CCA Ontario Integrated Pest Management Practice Exam

Fomesafen is a herbicide primarily used to control certain broadleaf weeds in corn and other crops. The symptom typically associated with Fomesafen in corn is yellowing at the veins of leaves, which indicates that the plant is experiencing a nutrient transport issue often linked to herbicide damage. This symptom arises because Fomesafen affects the photosynthetic process, interfering with the plant's ability to effectively utilize nutrients, leading to discoloration primarily pronounced along the leaf veins.

Understanding the symptomatology is crucial in Integrated Pest Management, as it helps identify herbicide injury versus other plant stressors, ensuring that any management decisions are based on accurate diagnosis. In this case, leaf discoloration is a clear indication of the herbicide's effect on the corn, confirming the direct connection between Fomesafen application and the resulting physiological symptoms in the plant.