Study on the Pathology of Jujube Black Tip Disease and Its Sustainable Control

摘要

The pathogenic factors of jujube (Ziziphus jujuba Mill.) black tip disease were analyzed in this paper. Five jujube orchards in Jinzhong city, Shanxi province were chosen for investigation on the occurrence, pathogen filtration, and inoculation testing. Additionally, the fluoride content in the jujube leaves, fruits and the atmosphere around the orchards was determined. The conclusion showed that the occurrence of jujube black tip disease was different from the infectious disease, which appeared during the fruit swell period, ripe period and mature period. Although six fungi were separated from diseased fruits, they manifested varying symptoms when inoculated in healthy fruits. However, black tip disease was consistently induced on healthy fruits bycontrolled exposure to hydrogen fluoride. We also found that fluoride concentration in the atmosphere was positively correlated with fluoride contents in jujube leaves and fruits and the incidence of jujube black tip disease. Furthermore, anti-fluorideagents had a significant effect on controlling the disease. For these reasons, we concluded that close proximity to excessive fluoride pollution was the foremost reason for the outbreak of black tip disease in jujube orchards.