Paraquat Label Changes

Paraquat (gramoxone) has seen some label changes that will affect applicators, including growers who spray their own crops. Below are four key things to be aware of on the new label:

-Label's changes highlight the toxicity & danger to human life.

There are 17 reported deaths since 2000 from accidental ingestion of this product. EPA says that: "Paraquat is highly toxic to humans. One small sip can be fatal, and there is no antidote."

-Now the use of the product will be restricted to only certified applicators.

Anyone who mixes, loads, applies the chemistry, or other related activities must have Pesticide Applicators License, not just work under them.

-Targeted training for paraquat users is required.

This is in addition to the certified applicator license. You can access the training module here: https://campus.extension.org/enrol/index.php?id=1660

-There will be a closed system packaging for non bulk containers of end use product containing paraquat.

This change will affect manufacturers of this product.

What has been learned after Four Years of Studying Temperature inversions.

Missouri Temperature Inversion

Integrated Pest Management of Missouri University has been monitoring inversions since beginning of 2015. This has been through a monitoring network established throughout the state. They have also studied how inversions affect auxin chemicals, particularly dicamba. With Xtend already in the market place for several years and Enlist on the horizon, there continues to be a concern on how successful apps on our phones predict inversions, whether inversions occur only at sundown, & the fact that not every field is created equal when it comes to the temperature inversion. Below is the link to read their article. I have included the bullet points from the paper for those who want to just skim the highlights. If you have time, though; it is a thorough piece based on real world studies.

Network of inversion monitoring stations that are tracking inversions at heights relevant to ground pesticide applications. Counties in blue indicate the 3 original inversion monitoring stations which were equipped in 2015. Counties in red indicate newer inversion monitoring stations that went online in 2017 and 2018.

1. Inversions are common. In June & July, 2018: Inversions formed more than 60% of the evenings.

2. Inversions begin forming prior to sunset. Sometimes more than 2 hours.

3. A field's surroundings influence the time when inversions form. Inversion form more quickly downwind of tree lines, for example.

4. Cool air is going to the lowest point of a field. Low areas are at greater risk for dicamba injury.

5. Mobile apps are still in validation stages. Most apps base data on higher heights than at ground level where the inversion forms

6. Dicamba can be detected in the air more readily following application during inverted air temperatures. IPM detected 3x more dicamba in the air applied in an inversion versus on label app during the day.

7. Smoke bombs are good indicators of inversion forming. MU used Enola Gaye Smoke Grenades to see how quickly the smoke cloud dissipates.

-In conclusion, much has been learned about inversions and much more is to be learned on this topic. On the ground "cues" like clear skies, reduced winds, & sound/smell amplification can be signs of an inversion to be formed or forming.

Here is the link to the article: https://ipm.missouri.edu/IPCM/2019/4/inversion/

All credits go to: AUTHOR

Mandy D. Bish University of Missouri Division of Plant Sciences (573) 882-9878 bishm@missouri.edu

Kevin Bradley University of Missouri Division of Plant Sciences (573) 882-4039 bradleyke@missouri.edu