volume 74, Issue 4
Displaying 1-10 of 10 articles from this issue
Show all abstracts
    • |<
    • <
    • 1
    • >
    • >|
Originals
  • The effectiveness of simultaneous application of benzimidazoles and iminoctadine triacetate on the control of green mold in orchards of very early ripening Satsuma
    N. TASHIRO, Y. IDE
    2008 Volume 74 Issue 4 Pages 297-303
    Published: 2008
    Released on J-STAGE: December 03, 2008
    DOIhttps://doi.org/10.3186/jjphytopath.74.297
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    Benomyl wettable powder control of green mold of a very early ripening variety of mandarin orange, Satsuma, decreased to unacceptable levels for practical use against benzimidazole-resistant strains of Penicillium digitatum in orchards. Application of an iminoctadine triacetate liquid formulation that achieved a high fungicidal efficacy in vitro against benzimidazole-resistant and -sensitive strains of P. digitatum gave variable effects in the control of the disease under field conditions. When the disease incidence was severe, the efficacy of the iminoctadine triacetate application was significantly lower. However, simultaneous application of an iminoctadine triacetate liquid formulation and benomyl wettable powder improved the control efficacy to levels acceptable for practical use. Interestingly, the effect was not additive but synergistic. Although thiophanate-methyl wettable powder is also a benzimidazole like benomyl wettable powder, it was not as effective. In addition, no significant effect on application timing during 3 weeks before harvest and cumulative precipitation of up to 150 mm during the treatment period was detected.
    View full abstract
    Download PDF (544K)
  • Detection of Acidovorax avenae subsp. citrulli from seed using LAMP method
    H. OYA, H. NAKAGAWA, N. SAITO, H. UEMATSU, T. OHARA
    2008 Volume 74 Issue 4 Pages 304-310
    Published: 2008
    Released on J-STAGE: December 03, 2008
    DOIhttps://doi.org/10.3186/jjphytopath.74.304
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    Because detection methods for the causal agent of bacterial fruit blotch, Acidovorax avenae subsp. citrulli (Schaad, Sowell, Goth, Colwell, Webb, Willems, Goor, Thielemans, Gills, Kersters & DeLey), from seeds are time-consuming we evaluated a new assay using membrane filtration and loop-mediated isothermal amplification (LAMP). A LAMP primer set was designed for specific amplification of the hrpG-hrpX gene spacer region in A. avenae subsp. citrulli. The detection sensitivity of A. avenae subsp. citrulli of this procedure was approximately 103 cfu in 100 ml of water used to wash 1000 artificially infested seeds of either watermelon, wax gourd or melon. The complete assay took approximately 2 h. When naturally infected seeds were tested, A. avenae subsp. citrulli was detected from melon and watermelon seeds. This method is valuable for the rapid and precise detection assay of A. avenae subsp. citrulli on seeds.
    View full abstract
    Download PDF (548K)
  • Control of tomato bacterial wilt in a hydroponic system with iodine
    R. OGAI, H. YAMAGUCHI, M. HUKUOKA, T. MARUO, Y. AMEMIYA, Y. SHINOHARA
    2008 Volume 74 Issue 4 Pages 311-315
    Published: 2008
    Released on J-STAGE: December 03, 2008
    DOIhttps://doi.org/10.3186/jjphytopath.74.311
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    Iodine (I2) as a disinfectant of the nutrient solution for a hydroponic system was evaluated. In a test tube experiment, I2 at 1 μg/ml sterilized distilled water for 5 min inactivated Ralstonia solanacearum (Rs). Treatment of nutrient solution with 3 μg/ml of I2 for 15 min before transplanting tomato seedlings into a hydroponic system sufficiently controlled the bacterial wilt disease. In contrast, 83.3% of the plants in the control system were diseased at 30 days after inoculation. In a nutrient solution in which tomatoes were already growing, Rs was not detected immediately after I2 treatment but was detectable 3 days after the treatment, and eventually the bacterial population reached the same level of the control. The disease incidence in systems treated with 3 and 5 μg I2/ml nutrient solution was lower than that in untreated control. These results suggest that I2 is a highly effective disinfectant against Rs and can control tomato bacterial wilt in a hydroponic system.
