>L.OGICAJL -. ACTION'.''
TREATMENT OF COTTOiV SEED
PIMv BOU. WORM
(Gelechia yossypiella Saund.),
G. STOREY, B.A., F.K.S.,
KNTOMOLOI*IST TO THE MnnsTBv nh AI;HICPLTITRK.
<*ihmined for printing on July 33, 1817
ccrctary of Stat
Director ., ...
Director ... ...
Director H. Mas
Director D, S.
Director ... ... Abde)
Addre Ministry of Agr
_ CT .ams ... "Rural," Cairo
Offices 12, Sharla El Falaki, Heidar Pasha's Palao.
Telephone Numbers 5406, 5407, 5408, and 5409.
MINISTRY OF AGRICULTURE, EGYPT.
TECHNICAL AND SCIENTIFIC SERVICE.
i KNTONK >!,( )( ;K !AL -KC.TK >\.
MACHINES FOB THE TREATMENT' OF COTTON SEED
AGAINST I'IM\ BOLL WORM
'id yossi/])iclla Saund.),
(.. STOK'KY. I'-. A.. F.E.S.,
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MINISTRY OF AGRICULTURE, EGYPT.
Bulletin i\o. l'.
(ENTOMOLCH.K iAL -<K( :TH>N I.
MAC1IINKS KOI! TIIK TREATMENT OF CO'ITOX SEED
AGAINST 1MNK I'.OU, WORM
vr/m/ ifo.^tf/iifUn S\rxi>.).
It is now a. matter of general knowledge that the pink boll worm
passes through the winter in a rendition, either in the, dead
bolls Ml on the cotton slicks and the ground alter t Ir- previous, year's
harvesl. or in the cotton seed. As regards the former, for the last
three years the Mimstrv of Agriculture has endeavoured by its boll
\vonn campaign to induce cultivators to collect and burn the dead
bolls in order to reduce the menace to the next year's crop. The
present paper deals only with the question of the cotton seed which
has occupied the attention of the Entomological Section since 1!U'J.
Siii< e the completion of the laboratory stage, of the experiments
progress has been slow, partly owing to the general attituti' >thy
and. in som> even of opposition on the part, ol gi niters and others
concerned, and partly owing t-> the dilliciilt ies of various kinds
occasioned bv the war. Ho\vevei-, a law has now been passed making
the treatment, of cotton seed against pink boll worm compulsory,
and it has therefore, been thought advisable to publish a brief rt-sinin'-
of what has be-n done. gi\ ing short accounts of the various types of
machines t hat have, been proposed.
In December l!)i:i. when the pink boll worm was just beginning
to be regarded a 'rlv exhaust i\v .f laboratory
experiments Was cari'ied out to test the various methods of killing
the worms without damaging the seed. The results of these experi-
irients weiv jtublished in tlu> " Agricultural Journal of Egypt." 1913,
Volume III, Part II (Gough and Storey, " Methods for the Destruction
of the Pink Boll Worm in Cotton Seed"), the conclusions arrived at
" Three different methods of destroying Gdechia larvae have been
found effective and. commercially applicable, namely :
" (1) Hot-air treatment.
" (2) Treatment by poisonous gases.
"(3) Treatment by soaking in cyllin solution 1 : 1,000.
' The methods indicated under (1) and (2) are applicable on a
large scale at the time of ginning and (3) only immediately before
sowing. No treatment is possible when the seed is in the sacks."
As soon as these conclusions had been reached, an experimental
hot-air machine was erected by M. Crovisier of the State Domains
Administration, and a carbon bisulphide fumigation machine was
constructed by Messrs. Thos. Cook & Son to a design of the
Entomological Section. Both these machines were exhibited at
Sakha in June 1914 to a meeting of ginners and others interested, and
reports on them wsre published in the "Agricultural Journal of
Egypt," 1914, Volume IV, Part II (Storey, " Notes on Large Scale
Experiments against the Pink Boll Worm in Cotton Seed "), together
with a note on a mechanical cleaner devised and built by Messrs. W.
