How to prepare a phytovermicide for spider mites?

Question

admin · Accepted Answer

How to prepare a phytovermicide for spider mites? - briefly
Mix neem oil at a 5 % v/v concentration with water and a few drops of mild dish soap as an emulsifier, then spray the solution onto all plant surfaces, especially the undersides, and repeat every 5–7 days until mites are gone. Use approximately 50 ml of oil per litre of water to ensure effective coverage without causing phytotoxic damage.

How to prepare a phytovermicide for spider mites? - in detail
A botanical pesticide targeting spider mites can be made from readily available plant extracts, oils, and adjuvants. Follow these steps to produce an effective formulation.

Select the active plant material

Neem seed kernels (Azadirachta indica) – high azadirachtin content.
Garlic cloves – sulfur compounds with acaricidal action.
Peppermint leaves – menthol and essential oils that repel mites.

Prepare the extract

Grind 100 g of dried neem kernels or 150 g of fresh garlic cloves into a coarse powder.
Add the powder to 1 L of warm (45 °C) distilled water.
Stir for 30 minutes, then let the mixture steep for 12 hours in a sealed container.
Filter through a fine muslin cloth or coffee filter, collecting the clear liquid.

Incorporate a carrier oil

Measure 50 mL of horticultural oil (e.g., canola or sunflower) and warm it to 30 °C.
Slowly pour the filtered extract into the oil while whisking to create a stable emulsion.

Add a surfactant

Introduce 5 mL of non‑ionic surfactant (e.g., Tween 20) to improve leaf coverage.
Mix thoroughly until the solution appears uniform.

Adjust pH and preserve

Test pH; aim for 6.0–6.5. If necessary, add a few drops of citric acid solution to lower pH.
Add 0.2 % potassium sorbate as a preservative to extend shelf life up to two weeks when stored in a cool, dark place.

Dilution for field use

For moderate infestations, mix 100 mL of the concentrate with 10 L of water.
For severe outbreaks, increase the concentrate to 200 mL per 10 L of water.
Apply the spray early in the morning or late afternoon to minimize leaf burn.

Safety and handling

Wear gloves, goggles, and a mask during preparation.
Label the container with concentration, preparation date, and safety warnings.
Keep out of reach of children and pets.

Storage

Store the concentrate in amber glass bottles at 4–10 °C.
Discard any batch that develops off‑odors, mold, or separation after 14 days.

By adhering to these precise procedures, growers can produce a reliable botanical pesticide that suppresses spider mite populations while minimizing chemical residues.