HOP PESTS AND THEIR CONTROL
A REPORT OF
THE CONTROL OF THE HOP
RED SPIDER AND OTHER
CLOSELY RELATED PROBLEMS
DURING THE SEASON OF
1940
by
H. E. Morrison, Assistant in Entomology
and
J. D. Vertreea, Research Fellow,
Dow Chemical Company
Table of Contents
Summary
Introduction
Acknowledgements
Objectives
Proceedure
Seasonal history of Hop aphis and Hop red spider
Development of Commercial duster
Insecticidal, acaricidal and phytocidal action
of DN Dusts on hops
Discussion of Results
Summary of data
The effect of DN Dusts on the physical and
chemical quality of hops and the brewing
qualities of beer
Continued compatibility studies with DN dusts and
other insecticides
Discussion of results
Summary of data
Fungicidal properties of DN Dusts
Phytocidal action of various DN dusts
Time mortality studies of DN dust
The leaf area of a hop plant and method of estimation
Appendix
Report on physical and chemical properties of DN
dusted hops
Report of DN deposits on dusted hop leaves
Comments by Growers on the seasons work
Page No.
1
7
8
9
10
10
12
18
21
35
36
38
39
40
46
55
55
62
65
68
2
8.
To make residue analysis on hop foliage which was treated with
DN dusts and to correlate these results with mortality of red
spiders.
9.
To initiate the study of the fungicidal properties of IN dusts.
These objectives were carried out during 1940 and are reported in
detail in this annual report to the Department of Entomology.
A sumary
of the accomplishments is given as follows:
1.
Development of Commercial Luster
A satisfactory means of contacting the under surfaces of
'hop leaves was demonstrated commercially.
percent of all leaves can be contacted.
Data show that 95
Slight modification of
equipment now owned by growers has been found necessary and one
grower has been able to transform his old duster into an efficient dusting apparatus with the expenditure of only $60.00.
2.
Experimental Results and Cost Studies
Field experiments were carried on at Grants Pass, Eugene,
Corvallis, Buena Vista, Independence, and Canby, Oregon.
Effec-
tive results (97-99% dead spiders) were obtained by the application of 50 pounds of ON dusts to the acre.
At present the cost
of controlling spiders approximates $4.75 per acre or $0.0475
per hundred pounds of dried hops.
3.
Phytocidal Studies
ON dusts were applied to Fuggles, Early Clusters, Late
Clusters, and Red Vines at dosages ranging from 50 to 100 pounds
per acre with safety.
Slight burning to young foliage was noted
in one instance and this was correlated with exceedingly high
temperatures (over 100° F.) which occurred the day after application.
3
Chemical Analysis
There was no correlation between the amount of DN deposited
and percentages of red spiders killed.
Walnut shell flour was
shown to be superior to Frianite in depositing IN to hop foliage.
5.
Aphicidal and Compatability Studies
DN dusts were shown to have no toxicity to hop aphids, but
the combination of nicotine and rotenone to DN dusts have given
encouraging indications.
Certain preliminary studies have also
indicated that a combination of DN sulf4r may successfully control sooty mould.
6.
Meetings with Growers
Six meetings with hop growers were held at each experimental yard at the time of dust application and again several
days afterward.
Growers were invited to pick their own leaves
at this time and observe the dead spiders under the microscope.
The results were always received with a great deal of enthusiasm.
Considerable progress has been made toward combating the hop red
spider, and the Department of Entomology feels that LW dusts will offer
the final solution.
unsolved.
1.
There are, however, certain problems which are as yet
These are listed as follows:
Commercial Control Measures
Hop growers have received the 1940 results with a great
deal of interest and enthusiasm, and many contemplate modification of their present equipment into efficient dusting units.
A certain amount of cooperation between the Experiment Station
and hop growers will be necessary during 1941 and 1942,
growers will need advice on modification of machinery.
The
14
Measurements of the red spider control obtained
by
various
grower applications will be essential.
2.
Coot Studies
The present cost of applying EN dust for spider control
approximates $4.75 per acre.
There is a possibility that this
may be reduced from 20 to 60 percent by continued field trials.
There are several ways in which this may be accomplished,
3.
A.
Reduction of the amount of material applied.
B,
Incorporation of a slicking agent to EN dusts,
order to obtain better deposit.
C.
Mechanical dilution of the proprietary product with
suitable and inexpensive diluents.
D.
Improvement in the efficiency of present dusting
machinery.
in
Hop Aphis
The hop aphis problem is yet unsolved.
