An IPM Primer

Definitions

Integrated pest management (IPM) is socially acceptable, environmentally responsible and economically practical crop protection.

Traditionally a pest is defined as any organism that interferes with production of the crop. We generally think of pests as insects, diseases and weeds, but there are many other types including nematodes, arthropods other than insects, and vertebrates. We now also deal with pests in many non-crop situations, such as human health and comfort.

Process

Efficiently collect and use valuable information to make good crop protection decisions.

A Framework for Practicing IPM

Integrated pest management is a process, defined by each particular situation. One way to understand IPM is to consider the following general framework which can be applied with modifications to most specific situations:

Preparation:
Be aware of the potential problems and opportunities in your fields. What pests can you expect, what practices can you take to avoid them, and when and how should you watch for them? What control tactics are available if, despite your best efforts, pests attack the crop. What are the beneficial species that will help you out? What are the strengths and limitations of your operation (labor, equipment, markets, $) ?

Prevention:
Use practices that contribute to crop protection for the long term. These include:

• Biological controls; Preserve biological diversity.
• Crop rotation; breaks pest life cycles, often improves tilth and fertility.
• Host plant resistance; Use varieties that are resistant to common pest species.
• Sanitation; Remove or destroy debris and other sources of pest infestation.
• Site selection; Plant only on sites suited to the crop needs.

Monitor the Crop; "Scouting":
Collect valuable information in time to use it in making good decisions. Which of the expected pests are in your field? Know both "what" and "how many" by properly sampling the field. Use recommended scouting techniques toaccurately and efficiently collect this information.

Analysis:
Scouting indicates what pests you have, and how many of each. Now you must decide whether these pests should be controlled.

Compare the sample count of pests you find on the crop to the "economic threshold" or "action threshold" to determine if action is necessary. The economic threshold is the pest count at which the benefit of taking action is greater than the cost of taken action.

Crops can tolerate a certain number of pests before economic loss is incurred because all control actions have costs as well as benefits. Determine whether the benefits derived from control justify the costs incurred.

Management options:
If action is called for, choose those that optimize cost and effect while minimizing adverse effects. Examples of different control options:

• Cultural: eg. Crop rotation to avoid corn rootworm damage
• Mechanical eg. Cultivation of corn weeds
• Biological eg. Release of parasitic wasps for fly control
• Genetic eg. Plant disease-resistant alfalfa varieties
• Chemical eg. Herbicides, insecticides, fungicides

Implementation:
If a control is justified, do so properly and at the right time. For instance, weed cultivation is often most effective before weed seedlings are even visible above the soil surface. Releases of biological control agents must be in the proper place, at the proper time. "If a job is worth doing, it is worth doing right."

Re-evaluation:
Short term. Was the management decision correct and did the action have desired results? How much has the situation changed from last week/yesterday? New judgments are required.

Long term. What worked well during the season, and what did not? Is the alfalfa stand healthy enough to keep in another year? Should the corn field be rotated out? Is a soil insecticide necessary?

Adapted by J. VanKirk from Sutton and Waldron, New York ProDairy Forage Manual, pp. 254-256.