R. Dell & Son, of London. In spite of the fact that the two former
machines were successful in doing what was asked of them, neither
of them found favour with the ginners, the hot-air machine on account
of its clumsiness and immense size compared with its output together
with the danger of damaging the seed by overheating, and the
fumigation machine on account of the poisonous and inflammable
qualities of carbon bisulphide. The objections to the latter were
apparently more serious than to the former. The Entomological
Section therefore turned its attention to the hot-air treatment and
designed an experimental machine, on much the same principle as
some of the tea-drying machinery made by Messrs. Marshall & Sons.
Though still very cumbersome, this was much less so than the Domains
machine, and having a larger ouoput gave one a better idea of the
commercial possibilities of the process. This machine was to have been
completed by February 1915. Owing to difficulties caused by the
war, however, it was not actually delivered till November of that
In the meantime a proposal was made by Mr. Victor .Mossed to
fumigate the seed with hydrocyanic acid ga< /// rm-no. He also
elaborated an apparatus for recovering the gas after treatment, thus
reducing the danger of poisoning to a minimum. Laboratory experi-
ments to test the method had proved id. and as a very similar
method is used in America for fumigating steam -pressed cotton
bales, apparently with romplei' 3, it wai 'hat
the process would prove equally so ting col d on
the large scale. A full-sized apparatus was therefore ordered from
.Messrs. Sulzer Freres of \Vinterthur. Switzerland, lo Mr. Mosseri's
design. Dem oust rat ions of the process with a,n .e\ peril! Cental apparatus
\\ere made in May I!)!..") be fere 11.11. the SuHaii. and in June before
delegates from the Ministrv of Agriculture. The full-si: - .ed machine
was definitely ordered in S/ptember and was to have been )<
for use during December. Howeve,. owini: to various delays it
was not ready for trial till August ]!)!(. By that time practically
all the pink boll worms had left the pre\ i
could not be made until the new season's seed was available.
During this delay, liov big advance had been mad'
erection of a new type of hot-air machine as a, commercial enter].
Hitherto all experimental machines had l>. led at Covernment
; und the (iovenimcnt had borne all other expenses conn< -
with the experiments. In the latter half of ]!)]">. however. Me
Mosseri. Curiel & Co.. 7>f Cairo, brought from Kngland a malt-drying
machine of the type made by Me.-^rs. Richard Simon & Sons, of
Nottingham, and a<l-.ed the Ministry of Agriculture to test it- \\h
view to finding whether il could be utilized for treating cotton seed.
A preliminary i-rial was carried out during February J!)l(i. This
uas. however, of little, use owing to the absence of certain accessories.
Further Trials were carried out in April after tli more impor
defects had been remedied, the results beinir published in the Mini
of Agriculture's Bulletin No. II (Store mon'a Hot-air Mac 1
for the Treatment of Cotton Sed against Pink Boll Worm").
This machine dilTered in principle from the pre\ -air
hines that had been proposed, the seed being heated, not by
air, but by direct contact with steam-tubes. In fact the maehii
not really a " hot-air " machine at. all. The na.me has. hov, >me
to be adopted for want of a. better, so it is idle to try to chang" it now.
This change in principle immediately overcame the great objection
to the true hot-air macliinrs. namely, their immense size compared
with their output. The results of the experiments proved quite
satisfactory, particularly so considering that the machine in question
was only erected as an experimental model ;MH| wns not fitted either
with a satisfactory feed or with adequate means for regulating the
In spite of demonstrations, however, it became increasingly
obvious that nothing would ho done by the ginners until it was nunlr
compulsory by law to treat all the seed in the country against pink
boll worm. There were many difficulties in the way of such a law.
particularly during war time, and inquiries connected with them
occupied a considerable amount of time. However, the law (No. 29
of 1916) was eventually promulgated on December 15, 1916, to the
effect that during the coming ginning season, i.e. 1917 to 1918, all
cotton seed must be treated ;i gainst pink boll worm with a machine
approved by the Ministry of Agriculture. At the same time an
effort was made to rediice the danger from worms in the seed to a
minimum during the current season by prohibiting the storage of
cotton seed and unginned cotton in the country after May 1. except
in licensed moth-proof stores. Later it was found to be impossible
to obtain a sufficient number of machines for the whole of Egypt for
the 1917-1918 ginning season. Consequently it has been decided not
to enforce the law during the coming year.
