New York State Agricultural Experiment Station.

Annual report of the Board of Control of the New York Agricultural ..., Issue 19 online

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three reasons:

(1) Exi)erience is said to show that spraying when in bloom
gives more and better fruit.

(2) Even as a matter of necessity and not of choice, some
spraying must be done at that time. With the extent of orchards,
it is sometimes impossible to complete the first spraying before
blossoming time, even though the work is begun when the bnd«
first show pink.

(3) It is doubtful whether bees are killed by arsenical sprayB
under normal orchard conditions.



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Kew Yobk Agbioultubal Experiment Station. 371

(4) Even if arsenical sprays at blooming time do kill bees, the
value of the bee interes-ts in the orchard counties is very small as
compared with the value of the fruit interests.

(5) It is not proven that bees are necessary for the f ruitf ulness
of apples, at least of the varieties which are most grown.

The first argument of the fruit-growers is yet to be proved, but
no one who has been in these great apple orchards during the
blooming season can fail to feel the w^eight of the second point.
A fruit-grower may set out to spray his twenty-acre apple
orchard when the blossoms show pink, as directed in the spray
calendars, but after a short " spell " of warm May weather he
finds his trees in full bloom and only half of the orchard sprayed.
Spring rains may prevent him from spraying till the blossoms
are just ready to burst; then come two or three days of sunny
weather, and his trees are in full bloom.

The third point — are bees killed by arsenical sprays at blos-
soming time under normal orchard conditions? — ^is also worthy
a moment's review. The fruit men are in such overwhelming
majority in the apple sections that the bee men are not often
heard. In order to approach this question from the bee-keeper's
point of view, three apiarists were visited and asked to give their
experience and opinions on this much discussed subject. A bee-
keeper of Orangeport has his hives under an apple tree which
he has sprayed with arsenites when in full bloom for three years.
He has not noticed more than the usual number of dead bees by
the hive at this season, and the colonies have api)arently done
just as well as in previous years. A bee-keeper of Gajsport has
had the same experience. Another at Medina, who has about
forty colonies, sprayed his trees with the Kedzie (arsenic)
mixture last year when they were in full bloom. There was no
more than the normal mortality among his bees that year. All
these men believe that few, if any, bees are killed, because poi-
soned blossoms are distasteful to them, or else they have instinct
enough to keep away. The feeling of these men on the subject
is said to be shared by other bee-keepers in Western New York;
but there are many who are equally certain that their colonies



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372 Report of the HoBxicuiiTURAL Dbtpabtmbnt of thb

would be seriously reduced in numbers if Bpraying at bloseoming
time became a common practice. The subject is still in need ol
careful inyestigation*

There have been few satisfactory experiments to determine
whether bees are likely to be killed if they visit a large orchard
whieh has been sprayed with arsenites when in full bloouL In
some cases the exi)eriment has consisted in covering the BprajeA
tree with sheeting or netting and placing bees inside. After
awhile dead bees are found <m a sheet which has been spread
beneath the trees. These dead bees are then washed with ammonia
water to remove any of the spraying material which might have
been brushed onto their bodies. If, after this washing, the
chemist finds arsendc in the bodies of these bees the conclusion
is reached that they died from arsenic poisoning. These
experiments merely show that if bees eat poison they will die;
they do not prove that if an orchard is sprayed with an arsenite
when in full bloom most of the bees visiting it will be killed.

