Soap has been used as an old remedy to control pests. Salts and fatty acids are found in many soaps which act as selective pesticides.
Mix 1 tablespoon of dishwashing soap with 4 liters of water (Schalau, 1999).
Mix 2 teaspoons mild detergent with 4 liters of water (Barrett, 2001).
Mix 3 tablespoons of soap flakes (not detergent) with 4 liters of water (Evans, 2000).
Mix 1 tablespoon of dishwashing detergent with 1 cup of cooking oil, to make a stock solution. For a gallon of spray, add 5 to 8 tablespoons of stock solution to a gallon of water.
Mix 2 1/2 tablespoons of liquid soap to a gallon of water. Stir well (Brooklyn Botanical Garden, 2000).
- Add soap to water. Use mild soap or potash-based soap.
- Start with a lower concentration and make adjustments of the strength after testing on few infested plants.
- Always try on few infested plants before going into full scale spraying. Soaps can cause burnt leaves on sensitive plants, like cole crops and certain ornamentals. Several applications in short periods can aggravate drying of leaves.
- Apply on the infested plants thoroughly, including the undersides of the leaves. Spray early in the morning or late afternoon.
- Fruit fly
- Spider mite
- Black spot
- Leaf spot
- Powdery mildew
Standard procedures for the preparation and application of homemade extracts
- Use utensils for the extract preparation that are not use for your food preparation and for drinking and cooking water containers. Clean properly all the utensils every time after using them.
- Do not have a direct contact with the crude extract while in the process
of the preparation and during the application.
- Make sure that you place the extract out of reach of children and house pets while leaving it overnight.
- Harvest all the mature and ripe fruits before extract application.
- Always test the extract formulation on a few infected plants first before going into large scale spraying. When adding soap as an emulsifier, use a potash-based one.
- Wear protective clothing while applying the extract.
- Wash your hands after handling the extract.