All tree species can be damaged by herbicides. Identifying the Causal Agent. Symptom expression can be variable for a given chemical and is often unreliable when used as the only diagnostic tool. Identifying the Injury. Some herbicides cause growth abnormalities such as cupping or twisting of foliage while others cause foliage yellowing or browning, defoliation, or death.
Chemical burn to nursery stock.
Environmental conditions such as temperature and humidity affect the degree of symptom expression by the host. Since symptom expression is so variable, professional help is desirable in diagnosing the problem.