Whether or not bees will avoid poisoned blossoms if untainted
flowers are to be had is a question that fruit-growers are always
asking. In 1896, Professor F. M. Webster reported three obser-
vations on this point. (1) Six apple trees were sprayed in full
bloom with Paris green and water at the rate of four ounces to
forty gallons. Sheets were placed under the trees and on the
sheets were two hives of bees. Fifty-six dead bees were found
near the hive within a week. Analysis of some of these showed
traces of arsenic. (2) On the morning of a clear warm day, two
apple trees were sprayed with Paris green and water at the rate
of one ounce to twelve gallons. In the afternoon a number of
bees which visited the blossoms were caught and marked. None
of these marked bees were afterwards found dead near the hives.
The next day other bees were caught, dissected and analyzed.
Arsenic was found in the honey-sacs and the abdomens of some
of these bees. (3) A small apple* orchard was sprayed when In
full bloom with Bordeaux, to which was added Paris green at
the rate of four ounces per fifty gallons. Three apparently
healthy colonies of bees were located on the premises. All the



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New Yobk Agricultural Experiment Station. 373

bees in one colony died a few days after the application, and
many in another. Areenic was found in the bodies of the dead
bees and in th-feir dead brood. Thus bees may take the poison
home and feed it to the young, killing the brood in the
hive. A recent instance of great destruction of bees from spray-
ing trees when in bloom is given by E. P. Felt, New York State
Entomologist, in C<mntry Oentleman for June, 1900. In some
cases 80 to 95 per ct. of the working bees were killed. " The des-
truction was fearful, and there is every reason to think that it
was due to i)oison thrown upon trees in blossom."

The observations of many practical orchardists seem to throw
much douj^t on the whole question of the relation of bees to i)ol-
linatioB and to spraying, and seem to demand that the subject be
opened for further inquiry. TMiile working in the orchards of
Orleans and Niagara counties every day for ten days during the
past blossoming season, not a single bee or other insect was
observed working on the blossoms. This was probably due to
the cold and windy weather which prevailed d»uring most of the
blossoming season. Several fruit-growers in that section like-
wise reported the absence of all insect pollination in their or-
chards. Yet the set of fruit was the best since 1896. The wind is
probably a factor in the cross-pollination of apples. If the pollen
id moifit or sticky, as in most varieties of pears, it is not readily
blown away by the wind; hence insects are more important in the
cross-pollination of this fruit. But the pollen of apple blossoma
is usually nearly, or quite, dry and is probably carried by wind.
But even if apple blossoms can be pollinated by wind, it may
yet be true that insects are more eiHcient agents. Again, the
varieties most commonly grown in Western New York, Baldwin
and Rhode Island Greening, do not usually need cross-pollination
in order to produce good crops. They are self-fertile. It wa«
shown in Cornell Bulletin 181, however, that cross-pollination
even of these varieties may be expected to give better fruit than
self-pollination.



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374 EacpoRT OF the Horticultueal Department of thb

II. INVESTIGATIONS OF 1900 BY THE NEW YORK AGhRI-
CULTURAL EXPERIMENT STATION,

S. A. Beach.
EFFECT OF SPRAY MIXTURES ON POLLEN AND ON BLOSSOMS.

The effect of spray mixture upon blossoms was studied in the
laboratory and also in the orchard. Open blossoms in the
orchard were sprayed and then tagged so that they might be
kept under observation and the final effect of the treatment be
known with certainty. In the laboratory pollen grains were put
into oultures which contained neither iufiecticide nor fungicide
and the germination and growth in these cultures were compared
with the germination and growth in corresponding cultures oon-
taindng either a fungicide or an insecticide or both.

Laboratory Studt of the Effect of Sprat Mixtures upon thb
Germination of Pollen and the Growth of Pollen Tubes.

In the laboratory pollen cultures were made in distilled water;
in sugar solutions containing various percentages of cane sugar
in water; in weak sugar solution combined with various dilutions
of Bordeaux mixture made of commercial copper sulphate and
lime; with Bordeaux mixture made of chemically pure ingre-
dients; with Bordeaux mixture combined with «ome arsenical
compound as commonly used in spraying orchards; with arsenical
spray mixtures alone; and with lime alone.

Method of selecting pollen for the cultures, — The blossoms which
were to furnish pollen for cultures were taken to the laboratory
before they opened so afi to avoid the possibility of some other
kind of pollen being brought to the flower either by wind or
insect. The stem which supported the blossom cluster was put
into water so that the blossom buds might open. From blossoms
thus treated a single anther was selected to furnish pollen for all
of the cultures in a series. It is believed that by this method
pollen of as uniform vigor as it was possible to obtain was fur-
nished for all cultures which were to be compared in a single
ceriee.