The promulgation of the law, however, had an immediate effect
on the activities of the ginners and local manufacturers such as all
the previous demonstrations and recommendations had failed to
produce, and during the four months following its publication the
Ministry of Agriculture received more than twice as many suggestions
for machines for treating cotton seed as had been received in the
previous four years. Some of these were merely adaptations of
others, some have not proved successful, and others have not yet
been tested. All, however, are briefly described below, in the hope
that the descriptions will prove of interest and value to any one
contemplating the erection of machinery for the treatment of cotton
Five more or less different machines have so far been proposed
involving the use of poisonous gases : the Ministry's original machine
and one proposed by M. ( Jayet, involving the use of carbon bisulphide ;
.Mr. Mosseri's and an adaptation of the American baled cotton
fumigator, employing prussic acid gas ; and, finally, a machine
proposed by Messrs. Wells and Hayman, in which the fumes from the
distillation of cotton sticks are iised as the killing agent.
(1) The M/itix/i-// "f Aijricultiire's Carbon #/*////>// /We
A full description of this machine was given in the " Agricultural
Journal of Egypt," 1914, Volume I V. I 'art II, page 119. It is therefore
of little use repeating it here. Suffice it to s;iv that. 90 tar as the
treatment itself is concerned, this machine is the most successful of
any yet erected, giving a regularly con plete mortality of the worms
with no possibility of damaging the seed i>i any circumstances whatever.
The machine was verv cheaply erected. h;ul ;i capacity of tw-nty ardebs
per hour, and was economical in running, the only cing
chemicals at less than I'.T. I per ardeb, and a small amount of power
and labour. The objections raised to the use of carbon bisulphide
on account of its poisonous find inflammable qualities were, however,
so strong that the machine was abandoned.
For further particulars, see th> I to above or apply
to the Ministrv of Agricultun .
(2) Mosseri's Ci/nti/dc /''inu/nator. This machine has already
been referred to at some length above. The installation at KalY el
Zavat consists of eight cylinders, each with a capaciiv of about ten
ardebs, a powerful air pump worked by an oil engine for exhausting
the cylinders and the necessary apparatus for producing, drying,
and distributing the hydrocyanic acid gas. At first an apparatus
was also attached for recovering the gas after use by means of caustic
soda, but owing to ' he difficulties and dangers of handling this without
employing a trained chemist it was decided to burn the ifas after
use by passing it through a small fum
In practice a cylinder is filled with seed and closed down. The air
is then exhausted a 3 possible. The gas, mixed with a certain
amount of air. is admitted and left for half an hour to take el;
At the end of this time the gas is drawn out again, and then a current
of air is circulated to remove the last traces of the gas as far as possible
before the seed is taken out and sacked.
The machine has been tested by Mr. Aladjem, the Ministry's
Assistant Chemist. He states that in the first trials carried out
during August, when the temperature was high, the results were
entirely satisfactory, but that when the weather became cooler it was
found to be necessary, as was anticipated by Mr. Mosseri, (1) to dry
the gas, and (2) to keep the temperature of the seed and apparatus
above 27 in order to prevent the condensation of the gas. For the
latter purpose, owing to the lack of facilities for having an elaborate
piece of apparatus made, the seed was either spread out in the sun or
heated by means of a somewhat primitive hot-air machine improvised
from the materials available. In this way it was found that when
the temperature of the seed was about 30 C. the mortality of the
worms was generally about 93 per cent.
