Issue No. 7, Article 2/May 6, 2005
Soil Insecticide Use and Replant Decisions: What Do the Labels Say?
During the past week, seedling plants in many cornfields across central Illinois have been exposed to several consecutive nights of below-freezing temperatures. Not surprisingly, questions are beginning to surface regarding the impact of these very cold temperatures on plant survival. Some producers are beginning to investigate the need to replant some fields. For fields in which soil insecticides have been applied to prevent corn rootworm larval damage, producers should be aware of product label statements that clearly prohibit second applications of certain insecticides. In essence, is it legal to apply a soil insecticide to a field that has already received one application at planting? Labels for the various products offer the following guidance:
Aztec 2.1/4.67G--A maximum of 7.3 pounds of Aztec 2.1G may be applied per acre per crop season. A maximum of 3.27 pounds of Aztec 4.67G may be applied per acre per crop season.
Capture 2EC--Do not apply more than 0.1 pound active ingredient per acre per season as an at-plant application.
Force 3G--Use only once per crop.
Fortress 2.5/5G--Do not make more than one application per year.
Lorsban 15G--For soil insect control, do not exceed the equivalent of 16 ounces of Lorsban 15G per 1,000 feet of row or 13.5 pounds of Lorsban 15G per acre applied as a broadcast application per crop season.
Please consult the labels for these insecticide products for more complete instructions on their use.
These label statements do not offer growers much flexibility with regard to the use of a soil insecticide a second time during a replanting operation. If a grower is able to match up rows during the replanting operation, the soil insecticide used during the original planting operation should be able to provide the necessary root protection.
What if a grower can't match up the rows because the field has "been worked?" The use of a soil insecticide a second time (two planting-time applications) would constitute a label violation for most products. The use of Lorsban 15G a second time appears to be an option, particularly if a reduced application rate was used during the original planting operation. Some folks may wonder, Is it OK to just use a different soil insecticide while replanting? In my opinion, this approach violates the spirit of the label for the various products. The main goal behind each label's planting-time use restrictions is to limit the overall amount of insecticide applied per acre in a growing season. Simply switching to another product to skirt the real intent of the label has potential environmental consequences.--Mike Gray