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Nbw York Agricultural Experiment Station. 375

The cultures. — Hanging drop cnltores were made in Van Tieg-
hem cells 10 to 12 mm. inside ddameter and about 10 mm. liigh
sealed with a mixture of wax and vaseline. The pollen was
placed on a clean cover glass, a drop of the culture liquid was
applied and some of the same wa« put into the bottom of the
cell so that the liquid in the cell would be of the same composi-
tion as that in the drop. The cover glass was then put into its
place and sealed.

POLLEN cultures IN HIXTURS A.

A spray mixture which for convenience of reference is here
called "A" was made from the ordinary commercial materials.
It consisted of Bordeaux mixture prepared as is usually done for
spraying orchards. This was made according to the 1-to-ll
formula.^ • An arsenical poison, the green areenite of copper, was
then added at the rate of about 1 lb. to 150 gallons, the amount
commonly recommended for spraying orchards. Mr. W. H.
Andrews very kindly analyzed this green arsenite and found 57.5
per ct. arsenious oxide and 25.2 per ct. copper oxide. This shows
that as an insecticide it is eqiiivalent to good Paris green.

An anther from a Ben Davis apple blossom was selected May
18 in the way already described. From the pollen which it fur-
nished a series of cultures was made as recorded below. This ifi

here called Series I.

Sebies I.

ITiimber of poUui
Cnltnre grain* in the

Ko. Media m. enltuie.

9 2 per ct aqueous cane sugar solution, 09 parts; mix-
ture A, 1 part 250 to 300

10 2 per ct. aqueous cane sugar solution, 99% parts;

mixture A» % part 125 to 150

11 2 per ct. aqueous cane sugar solution, 99.98 parts;

mixture A, .02 part. 125 to 150

12 2 per ct aqueous cane sugar solution, 99.99 parts;

mixture A, .01 part 100 to 125

As 0oon as these cultures were made, 5.45 p. m., they were
put into a room having a nearly constant temperature of about

^Thls formula requires 1 lb. of copper sulphate, and the necessary
amount of lime, In making 11 gallons of the mixture. It is equivalent to
10.9 grams of copper sulphate for 1 litre of the mixture.



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370 Repobt op the Hohtictdltural Department op thb

70° F. or slightly more. At 9.30 a. m. of the following day per-
hai>s half of the grains in No. 9 had germinated but they showed
decidedly the retarding effect of the poisons. In No. 10 the ger-
mination and growth were no better than in No. 9, really not
qnite so good. In No. 11 the grains germinated freely; nearly
or quite all of them had germinated and the tubes had made free
growth. In No. 12 germination and growth had progressed as
freely as in No. 11.

At 5.20 p. m. of the same day, about 24 hours alter the cul-
tures had been started, these notes were made.

No. 0. Pollen tubee vary from 1.96/x to 18.48;^ long: average
length perhaps 10/^. Many tubes which were apparently in per-
fect condition this morning have now broken down and
become disintegrated. Many of the pollen grains have not yet
germinated.

No. 10. Pollen tubes vary from 1.68m to Ufi long. They
average perhaps Ta*. Some of the pollen tubes have become dis-
integrated like thosenoted in No. 9.

No. 11. The pollen tubes have made good growth. They
vaiy in length from 10.67^* to 87.36/* and average perhaps from
60/^ to 75. V. Occasionally tubes are seen which are abnormally
swollen and give some appearance of breaking down.

No. 12. The pollen tubes have made good growth. The tufbes
vary in length from 8.4m to 75.6At or more. No disintegration of
pollen tubes was noticed.

At 5 p. m., May 22, four days after these cultures were made,
the following notes were taken and the cultures were then
discarded.

