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Circular Leaf Spot of Sweet Basil Caused by Cercospora guatemalensis New to Japan

Authors:
  • Sakata Seed Co.

Abstract

A leaf spot disease on sweet basil (Ocimum basilicum L.) was observed in Chiba Prefecture in 1997. The lesions were amphigenous, circular to irregular, hygrophanous, dark brown. Stromata were amphigenous, composed of a few brown cells. Conidia with a thickened truncate base, filiform to cylindrical, hyaline, were produced from conidiophores with thickened conidial scars. These morphological characteristics agreed with those of Cercospora guatemalensis Mueller et Chupp. This species was new to Japan. The symptoms appeared 10 days after inoculation and the inoculated fungus was re-isolated. Artificial sporulation and detection from commercial seeds were not successful.
The Phytopathological Society of Japan (PSJ)
NII-Electronic Library Service
The Phytopathological Society of Japan (PSJ)
NII-Electronic Library Service
The Phytopathological Society of Japan (PSJ)
NII-Electronic Library Service
Article
Basil leaves are the major ingredients in traditional medicinal drugs with significant health benefiting phytonutrients. The quality of leaves describe the measure of excellence from deficits, substantial variations and defects. Also, the disease on leaves poses threats to the economic and production status in the agricultural industry worldwide. So, a new classification model using survival of fittest approach with successive generation of best results is proposed in this study. A three level hierarchical approach is developed to recognize basil leave diseases. Healthy and diseased leave samples with downy mildew and cercospora leave spot are taken as experimental objects. For enhancing contrast, a Contrast Limited Adaptive Histogram Equalization algorithm is performed by adjusting intensities of the image in order to highlights the target area for the segmentation of the disease from their background. Experiments are performed by utilising combination of texture and color features. Afterwards Random Forest, feature selection technique is used to attain the high informative features. Finally, a new approach of classification is employed to characterize the leave diseases. Our new classification model effectively detects, classified basil leaves diseases with 95.73% accuracy. Proposed model attain the maximum success rate than other existing methods.
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Diseases of basil and their management. Plant Dis. 81 : Guo, Y.L. and Hsieh, W.H. (1995). The Genus Pseudo-cercospora in China. pp. 127-132, International Aca-demic Publishers, Beijing. Hsieh, W.H. and Goh, T.K. (1990). Cercospora and similar fungi from Taiwan. p.155, Maw Chang Book Company, Taipei.
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