Certain important
leads were obtained during 1940, but aphis were not present
in
sufficient numbers during the growing season for aphicidal
studies.
Hop Mould
Preliminary results
indicated that hop mould may be con
trolled by the use of ON dusts.
Work is being carried on on
this problem during the winter months.
Field tests during 1941
and 1942 should prove the value of this discovery.
5.
Downy Mildew
There is no data on the effect of DM dusts on downy
but there is evidence that DM dusts have fungicidal properties.
5
The ultimate objective of the Department of Entomology is to
find a satisfactory dust mixture which will serve for red spider,
aphis, mould, and downy mildew.
6.
New Materials
New and untried DN materials are now appearing on the
market.
These materials should be tested by the Experiment
Station for red Bider control.
If these materials should
prove to be of value, the competition between different commercial concerns will result in reduced material costs to growers.
7.
Feasibility of DN Dusts
DN dusts have been applied comercially for the first time
during 1940.
The promising results which were obtained apply
only to the seasonal conditions which existed during 1940
The Experiment Station should check on various grower
applications during 1940 and 1941 in order to determine the
ultimate safety of DN dusts under varied seasonal conditions.
8.
Chemical Analyses
The importance of chemical analysis in determining the
amount of DN deposited on hop foliage was demonstrated during
1940.
These testa should be continued on a more extensive scale
during 1941 and 1942.
9.
Red Spiders as an Economic Problem
The common red spider, the European red spider, the clover
mite, and the Pacific mite are a few of the economic forms which
are pests to truck, greenhouse, fruit, nursery, small fruit,
and floral crops.
DN dusts have been demonstrated as being
6
specific for spiders and mites and may serve as a control on
most of these crops.
However, each crop presents a new prob-
lem in method of applying duets and plant tolerance.
The Ex-
periment Station could be of great service to Oregon agriculture by attacking the red spider problem in general and developing controls for each crop.
The following budget to cover the proposed program is submitted
and is based on the monetary expenditures during 19401
A new duster designed to serve for pest control in
the experimental hop yard, demonstration experiments,
and commercial control experiments
$300.00
Travel -- 20,000 miles
800.00
Labor
800.00
Materials
400.00
Supplies
100.00
Total
Salary
Total
$2700.00
7
Introduction
The hop red spider, Tetranychus telarius Linn, is considered by
hop growert as the most important economic pest of hops.
Work on the con-
trol of this pest was first undertaken in 1937, and has continued throughout 1940.
Laboratory and small plot field teats have shown that the pro-
prietary DU dust (dinitro-o-cyclohexyl phenol) at 1 percent concentration
in walnut shell flour was outstanding in 1938.
Subsequent small plot field trials have indicated that mechanical
dilutions of the 1
percent dust to .03 percent were quite satisfactory
in red spider control.
Other small plot tests during 1939 indicated that
loin, rotenone, pyrethrum, and nicotine sulfate were compatible when
freshly nixed and mechanically diluted with the 1% D! material.
Various
diluents, such as talc, hydrated lime, diatomaceous earth, and bentonite
were used as diluents.
There were no noticeable toxic differences with
these materials when they were freshly mixed.
Bentonite and diatomaceous
earth possessed undesirable physical properties for hop dusting.
Several growers obtained and applied DU dusts during 1939, and the
results were quite unsatisfactory.
The writer observed on© of these com-
mercial trials, and concluded that inadequate machinery was responsible
for poor coverage on the undersides of hop foliage and the subsequent poor
control of the hop red spider.
it was evident that some research on dust-
ing machinery would be necessary before commercial control could be obtained.
The Department of Entomology, accordingly, enlisted the aid and
cooperation of the Department of Agricultwal aligineering of Oregon State
College and the United States Department of Agriculture Division of Drug
8
and Related Crops.
An experimental duster which featured low velocity
and high volume of air outlet VAS constructed.
field trials late in the 1939 season.
This was given preliminary
The huge fish-tail nozzle was
generally unsatisfactory, but several practical ideas resulted from this
trial, and plans were made to construct a more efficient unit during the
1940 season.
Results of the 1939 trials are reported in the seasonal
report to the Department of Entomology, and in the Journal of Economic
Entomology, Volume 33 (4) 614-619 - 1940.
It was generally believed that sufficient small scale tests with
the use of DN had been carried on over a period of two years to warrant
some large scale field trials.
Work was started on the construction of
a dusting unit during the winter months.
The Dow Chemical Company estab-
lished a $1,000.00 fellowship and donated materials in carrying out this
undertaking.
