Use care and control to get rid of pests Management: Before using insecticides, gardeners should assess the damage, identify the enemy and search for a weapon with limited environmental toxicity.

March 16, 1997|By Ary Bruno | Ary Bruno,SPECIAL TO THE SUN

Integrated Pest Management is the thinking person's way of dealing with pest problems in the garden. It does not necessarily eschew chemicals, but saves them as a last resort. The problem is treated with the least drastic -- and least potentially harmful -- methods first.

This philosophy runs somewhat counter to the mode of operation that has been popular over the last few decades. That approach could be best summed up this way: Hit 'em with everything you've got.

The problem was, too often it was rather like having major surgery to take out a splinter. It has also encouraged the development of resistant strains of pests. This may have been good for the chemical companies, because it created an ever-escalating demand, but it is not good for you, your garden or the planet. It is also usually unnecessary.

IPM by contrast, counsels identification, assessment and strategy. It involves more of the gardener's gray matter, and calls for partnership and control, not annihilation.

Wise management

In order to exercise that control, the gardener must be a good manager. As in any business, the manager manages best who is familiar with the day-to-day operations of his or her enterprise. Maintain a close relationship with your garden. Visit it often, every day if possible. That way you will notice any changes before they get out of hand. Catching a problem early is half the battle. It gives you time to analyze the situation and react sensibly.

Assess the damage in light of how long it has been occurring.Determine exactly what pest or disease you are dealing with. I suggest a good, easy-to-use, comprehensive guide with lots of color photos and pictures for quick reference. My personal favorite is the Organic Gardener's Handbook of Natural Insect and Disease Control (Rodale Press, 1992).

A simple, good-quality magnifying glass and a sheet of plain white paper are the only other diagnostic tools you will probably need. (If you can't see the insect straight away on the plant, hold the paper up under a leaf or branch and shake the branch. This usually knocks one or more of the troublemakers onto the paper so you can get a clear look at them.)

Check your bug against the photos in your reference book. Once you've identified your adversary, plan your strategy. This involves deciding what level of retaliation is appropriate -- if any. I say "if any" because there are times when you will decide that the risks or potential side effects from treatment outweigh the damage being done. You may need to ask yourself, "How much damage can I (or my plants) live with?"

If, for example, flea beetles are making the leaves of your 3-foot-tall eggplants look like pincushions, but the plants are bearing well, do not seem stressed, and the fruit is beautiful and leaves green, should you bother to dust with an insecticide like rotenone? At this level of damage, I would not. Obviously the plants are not being overly taxed by this invasion; why then introduce an environmental risk, no matter how short its effective life?

Start with the least disruptive treatments first. For slug damage in lettuce, for instance, first try sprinkling wood ashes mixed with lime and diatomaceous earth around the plants and dusting the plants themselves with diatomaceous earth. I have found this a speedy deterrent to slug problems and, in fact, use it as a preventive measure when plants are small.

Manual controls are often very effective, especially in the early stages of an infestation. By this we mean using things such as floating row covers after a light initial dusting of rotenone on susceptible crops, or applying Tanglefoot around fruit tree trunks to trap caterpillars. In a small garden, it can also mean removing the offending beasts by hand if they are few, as with squash vine borers or tomato hornworms.

Whatever form of warfare you choose, make sure the weapon is targeted to the pest you want to kill or deter. Not all poisons are effective on all pests, and many are poisonous to beneficial insects and other wildlife as well (including humans). Read the label. All of it.

For this reason, natural poisons, such as rotenone and pyrethrin are not panaceas. All should be used with caution and full knowledge of their effects. They are powerful, naturally occurring compounds that can have environmental dangers unless used wisely and with all the suggested precautions.

Rotenone, for example, is a potent poison for fish, swine, birds and many beneficial insects. It should never be used near water or where runoff into sources of water supply, streams or ponds may occur. It is also toxic to humans, and protective clothing and masks should always be worn during any application.

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