Date

12-2010

Degree Name

BS in Wine and Viticulture

Department

Agribusiness Department

Advisor(s)

Xiaowei Cai

Abstract

This study was undertaken to determine the economical threshold that commercial growers can endure before they need to begin controlling pocket gophers (Thomomys bottae), specifically in wine-grape vineyards. Pocket gophers cause extensive damage to grapevine roots year round and can cause economical loss from the elaborate underground tunnels they create while burrowing.

This report represents six different methods of controlling pocket gophers in a wine-grape vineyard during the late summer and early fall seasons. An analysis of control and cost analysis has been performed to forecast the most economical way for commercial growers to control gophers. Four different restricted use material pesticides were used in separate plots to measure the amount of emerged gopher holes after application of poisons. One plot measured the possible amount of gophers that can be trapped underground and one plot was left alone for a control measure. The cost to purchase the pesticides, the amount of time it took to apply the poisons, the rate at which they were applied, and the overall control were collected to determine the most effective method.

It was concluded that the most economical method for commercial growers to control pocket gophers in vineyards was to apply .05% or 1.8% Strychnine alkaloid gopher bait with a Rid-O-Rodent gopher bait applicator. The conclusion is based on the effectiveness of the poison after it was applied and consumed, as well as the more economical cost per acre to apply. Strychnine can cause possible unwanted secondary poisonings therefore it is important to be aware of all native vertebrate species.