Inoculation Method for the Attenuated Virus Water Soluble Powder Using Simple Sprayer

Abstract

For farmers to inoculate seedlings with attenuated virus easily we examined an inoculation method using an irrigating device as a simple sprayer. Experiments were conducted using cucumber ‘Excellent fushinari No. 2’ and the attenuated Zucchini yellow mosaic virus (ZYMV) water-soluble powder. We investigated the rate of infection by the attenuated ZYMV under conditions that consisted of two sizes of carborundum (600 and 1200 mesh) combined with two treatments of carborundum (mixed inoculum and dusted cotyledons). As a result, we could inoculate more effectively by spraying the inoculum on 600 mesh carborundum-dusted cotyledons. In addition, we obtained a stably high infection rate (72%) on spraying at a distance of 10–17.5 cm from the cotyledon. On the other hand, the susceptibility to the attenuated ZYMV using a rubbing-based inoculation method was tested among six varieties of cucumber including ‘Excellent fushinari No. 2’, showing that the susceptibility differed among the six varieties.