Vineyards: Controlling Deer and Ground Squirrel Damage

We experienced a 30% increase in yield—representing well over $1 million


January, 2014.

This is a follow-up post-harvest report on our work with Plantskydd Animal Repellent. The product was used to reduce damage on grape vines from ground squirrels and deer. An initial report was submitted in May, 2013.

Now that our season is over and the wine grapes have been harvested we can say that 2013 was a good year indeed. Even considering that the harvest was the best on record for all of California the results on Plantskydd treated sites were outstanding.

We attribute at least a 30% improvement in yield on the 1,000 acres that were treated with the product in this operational trial. This represents well over $1 million. Planstkydd will definitely be included in our plans next year and we will likely use on it more acreage where we suspect underperforming sites.

Thank you for all your assistance,

Matt Boughner
Diamond West Farming

May, 2013.


I want to take a few moments to sum up my experience with Plantskydd. VMI is a management company located in CentralCalifornia we manage 5,000 acres of wine grapes. We have multiple locations from Livermore, Paso Robles, Monterey, Salinas, and Santa Barbara Ca. We have a high pressure of deer and squirrel in about 800-1000 acres of the vineyards we own/manage. The reason for the pressure is due to numerous reasons including urbanization, open fields next to vineyards, and soil conditions.

My boss spoke with Richard Getzkow–Plantskydd® Ag-specialist–Tree World Plant Care Products Inc.who was very helpful and knowledgeable with the product. I then spoke with Richard and we discussed the process from ordering, mixing, when to apply, rate of application etc. Richard let us know that this product was to be applied foliar. But due to uncertainty of the product and apprehension we agreed that we would do a ground application at the base of the vine with 18” of spray per side of the vine crossing in the middle and spraying up the vine about 2.5 feet. The reason for ground application is because we were unsure about the reaction if any with the fungicide we would be spraying and the Plantskyyd.


I determined the acres that were the most damaged in 2012 and ordered sufficient product for the area. The rate used was 15 gallons of water per acre with 3 lbs. of product per acre was advised to use a de foaming agent so we used Miller brand foam fighter. We used a clean 5 gallon bucket added 1 bag of product with 4 gallons of water and mixed with the stirrer that was provided. We filled the spray tank half full with water (50 gallons) would then dump the premixed 5 gallons of material in the tank until the desired amount was achieved and then filled the remainder of the tank. We used a combination of herbicide sprayers that had PTO agitators as well as hydraulic pump that mixed the product. The only issue with the pumps if the product settled from driving to new field or lunch break etc. the pump would become clogged and inoperable. In one case we did burn up a pump. On our second order we received new OMRI listed wetting agent/spreader and an anti-foamer along with the Plantskydd. This helped condition the water before we added the product and made for a much quicker and smoother time. We used only a PTO driven sprayer and filled half with water (150) gallons added the added 15 oz. (5 oz. to 100 gal) of surfactant and 12 oz. (4 oz. to 100 gal) of anti-foamer. We mixed the water with additives for 5 minutes we then added the remainder of the 150 gallons to total 300 and mixed another 5 minutes. After the tank was full we then added the Plantskydd product very slowly added 60 lbs. of material. We then let this mix for 10 minutes and sprayed the field.

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We made two passes in the field at different times about 10-12 days apart. The first application for Diamond West Farming and Viticultural Management (Both companies we manage) in Livermore was applied to vines when buds were swelling and nearly ready to come out. Then the second spray application was sprayed when vines were roughly 3-4 inches of growth. This time frame is essential to the product from my findings getting the product on before the damage occurs really helped out overall outcome. We also applied the product to TWG (The Wine Group) in Livermore another company we manage due to processing and the TWG secretary being slow on getting the credit app filled out we were slightly later with the TWG properties. Bud break was underway and there was damage beginning before we could apply the product. We applied the first pass when vines were approximately 2 inches of growth. We began the 2nd pass Wednesday 4/17/2013. Applying the product on the vines was completed roughly 3 times faster than when using adjuvants provided and mixing directly in the main tank. The squirrels were already eating the vines pretty bad in a few areas, but 48 hours after applying the product, we observed a large reduction in the squirrel activity. In the past we have estimated observing hundreds of squirrels in minutes. The reduction in squirrel activity was phenomenal.

We also used the ground application of the granular material on the borders of the heavy hit areas in the vineyards we manage. There was a great reduction in the amount of damage this year compared to last year. We applied the granular product with simple lawn fertilizer spreaders from Home depot.

All in all I had a very positive experience with the Plantskydd. I believe that it is effective and beneficial we applied this material to the ground and I believe this is a feasible way of applying for anyone who is nervous about applying directly to the plant in the case that they didn’t want to mix fungicide applications with Plantskydd which was our biggest concern thus is the reason we applied to the ground. I do think that the ground application was exceptionally beneficial for us because our biggest threat is ground squirrels where it may not be as effective with deer when the new growth itself doesn’t have any material applied. In areas with deer problems, a foliar application should be considered.

Matt Boughner
Diamond West Farming, Inc.

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