Mildew. 
GRAPE MANUAL. 
Peronospora. 4% 
VITICULTURAL REMARKS. 
The Ameri Miupew (Peronospora viticola) first 
—* itself in the form of spots ieciaabting a small 
umulation of powdered sugar, not larger than a 
lent on soe a underside of the leaf; but imperceptibly 
end and join until they cover a larger 
niga face of the foliage. Later 
tack dry up and take the color of 
leedwii or dead eae so that these mildewed, Se 
elled, dried-up leaves are often confounded with o 
taken for ‘‘ sun-scald’’; but on closer observation mil. 
dew can easily be di ished from sun-scald. 
the effect of the latter, there is no white powdery 
mushroom vegetation visible on the lower face of the 
leaf. Mildew mostly attacks the foliage, sometimes 
also the young gree n stems; rarely the small, young, 
never the full-grown, ripenin; i 
The important difference between Perinospors (the 
Am. mildew) and Oidium (the European mildew) is 
not sri are that Perenospora appears on ee while 
appears on the upper surface, but that the 
ar penetrates the Bim i tissue of ‘he! “i while 
Oidium grows on its wu surface only. ee 
ness exert a preponderating influence on the 
om eae of the disease; rain, dew, even ta ‘ever 
the spread and germination of the spores, while a pro- 
longed pertaos restricts and kills them 
Dp. 
a remedy sulphuriz: 
any mildew is 
mode of using it. Bellows were specially man 
for this e ine-growers were found to testify 
to'the efficacy of this panacea; none co ed ;f 
repeated trials, merely venturéd to say in the former 
To distinguish this from the Oidium (the European 
waiidow) we call the P “ American mildew”; 
but this dangerous fungus in 
ys ena we ‘doubt that 
WwW. Pearson, from 
of unee here who here weed eutphar 
if ot all, ted in the 
edition of this Catalogue, | “with our prices of labor 
it would scarcely be practicable—and it is best not to 
plant largely of those semicon which are very liable to 
+ isease,’’ 
Not until this course a had also been 
observed and st e, where it was first 
noticed in 1878, esr aap sh these last four years, 
spora, 
Oidium, lives not merely on the surface of the leaf, but 
pra its tissue. 
we are not without hope that some 
fe) s. We have now before us an ‘‘Es- 
SAI SUR LE DIOU, PAR pEt, Professeur 4 
la Faculté des Sciences 4 Bordeaux,” Paris, ; he 
suggests, asaremedy, a mixture of powdered pore eon 
of iron, copperas (4lbs.), with plaster of, Paris, gyp- 
sum oad Ibs.), isducoeey: according to reports, was applied 
de Bordeaux), with marked success. Remedies of this 
kind must be used very cautiously; and until their 
and proper mode of appliance 
lished, our grape-growers will do best to select those 
varieties which are generally less liable to this disease. 
To — in doing so, the following table,* based on many 
experience, may be of service: 
TABLE OF rgprocggean VINES (PRINCIPAL VARIETIES) WITH 
REGARD TO THEIR RESISTANCE TO MILDEW (Peronos- 
pora). 
I. Catecory: almost sahicdly exempt, even in unfa- 
yorable seasons and localities 
4istivalis, Northern Division ; ‘Cviiiiain, Nor- 
ton’s sien 
orthern Division: Concord, Hartford, 
eterg Beckton: also, Champion, Cottage, North 
enango. 
Riparia and its ts crosses with Labr.: Elvira, Mis- 
souri Riesling, Montefiore, — Taylor. 
ee 
. : WT £. Ay At 1 
