—

=

fceinen ge 56.

United States Department of Agriculture,

BUREAU OF ENTOMOLOGY,
L. O. HOWARD, Entomologist.

THE MOST IMPORTANT STEP IN THE CULTURAL SYSTEM OF
CONTROLLING THE BOLL WEEVIL.

By W. D. HUNTER,
In Charge of Cotton Boll Weevil Investigations.

The agitation of the necessity for procuring an early crop in order to
avoid damage by the boll weevil has been carried on to such an extent
by the Department of Agriculture that the details have become common
knowledge. There is, however, a tendency on the part of many planters
to lose sight of the fact that procuring an early crop is but one step and
is strictly secondary to the great essential step, namely, the destruction
in the fall of the plants in the field. As a matter of fact, early planting,
the use of early varieties, and the use of fertilizers, are simply to further
the advantage gained by the process of fall destruction.

REASONS FOR THE DESTRUCTION OF THE PLANTS IN THE FALL.

There are four principal reasons why the process of fall destruction
recommended in this circular should be practiced universally by planters
in infested regions.

First.—Fall destruction prevents absolutely the development of a
multitude of weevils which would otherwise become adult within a few
weeks of the time of hibernation. The destruction of the immature
stages of weevils in infested squares and bolls is accomplished, while
the further growth of squares which may become infested later is also
prevented. This stops materially the development of weevils which
would normally hibernate successfully, and by decreasing the number
of weevils which will emerge in the spring the chances for a successful
crop the following season are very greatly increased.

Second.—A proper manipulation will bring about the destruction of a
great majority of the weevils which are already adult.

Third.—It has been shown conclusively that the only weevils which
survive the winter are those which reach maturity late in the season.
Those maturing earlier are unable to survive the long period of hiberna-
tion. In one instance, out of 240 weevils taken from the field at the
middle of December and placed in hibernation, 38, or 15.8 per cent,
passed the winter successfully, while out of 116 which became adult
about November 15, only 1, or less than 1 per cent, survived. It is evi-

2

dent that the weevils that pass the winter and attack the crop the fol
lowing season are among those developed latest in the fall and which,
in consequence of that fact, have not exhausted their vitality by depos-
iting eggs for any considerable length of time. Fall destruction of the
plants, thereby increasing the length of the hibernating period, will
undoubtedly cause the reduction by many fold of the number of weevils
in the fields that would otherwise emerge in the spring to damage the
cotton.

Fourth.—Clearing of the field in the fall makes it possible to practice
fall plowing, which is not only the proper procedure in any system of
cotton raising, but also greatly facilitates the early planting of the crop
the following spring. The ground becomes clean by this practice, so
that but few places for shelter are left for the weevils, and various cli-
matic conditions still further reduce the numbers of the survivors.

TIME FOR DESTRUCTION OF THE PLANTS.

It is naturally impossible to fix any date for the destruction of the
stalks which would apply to all localities and under all conditions.
The condition of the soil must be considered as well as the maturity of
the crop. While the condition of the soil can not be controlled, the
time of the maturity of the crop is largely within the power of the
planter, since by early planting of early maturing varieties the entire
crop may be mature before the usual time of picking of the first cotton
from native seed. Nevertheless, whatever modifications are necessary
in different localities and during different seasons, they do not decrease
the general strength of the recommendations.

The proper time for the destruction of the plants in the fall is when-
ever the weevils have become so numerous that there is no prospect
that any more cotton will be made. It will be an easy matter for any
planter to determine this point by an examination of a few plants in his
field. Whenever it is found that all, or nearly all, of the squares and
some of the bolls are being punctured, there is no hope for producing
any more cotton. The farmer should then wait until the bolls already
set on the plants have opened, and destruction should then take place
immediately.

