Occurrence of Jujube Witches’ Broom Disease and Control Efficacy of Trunk Injection with Oxytetracycline in Boeun Area from 2018 to 2019

Jujube witches' broom (JWB) disease is a high-risk plant disease that occurred on and devastated jujube orchards throughout South Korea in the 1950s.Recently, as the jujube cultivation area has been significantly increased nationwide, we investigated the disease in jujube orchards in the Boeun region to obtain basic information for proactively evaluating the risk of JWB outbreaks from 2017 to 2019.A field trial was conducted to evaluate the effect of the trunk injection of Sungbocycline (a.i. oxytetracycline calcium alkyl trimethyl ammonium 17%, OTC).The incidence of JWB disease was very low in Boeun, but it was gradually increased mainly in the area and on the farms where it had occurred previously.The trunk injection with OTC was most effective in the early stages of growth.However, even though the trees were treated with OTC, disease symptoms appeared in other healthy branches in severely affected trees.When the tree was first injected with OTC in June, the control efficacy of second injection was higher one month after the first injection than five months.These results suggest that early diagnosis based on various symptoms and early control based on them can be very effective in preventing JWB disease in advance and increasing control efficacy.