”Chlorogenic acid was the phenolic acid detected in the highest concentration, with an increase of more than 80% in Si+ inoculated compared with Si− uninoculated plants. Among the quantified flavonoids, rutin and quercitrin were detected in the highest concentrations, and the rutin concentration increased more than 20-fold in Si+ inoculated compared with Si− uninoculated plants. Both rutin and chlorogenic acid had antimicrobial effects on P. pannosa, evidenced by reduced conidial germination and appressorium formation of the pathogen, both after spray application and infiltration into leaves. The application of rutin and chlorogenic acid reduced powdery mildew severity by 40% to 50%, and observation of an effect after leaf infiltration indicated that these two phenolics can be transported to the epidermal surface”
This study focuses on powdery mildew but it should work for other fungi as well. I’ve been using it against black spot with nothing but success.
I’m currently using mono silicic acid from elite 91 (I wouldn’t recommend this as it’s quite pricey) + Jack’s 3-2-1 both of which are at 25% strength as I feed weekly. I plan on switching to AgSil16H once I run out of the mono silicic acid as it is a bit cheaper.
With Agsil 16H $30 you’d mix 74 grams in a 16.9fl oz water bottle. This will result in a 7.8% solution of which you’d use 1/8 teaspoon - 1/2 teaspoon (.625ml - 2.5ml) per gallon.
This will give you about 1,514 gallons - 6,056 gallons. I do plan on moving up from 25% strength at .625ml to 50% strength at 1.25ml if I see any resurgence.
If you want the same fertilizer I use here is the Jacks 3-2-1 25lb Part A and 25lb Part B $120 and Epsom salt 19lb $24. At full strength it’s 3.6 Grams of Part A, 2.4 Grams of Part B, and 1.2 Grams of Part B per gallon. I personally use .9 Grams of Part A, .6 Grams of Part B, .3 Grams of Part C per gallon. With the 3 part listed above you’ll have enough for 12,583 gallons for less than $160.
The Jack’s 3-2-1 does come in smaller amounts but with 2.2lbs of part a/part b running you $60 it’s pretty much a no brainer to get the 25lbs of part a/part b for $120