Develop an IPM calendar to proactively plan for insect pest control in vegetables

Draft a timeline of your growing season to target monitoring and control efforts for insect pests.

Developing an integrated pest management (IPM) calendar for your farm before the season can help you accurately time monitoring and control efforts for key insect pests. To accomplish this, Michigan State University Extension recommends using the following steps.

1. Draft a timeline: Either hand-write or use spreadsheet or word processing software to create a calendar of the growing season with separate columns for each week of the growing season. You can also add a row showing average growing degree days expected to accumulate by each date (since March 1, base 50 degrees Fahrenheit). An example of an IPM calendar in the attached Excel file uses data from an Enviro-weather station in Hart, Mich., to plan IPM for sweet corn. Open it and follow along as you read this article. (A table defining abbreviations used in the Excel file is located at the bottom of this article.)

2. Add your projected planting date for the crop planted at the location you are planning for. Then add a row for “days since planting.” The example is for a May 13 sweet corn planting.

3. Use information on “days since planting” to count forward to your projected harvest date, using information on days until harvest from your seed catalog. The attached example is for a 72-day variety of sweet corn. After you determine your projected harvest date, add a row containing “days before harvest” to help with the next step.

4. Now indicate the predicted date of key plant developmental stages that define the treatment window for the major pests you will face. To do this, use information on the days before harvest that each plant stage typically occurs (contact your seed dealer or extension educator). For sweet corn insects, it is critical to control pests between row tassel and brown silk, or between about 30 and 10 days before harvest.

5. For each pest, note treatment thresholds for key plant growth stages. If thresholds vary by plant stage or date, list different ones at different parts of the timeline. For example, for sweet corn plantings that silk before mid-July, new data suggests that any non-zero catch of corn earworm justifies treatment. For plantings that silk after this date, a threshold of 10 moths per night is acceptable.

6. As the season progresses, update your predicted calendar with observed degree day accumulations (available on Enviro-weather) and field observations of plant growth stages and adjust timing of controls as necessary. In specific, make sure to shift the projected dates of the treatment window for each pest earlier or later as needed.

7. Update your calendar weekly and begin monitoring for pests two weeks prior to the anticipated date of the treatment window for a pest.

8. When thresholds are exceeded during the treatment window, begin treatments. Chemical controls for key pests can be identified pre-season through the use of MSU Extension’s E-312 bulletin, “Insect, Disease and Nematode Control for Commercial Vegetables.” In the attached example, corn earworm numbers exceeded threshold on June 24, justifying treatment.

9. After the season, look for patterns and note control successes and failures.

Definitions of abbreviations used to delineate treatment windows for sweet corn in the example Excel file accompanying this article.

Abbreviation

Definition

TW

Treatment window: Period during which a pest damages a crop AND can be controlled using insecticides

P

Planting: Planting date for sweet corn

W

Whorl stage: Sweet corn plant has 4-12 leaf collars and well-developed whorl at top

RT

Row tassel: Occurs when you look down a row and tassels have emerged on the majority of plants

S

Silk: Green silks have begun to emerge

BS

Brown silk: Majority of silks have dried and turned brown

H

Harvest: Harvest date

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