The rule should consequently be that the plants should be destroyed
in the fall whenever all, or practically all, of the fruit is being damaged,
regardless of whether this is in September or November. In the great
majority of cases in Texas, from the 1st of October to the 15th of Octo-
ber would be the proper time. In many cases much earlier destruction
could and should be practiced. Nevertheless, it should not be thought
that fall destruction will be useless after the last date mentioned.
Even up to the 15th of November many weevils in the remains of bolls
hanging to the plants may be destroyed, but the process loses value
the longer it is deferred. By all means, if possible, destruction of

3

plants should take place before frost, but destruction after frost, though
not nearly as efficacious as earlier destruction, should always be prac-
ticed when it has not been possible to remove the plants previously.

METHOD OF REMOVING THE PLANTS.

The common practice of removing the cotton stalks from the fields
_ by the use of the stalk cutter (a wheeled cylinder provided with oblique
knives) is not effective in the fall destruction that should be practiced
to avoid the damage by the boll weevil. The stalks remaining in that
case during mild weather give rise to sprouts which furnish an abun-
dance of food to weevils that would otherwise starve. Moreover, the fact
that this machine cuts the stalks into short pieces makes the necessary
collection of them difficult.

There are two effective methods of removing the plants from the
ground. One of these, the method to be preferred, is to cut the roots
2 or 3 inches beneath the surface by the use of an ordinary plow or a
lister. The other is to pull out the stalks by the use of a lever provided
with a toothed notch which grasps the base of the plant. The latter
process is better adapted for use when the plants have been killed by
frost. When they are still green, or the ground is dry, it is frequently
a difficult matter to remove them with these levers. The Department’s
general recommendation, therefore, is that the plants should be plowed
out. As soon as possible after this is done, they should be collected by
hand, or by means of rakes, and brought together in large heaps or
windrows. It is- very important that this collection should take place
before the leaves have become dry and have dropped off. When the
plants are carried to heaps immediately after uprooting, all of the leat-
age, which will dry in a few days, remains to facilitate the burning of
the plants.

After the stalks have become dry enough, they should be burned.
If the weather is fair, this could be done in about two weeks. If rains
cause a lengthening of this period, it would undoubtedly be worth the
cost to the planter to purchase crude oil sufficient to bring about the
complete burning of all the stalks.

It is not considered necessary to leave any trap rows to attract such
weevils as may have escaped the burning. The weevil seems to have
but little tendency to be attracted to such plants. After the destruc-
tion of the main crop the spread would probably be in all directions
and the numbers collected on the trap rows would consequently be
inconsiderable. The time and expense of properly carrying on the
hand picking of the weevils and infested fruit on trap rows would be a
considerable handicap to the method on many plantations. Neverthe-
less, on small places where suitable labor is abundant, traps could con-
veniently be left. In such cases they should be situated on those sides
of the fields which are generally leeward. They should be examined

4

daily for weevils and infested squares and bolls, which should be
immersed in crude oil. After such collection for ten days, the trap
plants should be uprooted and burned immediately with the aid of
crude oil.

The suggestion has been made at various times that grazing the cot-
ton fields with cattle is in some cases equivalent to destruction in the
way that has been suggested. However, in many parts of Texas there
are not sufficient cattle to accomplish the work, and, moreover, in very
many fields the cattle, by disseminating Johnson grass and other plant
pests, would undoubtedly do more harm than good. At the same time,
the most thorough grazing always leaves a few green sprouts or leaves,
upon which weevils may feed, and of course leaves the stalks standing,
so that the process of leafing, for the benefit of the weevils, may con-
tinue indefinitely. Where the conditions of the fields allow it and the
supply of cattle is sufficient, grazing the fields should be practiced, but
it is not likely that this can generally be the case in Texas.

DIFFICULTIES.

The Department of Agriculture understands that there are some dif-
ficulties in the way of a universal following of the recommendations
given in this circular. The principal ones are the almost universal
hope for a top crop and in the labor conditions consequent from the
universal tenant system of producing the staple. These difficulties are
increased by the general scarcity of labor in the South, which is becom-
ing more and more a serious problem in raising cotton.

