Kentucky IPM Pest Information Pages
Scouting Corn
There are several important procedures to follow when scouting corn for insects, weeds and diseases. The following table indicates the type of monitoring locations required for each pest group as well as the procedure to follow each week once those locations are established.
| Pests | Procedure/Location | Monitoring Stations |
|---|---|---|
| Insects | 20 Plants OR Rating | Random |
| Weeds | 30 feet of row | Permanent |
| Diseases | 10 foot radius OR 20 plants or ears OR 3-4 rows of plants 20 feet in length | Random |
The actual number of locations you scout depends on field size. Use the following table to determine the number of locations and make sure you select your monitoring sites to insure that you are sampling each representative area of the field.
| Field Size(acres) | No. of Locations | Field Size(acres) | No. of Locations | |
|---|---|---|---|---|
| 1-14 | 2 | 151-164 | 14 | |
| 15-24 | 3 | 165-174 | 15 | |
| 25-34 | 4 | 175-184 | 16 | |
| 35-50 | 5 | 185-200 | 17 | |
| 50-64 | 6 | 201-214 | 18 | |
| 65-74 | 7 | 215-224 | 19 | |
| 75-84 | 8 | 225-234 | 20 | |
| 85-100 | 9 | 235-250 | 21 | |
| 101-114 | 10 | 251-264 | 22 | |
| 115-124 | 11 | 265-274 | 23 | |
| 125-134 | 12 | 275-284 | 24 | |
| 135-150 | 13 | 285-300 | 25 |
How to Scout a Field
Specific survey procedures are described for each pest.
- In general, you will EXAMINE 20 PLANTS PER LOCATION and record the number of insects, percent of damaged plants, or a rating for the field.
- Select locations randomly so that they will be representative of the entire field.
- Don't survey along field margins unless specifically directed to do so.
- Don't limit surveys to one side or end of a field.
- If your survey is not random, it is not representative of the whole field and you may find a lot of problems on your return visit.
The number of locations to be surveyed will be determined by the number of acres in the field.