266 MANUAL OF FRUIT DISEASES 
BRUNISSURE 
Cause not definitely determined 
Brunissure is a name taken from the French which means a 
browning. The term refers to the effects on the foliage. The 
first manifestation of the disease is the appearance of irregular 
brownish spots on the upper surface. The epidermal cells 
finally slough off, exposing the underlying parenchyma, and 
numerous white spots appear on the dark background. Ulti- 
mately the browning involves the tissues through the leaf and 
the lower surface is reached. The trouble shows from July to 
November. Asa result of the affection the berries ripen poorly, 
their sugar content is reduced, the vines fail to mature, and black 
zones appear in the wood as far down as the roots. 
The disease is known in France, where it appeared in the 
autumn of 1892. It is also known in Italy and elsewhere 
abroad. Typical cases have been observed in the United States, 
notably in California. It is destructive only in isolated cases. 
The disease is thought to affect other plants such as the lily, 
tobacco, tomato and rose. 
The cause of brunissure has not been positively determined. 
At first it was thought to be due to scale insects, then to a slime 
mold, Plasmodiophora Vitis (Pseudocommis Vitis). Unfavor- 
able soil and weather conditions have been suggested as possible 
causes. It is generally agreed at present that the disease is 
non-parasitic, but this helps but little in disclosing the true 
cause. Control measures are unknown. 
REFERENCE 
Woods, A. F. Brunissure of the vine and other plants. Science, n. ser. 
9:508-510. 1899. 
