Onions

Visual Description:

Bulbs become soft and watery, often starting at the neck. The affected tissue turns brown to gray and develops a foul odor. When squeezed, the rotted tissue may squirt out. The disease progresses rapidly, especially in warm, humid conditions. Infected bulbs may appear normal on the outside but be completely rotted inside.

Visual Description:

Plants show wilting and yellowing, especially in young plants. When pulled up, small (1/4 inch) white maggots can be found feeding in the bulb and roots. Entry holes and tunnels are visible in the bulb tissue. Damaged areas often develop secondary rot. Multiple maggots may be present in a single bulb. Severely affected plants die.

Visual Description:

White, fluffy fungal growth appears on the bulb base and roots. Affected tissue becomes soft and water-soaked. A characteristic sign is small, black, poppy seed-sized sclerotia embedded in the fungal growth. Plants yellow and die from the oldest leaves down. The disease can persist in soil for many years.

Visual Description:

Small, elliptical spots appear on leaves, initially water-soaked, then turning purple with light centers. Spots may have concentric rings and can enlarge rapidly in humid conditions. Affected leaves die back from the tip. The disease can spread to bulbs during harvest and storage, causing dark staining of outer scales.

Visual Description:

Infection typically starts in the neck area where tops are cut. The affected tissue becomes sunken and water-soaked, often with gray to black fungal growth. The rot progresses downward into the bulb. When cut open, infected scales appear translucent and water-soaked. A gray fungal growth may develop between scales.

Visual Description:

Bulbs split into two or more sections, often after a period of rapid growth following dry conditions. The splits can occur anywhere on the bulb but commonly start at the base. Split bulbs are more susceptible to rot and have poor storage quality. The condition is most common when heavy rain or irrigation follows a dry period.