ALTERNATIVES TO METHYL BROMIDE FOR WEED CONTROL

摘要

The use of methyl bromide as a broad-spectrum soil fumigant has contributed significantly to the control of weeds and soilborne plant pathogens in vegetable production and has served as a "stand alone" weed control tactic in Florida, U.S.A. for many years. The pending loss of this biocide due to environmental issues, has created a need for alternative weed control measures, particularly for minor crops, such as tomato, pepper, and strawberry, for which there are few chemical herbicides registered for use. Losses in fresh market tomatoes in Florida due to weed pressure, with methyl bromide available, have been estimated at more than US$291 million (Bridges, 1992). In the absence of methyl bromide, these losses could increase substantially and represent an area of great concern to vegetable producers. Alternative soil disinfestation methods have been tested in several locations throughout Florida and several methods have provided adequate control of some pathogens and weeds, to date there is no single universal replacement for methyl bromide. Yellow and purple nutsedge have been the focus of several studies and are the most significant weed problems facing growers immediately after cessation of methyl bromide use. However, a greater diversity of weed problems is expected to develop without the broad-spectrum activity of methyl bromide. Studies were conducted to identify what weed problems arise with the use of alternative soil disinfestation practices and biological control agents for these target weeds sought and developed.