Black speck/pepper spot in vegetable brassica

Black speck (also called pepper spot, spot necrosis, petiole spot, and gomasho) is a disorder that consists of very small to moderate size discolored lesions on the midrib and veins of the leaves.

It is most significant in cabbage and the symptoms can occur after low temperatures in the field and by harvesting over-mature heads but are usually associated with transit and storage conditions.

Crop nutrition

High rates of potassium in the soil have been shown to significantly reduce the severity of the disease.

Low storage temperatures followed by warmer temperatures enhance development. Although the cause is unknown, high rates of fertilizer, especially unbalanced use of nitrogen, cultural conditions promoting vigorous growth, and temperature fluctuations have been reported to increase plant susceptibility.