MilStop SP: How it works and best practices

Effective pesticides come with many different active ingredients. For example, you may recognize potassium bicarbonate as a fertilizer, water buffer, or even component of some foods. In horticulture, potassium bicarbonate is also  a safe and effective foliar fungicide. The FDA allows potassium bicarbonate use as an effective, organically-approved fungicide on many crops. These qualities make products such as MilStop SP from BioWorks (85% potassium bicarbonate) a wonderful choice for foliar fungal disease control. But how does MilStop SP work?

Picture credit: BioWorks; untreated [front] vs treated fungal spore [back right]

MilStop SP and other potassium bicarbonate products work on contact through two mechanisms. First, fungal material sprayed with product immediately begins to desiccate, killing active spores and hyphae. Second, the pH of the leaf surface tissue begins to rise, making it more difficult for future inoculum to establish. 

MilStop SP is tank mix compatible with a number of biopesticides, which expands its usefulness. A favorite combo among food and cannabis producers is the one-two punch of MilStop and a Bacillus species tank mix. MilStop can be combined with products like CEASE to provide well-rounded disease prevention. While MilStop provides an immediate contact kill, the Bacillus bacteria in CEASE colonize the leaf surface and shield against future fungal or bacterial infection.

Some best practices to keep in mind when spraying MilStop:

  • Remember prevention! While MilStop is a curative against powdery mildew, you do not have to wait until visible signs of diseases to start treatment. Treat when conditions are favorable to promote disease and kill the spores and hyphae before they penetrate the leaf surface.
  • Do not acidify spray water. MilStop has a pH of 8 in solution – this is a key component of its mode of action.
  • Do not add surfactants. MilStop contains a proprietary blend of surfactants; adding more is unnecessary and can lead to phytotoxicity.
  • Apply only when temperatures are under 85°F and dry times are less than two hours.

Though MilStop is a powdery mildew specialist, it can be used to control a number of foliar diseases, such as Alternaria, Anthracnose, Botrytis, Penicillium, and various leaf spots. A long-standing product of choice for food producers, MilStop is now officially labeled for use on Hemp in the greenhouse and field. MilStop SP’s short re-entry interval of one hour and zero-day pre-harvest interval make it an ideal choice for problems arising late into production or any time close to harvest. Ask your Griffin rep today about MilStop SP!