Tests were conducted using 15 O'Henry trees per treatment using ten substances during the 1993 peach season:

1. Algrow kelp (dry kelp product)
2. Algrow kelp mixed with Basalt Rock Dust
3. Compost tea
4. Compost tea mixed with pink mucoid yeast
5. Hydrogen peroxide
6. Hydrogen peroxide mixed with pink mucoid yeast
7. Copper hydroxide mixed with wettable sulfur
8. Farwell (anti-fungal organism)
9. Blend + Yeast: Algrow kelp, basalt rock dust, hydrogen peroxide, compost tea, powdered sugar, pink mucoid yeast and white wine vinegar
10. Blend: Algrow kelp, basalt rock dust, hydrogen peroxide, powdered sugar, white wine vinegar and compost tea

Average harvest from the O'Henry peach orchard in 1993, a bad year, was only 34 pounds per tree, compared with an average marketable crop of 100 pounds of fruit per tree in good years. Saleable peaches from all treatments were of higher quality than conventional peaches, while Algrow and basalt rock dust milk had the highest success in combating rot, with 55 percent marketable fruit. Algrow kelp was the second most successful with 42 percent, followed by compost tea and pink mucoid yeast with 41 percent, hydrogen peroxide and pink mucoid yeast with 40 percent, and blend + yeast with 37 percent.