• Korean Journal Plant Pathology
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• v.14 no.6
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• pp.729-731
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• 1998

A black leg disease in wasabi occurred, showed black spots on the leaves, changed a rhizome color to black by invading the vascular bundles of stem and root, thus lowered the quality of the rhizome. The mycelium of the pathogen was yellow at first and then turned to dark yellow on oat meal agar medium. The pycnidium was globose or subglobose, dark brown in color, and 44~120$\times$28~170 ${\mu}{\textrm}{m}$ in size and had one or two ostioles on the upper part. The pycnidiospores are single-celled, hyaline, and 4~6$\times$1.2~2.3 ${\mu}{\textrm}{m}$ in size. The causal pathogen was identified as Phoma wasabiae. The black leg disease of wasabi occurred within the range of 28 to 32% at Chonbuk province in 1994~1995. The disease was appeared from April to October and severe in June and July. The black leg caused by P. wasabiae was first described in Korea.

• Journal of Bio-Environment Control
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• v.4 no.2
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• pp.240-245
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• 1995

In order to find out the effect of temperature and shading on the growth and major disease infection of Eutrema wasabi Matsum., experiments were at growth chamber condition and field. Plant height, petiole and rhizome of wasabi were obvious decreased with increase the temperature, from which the optimum air temperature for the plant growth were estimated to be 17$^{\circ}C$. The light intensity of the treatment with 75% shading net was favorable to the length of main rhizome, rhizome weight and whole plant weight. Infection ratio of black leg and soft rot were increased at high temperature condition, however their infection ratio were decreased with increase the shading condition.