5 12 
THE NATIONAL NURSERYMAN 
LIME-SULPHUR PREPARATIONS FOR THE SUMMER 
SPRAYiNG OF ORCHARDS 
By W. M. Scott, U. S. Department of Agriculture 
Because of the injurious effect of Bordeaux mixture on 
both the peach and the apple, there has been in recent years 
great activity in the development of new fungicides. 
Preparations containing sulphur as the active principle 
have taken the lead and it appears now that Bordeaux mix¬ 
ture will be largely supplanted by lime-sulphur preparations 
in the summer treatment of apple and peach diseases. 
SELF-BOILED LIME-SULPHUR FOR PEACH DISEASES 
The self-boiled lime-sulphur mixture has passed through 
three years of experimentation and its efficiency as a fungi¬ 
cide for the control of certain peach diseases has been well 
established. During the past season the writer, assisted by 
Mr. T. W. Ayres, conducted experiments in the Hale orchard 
at Fort Valley, Georgia, the result of which demonstrated 
beyond doubt the practicability of controlling peach scab 
and brown-rot with this mixture. On a block of 568 
Waddell trees the yield of good fruit was increased 100% by 
two applications of the self-boiled lime-sulphur mixture, as 
compared with the yield from unsprayed trees in the same 
orchard. 
In order to prevent the curculio from puncturing the 
skin of the fruit and thus opening the way for brown-rot 
infections we sprayed a block of 1100 Elberta trees with the 
self-boiled lime-sulphur and arsenate of lead combined. 
Four applications were made, the first two of which con¬ 
tained the arsenate of lead at the rate of 2 lbs. to each 50 
gallons of the mixture. No injury whatever resulted from 
the treatment and the sprayed block yielded ten times as 
much good fruit as the adjacent unsprayed block of the 
same number of trees. Of the sprayed fruit only 
was affected with brown-rot and b%% with scab. The 
fruit from the unsprayed trees was 63% rotten and 99% 
scabby. On the New York market the sprayed fruit from 
the lime-sulphur arsenate of lead block sold for 50c a crate 
more than that from the unsprayed block. 
Another orchard of 15,000 peach trees, located in West 
Virginia, was sprayed with self-boiled lime-sulphur under 
the writer’s directions. As very little brown-rot occurs in 
that section the treatment was directed against the scab 
disease alone. A small block of Elberta trees was left un¬ 
sprayed and all of the fruit from this block was affected with 
scab and 86% of it so badly affected as to be unmerchant¬ 
able. On the other hand none of the fruit from a block of 
Elbertas sprayed twice was badly affected and only 15% 
showed any trace of the disease. 
The results cited above are convincing and it appears 
that there is no longer room for doubt that peach scab 
(Cladosporium) and brown-rot can be controlled by spray¬ 
ing with self-boiled lime-sulphur. The courses of treatment 
to be followed under most of the conditions existing in the 
East are as follows: 
Scab Treatment. —For the treatment of peach scab alone 
where brown-rot does not occur, spray the trees with 8—8-50 
self-boiled lime-sulphur about one month after the petals 
fall and again three to four weeks later. In mild cases one 
treatment thoroughly applied about a month after the 
petals drop will so nearly control the disease that a second 
application may not be necessary. However, two treat¬ 
ments will usually be required, especially on late maturing 
varieties. 
Brown Rot and Scab Treatment.—In orchards where both 
brown-rot and scab are to be combated, the following is the 
course of treatment required: 
Spray with 8-8-50 self-boiled lime-sulphur (1) three to 
four weeks after the petals fall (2) about three weeks later, 
and (3) about one month before the fruit is expected to 
ripen. This applies especially to the^Elberta, Belle and 
other mid-season varieties. The season being shorter with 
earlier maturing varieties such as Waddell and Carman, only 
two applications, the first and the third of the above outline, 
will be required. 
Combined Scab, Brown-rot and Curculio Treatment .— 
Where the curculio occurs in injurious numbers it is neces¬ 
sary to control it in order to obtain the best results from 
the brown-rot treatment. Arsenate of lead should be used 
for the purpose and the treatment would then be as follows: 
1. About the time the calyces are shedding, shortly 
after the petals drop, spray with arsenate of lead at the rate 
of 2 lbs. to 50 gallons of water. 
2. Two to three weeks later, or about one month after 
the petals drop, spray with 8-8-50 self-boiled lime-sulphur 
and 2 lbs. of arsenate of lead. 
3. About one month before the fruit ripens spray with 
8-8-50 self-boiled lime-sulphur, omitting the poison. 
An account of the experiments referred to above and full 
directions for spraying peach orchards will be issued at an 
early date as Bulletin No. 174 of the Bureau of Plant 
Industry. 
LIME-SULPHUR SOLUTION FOR APPLE DISEASES 
In recent years Bordeaux mixture has proved to be 
objectionable as a spray for the control of apple diseases on 
account of the russeting of the fruit and the burning of the 
foliage caused by it. During the past three years experi¬ 
ments with lime-sulphur preparations in the summer spray¬ 
ing of apples have been conducted by several of the experi¬ 
ment stations and by the Bureau of Plant Industry. The 
results have been fairly uniform, indicating that a lime-sul¬ 
phur preparation in one form or another is destined to 
largely take the place of Bordeaux mixture in spraying the 
apple orchard. 
A lime-sulphur solution containing, when diluted, about 
4 lbs. of sulphur to 50 gallons of water appears at present to 
