ARS | Publication request: Why Fungicides Fail

Submitted to: American Vegetable Grower
Publication Type: Abstract Only
Publication Acceptance Date: September 2, 2002
Publication Date: September 1, 2002
Repository URL: http://hdl.handle.net/10113/16384
Citation: Miller, S., Derksen, R.C., Riedel, R. 2002. Why Fungicides Fail. American Vegetable Grower. 50(9):12-13.

Technical Abstract: Most disease management programs depend on use of fungicides with protective or curative properties. Knowing the mode of action of the fungicide is essential to most effective use of these materials. Fungicides with protective properties must be applied before infection and only provide protection where they are applied. Curative fungicides can halt pathogen growth and usually move even short distances through plants. Fungicide choice is also critical since few provide broad spectrum control. The timing for pesticide application is critical since their effectiveness will depend on how long the fungicide can provide protection, weather conditions, the rate at which the plant puts out new growth, and the biology of the pathogen. Good coverage is usually important to maximize fungicide effectiveness. Droplet size and application rates must be matched to the formulation as well as the amount of plant material that requires protection to provide the most effective spray coverage. These factors are determined mostly by nozzle choice. The need for good coverage must be balanced against the risk of spray drift. These research results will not necessarily guarantee disease control in each situation but provide information on how to achieve the most efficacious results with fungicides as well as an understanding of their limitations.