Planters in infested localities must understand that with the presence
of the weevil there is no longer any hope of a top crop. It is true that
after considerable cotton has matured and after the plants have applied
their energy to the formation of seeds and lint, fall rains often stimu-
late the production of a great number of squares. Many planters are
misled by this into the hope of gathering a large top crop. The joints
of the plant are short and the squares are formed rapidly and close
together. Though weevils may have been exceedingly numerous in the
fields, the presence of this abundance of food causes them to. scatter
and they are consequently temporarily somewhat less in evidence. In
many cases blooms appear and the hope for a top crop increases.
Nevertheless, this production of squares also contributes to the produc-
tion of a large number of weevils late in the season and just at the
time for their successful hibernation. As a result of this fact, great
injury is done to the crop of the following season, with no gain what-
ever, or a very small one, in the yield of the current season. From
these considerations it seems plain that within the weevil territory all
hope of a top crop must be given up and the destruction of the plants
be practiced as early in the fall as ‘possible.

Another important difficulty lies in the tenant system. It is usually

5

the practice to terminate the work of the tenant with the picking of the
cotton, leaving the clearing of the field for the next cropper. At pres-
ent, after the cotton is picked the tenants frequently move to other
plantations or to other parts of the same plantation. It should not be
a difficult matter for planters to induce their tenants to practice the fall
destruction of the plants as the last step in the production of a crop.
In any case the plants have to be removed before the ground can be
prepared for planting the following season; and the present recom-
mendation merely involves applying, at a time some months earlier,
the same amount of labor as is necessary in the spring. The best
solution of the difficulty arising from the tenant system would be in the
inclusion, in the agreement between the landlord and the tenant, of a
provision which would bind the latter to clean the land thoroughly
before leaving it.

In a comparatively small area in southwestern Texas it might be
considered that there would be a further objection in the practice,
which some farmers have, of encouraging the growth of volunteer or
seppa cotton in the hope of procuring an early and inexpensive crop.
As has been repeatedly pointed out by the Department of Agriculture,
this is beyond question the worst possible practice in weevil-infested
regions. The disastrous experience of several counties in the southern
portion of the State during the present season has abundantly demon-
strated the force of the warnings that have been issued from time to
time. The staple produced by volunteer plants is short, kinky, and
undesirable. Before the advent of the weevil, the only reason for en-
couraging such growth was to procure the first bale. Now, on account
of its very detrimental bearing on the weevil problem, any attempt to
raise cotton from volunteer cotton should by all means be discouraged.

The point may be raised that the burning of the plants in the fall
removes valuable fertilizing constituents and that the continuance of
the practice would seriously reduce the fertility of the soil. In refer-
ence to this matter, however, it must be stated that the present general
practice is to clear the fields by burning the plants in the spring.
Therefore, practically the only additional draft upon the soil by the
method recommended is in the burning of many of the leaves and a
portion of the roots. However, destruction of the plants can only take
place after many of the leaves have fallen, and, in other cases, when
the plants have become completely defoliated by the cotton caterpillar.
The fertilizing constituents in various parts of the cotton plant have
been carefully determined.! An estimate of the value of all the con-
stituents which could possibly be removed by fall destruction, based
upon the schedule of trade values adopted by experiment stations for

1 See Bulletin 33 of the Office of Experiment Stations of this Department, pp.
81 to 142.

6

1898, shows that the loss per acre would be very small. It is plain
that the planter could not only regain this small loss, but actually
greatly increase the fertility of the land by the use of commercial fer-
tilizers, which would cost an inconsiderable amount in comparison with
the gain in the following crop, as a result of lessened damage by the
boll weevil.

As a matter of fact, the preceding objections are not necessarily
serious. They deal with general changes in cotton culture made neces-
sary by the ravages of the boll weevil. As is beginning to be well
known to Texas planters, it will not be possible for tenants to work as
much land as formerly. More cotton will be produced by decreasing
acreages and increasing the attention given to what remains. If this
is done, the objections mentioned will largely disappear.

