Well it is that time again, fall armyworms are certainly showing up in numbers. I have seen a few fields this week that were at treatable levels for armyworms. This pest can devastate a forage crop in a few days time so scouting for them is a must.
Where we have heavy growth from the recent rainfall and our inability to cut, we are at risk for greater damage. This is largely because of the canopy protecting the armyworms from the pesticides that we are applying.
Dr. Dennis Hancock, UGA Cooperative Extension Forage Specialist, has noted that many producers south of the fall line are at or above treatment thresholds.
We’re getting a bit of a double whammy. There are a lot of hay fields that haven’t even been cut the first time because of the rainy weather. By now, we would typically have made the second cutting (or even third in far south GA).
The problem that this poses is that getting the insecticide to penetrate into such a thick biomass is nigh impossible. Plus, many areas have been taken over by tall growing weeds (johnsongrass, vaseygrass, etc.), which will pose major problems, as the spray booms are unlikely to clear many of those patches.
Some are reporting that complete fields have been stripped and that only the stems remain. This obviously poses a major economic loss, but if producers do not act, the effects could ruin the next cutting.
In my conversation with Dr. Hancock, we also discussed the need to remove the excessive growth to improve the next cutting. In some cases this is the remaining stems from armyworm feeding, while others may not have been able to cut because of weather conditions. Over maturity will not only effect this cutting but the next if not removed from the field.
I am including a scan of the pest management handbook for a list of labeled pesticides used to control armyworms in pastures. For more information contact your local extension agent.