The Delta independent., 1914-05-08
FIGHTING THE COOLING
MOTH IN NEW MEXICO


the codling moth can be as effectively
controlled there as in any other apple
growing region. In the past there
have been complaints that the usual
methods were not SO satisfactory in
the Pecos Valley as elsewhere and
that in consequence a large part of
the crop was found to be unstable.
In one case. however, the investiga-
tors succeeded in obtaining 9939 per
cent sound fruit.
To obtain this result, the investiga-
tors sprayed the trees five times with
arsenate OF lead. The oftener the
trees were treated. the greater was
the PERCENTAGE of sound fruit, they
discovered, but at what point the in
creased value of the crop ceased to
equal the increased expense of treat
ment was not definitely determined
In conducting these experiments an
orchard at Roswell, New Mexico, was
divided into four parts. each of which
received different treatment. One was
left entirely alone; the others were
respectively. In each case the first
application consisted of solution of
six pounds of arsenate of lead to 200
gallons of water Sixteen and half
gallons. distributed through Bordeau
nozzles with a pressure of 235 pounds
were used for each tree. For sue
ceeding applications, the strength of
the solution was increased 70 S pounds
of arsenate of lead to 200 gallons of
water. and Vermorel type nozzles with
a 200 pound pressure substituted for
Bordeaux on its second spraying
each tree received 1884 gallons.
15 3-4 on its third. Il IA on the
fourth and 9 l-3 on the fifth An in
spection and count OF the fruit.
through the season. showed the follow.
ing significant results.
Unspraycd -40.77 per cent sound
fruit
Sprayed three times-e5lS per cent
sound fruit
Sprayed four times-ss.72 per cent
sound fruit
Sprayed five times-9e39 per cent
sound fruit.
In considering these figures 1t should
be remembered that the applications
were probably more thorough than the
ordinary practice of growers and that
this care is essential to the best re-
suits.
The time of spraying is also of great
Importance. for when the trees are I'M
sprayed II is found that more than
half of the larvae entered the fruit
the calyx lobes of the little apples do
not draw together for two to three
weeks after the petals fall. AS soon
as the petals have fallen. therefore.
the trees should be sprayed with great
care and the treatment repeated about
two weeks later before the calyx cups
are entirely closed. Every effort
should be made to direct the spray
straight into the cups. an elbow or
crook on the end of the spraying rods
being used for the purpose. A tower
IS also necessary for high trees.
Six or seven weeks after the second
treatment the trees should be sprayed
again. but this time the foliage and
fruit should be covered as uniformly
as possible with the poison. II these
three applications have been properly
and thoroughly made. Il will probably
not be necessary to repeat them: but
II the codling moth persists in its
work in spite OF them. one of two fur
ther sprayings will doubtless be use
full.
In regard TO the kind of spray, 1t
will be noted that the investigators
made no attempt to ascertain the rela-
tive merits OF the Bordeaux and the
Vermorel nozzles. Some authorities.
however. believe that n coarse spray
is better for the first treatment i'm
mediately after the falling Of the pet
ais, and for this reason Bordeaux
nozzle has been employed at that time.
In the absence of definite tests, 1t may
be safer for growers to do the same.
The results of the investigation are
set forth In detail In Department
Bulletin IS. The Control of the Cod
ling Moth in the Pecos Valley in New
Mexico" which the U. S. Department
of Agriculture has just published.
This bulletin will be sent free on re-
quest.