Acknowledgements in this field program are hereby extended to the
following:
1.
The Dow Chemical Company of Midland, Michigan, for the establishment of a commercial fellowship to the value of $1,000.00,
and for furnishing proprietary dusts to the value of $500.00,
2.
Mr. F. E. Price and Mr. R. N. Lunde of the Department of Agricultural
ering of Oregon State College for construction
of the experimental duster.
3.
G. R. Roemer, Division of Drug and Related Crops of the
United States Department of Agriculture, for furnishing hands
and equipment for the construction of the experimental duster.
4.
Dr, R. E. Fore, of the Department of Farm Crops, fOr furnishing labor and care of the experimental hop yard.
5.
Dr. D. D. Hill, of the Department of Farm Crops, and Dr. D. E.
Bullis, of the Department of Chemistry, for physical and dhemieel analysis of 1i dusted hops.
9
6.
Dr. R. H. Robinson, of the Department of Chemistry, for making
chemical analyses of DN dusted hop foliage«
7.
The various hop growers who were found to be excellent cooperetors are listed as follows:
Mr. Ben Hull, Grants Pass, Oregon
Mr. Ben Hilton, Grants Pass, Oregon
Mr. George Hilton, Grants Pass, Oregon
ur. Frank Kennedy, Horst Hop Ranch, Independence, Oregon
Mr. Dane J. Purvine, Buena Vista, Oregon
Mr. H. L. Pankalla, CorvAllis, Oregon
Mr. John Nordenhausen, Canby, Oregon
Mr. L. S. Christofferson, Eugene, Oregon
Mr'. Co A. Sloper, Albany, Oregon
mr. R. E. Chittenden, Salem, Oregon
8.
The several county agents and assistant county agents, who
arranged for and participated in the field meetings, are listed
as follows:
Mr. 0. K. Beals, County Agent, Grants Pass
Mr. Chester Otis, Asst. County Agent, Grants Pass
mr. H. L. Riches, County Agent, Salem
Mr. R. E. Rieder, Asst. County Agent, Salem
Mr. F. C. Mullen, County Agent, Albany
Mr. IV. S. Averill, County Agent, Corvallis
Mr. J. J. Inakeep, County Agent, Oregon City
M. 0. S. Fletcher, County Agent, Eugene
Ur. W. C. Loth, County Agent, Dallas
The objectives of the season divided themselves into the following
general phases:
1.
The continuation of seasonal developmental studies on hop
spider and hop aphis.
2.
The development of a commercial duster for application of DN
and other dusts for hop pest control.
3.
The study of the insecticidal, acaricidal and phytocidal
properties of DN dusts when applied to hops under the varied
climatic conditions which exist in the hop growing sections
of Oregon. Supplemented under this objective were certain
other items such as
a.
The determination of the amount of DN dusts necessary for commercial control.
b.
Chemical analysis of DN deposit on hop foliage as
correlated with different diluents.
10
c.
The demonstration to hop growers of proper methods
of dusting for hop red spider control.
4.
Investigations on the effect DN dusted hope might have on the
physical and chemical quantity of hops and on the brewing
(polities of beer.
5.
Continued compatibility studies of DN and other insecticides.
6.
The initiation of the stub' of fungicidal properties of DN
dusts.
7.
The phytocidal effect of DN dusts on various crops and the
associated control of red spiders on these crops.
8.
Time mortality laboratory studies of DN on the hop red spider.
9.
The development of a technique for estimation of surface leaf
area of a hop plant.
Procedure
1.
The Seasonal Development of Hop Aphis and Hop Red Spider.
A great quantity of data on seasonal development of the hop aphis
and hop red spider has been collected during the last several years.
This
information has been taken largely at Corvallis, Oregon, but is also supplemented by quantitative data from other hop growing sections.
There is
sufficient material of this nature to warrant a special report and this will
be written in the near future.
2.
The Development of a Commercial Duster for Application of DN Dusts and
Other Materials Dar Hop Pest Control.
An experimental duster was built through the cooperative efforts of
the Department of Agricultural Engineering, Department of Entamdlogy of
Oregon State College and the Division of Drug and Related Crops of the
United States Department of Agriculture.
This duster consisted of an old
type Niagara dusting unit which was propelled by a six horsepower motor
by means of fiber belts.
Dusts were distributed by means of a centrifUgal
Fig. 2.
Side view of hop duster used at 0. S. C. Note Y's used to divide
dust stream.
Also note that this is old type duster with dust
entering air-stream after the air leaves the fan. This type is
quite inferior to the newer types which thoroughly mix the air
and the dust by passing the dust through the fan. See Figures 3
and 4.