No. 9. It is estimated that from 30 per ct. to 50 per ct. of the
pollen grains in this culture have germinated. One of the
longest tubes measured 51.96/*, but such length was quite excep-
tional. Most of the tubes were less than one-half or even one-
third of that length; many were no longer than from 5/ito lO/i
The tubes are apt to be abnormally curved or twisted and the
giowth is not vigorous. Indeed there is an appearance of dis-
integration of some of the tubes.



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New York Agricultural Experiment Station. 377

No. 10. It is estimated that no more than 25 per ct. have
germinated. The growth is correspondingly less than in No. 9.
One of the longest tubes measured 21 fi. The tubes probably do
not average half that length. Oftentimes they are abnormally
bent and in many cases disintegration is seen.

No. 11. This culture shows a network of long tubes. One
which was measured was 98.4 ^u lonj', but it cannot be said that
this is one of the longest of them. Only in a few cases can tubes
be traced through their entire length because they are so much
tangled, and a close estimate of their average length cannot be
made. It may be said, however, that they have made abundant
growth.

No. 12. Pollen tubes are tangled so much that only in few
instances can they be traced throughout their entire length.
One measured 52.56At, but others were certainly longer. The
average length is estimated as considerably less than in No. 11.
Only occasional indications of disintegration were seen.

POLLEN CULTURES IN MIXT RE B.

The spray mixture which is here designated " mixture B " was
simply a Bordeaux mixture made as for "mixture A," but it
did not have any arsenical poison added to it. A single anther
from a Ben Davis apple blossom was selected May 17 in the way
previously described, p. 374, to furnish pollen for a series of
tests in which the growth of pollen in solution of sugar in water
might be compared witL. its growth in a similar suf-^i* solution
combined with various proportions of the Bordeaux mixture B.
The following cultures were made at 5 p. m., May 17. They
were put into a room in which by means of an automatic appara-
tus the temperature was kept nearly constant at about 70° F.

to 72° F.

Series II.

Number of pollen
Cnltnre fLnAnn in the

Ifo. Medinm. culture.

4 2 per ct. aqueous solution cane sugar Several huudrod

5 5 per ct. aqueous solution cane sugar Not recorded

6 10 per ct. aqueous solution cane sugar About 250

7 5 per ct. aqueous solution cane sugar, 95 parts;

Bordeaux mixture B, 5 parts '. About 300

8 2 per ct. aqueous solution cane sugar, 98 parts;

Bordeaux mixture B, 2 parts Several hundred



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378 Rtsport oar the Horticultueal Department op the

May 18, at 10.30 a. m., the following notes were made on these
cultnres.

No. 4. Nearly every grain has germinated and gent out a
vigorous pollen tube. The tubes vary in length from about 15
to 130/1 or more. The growth is so much tangled that it is
impossible to measure each tube. The average length may be
estimated at about 80/a.

No. 5. The percentage of germination is almost as high as in
No. 4. The tubes vary in length from 9.5;^* to 175 ,a or more.
The growth is matted as noted under No. 4 so that it is impos-
sible to get the exact measurement of each tube.

No. 6. It appears that 50 per ct. of the pollen grains have
germinated, but the average length of the tubes is much shorter
than either those of No. 4 or No. 5. The tubes vary from about
Ifi to about 86/1 or possibly more.

No. 7. None has germinated.

No. 8. None has germinated.

At 6 p. m. the same date neither 7 nor 8 had yet shown any
germination. The condition of Nos. 4, 5 and 6 was relatively
about the same as when the last observation was made. This
series of cultures was discarded at 4:40 p. m., May 22. At that
time 50 per ct. of the ppllen grains had germinated in No. 6, the
10 per ct. sugar solution. In No. 7, which contained 5 per ct.
Bordeaux mixture B and 5 per ct. sugar solution no germination
was found. But in No. 8, which contained 2 per ct. Bordeaux
mixture B and 2 per ct. sugar solution a single pollen tube was
found. This was 3.36/* long. One other pollen grain had the
appearance of having sent out a tube of about the same length
which had disintegrated before it was observed. The other
cultures, 4 and 5, so far as could be determined retained about
the same relative rank as to growth as was noted before, but
the growth was too abundant and the tubes too much matted
together to make definite conclusion on this point. It waa
noticed, however, that some pollen grains in 5 had not yet ger-
minated.