It appears from this that the question of condensation makes it
essential that machines of this type should be provided with some
apparatus for keeping the temperature of the whole plant at least as
high as 27 C.
Fumigation with hydrocyanic acid gas has no effect on the
germination of the seed.
The machine has been approved by the Ministry of Agriculture,
subject to certain conditions imposed by the Department of Public
For further particulars apply to Mr. Victor Mosseri. Ingenieur
Agronome, Cairo, or to the Ministry of Agriculture.
(3) American Cyanide Fumi gator. During 1914 a proposal was
made by Mr. Dudgeon, Consulting Agriculturist to the Ministry of
Agriculture, to employ a machine of the type used by the American
Government for fumigating imported bales of cotton. In principle
the machine is exactly the same as the last, but the seed, instead of
being fed into cylinders in bulk and sacked after treatment, is first
sacked and then run on trucks into a horizontal cylinder. A machine
of this type was actually ordered, but, owing to the difficulty of getting
the work executed during the war. the order afterwards had to be
cancelled. The machine has apparently proved quite successful in
fumigating steam-pressed bales of cotton, but whether it would
meet with the Bade difficulty as Mosseri's machine, owing to the
absorption of t 1 by the- seed, it has been impossible to i
Possibly the aii between II \\oulcl enable the
penetrate more thoroughly .
For further particulars apply to the Ministry of Agriculture.
(4) Gayet's Carbon Bisulphide Mtidiim'. \ method proposed by
M. Gayet, engineer to Mr. J. (\. .loannides' giunei-y at Tanf
of a combination of the principles involved in all the thre
machines. The inventor proposed to have a fumigation chan
similar to the American one, and after it had been charged \\ith
and the air :ed from it, it was to be connected with an iron
retort containing charcoal, on t> which sulphur could be dropped
through a broad alve, the retort being kept red-hot in a fun
The evolved carbon bisulphide \voii!d then Ho\v into the fumigation
chamber and. owing to th;> vaciium iliat had been produced, would
M. (lavet fitted up a small experimental apparatus taking about
one ardeli of seed and got perfectly satisfactory results with it. It is
possible that on th.' la rue scale coiidensafion ell'ects such as \\cre
obtained with Mosseri's machine might interfere with the results,
but carbon bisulphide does not seem to be absorbed by cotton
in the same way as hydroc-. and the fact that there wa>
no difficulty in getting a free circulation of the vapour in the Ministry's
machine, would indicate that the probabilities of difficulty from this
source are n >i However. the objections to the machine are
the same as the objections to t lie Ministry's machine. nameh . the
poisonous and inflammable qualities of carbon bisulphide. The
separate production of each dose on the spot reduces these objections
to a, minimum by avoiding the necessity of keeping any stoi
carbon bisulphide, and as ar. its could be made for washing
the carbon bisulphide out of the seed with a, current of air before
opening the fumigation chamber, the danger, either of poisoning or of
explosions, should be very small -indeed. However, before erecting
a machine on these lines it would certainly be wise ; :tain the
opinion of the insurance societies and of the Department of Public
For further particulars apply to .M. A. .Mr. .1. (i.
(5) Wells and Hayman's Cotton Seed and Cotton Stick Fumigator. -
Mr. John Wells, Consulting Engineer to the Egyptian Government,
has recently submitted the plans for a machine designed by. himself
in conjunction with Mr. Hayman, for killing pink boll worms in
the bolls left on cotton sticks after the last picking by fumigating
them with the fumes given off by distilled cotton sticks. He remarks
that this method could also be used for treating cotton seed. The
apparatus figured consists of a vat which will hold forty tons of cotton
sticks after they have been chopped up into pieces not more than
two inches long, this chopping causing a reduction in volume to about
one-sixth of the volume of the unchopped sticks. Into the top of
this vat is led a tube from a retort in which the cotton sticks are
distilled, the air forced out during the process being allowed to escape
from the bottom of the vat. Presumably, if this machine were to
be used for cotton seed, considerable modifications would be made in
order to adapt it to the requirements of the ginnery.
