Key Features
- Multiple species affected
- Symptoms follow spray or splash pattern
- Spotting, to entire leaf discolor
Symptoms
Plants can be injured by pesticides (including insect repellent!) when applied improperly. This can occur when those chemicals are applied directly to the plant during adverse environmental conditions (higher or lower than recommended temperatures), or when a spray, dust, or vapor drifts from the target crop to a sensitive crop. The likelihood of pesticide injury is greatest when pesticides are applied when temperatures exceed 85 degrees F, when plants are drought stressed, or when plants are sprayed resulting in the pesticide remaining on plant surfaces without drying. Every day cleaners, like those used for washing a car or deck, can also damage plants. Trees in the vicinity of pools often exhibit symptoms of chlorine damage.
Biology
Chemical injury can occur during any point in the plant's life cycle, but is usually more damaging on young tissue.
Management Recommendations
Dilution of the damaging chemical is often the best approach, or using tolerant trees in areas where the situation cannot be avoided are the best management options available.
Effective Pesticides
Pesticides are neither available nor recommended for managing this condition.
Resources
- Not satisfied with ID? Contact the Purdue Plant and Pest Diagnostic Lab
- Sign Up for the Purdue Landscape Report
