The colorful array of pesticides in cans, packages, bombs, or bottles seen in horticultural supply and hardware stores must be confusing to the average gardener—perhaps even frightening.
In addition to the problem of choosing the right one for his particular trouble, he must also wonder about all the warnings and precautions printed on the labels.
Of course, the salesman in the store can be of some help in making a selection, but even he finds it challenging to keep up with all the new chemicals that come on the market each year.
Only a few years ago, all we had to know about pesticides were a few standard materials and their capabilities—that lead and calcium arsenate were effective against chewing insects; that nicotine sulfate was to be used for sucking insects; and that Bordeaux mixture was a preventive for blights and: leaf spots caused by bacteria and fungi.
These names have now been replaced by new materials like malathion, Neem Oil, diatomaceous earth, and captan.
Today, we not only have a wider variety of new chemicals, but to make matters more confusing, we have several different formulations of a single material.
Read Labels for Information
Perhaps the most reliable information about a product is printed on the label itself. It requires years of research to determine the most effective way to use a specific product and, at the same time, protect the user, animals, and plants.
The Federal Insecticide, Fungicide, and Rodenticide Act requires the manufacturer to produce convincing evidence that, when used as recommended, his product.
Will control the pest as claimed and will not have serious adverse effects. Such evidence must be supplied even before the product is registered.
Furthermore, the law requires that the manufacturer include necessary warnings, preventive measures, and antidotes on the labels. Thus, if the user of pesticides adheres closely to the manufacturers’ directions, no undue hazards should be encountered.
Before listing some of the more critical ingredients in present-day pesticides, discussing some of the hazards involved might be wise. There has been so much adverse publicity on the dangers associated with insecticides that some folks actually “worry themselves sick” when exposed to them.
Practically every insecticide indeed has properties toxic to warm-blooded animals and man. If it didn’t have such properties, it would not be capable of killing insects that also belong to the animal kingdom.
But merely because insecticides are toxic to man and animals does not mean they cannot be used safely!
I do not want to minimize the inherent dangers of all pesticides for one moment. I believe that they should be regarded with mixed feelings. On the one hand, they should be welcomed because of their ability to control harmful pests and diseases of plants, animals, and humans.
But, they must also be feared because they can harm the user, his pets, and his plants. A thorough appreciation of both properties will lead to their proper use. After all, even fire, one of man’s best friends, can be his worst foe.
The modern, widely available insect killers in everyday use fall mainly into three groups: the organic phosphates, the chlorinated hydrocarbons, and the botanicals.
The most widely available organic phosphate is malathion. It is perhaps the best all-purpose insecticide yet developed and the safest of the organic phosphates to handle.
It controls most of the “hard-to-kill” insects such as scales, mealy-bugs, whiteflies, and mites. It is compatible with most other pesticides, but many decompose on standing in some combinations.
Malathion has two drawbacks, one of which – a disagreeable odor when in concentrated form and when first applied to plants. Then, too, it is far less effective in combating the leaf nematode of hardy chrysanthemums than its more deadly predecessor, parathion.
Even malathion should be handled with great care, despite its relative safety. Avoid breathing the powder when mixing it in water and keep out of the spray drift when applying it.
One of the oldest and most famous chlorinated hydrocarbons is DDT. Others in this group were methoxychlor, lindane, chlordane, toxaphene, aldrin, and dieldrin. These have a lower order of toxicity than do phosphates like parathion.
They are, however, more persistent on the foliage and in soil and, hence, arc more hazardous to use where residues or contamination of treated products are involved.
Rotenone and pyrethrins are the two best-known insecticides of plant origin. They are among the safest to use because they are relatively unstable and have no prolonged residual effect.
Nicotine sulfate was an old reliable for dealing with sucking insects, is also derived from plants but is one of the deadliest of all materials, especially when in concentrated form.
Because mites have become increasingly essential pests on all kinds of plants, chemists have concocted unique materials for combating them. We no longer rely on forceful syringing of infested plants with water or lime-sulfur sprays.
Materials like malathion are highly effective against mites. Most of these have a relatively low order of toxicity to humans and pets, but again, the user must be guided by the precautions on the package.
In the field of disease-preventives, perhaps the newest addition to many combination spray packages is captan. This is a coined name for the organic M-trichloromethyl thio tetrahydrophthalimide. I am sure everyone will agree that the shorter coined term is highly desirable.
Caplan is effective against the following diseases: apple scab, peach brown rot, cherry leaf spot, rose black spot, and brown patch of turfgrasses. It can be combined with malathion to make an excellent all-purpose pesticide.
Mancozeb is a chemical that protects against diseases like scab and rust on apples, black rot on grapes, and black spots on roses.