Vol. LXII. No. 2778. 
NEW YORK, MARCH 21, 1903 
*1 PER YEAR. 
THE "LITTLE PEACH" DISEASE. 
DISCUSSER BY A PRACTICAD GROWER. 
A Hard Problem for Michigan Peach Men. 
A SINGULAR AILMENT.—Doubtless many R. N.- 
Y. readers have heard of the strange, mysterious dis¬ 
ease known as the “little peach,” which has been de¬ 
vastating the peach orchards of western Michigan, 
more especially western Allegan County, where per¬ 
haps more peaches are raised than in any other place 
of equal size in the United States. As far as I have 
been able to learn, this dis¬ 
ease first appeared or be¬ 
came troublesome about 10 
or 12 years ago. Unfortu¬ 
nately the “little peach” is 
not as easily nor as surely 
recognized as the yellows. 
The leading symptom, and 
the one which has given 
the name to the disease, is 
tlio dwarfing of the fruit. 
I’crliaps I would best de¬ 
scribe the way the “litlle 
peach” (ieveloi)e(t in my 
own oi'cbard. 
GOOD ORCHARDING 
NO P R E V ENTIVE.—In 
March and April, 1901, the 
orchard was pruned, 
sprayed with Bordeaux for 
curl-leaf, and f e r t i lized 
with about two tons of un¬ 
leached ashes per acre. 
After growth commenced 
200 i)ounds of nitrate of 
soda per acre were applied. 
Although the soil was light 
the result was as Jhrifty 
an orchard as one often 
sees on such soil. The 
trees set a good crop, and 
everything went well until 
rii)ening time in Septem¬ 
ber. The first tree to go 
wrong was a St. John; part 
of the tree began to look 
as if it were ripening for 
IV i n t e r, s o m e of the 
I)eaches grew extra large 
and highly colored, while 
some were green and about 
the size of hickorynuts. As 
sometimes varieties of the 
Crawford type have some 
little green peaches when 
the main crop is ripe, I let 
the tree stand, ascribing 
its appearance to the effect 
of black-leg. When the 
later varieties began to 
fipen a good many trees 
began to look a little “off.” 
The peaches were about 
normal size, but the color was not quite right, and 
the skin seemed to be more fuzzy than natural. Alto¬ 
gether they looked like fairly good trees which had 
not been fertilized. Although I could recognize a 
well-developed case of “little peach” as well as most 
peach growers, I was unwilling to believe that the 
dread disease had invaded my best orchard, and in 
order to be sure, and to test the effect of fertilizers, 
all the trees were allowed to stand. A bag of ferti¬ 
lizer was applied as far as it would go, five to six 
pounds per tree; one bushel to bushel of ashes to 
each tree affected was applied during the Winter. 
FURTHER DEVELOFMENTS.—Last Spring the 
orchard was sprayed and cultivated as usual. Soon 
after growth commenced all the trees which showed 
signs of disease during the Fall of 1901 began to turn 
yellow, and the peaches stopped growing when little 
larger than hickorynuts, and as many more healthy 
trees aho’vC^ed the first signs of disease. Very often 
on the St. John part of the peaches would be extra 
large and highly colored, while the remainder would 
be about an inch in diameter, perhaps both on the 
same twig. The other varieties did not show this 
variation, but were all of one size. One tree of Early 
Rivers bore a good crop of fine peaches, grew thriftily 
and looked well all Summer until the latter part of 
September, 1901, when in one day’s time it took on 
the peculiar yellow color of the “little peach.” I did 
not believe it possible for a case to develop so quick¬ 
ly, but this season it was a fully formed case. 
WHAT THE DISEASE IS.—The symptoms seem 
to be just two. First the fruit stops growing when 
aboir. an inch in diameter, and is usually from one 
to two weeks later in ripening; the flesh seems to be 
firmer, pit well developed, flavor not as good as in 
normal fruit. Then the tree takes on a peculiar cop¬ 
pery yellow color, and the leaves are likely to be 
somewhat curled. So many other things will cause 
symptoms closely resembling the “little peach” that 
even an expert may often be mistaken. Root aphis 
produces a yellow sickly appearance, which many 
growers have mistaken for the “little peach.” Sour 
soil, lack of cultivation, starvation, overbearing com¬ 
bined with a dry season will often produce symptoms 
closely resembling the first stages, and especially in a 
poorly cared-for orchard it is very difficult to say just 
what the trouble is. If any tree in a well-cared-for 
orchard has a few small peaches which do not ripen 
at the usual time it should 
be closely watched, and if 
the leaves turn yellow be¬ 
fore the usual time the 
owner would better not 
wait, but cut it down and 
burn it. 
SUSPECTED CAUSES. 
—Now as to what we know 
about the cause. When the 
disease first appeared the 
growers appealed to the 
State K.xpcriment Station 
for aid. Prof. Taft studied 
the disease and advanced 
the theory that it was 
caused by freezing. This 
did not satisfy the grow¬ 
ers, because they had often 
seen trees almost killed by 
the cold which would so 
far recover as to make a 
vigorous growth, and pro¬ 
duce fruit of fine quality. 
Then they appealed to 
Washington, and in 1898 
Dr. Erwin F. Smith was 
sent to make a study of the 
disease. He was here just 
the one season. He gave 
the results of his study be¬ 
fore the Saugatuck and 
Ganges Pomological So¬ 
ciety. After listening to 
his address, although he 
said he could not yet tell 
what caused it, I went 
home with the idea that he 
thought a combination of 
very dry seasons, heavy 
crops and the curl-leaf, 
with perhaps a lack of 
available plant food, might 
be at the bottom of the 
trouble. When I got home 
1 found in a neighbor’s or- 
c h a r d a well-developed 
plain case in a three or 
four-year-old tree standing 
on new soil which never 
suffers from drought, and 
as the tree had not borne 
before, these causes would 
not explain. Since the “freeze” of Febrtiary, 1899, the 
seasons have been very favorable for the growth of 
peach trees. But the “little peach” is more destruc¬ 
tive and virulent than ever; it attacks trees of all 
ages, of all varieties, and on all soils. Prof. Smith 
found a fungus growing on the roots of affected trees 
which he thought might have produced the trouble 
by killing the little feeding roots, and then the larger 
ones. Prof. M. B. Waite, who has been studying the 
disease since 1899, is of the opinion that this fungus 
is what causes “little peach.” Prof. Waite is author¬ 
ity for the statement that another tree may be plant¬ 
ed on the same soil and do well. This is difficult to 
WHERE THE COMPRESSED AIR SPRAYER IS CH ARGED. 
THE LOOP COMPRESSED AIR SPRAYER IN THE FIELD. 
Fig. 77. 
Fig. 78. 
