It’s 94 degrees outside as I sit here in my office wondering how this may be affecting the start of this growing season. One thing for sure, is that we need to take into account the environment these plants are growing in before scouting with our thermal imagery. I’m probably stating the obvious, but it’s simply not possible for me to get you a picture with high enough resolution for you to actually see pests or disease. Therefore, we scout for them by looking for a habitat or environment that they might want to grow in. Normally at this time of year, I am most suspect of the warm areas of the field, but with the recent heat, it has been the cooler areas that I am finding the most insect pressure. (I guess they don’t like hot weather, either.)
At any rate, the best way to scout in nearly every case is to make sure you visit the warmest spot in your field, and also the coolest. That way you bracket the field’s environment, and see both ends of the scale. This can be done very efficiently by walking a triangle pattern from your entry point. If I don’t run into anything that requires my attention or remedy on that route, I feel fairly comfortable with the rest of the field. Considering none of us have time to walk every inch, that’s a pretty good strategy. If I do see a problem in one of these areas, I go to another spot that is similar in temperature to see if I can confirm a trend before making a decision on a remedy.
From my experience, both insects and disease tend to come from my grassy waterways, field edges, or other high residue areas. For this reason, we can sometimes save ourselves a bit of trouble later in the season by spraying these areas with a pre-emptive hit if you begin finding pests using the method I previously mentioned. In the thermal image above, you can see where I found early insect damage in a cool area near one of our waterways. Now that I know where these critters are wanting to call home, I can be selective and avoid the cost of having to spray the entire field.
Once again, I hope you have found this tidbit of information to be helpful in gaining value from your AirScout imagery. Just remember, always put the image into context! The image can be affected by a multitude of factors that I don’t have time to get into with this type of forum, but rest assured, the camera is NEVER lying. It’s great to see most of the crop off to a good start this year, and I will be shortening the duration between flights very soon to be sure we get that ever-so-important biomass picture that drives our late-season nitrogen prescription.