474 
JOURNAL OF HORTICULTURE AND COTTAGE GARDENER. 
[ December 3, 1691. 
“11 —The value of a mixed treatment, consisting of three early 
treatments of the Bordeaux mixture, and three late sprayings of the 
ammoaiacal solution. 
“ III.—The value of early against late sprayings. By early is meant 
the first treatment when the buds begin to swell, and by late the first 
treatment when the Grapes are the size of bird shot.” 
Full accounts of the experiments are given with diagrams. From 
the extended particulars relative to the experiments we gather the 
following remarkable facts, but it will be necessary to observe that the 
experiments were conducted at Greenville, South Carolina. “ The 
vineyard chosen by Mr. Howell (who carried out the work) for the 
experiment was one which had been well cultivated and cleared, but 
had never before received any treatment for Vine disease, and for three 
years had regularly lost from 50 to 75 per cent, of its crop by black rot. 
Besides this it had been invaded by downy mildew and anthracnose.” It 
may be as well to state that none of these fungi have appeared in this 
country, except it be downy mildew (Peronospora viticola) and that 
not making much headway in our vineries. 
reduced the amount of rot to less than 1 per cent., while on the un¬ 
treated V ines the loss averaged 40 per cent. This was much less than 
in an ordinary season on account of the dry weather. In such cases 
about 75 per cent, would have probably been lost. The present season 
was not one, either, that furnished a good test of fungicides. If more 
rain had fallen there is little doubt that there would have been more 
rot on the treated plats, more striking differences in the degrees of 
efficacy of the different fungicides, and more Grapes actually saved— 
that is, the difference between the amount lost on the treated and the 
untreated plats would have been much greater. 
“ As to the comparative value of the fungicides, the ratios found in 
the figures as given can scarcely be considered such as will hold for 
other seasons and in different climates. This season’s work has shown 
that a difference in locality affects the action of fungicides on foliage. 
For example, the copper acetate, which proved very efficacious with 
Mr. Howell of South Carolina, burned the foliage so badly in Missouri 
as to ruin the crop for the year.” 
The experiments at the other iplaces were practically the same as 
Number of Vines, Date, and Manner of Treatment. 
Yield of 
sound fruit 
per plant. 
Average yield 
per Vine. 
No. of rotten 
berries per plot. 
No. of rotten 
berries per Vine. 
Total rot per 
plot in pounds 
of sound fruit. 
Per-centage of 
loss. 
Total cost of 
treatment. 
Fifty Vines treated April 30th, May 15th, and 30th, and June 14th, with 
Bordeaux mixture . 
Pounds. 
260 
Pounds. 
5-20 
275 
5-50 
1-56 
0-60 
Cents. 
Gd.) 
54 
Eight untreated Vines . 
23 
2-87 
2464 
308-00 
14-00 
38 00 
00 
Fifty Vines treated, on dates given above, with ammoniaeal copper carbonate 
solution. 
255 
5 10 
236 
4-72 
1-34 
0-60 
22 
Eight untreated Vines . 
20 
2-50 
2816 
352-00 
16 00 
45-00 
00 
Fifty Vines treated, same dates, with Bordeaux mixture and ammoniaeal 
solution. 
255 
5-10 
188 
3 76 
1-06 
0-40 
40 
Eight untreated Vines . 
20 
2-50 
2827 
353 00 
16-00 
45 00 
00 
Fifty Vines treated with modified eau celeste . 
260 
5-20 
68 
1-36 
0-33 
010 
Not gvn. 
Eight untreated Vines . 
24 
3-00 
2466 
308-00 
14-00 
37-00 
00 
Fifty Vines treated with copper carbonate in suspension. 
246 
4-92 
268 
5-36 
1-52 
0 60 
11 
Eight untreated Vines . 
18 
2-25 
2998 
375-00 
17-00 
48-00 
00 
Fifty Vines treated with milk of lime . 
190 
3-80 
8599 
172-00 
48-86 
20 00 
03 
Eight untreated Vines . 
20 
2-50 
2819 
352-00 
16 00 
45 00 
00 
Fifty Vines treated with Bordeaux mixture prepared in advance . 
230 
4-60 
367 
7-34 
2 08 
0 90 
54 
Eight untreated Vines . 
