Tuesday, August 25, 2015

US-EPA Grants Section 18 Emergency Exemption Label for Use of Transform™ WG for Control of Sugarcane Aphid on Grain Sorghum in Kentucky.

Doug Johnson, Extension Entomologist, University of Kentucky

The United States Environmental Protection Agency (US-EPA) has granted the use of Transform™ WG for control of the sugarcane aphid, (Melanaphis saccahri) on sorghum.

Emergency Label Highlights

 Use of this product is provided through the Specific Exemption under provisions of Section 18 of the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA). Important highlights of the label are:

  • All applicable use directions, restrictions, and precautions on the EPA-registered Section 3 label and the specific use directions outlined in the Section 18 label must be followed.
  • The applicator should have a copy of the Section 18 Emergency Exemption Label in hand when making an application. A copy of this label is posted aton the UK Extension Entomology web site. You may also find this label at other label providers, once the notice has penetrated the information system.
  • Foliar applications may be made by ground or air at a rate of either 0.75 or 1.5 oz. of product per acre with a maximum of 2 applications per acre per year; OR at a rate of 1.0 oz. of product per acre with a maximum of 3 applications per acre per year.
  • The minimum application re-treatment interval is 14 days.
  • The Restricted entry interval (REI) is 24 hours.
  • The Pre-harvest interval (PHI) for forage is 7-days, and 14 days for grain or stover.
  •  A maximum of 13,000 acres of sorghum fields (grain and forage) may be treated in Kentucky.
  •  Specific exemption ends on November 30, 2015.
 NOTE this product is highly toxic to bees exposed through contact during spraying or while spray droplets are still wet. Risk to managed bees can be minimized when applications are made before 7:00 AM or after 7:00 PM local time, or when the temperature is below 55 degrees F.

The information in this newsletter does NOT constitute a label, is not a substitute for a label, and is provided only for educational purposes. Applicators should acquire a copy of the Section 18 Emergency Exemption label, and follow the directions.

 Scouting and Management Options

With the addition of the Transform™ WG label along with the Sivanto 200 SL label, we now have access to two of the newer products for control of sugarcane aphid. This should provide Kentucky producers with the most up-to-date products for control of this pest.

 Treatment thresholds are based on the experience of our colleagues further south.

Make sure you have sugarcane aphid (SCA) and not one of the other aphids that may be found on sorghum (e.g. yellow sugarcane aphid, corn leaf aphid, green bug).

To detect early infestation, conduct a weekly check of one leaf on each of 50 plants scattered across the field.

If not present, check again in one week.

Start scouting more frequently once SCAs have been found in your field. IF present, scout two times per week and use a threshold of an average of 50 to 125 SCA per leaf on 50 leaves taken from plants scattered across the field. If this number is exceeded, an insecticide application is warranted.

It is vitally important that one does not begin insecticidal control before it is warranted. Once the first insecticide application is made, the many and various natural enemies that are feeding on SCA will be killed and the SCA populations will be left to increase unhindered by these natural controls.

Most of the insecticides labeled for use on sorghum provide poor control of SCA. Lorsban, dimethoate, and malathion are registered for control of aphids on grain sorghum, but are not as efficacious against SCA as the newer products.

Although the granting of the emergency label for Transform WG adds a very important tool to our toolbox, one needs to remember that we are quite late in the season, and the closer to maturity the crop is, the less likely it is to need protection.

 Additionally, though sugarcane aphid has been collected from sorghum in four Kentucky counties, (Fulton, Calloway, Lyon, and Caldwell, in order of discovery) there are as yet no infestations that have been shown to be of economic importance. We need to protect all the tools we have for control of this potential problem and proper discretion in application will aid in preventing resistance, provide protection to non-target species, and show the appropriateness of granting Kentucky producers the use of this product in successive years.

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