By Harvey Goodman
The scourge of every gardener is the yearly battle of the gardener against plant pests and pathogens.
There is probably nothing more stressing then visiting your recently germinated seedlings only to view a bunch of scraggly, leaf-eaten vegetation.
The arsenal of chemical weapons is endless — and actually, that is the problem. The urge to declare total war on the garden invaders may produce a short-term effect, but in the long run it will prove disastrous to the environment and unhealthy for you and your family.
Knock them down, drag them out insecticides will probably do their job on most pests, but they will also kill beneficial organisms, and expose both you and the environment to toxic chemicals.
The alternative is to use an organic approach that makes use of basic biological principles of ecological plant control. With a little patience you can learn to work with nature to control pests and diseases.
The biological control most commonly used in gardens is bacillus thuringiensis, commonly known as BT. Commercial products such as Dipel or Thuricide contain this organism in dust or liquid form.
The bacteria works by paralyzing the digestive system of insect larvae. The bacteria apparently do not harm other creatures that inhabit the same environment.
Milky Spore (bacillus popillae) is another example of biological pest control. Once the bacterium becomes established in the soil it can effectively eliminate several kinds of organisms, most notably the Japanese beetle, for up to 20 years.
DE, or Diatomaceous Earth, most commonly used as a filtering agent in swimming pools, is made up of the skeletons of marine organisms known as diatoms. When worked into the soil, the razor-sharp particles, mostly microscopic, can pierce the soft body underside of slugs, spider mites, and hornworms, as well as the larvae of many other insects.
Insecticide soaps contain potassium salts of fatty acids. They induce dehydration and will not cause major harm to most beneficial insects.
Botanical insecticides such as pyrethrum, rotenone, nicotine, sabadilla and ryania are derived from plants and replicate natural defenses that plants utilize. The products are toxic and should only be used in accordance with labeled instructions. The substances break down easily when exposed to light, and so are less likely to contaminate soil or groundwater.
Botanical insecticides should be used as a last resort. As with other insecticides, wear gloves and protective clothing.
Biological control does not mean 100 percent safe — the substances are designed to kill garden pests, and if used incorrectly can easily harm humans, fish and other animals as well as beneficial insects.
Questions or comments on gardening and plant care can be addressed to: The Plant Doctor c/o Queens Publishing Co., 41-09 Bell Blvd. Bayside, N.Y. 113612, or by e-mail at Harvey.goodman @ worldnet.att.net
