Water hyacinth in China: its distribution, problems and control status.

Abstract

Water hyacinth is one of the most important invasive alien plant species in China, into which it was introduced in the early 1900s. Now the weed is distributed in 17 provinces, and in Guangdong, Yunnan, Fujian, Zhejiang and Taiwan has become a bio-disaster. Compared with the situation in 1960, few people now use water hyacinth plants to feed pigs or ducks, or to make fertilisers. It poses a great threat to agriculture, fisheries, transportation and the environment. It is estimated that each year more than 100 million RMB yuan (US$12m) is spent on control of water hyacinth throughout China, but in most areas the weed remains vigorous and continues to spread. Chemical, mechanical and biological control, as well as integrated control strategies, have been employed to combat water hyacinth in more than 10 provinces. Two weevils, Neochetina eichhorniae and N. bruchi, which were introduced from Argentina and USA in 1995, have established and spread their populations in Zhejiang and Fujian provinces. The weevils greatly suppressed the plants around the release areas. In early 2000, a mirid, Eccritotarsus catarinensis, was introduced from South Africa but did not establish. A survey for pathogens of water hyacinth began in spring 2000 in southern China. WATER hyacinth was introduced into China in the early 1900s. As an ornamental plant, it was first introduced