2021 Volume 63 Pages 93-97
Shiso mosaic disease is caused by the perilla mosaic virus (PerMV) and transmitted by shiso rust mites (Shevtchenkella sp.). Twenty PerMV-infected shiso rust mites were released in the center of a perilla plant field to investigate horizontal disease transmission. Disease in the surrounding plants started developing after 19 days; 47% of plants displayed symptoms after 40 days; and all plants displayed symptoms after 69 days. The diseased-plant density was the highest in the northeast, northwest, and southeast of the inoculated field, and was lowest in the southeast. The wind direction frequency during the one to two weeks before the field observation seemingly correlated with the density of disease-developed plants in the field.
