Characteristics of peach twigs expressing spring canker bacterial shot holes and the effects of the early elimination of spring cankers

In 2016, 2017, and 2021, the early detection and excision of overwintering twigs with spring cankers (caused by Xanthomonas arboricola pv. pruni) were performed to understand the growth of peach twigs prior to disease outbreak. A survey was conducted at the peach cultivation field, Hikawa Hakuho, in Nagakute City, Aichi Prefecture. Twigs with spring cankers tended to have a lower leaf germination rate and shorter average leaf length than those without spring cankers. In 2017 and 2018, early resection of the spring canker was performed in fields where chemical control against peach shot hole disease from the germination stage to the end of harvest had not been practiced. In the plots where early elimination was practiced, the incidence of diseased leaves tended to decrease in 2017 and 2018 compared to the plots where early elimination was not practiced. When the peach twigs that were perforated bacterial disease were isolated from the early eliminated and healthy twigs using a medium, the detection rate of the early eliminated twigs was higher than that of the healthy twigs.