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New York Agricultural Expdrimknt Station. 379

pollbn culturbs in mixturb a

The mixture which for convenience of reference is here called
C consisted of a Bordeaux mixture made wholly of chemically
pure ingredients combined with a solution of cane sugar in
water. The formula used was 1 gram of copper sulphate and f
gram of lime to make 100 cc. Bordeaux mixture.^ After the cop-
per sulphate solution and lime had been combined and diluted
to 96 cc. with distilled water 4 cc. of 50 per ct. aqueous cane
sugar solution were added to bring the whole mixture up to
100 cc. Work with mixture C did not begin until after apples
were out of bloom and so the results given with it were obtained
with other kinds of pollen than that used for the cultures in
mixtures A and B.

Van Tieghem cell cultures which were made in the way
previously described, p. 375, were prepared June 28. In each
one was put some blackberry pollen from the same anther. The
following statement shows the medium used for each culture.

Series III.
Culture ' Number of pollen

No. Iffedium. gralna in onitim.

15 Mixture 0, 100 parts 128

16 Mixture C, 2 parts; 2 per ct aqueons solution of

cane sugar, 98 parts 115

17 Mixture C, 1 part; 2 per ct aqueous solution of

cane sugar, 90 parts 108

18 Mixture G, % part; 2 per ct aqueous solution of

cane sugar, 99% parts 04

19 Mixture G, ^o part; 2 per ct. aqueous solution of

cane sugar, 99 I! parts 43

20 Gopper araenlte and lime, 1 gram to 1% liters; in

2 per ct aqueous solution* of cane sugar. ./ About 12

21 Lrime, 1 gram to 1.25 liters of a 2 per ct aqueous

solution' of cane sugar 69

22 Gane sugar, 2 per ct aqueous solution 107

'This is the same as 10 grams copper sulphate to make 1 liter of Bor-
deaux mixture which formula is nearly equivalent to the 1-to-ll formula.
See p. 875.

"This is at the rate of about 1 lb. to 150 gallons.

'The copper arsenlte, GuHAsOs, was used at the rate of 1 gram to 1.25
liters. This is approximately the strength at which either this or Paris
green is used in orchard spraying; i. e., about 1 lb. to 150 gallons. Lime
was added at the same rate as the copper arsenlte; 1. e., 1 gram to 1.25
liters, and cane sugar solution at a rate to make the whole a 2 per ct
solution of cane sugar.



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380 Report op the Horticultural Department op the

When preparation of these cultures waa flnished, at 5 p. m.,
June 28, they were put into moist chambers and kept in a room
having nearly constant temperature of about 70° to 72° F.
When they were examined at 8.40 a. m., June 29, no pollen had
germinated in any of them except in No. 22 which contained
2 per ct. sugar solution in water only. In this culture out of
107 pollen grains 9, or about 8 per ct., had germinated.

The cultures were kept four days, till July 2, and then dis-
carded. During this time they were kept in the room above
mentioned except that on one day, June 29, they were for about
ten hours in a room where the temperature ranged from 80° F.
to 82° F. On July 2 the following notes were made;

No. 15 shows no germination.

No. 16 ditto.

No. 17 ditto.

No. 18. ditto.

No. 19. Twelve pollen grains, or 28 per ct, show evidence of
geimination. In these cases the germ tube has only attained
a length of from one-half to two-thirds the diameter of the pol-
len grain and then disintegration has followed.

No. 20 shows no germination.

No. 21 destroyed by accident.

No. 22 shows 52 germinations or 49 per ct.

