Extension Communications
3614 Administrative Services Building
Ames, Iowa 50011-3614
(515) 294-9915
5/1/00
Contacts:
Mark H. Shour, Extension Entomology, (515) 294-1101,
mshour@iastate.edu
Elaine Edwards, Extension Communication Systems, (515)
294-5168, eedwards@iastate.edu
Yard and Garden Column for the Week Beginning May 5
IPM -- Common Sense Pest Control
By Mark H. Shour
Extension Program Specialist
Iowa State University Extension
As you head out to rediscover your property this spring, how will you respond to the critters that you encounter? Will you "nuke" them all, tolerate harmless levels or let them carry on without any interference? Your approach to pest occurrences in the yard or garden affects not only the occupants of your property but also your neighbors' properties.
The plants and animals living in your yard and garden constitute an ecosystem. Most of these organisms are not harmful and many are actually beneficial to the survival of this quasi-natural habitat. It is in your best interest to adopt a "yard-keeping" philosophy that promotes good management and stewardship principles in a holistic way.
Integrated pest management (IPM) is a common-sense approach to managing pest problems in your yard and garden. Ideally, it involves understanding and carefully examining ALL of the factors influencing plant growth. These factors include soil, air, water, nutrients, insects, diseases, weeds, landscape design, beneficial organisms, weather and cultural practices. The goal of IPM is to reduce pests (when present) to tolerable levels, not to eradicate them. IPM is not strictly an organic approach to pest control because chemicals are used on occasion, but only after other techniques have failed.
Simply stated, IPM involves sleuthing, damage control, watchful wandering, exclusive membership, boosting plant health, hosting nature's army and chemotherapy. Let's briefly look at each strategy.
Most of us enjoy a challenge that cultivates our sleuth nature…we want to solve a mystery or find out what is causing a problem. Once identified, we learn more about it by reading books, watching videos or talking with someone "in the know." The same can apply to IPM. If the problem in your garden is due to poor drainage, soil compaction or drought, shift your attention to modifying the environment to remedy the problem. If a disease, insect or other living organism is the culprit, make a positive identification. Iowa State University Extension can help you. Then read more about the organism to learn how it fits into the environment, whether it's a friend or foe. Keep IPM in mind as you investigate the solution to this problem.
Damage control refers to determining what level of damage you are willing to accept. For some pests (e.g., aphids), your spinach can tolerate a large population without adversely affecting its growth or performance. Other pests (e.g., borers) can destroy a tree when there are only one or two individuals present. Remember, the less pest damage you tolerate, the more you rely on chemical control methods.
Getting outside on a beautiful day and spending time in the yard or garden is not too hard to take. While there, practice "watchful wandering." This principle is simply getting to know what your plants look like and how they grow. Then when a plant looks different during the season, you can examine it to see what is going on. Look at leaves (top and underside), stems, buds, flowers and where the plant meets the soil. A magnifying glass can be helpful. As a general rule, watchful wandering should occur once a week during the growing season.
One of the safest ways to manage a pest is to deny it access to your yard and garden. We all know of country clubs with exclusive membership, why not your property? Fences come in a variety of shapes, colors and sizes; they do a good job of keeping deer, rabbits and dogs out of areas where they are not welcome. Plastic netting over fruit trees and shrubs exclude birds and bugs alike.
There are many ways to boost plant health. Selecting the right plant for the soil, light conditions, water and weather it is going to have to grow in is important. While you are selecting a plant, ask for one that is naturally resistant to insects and diseases -- yes, they are available. Follow recommended watering and fertilization schedules to boost health and vigor. More fertilizer does not equal better growth! Prune off dead twigs or stems when you see them. You also can eliminate small pockets of pests on a branch by pruning and destroying the pests. Surround plants with nutrient-releasing mulch; this will keep the root zone cool and moist, keep the lawn mower at a safe distance and decrease weed competition.
It may seem a bit strange, but you should be a gracious host for nature's army, also known as predators, parasitoids and pathogens. These are the good bugs that control pest populations without much time and effort on your part. Key to this IPM strategy is knowing what the natural enemies look like. Predators include ladybugs, lacewings, praying mantis, spiders and ground beetles. Parasitoids are tiny wasps that lay an egg in their host; the larva that hatches from this egg feeds on and eventually kills the host. There are several fungal, bacterial or viral agents that infect pests and ultimately destroy them.
How can you help? Some of nature's warriors can be purchased mail order and sent to your property for release. Others can be attracted by planting species that are attractive to natural enemies. Decrease pesticide usage or use types of pesticides that are less harmful to predators and parasitoids to be a gracious host.
The correct and judicious use of pesticides, whether naturally-occurring or synthetically-derived, is a viable IPM tool for some pest situations. Know what products are effective against the pest you encounter. For best results, check with a knowledgeable garden center professional or ISU Extension personnel for assistance. Carefully read the entire product label before using a pesticide to make sure it is the right one for the job and that you can follow all the label instructions. The advantages and disadvantages of natural versus synthetic products is another topic for this column. Be aware that natural products can be as toxic as synthetic pesticides. Avoid home remedies; they are not only potentially dangerous to you but also have not been independently tested and could cause more harm to the plant than the pest. By all means, don't rely on chemotherapy to remedy every pest problem and revisit the mistakes of the 1950s and 1960s.
ml: isugarden
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