NECESSITY FOR A LAW.

The critical seriousness of the weevil problem, together with the
demonstrated necessity of fall destruction, led to the recommendation,
first made by Dr. L. O. Howard in Circular No. 14 of this Bureau,
February 12, 1896, that some legal means of enforcement be provided
by the legislatures of the States concerned. The recent work of the
Department has all pointed towards the prime importance of this matter.
Although there are no exact precedents for such a law, it is believed
that its passage and enforcement would plainly be within the police
powers of the State. It would not necessarily be essentially different
in principle from the laws regarding the control of insects injurious to
fruit trees, which are now in force in many States. Dr. Howard states:
‘The law should provide for the appointment of commissioners in each
county. These commissioners should be empowered to enforce remedial
work, to levy penalties, or to have the work done by their own agents,
the cost to be assessed upon the property. It will be well to let this
law have a wide bearing and not confine its application to this particu-
lar insect, but cover all injurious insects in case of future emergencies
of a similar nature.”’

Mr. Jefferson Johnson, of Austin, Tex., whose extensive experience
as a cotton planter and as chairman of the board of award under the
Texas law appropriating a large sum as a reward for the discovery of a
successful remedy for the boll weevil has made him thoroughly con-
versant with the habits of the pest, as well as with all means of con-
trolling it which have been suggested, is firmly of the opinion that the
time has come for the enactment of such a law.

From the present outlook, therefore, and as a result of extensive work
with the boll weevil for several years, the Department of Agriculture
warmly recommends the passage of Jaws regulating fall destruction of
the cotton plants in the manner described in this circular in the States
of Texas and Louisiana.

7

CONCLUSION.

Having studied and tested the methods of weevil control which have
hitherto been recommended, the writer firmly believes that the destruc-
tion of the stalks in the early fall is the most effective method known
of actually reducing the numbers of the pest. This destruction will
cost but a small fraction of the expense necessary in the frequent pick-
ing up in the spring of the squares infested by the hibernated weevils,
and is far more thorough as a means of reducing the numbers of the
weevils than is the practice of picking hibernated weevils from the
young plants. Early destruction of the stalks is essential to the greatest
success of any system of controlling the pest. All other practices rec-
ommended, though very valuable in securing a crop, are of the greatest
value as they are followed in connection with this one prime essential.
Since the earliest investigations of the boll weevil made by this Depart-
ment, it has been recognized that this practice is of the first importance,
and the experience of recent years has added but certainty to this con-
~viction. A number of planters have adopted it, and their work has
abundantly demonstrated its efficiency. Jt must not be thought that
the procuring of the immediate crop is the only thing to be desired.
Early and complete destruction of the stalks 1s undoubtedly the most
important single element insuring success for the subsequent year.

Concerted action in fall destruction is, of course, desirable. The
greatest benefit will only result when whole communities adopt the
method. But no planter should hesitate on account of the indifference
of his neighbors. The fact that weevils move about but little until the
time when the bulk of the crop is safe will assist materially in saving
one field though nearby ones have not been properly treated, and, even
under such circumstances, the success of the method in one field will
be a powerful stimulus toward its general adoption the following season.

It is true that the recommendations contained in this circular involve
considerable change in the practice of producing cotton. Nevertheless,
the important changes that have been brought about up to this time in
the use of improved seed and fertilizers have also been revolutionary in
their character. It is hoped by the Department that the agencies that
assisted in that matter—namely, organizations of business men—will
everywhere devote the same energy towards encouraging the practice of
what is, after all, the most important step in maintaining the supremacy
of the cotton crop in the weevil regions.

Approved:
JAMES WILSON,
Secretary of Agriculture.

WASHINGTON, D. C., October 10, 1904.

O

RIES

wi

; ———