About 11.30 a. m., June 19, the following cultures were made
with rose pollen.

Series IV.
Caltore Number of pollen

No. Hediam, grains in omtare.

30 Mixture 0, 1 part; aqueous solution of cane f^ugar,

99 parta About 150

81 Cane sugar, 2 parts; water, 98 parts About 150

These cultures were kept in moist chambers in the laboratory
till 5.30 p. m., or 6 hours. There were then no germinations in
!No. 30, but 36 pollen grains out of about loO in culture No. 31
had already germinated. The cultures were then kept in the



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Kew York Agricultural Experiment Station. 881

room having a temperature of 70° F. On July 2, after being
kept three days many more germinations were found in No. 21
but none in No. 30.

Cultures of jKvUen of the Virginia Creeper, Ampehpsis qum-
quefolia, all from the same anther, were made at 11:30 a. m.,
July 25, 1900, as listed below.

Series V.

Knmber Per ot.

of pollen Hnmber of get'

Cnltnro grains in f!ennt< mln*-

^'o. Medium. enltnre. iwted. tion.

35 2 per ct. aqueous cane sugar solution,

2 parts; water, 98 parts 88 66 75

30 Lime, 1 gi'am to 125 cc. of a 2 per ct.

aqueous solution of cane sugar 144

37 Copper arsenlte and llme^ and a 2 per

ct. aqueous solution cane sugar 230

38 Mixture C, ^ part; aqueous solution of

cane sugar 99IS parts 203 136 67

39 Mixture C, % part; aqueous solution of

cane sugar, 09% parts 118 5 4

40 Mixture G, 1 part; aqueous solution of

cane sugar, 1 part 187

41 Mixture C, 2 parts; aqueous solution of

cane sugar, 98 parts 122

After six hours it was found that many pollen grains had ger-
minated in Nos. 35 and 38. Five had also germinated in No. 39.
There were no germinations in any of the other cultures. At
8:30 A. M., July 26, after the cultures had been made 21 hours
it was found that there were 66 germinations in No. 35, or 75
per ct.; in No. 38 there were 130 or 67 per ct.; and in No. 39 there
were 5, or 4 per ct. In none of the other cultures was any ger-
mination found. After being kept 24 hours longer no further
germination was found and these cultures were discarded.

Cultures of the pollen of Japan ivy, or Boston ivy, Ampelopais
tricuapidata, were made at 11:30 a. m., July 30, using the same
media as in Nos. 37 to 41, and also one culture was made in a
2 per ct. sugar solution in water alone.

^Prepared as for cnltnie No. 20, see p. 379.



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382 BlQPOBT OF THE HORTICULTURAL De?PARTMENT OF THB

Bebies VI.

Nnmber Per ct.

ofpoU«a Knnber ofger-

OoltiUtt . grains in ofgeroii- mina-

Mo. Uedinu. eoltare. natloiM. tlon.

56 2 per ct aqueous solution cane sugar. . 119 90 76

57 Copper arsenite and Ume* and a 2 per

ct. aqueous solution cane sugar 161 O

58 Mixture O, ift» part; 2 per ct. aqueous

solution cane sugar 99iS parts 15 14 93

59 Mixture G, 1 part; 2 per ct. aqueous

solution cane sugar 99 parts*

61 Mixture G, 2 parts; 2 per ct aqueous

solution cane sugar 98 parts about 300 O

The cultures were kept in a moist chamber in a room at about
81° F. till 2:45 p. m., of July 30, or about 3i hours. It was then
fonnd that 76 per ct. in the culture No. 56 had germinated and
93 per ct. in No. 58. No germination was found in any of the
other cultures.

Twenty-one hours after the cultures were made they were dis-
carded because no further germination took place.

SUMMARY OF RESULTS WITH POLLEN CULTURES.



Online LibraryNew York State Agricultural Experiment StationAnnual report of the Board of Control of the New York Agricultural ..., Issue 19 → online text (page 29 of 37)