22 
2-75 
2126 
266-00 
12-00 
35 00 
00 
Fifty Vines treated with Bordeaux mixture, one-half strength prepared in 
advance. 
180 
360 
8730 
174-60 
49-60 
21-50 
27 
Eight untreated Vines . 
17 
2 12 
2372 
284 00 
13-00 
43 00 
00 
Fifty Vines treated with acetate of copper solution . 
260 
5 20 
227 
5-54 
1-57 
0-60 
Not gvn. 
Eight untreated Vines . 
20 
2-50 
2176 
272-00 
12-00 
37-50 
00 
Fifty Vines treated with mixture No. 5. 
255 
5-10 
113 
2-23 
0-63 
0-25 
Not gvn. 
Eight untreated Vines . 
25 
3-12 
2472 
309 00 
14G0 
36 00 
00 
Fifty Vines treated May 17th and June 2nd with Bordeaux mixture, late 
treatment. 
210 
4-20 
2112 
42-24 
12-00 
5-00 
22 
Fifty Vines treated May 25th and June 9th with Bordeaux mixture. 
200 
4-00 
2040 
40-80 
11-59 
5 50 
27 
Fifty Vines treated May 17th and June with ammoniaeal solution. 
220 
4-40 
2618 
5236 
15-00 
6 00 
11 
“ The variety selected for experimental treatment was the Concord, 
because of its regular habits of growth and fruitage, and its unvaring 
susceptibility to rot.” The vineyard was divided into plots :—“Three 
plots of fifty Vines each, containing no sub-plots ; elevem main plots 
containing fifty Vines each, having in the centre a sub-plot of eight 
Vines each.” The diagram given in the work shows the arrangement 
of the plots, but suffice for our purpose to state that the variation in 
regard to the plots was for the purpose of bringing out the value of 
early spraying as will be shown later.” “ The first spraying was made 
ten days before blooming, and would have been applied earlier but for a 
delay in some of the chemicals. The weather had been dry for two 
weeks and no disease was showing on the leaves. The next day, how¬ 
ever, a rainy spell set in, lasting five days. The second treatment was 
also given on a clear day, and the first traces of black rot had been 
discovered the day before. There were rains on May 18th, 19th, 
20th, and then none until June 1st. The day after the fourth 
treatment there was a light rain (June 15th), and this was followed 
by a drought, which put an end to any infection of black rot for the 
season. 
In order to get a fair estimate as to the value of the various treat¬ 
ments the diseased and the healthy berries on both the treated and 
untreated plats were carefully counted and weighed. The weight of 
diseased fruit was estimated by counting, in several cases, the number 
of berries in a pound of sound fruit, obtaining an average number and 
dividing the number of diseased berries by it. The result of this work 
is shown in tabular form above. 
The foregoing table explains itself. “ Seven of the fungicides used 
those given in detail in the preceding notes, and the entire work is 
summarised as follows :— 
“ I. All things considered the Bordeaux mixture still heads the list 
as a preventive of black rot. 
“ II. The Bordeaux mixture prepared in advance, according to the 
directions already given, is not satisfactory, and is therefore not worthy 
of further use. 
“ III. Copper carbonate in suspension and milk of lime are com¬ 
paratively useless as preventives of black rot and other Grape diseases. 
“ IV. Copper acetate has fungicidal value, but in most sections it is 
likely to injure the foliage. 
“ V. The cheapest and most effectual remedy for black rot and 
downy mildew (Peronospora viticola), taking everything into considera¬ 
tion, is the ammoniaeal solution of copper carbonate. Next to this is a 
mixed treatment, consisting of two or three early sprayings of Bordeaux 
mixture and the same number of late treatments with ammoniaeal 
solution. 
“VI. Mixture No. 5, while possessing value as a fungicide, is likely 
to injure the foliage. Until this difficulty is overcome its use on a large 
scale cannot be recommended. 
“VII. Early sprayings are absolutely necessary to insure the best 
results in the treatment of black rot.” 
Although the experiments relate to black rot and other Grape 
diseases little, if at all, prevalent in this country, they are valuable as 
showing the importance of proper, efficacious, and early treatment of 
fungoid diseases generally.—G. Abbey. 
(To be continued.) 
