Newark evening star and Newark advertiser. [volume] (Newark, N.J.) 1909-1916, 1914-05-02
LEAF CURL
MUST Be FOUGHT
EARLY IN SEASON

In reply TO an inquiry from a
reader relative TO the control of peach
leaf curl. we quote the following
from a recent bulletin on the subject
of the New Jersey State experiment
station at New Brunswick:
Peach leaf curl is q fungous disease
that attacks the leaves of the peach
III some sections of New. Jersey every
year, and is likely to occur in all por-
tons of the State. The disease mas
been known for nearly one hundred
years, and is widely distributed
throughout the peach growing dis
tricts of the world. It has been estl-
mated that leaf curl causes an an
nual loss of two millions to three
millions of dollars to the peach in
dustry of the United States. 1t is
largely responsible for the failure OF
the peach crop in some orchards,
and for the short life of the trees
The most familiar aspect OF the
disease Is the swollen. distorted ap-
pearance of the leaves in the early
spring When the disease first be-
comes apparent, the swollen portions
of the leaves are usually OF a nghe
red or pink color. The affected leaves
gradually turn yellow, finally blacKen
and fall to the ground. In some cases
the trees NAV be nearly defoliated,
thus making it necessary 10 deNslop
an entire second crop of leaves. TINS
is a severe strain upon the vigor ana
reserve energy of the tree. and I'M
less it is well cultivated. sprayed and
fortified it may be permanently
weakened. The curling and distor-
| ton of peach leaves may also De
/ cansed by aphis, or plant lice, but the
Lattsck of these insects can readlly De
distinguished from leaf curl Inc
| leaves affected by aphis do not be
1 come thickened and reddish or yell
| Iowish green in co.or
The spores of this fungus live IN
J ese~ the rough bark and in the
crevices of the twiss during the sum
/ u!er. and winter months, terminating
/ Early in the spring and attacking the
voung leaves as soon as the leaf buds
; hegin To expand. Cold. wet weather
during the months of April and May
! favors the development o. the fungus
and largely determines .he amount OF
injury. Warm. dry weather tents 70
check the growth of the fungus and
under such conditions the Injury is
slight. Leaf-curl is usually more in
iurlous In the northern part OF the
state than in the southern. the carry
spring months being warmer in The
latter section. However. serious IN
Jury often occurs in the southern
part of the state when the weather
is wet and cold in early spring.
The disease can readily be con-
trolled by a thorough application OF
| concentrated lime-sulphur before the
buds open in the sDring. Bordeaux
mixture applied early in the spring
before the buds start, also will con-
troll leaf-curl. but the lime and sui
phur mixture is advisable because it
will control San Jose scale as we'll
1t is essential that this application
of line-suIphur or Bordeaux mixture
he made in the spring before the leaf
| buds begin to open. Just as soon as
the buds start to expand. the spores
of the leaf-curI fungus may be scat
tered unon them terminate and pHSh
their l'tt'e hvphae or root1ets in be-
tween the bud scales. After this hos
taken place it is frnposs bic thorough
" to check the disease because = -
already inside the leaf tissues. The
object of the early spring application
of lime sulphur or Bordeaux mixture
= to xii the spores of the -leaf-curl
fungus before thew terminate. In
other words. snrayiug for leaf-curl
mist ne preventive. as no cur Is DOS
sible after the disease is established.
In using lme-sulphur it is essen
tial to use a solution that has been
properly prenared and diluted with
wa ter to a STRENGTH of not less than
I os specific gravity The snrav ma
terial shorld then be thoroughly ap-
nlied, so that every bud and small
tvis receives its coating ANY nor
ton OF the tree that is not covered
with the <nrsv material is likely to
become infected