Charles Krug Family Vineyards, St. Helena, CA, USA
37 acre, 22-year old vineyard with low Brix content fruit, averaging 23%, making the fruit unusable in wine production. In addition to low Brix, these vines were also suffering from Grapevine Leafroll Disease, resulting in many fruit bodies falling off the vines before maturity. Absent an effective solution, these vines required re-planting, foregoing an estimated 10+ year remaining useful life.
Standard three-stage TerraBella® application.
This treatment, should results be sustained, will result in a 10+ year extension of the useful life of these vines. During the initial 4-year period, during which production is otherwise lost as vines are replaced, the net economic gain is $60,000 per acre.
Fruit on treated vines showed an increase in potassium levels from 2.7% to 3.5%. No significant pH change was seen between treated and untreated areas. The following graphs support the above data. Tables 1, 2, and 3 show test results (TerraBella®-treated and untreated plots) for Brix, pH, and potassium levels, respectively. In Tables 1 and 2, the blue and red bars for each plot reflect duplicate testing done on the Brix content to ensure test reliability.
Conclusion and Explanation:
The ailing plot that was treated with TerraBella® had Grapevine Leafroll Disease (GLD), a common symptom of which is low Brix. TerraBella® contains numerous microbes that can help mitigate/prevent plant damage due to both abiotic and biotic stress. One potential mechanism a plant can use to suppress disease mediated by viral pathogens such as GLD is “induced systemic resistance”. TerraBella® contains beneficial microbes that have been shown to help induce systemic resistance in plants. In addition to the increased Brix, the evidence that TerraBella® helped mitigate grapevine damage from GLD included visual indicators. Says Joe Martinez, a vineyard manager with Charles Krug – Peter Mondavi Sr. Family Vineyards, “On the plots where I had the TerraBella® I did not see any red spots on the leaves that exist in the other plots which is a great benefit for us”.
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