Small, dark, water-soaked spots develop on leaves and may merge, causing yellowing and leaf drop. Fruit develops raised, rough, scabby spots that can crack and become corky.

mall round tan or grey spots with reddish-purple borders develop on leaves; heavy infection can cause foliage to yellow, wither and die.

Tiny, slender insects scrape and suck sap from onion leaves, leaving silvery-white streaks and patches that can weaken plants and reduce bulb growth.

Small cinnamon-brown, powdery pustules develop on both sides of corn leaves and may become numerous during cool, humid weather.

Long, grey-green to tan, cigar-shaped lesions develop on leaves and can merge, causing large areas of foliage to die.

Dark lesions spread up the stems, weakening plants and causing yellowing, wilting and eventual collapse.

Yellow V-shaped patches spread inward from leaf edges as veins darken, leaving plants wilted, stunted and damaged.

Dark, water-soaked spots spread into soft rot, causing roots, stems or fruit to collapse.

Dark, sunken spots develop on leaves, stems or fruit, spreading until infected tissue rots and dies.

Purple-brown blotches develop on leaves and stalks, often causing them to yellow, wither and die back.

Small white spots spread across onion leaves, causing the foliage to yellow, collapse and die back.

Pale green or yellow blotches appear on the upper surface of older leaves. On the underside, directly beneath those spots, an olive-green to brown, velvety mold develops. As the disease progresses, leaves turn yellow, curl, wither and may eventually die and drop from the plant

Leaves have dark brown to black spots with yellow halos.

Small, circular spots (about 1/16 to 1/4 inch wide) with dark brown edges and pale gray or tan centers.

Leaves have small brown spots. Distinctive "bullseye" pattern of concentric rings. Can be surrounded by a yellow halo.