Information Management to Maximize Your Yields

Herbicide Carryover Concerns

The 2012 season had exceptionally dry weather following herbicide application in many areas of the Midwest. Rainfall is one of several factors that help degrade herbicides, making carryover a risk next year. Extensive research and years of field experience have shown that rotational intervals established on product labels may effectively minimize risk to subsequent crop plantings.
Will rainfall from late summer to spring reduce the potential for carryover?

Yes, rainfall occurring late summer through next spring will have a significant impact on herbicide degradation, especially rainfall occurring before the ground freezes.
Will herbicides continue to degrade between now and spring? If we have a warm fall and winter, will this reduce carryover?
Yes, provided there is adequate soil moisture, warm soil temperatures will accelerate herbicide degradation lessening the chance of any potential carryover issues.
Will an extreme winter affect the rate of degradation? Do freezing and thawing cycles have an effect?
Herbicide degradation will stop once the soil temperatures cools in the fall (microbial activity slowed) and freezing and thawing cycles will not have an impact.
How many half-lives of breakdown do we see in a normal fall and spring?

There is no effective method to predict the number of half-life breakdowns that will occur in the fall or spring. Multiple factors including soil temperatures, soil moisture, soil pH, organic matter and microbial activity all play an important but interdependent role.


Taken from the Syngenta Performance Insight Newsletter