What symptom might indicate herbicide phytotoxicity to desirable turf?

• A. Discoloration, bleaching, or stunted growth after application
• B. Increased growth rate and darker green color
• C. Uniform deep green coloration without damage
• D. Sudden weed growth around treated area

Answer: (A)

Phytotoxicity in turf shows up as discoloration, bleaching, or stunted growth after a herbicide is applied. When the chemical interferes with essential processes in the turfgrass, it can reduce chlorophyll production and cell growth, causing pale or yellowed areas and slowed or halted growth on the treated spots. This kind of injury is a direct response of the desirable turf to the chemical, indicating non-target damage.

Increased growth rate and darker green color would signal healthy vigor or good nutrient status, not injury. Uniform deep green without damage suggests the turf is fine. Sudden weed growth around the treated area isn’t a symptom of turf injury and points to other factors like weed dynamics or application issues, not phytotoxicity to the desired grass.