A Guide to Grapevine Abnormalities in South Africa - P.G. GOUSSARD

Botrytis (grey rot) (80); sour rot (81).

PHOTO 80. The shrivelling, browning and hardening of berries in reaction to dry, warm periods following initial infection.

PHOTO 81. A typical example of harmful secondary organisms (such as sour rot) which attack when climatic conditions are unfavourable for the successful course of grey rot following initial infection.

58 • A Guide to Grapevine Abnormalities in South Africa