Fungicides
The 2 most commonly used acceptable fungicides are sulfur and copper.
- They are highly toxic to humans and other mammals, fish and aquatic invertebrates.
- Fungicides act as protectants that inhibit the germination and growth of fungal spores.
- Apply prior to periods of wet and humid weather when disease organisms can spread and grow easily.
- Since copper is a protectant, cover the entire plant surface to prevent invasion by disease organisms. Spray in the early morning in dry, bright weather so that plants have time to dry. If the solution remains on leaves too long, it may penetrate the cuticle and kill the tissue.
- Commercial Products: Bluestone (copper sulfate) Bonide Liquid Copper, Kocide, Top Cop, Top Cop with Sulfur.
*Never apply oils within 1 month before or after applying sprays containing sulfur.
SOME OIL SPRAYS AND FUNGICIDES ARE NOT COMPATIBLE - CHECK LABELS!
Oil Sprays
Prior to the 1970's, orchardists sprayed their fruit trees each spring with heavy petroleum oils known as dormant oils, which killed insect pests and their overwintering stages before the next season began. It was important to spray before leafing out, since the heavy oil damaged the leaves of plants. Most of today's horticultural oil sprays are lighter and contain fewer of the impurities that made the heavy dormant oils phytotoxic, so they can be used year-round on a variety of plants. These products are called superior, summer or supreme oils. They are especially effective at controlling pests because they spread thoroughly over the leaf surface. They work physically to smother and kill pests and their eggs. Superior oils are unique because they control a broad variety of insect pests while going easy on beneficial insects. Oils smother insects and their eggs. Use superior oils to control aphids, mealybugs, mites and scales on a variety of fruit, nut, ornamental and shade trees. Cover both upper and lower leaf surfaces as well as to reach the trunk and small branches. You cannot over apply oil unless you repeat a spraying after the first spray dries. (Label may provide directions for mixing in other pesticides for even-more-effective growing season control. Also check label to make sure your tree is listed - certain plants & conifers should not be treated with oils).
- Precautions: Do not apply oil when the temperature is lower than 40 degrees or higher than 80 degrees or if the humidity exceeds 90%, because these factors affect the oil's evaporation and plants can be injured. Nor should you spray with oil 30 days before or after applying any type of sulfur spray or certain fungicides.
- Commercial products: SunSpray Ultra-Fine oil, Volck Oil Spray.
Soap Sprays
Insecticidal soaps control insect pests by penetrating their cuticles, which causes their cell membranes to collapse and leak, resulting in dehydration. While some insects can overcome the effects of a soap spray, others are immediately affected and die.
- Protection offered: soft-bodied insects like aphids, mealybugs, and whiteflies. (Non-toxic to humans, but will kill beneficials, so limit their use to problem areas.)
- Household soaps that can be used: Ivory Snow, Ivory Liquid, or Shaklee's Basic H. (Shaklee Basic H - mix 1 tablespoon per gallon.)
- Soaps can be mixed with other insecticides, horticultural oil, pyrethrin and rotenone to boost their toxicity.
- Commercial Products: Aphid-Mite Attac, Safer Garden Fungicide (soap and sulfur), Safer Insecticidal Soap, Savona.