There are organic pesticide alternatives

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By Susan Brown, County Extension

I  used to grow roses for a living and if you know anything about roses, you know it is almost impossible to grow them organically. I was on a strict schedule to spray every other week with a fungicide and if I had insects (aphids, budworms, Japanese beetles or thrip), I had to spray with another product specific for that intruder. I rarely mixed products (fungicide/insecticide) for fear of what I may create chemically. I was very good about suiting up and wearing the proper protective equipment and considering the weather before I made the decision to spray. 

Well, I definitely do not miss spraying chemicals on a regular basis and try not to use them at all, if possible. There are some great products on the market that are safe for the homeowner to use and will not harm the beneficial insects you have invited into your garden. 

Horticultural oil is a petroleum-base product that is used to suffocate insects. The oil is a contact spray so coverage is imperative. Oils have different effects on pest insects. The most important is that they block the air holes (spiracles) through which insects breathe. In some cases, oils also may act as poisons, interacting with the fatty acids of the insect and interfering with normal metabolism. Oils also may disrupt how an insect feeds, a feature that is particularly important in the transmission of some plant viruses by aphids or thrips. Oils pose few risks to people or to most desirable species, including beneficial natural enemies of insect pests. This allows oils to integrate well with biological controls. Toxicity is minimal, at least compared to alternative pesticides, and oils quickly dissipate through evaporation, leaving little residue. Oils also are easy to apply. You can buy it already mixed or choose to mix it yourself. I bought an inexpensive one-gallon sprayer that works perfect for spot spraying insects or applying fungicides. 

Pyrethrum is the generic name given to a plant-based insecticide derived from the powdered, dried flower heads of the pyrethrum daisy, chiefly Chrysanthemum cinerariaefolium, but also in C. coccineum and C. marshalli. Pyrethrum is a fast acting contact poison that “knocks down” susceptible insects. Insects are left paralyzed by the toxic effect of pyrethrum. The normal function of the nervous system is affected, stimulating repetitive nerve discharges leading to paralysis; however, some insects are able to recover after the initial knockdown if the dose is too low. Do not confuse pyrethrum with pyrethrins. They are not approved for use in organic production.

Neem products are derived from the neem tree, Azadiracta indica. The neem tree is native to southern Asia and can grow in most arid sub-tropical and tropical areas of the world. Neem acts as an insect growth regulator, which means it disrupts the cycle of insect hormone development.

Spinosad is a fast-acting, somewhat broad-spectrum material that acts on the insect primarily through ingestion, or by direct contact. It activates the nervous system of the insect, causing loss of muscle control. Continuous activation of motor neurons causes insects to die of exhaustion within 1-2 days. It works best on caterpillars and worms.

Sometimes we have insect infestations and we have to break out the “big guns.” Just remember there are a lot of alternatives in the pesticide world. Making the right choice can lead you to spraying less and aiding in a happier ecosystem.