[Chris McGuire]

We sprayed 0.5% Sil-Matrix in the middle of apple bloom last year, together with sulfur and potassium bicarbonate. Did not see any noticeable ill effects.
Chris

[Chris McGuire]

Thank you Brian for the updated discussion of this topic in the recent Holistic Orchard Network Email.

Last year we continued to spray Carb-o-nator + Sil Matrix. As I’ve said before, we have sprayed it with tank pH’s between 7 and 8. Our water is pretty hard and reads about 7.6. Last year, In 50 gallons, we have mixed 1 qt Sil-Matrix (0.5% solution), 2.5 lbs Carb-o-nator, and about 6 fl oz citric acid, which gives a final pH around 7.5. At various times last year we included regalia, Ecoswing, and/or sulfur as well. Presumably Bt would work as well at that pH. In one spray we included Agro-K brand “Clean” micornutrients instead of the citric acid; the Clean micros are acidic and they lowered pH to around 7.5. I have not observed any physical incompatibility in these mixes.

Last year was a dry spring/early summer, with almost no disease, so did not give really good data. We did not end up relying on this spray for protection during any major scab infections. However we did apply the spray (including Ecoswing + Regalia) 2 days before a post-petal fall wetting event that should have given a CAR infection according the charts and we saw almost no CAR.

The Organic Fruit Growers Association, primarily a WI/MN group of growers is hoping to run trials of potassium silicate + potassium bicarbonate, along with some other organic products, from petal fall through July for various fungal diseases, including CAR, Marssonina, Alternaria, and fruit rots. We’ve applied for a grant to support trials in the 2025-2026 growing seasons.

[Chris McGuire]

Thank you for the kind words! I am glad it was helpful.