Vineyard Wildlife Control
Gophers can cause long-term damage if left unchecked in the vineyard. Gnawing on grapevine roots and trunks will lead to large patches of dead vines. Gophers can also damage irrigation systems and cause erosion by diverting water via their burrows. Although these pests have natural predators, growers should not rely on them solely for controlling large populations of vertebrates. Many tools are available for controlling gophers including trapping, baiting, fumigation, and birds of prey.
Effective and efficient trapping of pocket gophers requires three key elements. First, use plenty of traps. Set at least one trap for every fresh mound in the vineyard. Second, carefully inspect the vineyard to determine the location of the newly constructed mounds. Newly constructed mounds tend to be taller, have more granulated soil that is less compacted, and darker color. Mounds that are flattened with light tan coloration are old mounds and should be avoided. Third, trapping requires patience and effort.
For large populations, several rodenticides for controlling pocket gophers in vineyards have been registered with the federal government and are in current use.
Strychnine-treated bait is the most common type used for pocket gopher control.
Zinc phosphide is less effective than strychnine.
Anticoagulant baits (diphacinone) are also registered for pocket gopher control.
To be effective, pocket gopher baits must be placed in the main underground tunnel, not the lateral tunnels.
Many fumigants are not very effective against gophers due to their ability to detect and seal off tunnels quickly. However, aluminum phosphide (a Restricted Use Material) works well during the late winter or early spring months when the soil is moist.
Birds of Prey
Predators, especially barn owls and hawks can be used too, but in most cases, they are unable to keep pocket gopher populations below the levels that cause problems in vineyards.
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