Abstract:

Incidence of jujube black tip disease, a new disease which is very serious for the jujube, was investigated in 7 sites with the air polluted by fluorides and one site without air pollution in Jinzhong City of Shanxi Province from May to September 2009. The fluorides content of jujube fruits,jujube leaves and atmosphere in the jujube main production areas were examined,and the correlation of fluorides content among atmosphere, jujube leaves and jujube fruits were analyzed.The goal of the study was to test if there were the correlations between fluoride content and jujube black tip disease. The results showed as follows:The longer jujube leaves and fruits exposure in the air, the higher fluorides content jujube leaves and fruits had;The top of jujube tree had more fluoride content than the middle, the middle had more than the basal, fluoride content of fruit skin was more than that of the flesh;The absorption rate and accumulation of fluoride in jujube leaves and fruits were positively correlated with the fluoride concentration in atmosphere during the jujube growing period;The fluoride content of jujube leaves and fruits was negatively correlated with the distance to pollution source;The incidence of jujube black tip disease was positively correlated with the fluoride content of jujube leaves, fruits and atmosphere.

Key words: jujube black tip disease, incidence, fluoride content, correlation