Factors Affecting Yield Loss Due To Crop Injury

Herbicide injury or “burn” is generally caused by the plant’s failure to quickly metabolize and detoxify the herbicide before it accumulates to lethal levels that result in injury.  Although chemical stress doesn’t damage yields as much as wild oats do, growers wonder if those fields can still achieve their full yield potential.

Factors that cause crop injury:

Weather patterns: Weather extremes can worsen herbicide injury. According to University of Minnesota researchers, a low temperature of 33 degrees F on the day of application at Rosemount in 2000 appeared to have caused greater injury and subsequent yield loss across varieties and herbicides compared to other locations and years.

Variety: Trials have also showed that injury-related yield loss varies greatly depending on variety and soil type.  Some varieties are more susceptible to injury from certain modes-of-action than others, as specified on herbicide labels.

Application methods: Failing to follow the herbicide label accurately often causes injury problems as well.  Growers need to check for requirements, especially when tank mixing grass and broadleaf herbicides.

Herbicide: Some herbicides are more prone to cause injury than others. To prevent injury, some herbicides have a built-in safener that makes it easier for spring wheat to break down, or detoxify, the active ingredient.

Application timing: Some herbicides have a wider window of application than others—follow the product label closely.

Herbicide injury on wheat in Rosemount, MN.