    View full abstract
    Download PDF (750K)
  • Conditions for loop-mediated isothermal amplification (LAMP) and a nonmacerating DNA extraction method to assay for huanglongbing (citrus greening) disease
    M. OKUDA, S. KAWANO, Y. MURAYAMA, T. IWANAMI
    2008 Volume 74 Issue 4 Pages 316-320
    Published: 2008
    Released on J-STAGE: December 03, 2008
    DOIhttps://doi.org/10.3186/jjphytopath.74.316
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    A loop-mediated isothermal amplification (LAMP) assay to detect the causal organism of huanglongbing (citrus greening) was developed. Primers were designed from the nucleotide sequence of the rpl KJAL-rpo B operon of Candidatus Liberibacter asiaticus. DNA amplification was greatly accelerated when loop primers were added to the reaction, and the reaction kinetics was correlated with the reaction temperature from 61°C to 65°C. Sodium hydroxide was used in a rapid DNA extraction method (called alkali extraction) that does not require maceration of leaves, and specific amplifications in the LAMP reaction were obtained from all samples prepared from Ca. L. asiaticus-infected plants. With these methods, Ca. L. asiaticus was detected when one infected leaf was mixed with four healthy ones. The threshold times for turbidity were equal to those for samples prepared from the same leaves using commercially produced regents.
    View full abstract
    Download PDF (403K)
  • Morphology and fungal growth in elongated rice seedlings infected with Gibberella fujikuroi, and control of the disease in a flooded nursery
    H. NAITO, K. SAITO, H. FURUYA, S. FUJI
    2008 Volume 74 Issue 4 Pages 321-327
    Published: 2008
    Released on J-STAGE: December 03, 2008
    DOIhttps://doi.org/10.3186/jjphytopath.74.321
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    We studied the morphology of rice seedlings with typical elongation symptomatic of bakanae disease, the distribution of the fungus in the seedlings, and cultural methods to control the disease in nursery boxes. We used naturally infected seeds that either possessed husks (“ordinary seeds”) or had the husks removed (“processed seeds”). Ordinary seeds germinated to produce elongated seedlings with significant elongation of the first to the third leaf sheaths and the second to third leaf blades. In the elongated seedlings from ordinary seeds at the transplanting stage, mycelia were observed within vessels and the parenchymatous tissues adjacent to the vascular bundles in the bases of the culms and in vessels farther up the culms, but were limited to the region less than 2 cm above the bases of the culms. Then the elongated seedlings from both types of seeds were transplanted to pots. More than 30% of the hills from the ordinary seeds recovered and became healthy, but more than 50% had died by 63 days after transplanting. Recovery depended on the growth of tillers free of pathogen mycelia, because the diseased main culms died soon after transplanting. More than 80% of the hills from processed seeds recovered. Because of these results, we speculated that many of the elongated seedlings from the processed seeds were not infected, but had elongated as a result of diffusion of gibberellin from diseased rice seedlings in the environs. We then grew seedlings in a flooded nursery (pool nursery) to suppress development of the disease. In nursery boxes where the water level was kept above the surface of the soil until the seedlings reached the transplanting stage, the incidence of elongated seedlings was reduced. The suppressive effect may be due to reduced mycelial growth in the culum under flooding conditions.
    View full abstract
    Download PDF (908K)
  • Suppression of transmission of Glomerella cingulata with a hydrophilic, nonwoven fabric sheet
    K. YONEMOTO, T. MIKI, K. HIROTA, K. BANDO
    2008 Volume 74 Issue 4 Pages 328-334
    Published: 2008
    Released on J-STAGE: December 03, 2008
    DOIhttps://doi.org/10.3186/jjphytopath.74.328
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    We developed a new irrigation method for strawberry cultivation by covering the soil with a hydrophilic, nonwoven fabric sheet to suppress the spread of Glomerella cingulata, causal agent of strawberry anthracnose. A hydrophilic, nonwoven fabric sheet was placed on soil in cell trays, and drip-type irrigation tubes supplied water, which flowed from the sheets to strawberry roots through a cut in the sheet. This technique significantly reduced anthracnose in inoculation experiments. The use of this fabric as a rain shelter suppressed anthracnose even more. The soil application lowered humidity and increased the temperature 10 cm from the basal part of the plants in comparison to an overhead irrigation method, indicating that humidity may be more important than local temperature in the spread of the fungus.
    View full abstract
    Download PDF (1062K)
Short Communications
Disease Notes
    • |<
    • <
    • 1
    • >
    • >|
feedback
 Top