What is in this article?:
- Over-the-top herbicide injury in cotton, soybeans very high this spring
- Thrips get involved
• Rest assured, when we are spraying across these muddy fields the humidity is high which makes herbicides like Liberty more active.
• Moreover, the cuticles on cotton and soybean leaves are paper thin as a response to all this water, which makes them more susceptible to injury.
Judging by our research at Jackson and Milan, along with over-sprays last week, we are seeing more burn of both soybeans and cotton with over-the-top herbicide applications.
In soybeans it is not uncommon to see 20 to 35 percdent burn with herbicides like Blazer, Cobra and fomesafen products. Even Liberty on LibertyLink soybeans is showing about 10 to 15 percent injury with applications last week.
On the cotton side, Sequence is showing about 15 to 20 percent burn in our research.
Glufosinate on WideStrike cotton has been very hot. In our research and in a few over-sprays brought to my attention, injury has been in the 20 to 30 percent range. WideStrike cotton where Dual was tank-mixed with glufosinate and sprayed on cotton, injury was even higher ranging from 35 to 45 percent.
Liberty on LibertyLink cotton has been the one bright spot as I have yet to run across any burn from Liberty on this cotton.
Why are we seeing so much foliar burn this spring with these herbicides?
The one main answer to this question has been the saturated soil conditions and high relative humidity. Rest assured, when we are spraying across these muddy fields the humidity is high which makes herbicides like Liberty more active.
Moreover, the cuticles on cotton and soybean leaves are paper thin as a response to all this water which makes them more susceptible to injury.
On the positive side, Palmer amaranth control is better under these conditions.
Judging by the early results this year, one should approach spraying glufosinate on WideStrike cotton with caution. Every time glufosinate is applied to WideStrike cotton it will injure it. However, in research from Georgia, Tennessee, North Carolina, Mississippi, Arkansas and Louisiana that injury has rarely translated into yield loss.