Ringspot

Ringspot is a common disease of sprouts, cabbage, cauliflower and calabrese.

It can occur on all above ground parts but first symptoms normally occur on older leaves. Small circular blackish spots appear and gradually enlarge to 1.5cm in diameter. The spots develop into a series of concentric rings bounded by a yellow halo. As the spots age concentric rings of fruiting bodies can be seen on the upper leaf surface.

Severely affected leaves become yellow and wither prematurely. On sprouts the infection on the buttons can make them unmarketable.

The disease is spread by airborne spores released from infected crops and debris during cool, moist conditions. The disease develops at temperatures of 15-20ºC where there is high humidity.