"Citrus greening disease is a global citrus disease. In China, citrus greening disease is mainly found in Guangdong, Guangxi, Hainan, Taiwan and other provinces and autonomous regions. However, in recent years the disease has gradually spread and cases have been discovered in Jiangxi, Hunan, Yunnan, Guizhou and other parts of southern Sichuan, Zhejiang, Jinhua, Wenzhou and other cities and counties," says ChaoWu Zheng, an expert from the YiHao Farm and Agricultural financial network.

The only known boarder for the disease is temperature Generally, above 17 degrees latitude, the disease cannot survive through the winter, so the transmission of the disease is not so serious. At present, the most serious outbreaks are in the subtropical to tropical areas.

Citrus greening disease can infect all varieties of Citrus, including Mandarin citrus, grapefruit, kumquat and especially the yellow orange; FuZhou orange, tangerine banana, tea orange, sugar orange, Wenzhou citrus and naval oranges are all more sensitive varieties.

Most of the citrus producing regions are in the area of the outbreak, which has caused a serious threat to the development of citrus industry - leading to a 50% reduction of output and to the destruction of some areas.

"The Chaozhou Mandarin, the sugar orange (Guangning, Deqin and Zhaoqing Sihui city of GuangDong province) the navel orange, (GanNan city, JiangXi province) etc. - all these citrus planting areas have decreased sharply - from about 300 thousand acres to 10-30 thousand acres of production, or even less".

The citrus greening disease is a kind of bacteria that cannot be isolated or cultivated. Therefore, there are no effective drugs, antigens and resistant varieties for the treatment of the disease. Citrus greening disease can not be completely cured. However, in the production practice, as long as the appropriate measures are strictly implemented, the disease can be preventable and controllable.