Chapter 24

Pesticides for Grapevines

Fungicides

Probably the largest numbers of vine diseases are caused by fungi, and the most common chemical tools for the vine disease control are fungicides. Appendix E, Fungicides Registered for Use in Vineyards, list common names (active ingredient) along with trade names of currently registered fungicides in the United States for use on grapes.

Mobility

Contact Fungicides

Contact fungicides adhere to the leaf surface but do not penetrate the tissue.

Systemic Fungicides

Systemic fungicides are absorbed into the leaf tissue, and then translocate from their point of entry to other tissues.

Mode of Action

One way to classify fungicides is by their chemical structures, or their mode of action (MoA). MoAs serve to describe how a particular chemical or chemical group acts to kill or disable fungi. Fungicides kill fungi by damaging their cell membranes, inactivating critical enzymes or proteins, or by interfering with key processes such as energy production or respiration.

Breadth of Activity

Single-site

Single-site fungicides are active against only one point in one metabolic pathway in a pathogen or against a single critical enzyme or protein needed by the fungus.

Multi-site

Multi-site fungicides have multiple modes of action, so they affect multiple target sites, and simultaneously interfere with numerous metabolic processes of the fungus.

General Function

Protectants

These fungicides, sometimes referred to as preventatives, are applied to form a protective barrier on the vine surface preventing the fungi from successfully penetrating host tissue.

Curatives

Curative fungicides have the ability to inhibit or stop the development of infections which are not showing symptoms.

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