Dissemination of plant diseases by man

Name(s): 
Human vectors of plant disease
Nature 
Man is an important agent in the dissemination, over both short and long distances, of plant pathogens. Frequently in his commercial, agricultural or recreational activities, man has carried plant pathogens, previously confined to a particular area, to new localities where they have caused tremendous damage, even though they may have been relatively harmless in their native habitat.
Type 
(D) Detailed problems