So far, however, not even a small-scale machine has been built
on these lines, so that it is impossible to say whether the fumes would
penetrate the seed sufficiently to kill the worms, or whether the
tarry products in the distilled gases would have a deleterious effect
on the germination of the seed.
For further particulars apply to Mr. John Wells, Consulting
Engineer, Sharia Sheikh Abu el Sebaa, Cairo.
Before proceeding to deal with individual hot-air machines in
detail it will perhaps be well to discuss a few general problems in
connection with hot-air treatment.
The first question which is always asked is " What temperature
kills the worm and what length of time is necessary ? " There seems to
be, however, a very general misapprehension as to what is meant by
a reply to this question. For instance, if one says that five minutes
at a temperature of 55 C. will kill all the worms, this does not mean
that if seed containing worms is placed in a hot-air chamber, the air
in which is at a temperature of 55 C., and left there for five minutes,
all the worms will be found dead at the ,end of that time. They
probably would not be. What it does mean is that if the worms
themselves are heated up to 55 C. and maintained at that temperature
for five minutes they will all be killed. The difficulty is that it is
impossible to determine the temperature of an individual worm at
any given time, and still more out of the question to follow the
variations in temperature through which it passes during its transit
through a hot-air machine. It has been found in practice that the
most comparable results are obtained by registering the temperature
of the seed immediately after leaving the machine, lii the majority
of machines tWO exceptions to this are discussed below the seed
is then at its maximum temperature and the worms may be regarded
as being at as nearly as possible the same temperature. The time
during which the worms remain at, or near, this temperature depei
not on the time taken to pass through the machine, since during this
time the seed is not remaining hot but is being gradually heated
much as on the treatment of the seed after leaving the machine.
If sacked immediately, the seed cools at an astonishingly slow n
the temperature only falling one or two degrees per hour. If. on tin-
other hand, the xposed to the air in a thin layer immediately
after treatment, the tempo may fall well below the minimum
fatal temperature in less than half a minute.
The necessity for bearing the.-. m mind and the dillicultv
of giving a satisfactory reply to the question postulated above, are
well illustrated in Table I. which shows the mortality of the worm>
at different temperatures with various methods of treatment. The
temperature in everv ca temperature of the >eed immediately
after treatment. A black line has been drawn on the right-hand
side of every column as far .ninimum temp-
a regular mortality of !).") per cent or more. It will be seen at
that the tops of the bhick lines in the dilVerent columns vary in position
from 47 to GO" ('. What, then, are the causes of these discrepancy
In the first two columns are given the figures from some e.x:
ments in which small bags of infected cotton seed were dipped, for
one minute in one ca.se. and for live minutes in the other, in hot water
at various temperatures. After treatment tin- iieing in a small
mass and covered with water, cooled rapidly. It will be noticed that
with the one minute treatment complete mortality was only reached
at 59('.. whereas with the five minutes treatment practically all the
worms were killed at 50P C. The , mperature is probably very
nearly the minimum temperature which kills the worms, which shows
that the full effect of heat treatment is obtainable in live minnt
The next three columns give the results of experiments with
the Domains' experimental machine. This machine consisted of an
TABU: I. Showing Mortality of Pink Boll Worm at Different
Temperatures with Different Methods of Treatment.
Simon's Machi 1
endless band of cloth the upper half of which passed through a wooden
box the air in which was heated by a number of steam-pipes. The
quantities of seed delivered were so small that the rate of cooling
after leaving the machine was^onsiderably greater than it is in sacked
seed from machines with a bigger output. The three columns show
the results obtained with different speeds, the seed passing through
the machine in two, three and a half, and six minutes respectively. In
the first column the black line reach e nd in the second 47"C.
fn the third the ex;ict |>oint when- it -hould terminate is doubtful,