The symptom that can be used to identify maize rust is the presence of raised brown spots on the leaves. These spots can be small or large and may merge with each other as the disease progresses. The spots are usually surrounded by a yellowish halo, and the affected leaves may eventually dry up and fall off. Other symptoms of maize rust include the yellowing and browning of leaves, as well as the appearance of stripes of yellow and green on infected leaves. However, the most distinctive symptom is the presence of raised brown spots on the leaves.