Fig. 4.
Fig. 3.
This hop duster unit was very
effective in control of red
spider in 1940.
Side view of hop duster. Note
mushroom type of distribution
head and tractor power take-off.
fan through four 3-inch flexible tubes.
The tubes terminated into fish-
tail nozzles (1/8 by 10 inches at discharge and 12 inches long).
The
nozzles were mounted on a frame which was telescoped for height and width
adjustments.
This feature was especially convenient of adjusting the unit for
height of trellis, and width of hop rows.
One set of nozzles was mounted
approximately 2i feet from the ground, and the other set was fastened
5 feet higher on the frame.
The air stream as will be noted in figure 2
was divided by means of Vas.
Satisfactory control of the hop red spider was demonstrated with
this dusting unit.
It did have, however, certain definite disadvantages.
These are listed as follows:
1.
The unit was greatly overpowered and it was necessary to reduce
its speed in order to keep dust within hop yards.
2.
The V-type distribution was generally unsatisfactory, and in
spite of any attempted corrections, there was considerable
variance in distribution of dusts.
3.
It was not possible to cut the amount per acre below 50 pounds
because dust materials became clogged inthe air stream.
4.
The unit was unwieldy and attempts to duplicate its structure
commercially would have been prohibitive from the standpoint
of costs.
The problem of dust distribution was alleviated through the efforts
of Mr. Ben Hilton, of Grants Pass, and the Hardie Manufacturing Company
of Portland.
This was effected on Mr. Hilton's duster by means of the
so-called "mushroom type" of distribution, which is pictured in figure 3.
The dust-laden air is propelled directly into this mushroom device
and outlets are taken directly from it.
was entirely eliminated.
The principle of V distribution
Mr. Hilton dusted over 100 acres of hops which
12
were heavily infested with red spider, and was able to effect better control than was demonstrated by the experimental unit at any time during
the season.
The results of the season's experimental work on methods of dust
application were quite successful.
3.
It was demonstrated that:
1.
Commercial control of the hop red spider could be achieved
with proper dusting equipment.
2.
Most dusting equipment now owned by hop growers was generally
unsatisfactory for red spider dusting. This equipment with
small expenditures ($60.00 to $100.00) could be readily converted into satisfactory units.
3.
The transformation of this equipment should not interfere with
its efficiency for hop aphid control.
I.
Detailed particulars of the improved hop dusters are given in
Station CirculAr of Information No. 237, March 25, 1941.
The Study of the Insecticidal, Acaricidal and Phytocidal Properties of
DST Dusts when Applied to Hops under the Varied Climitic Conditions
Which Exist in the Hop Sections of Oregon.
Sections of hop yards varying in size from 5 to 15 acres were
selected in sax different Oregon hop producing localities.
Each location
was closely watched for signs of definite hop red spider infestation.
Grower cooperators were requested to sign articles of agreement, and these
382-95
are included in Paget, /
of the appendix of this report.*
It was the general policy to hold field meetings at the time of
dust applications and again immediately after data had been taken.
estimated 200 growers attended these meetings.
An
A summary of results at-
tained was presented at each meeting, and the growers were invited to pick
their own hop leaves and observe the number of dead red spiders with the
aid of binocular microscopes.
Several of the growers expressed their
appreciation, as is evidenced by their letters on pages 68-71 of the
appendix.
* See Department of Entomology report.
Code to Treatments
Can. Grants P
is.
Numbers
Treatment
Co
Treatment
DN Dust
1
3Sabsac32---LM.----.--z----2DN
7
DN
0
a Vista
Salem
1
1
Dust
2
lbs /acre
2
2
2
Dust
lb
Dust D-4
be =c
DK Dust D-4
21-11.13/ign
5 __............-1.-01........=.........gama5 orroaroorrooLVOMPOW
111 Dust D-4
6
Sq lbe/iere
6
6
6
6
6
DR Dust D.3
;49 lbs /afire
DN Dust D.3
7
7
7
7
7
7, lbs /acre
8
8
8
g
8
9
9
9
9
9
10
10
10
11
11
11----
DN Dust D.3
50 lbs /acre
DK.Dust D.7
100 lbe/acre
3.0
9
DN Dust D..7
11
75 lbp/acre
DN Dust D-7
be
Nicotine sulfate
11
lime.- sulfur
16
b
ere
Nicotine sulfate
lime.eulfur
14
75 lbs /acre
14
10
17
Nicotine sulfate
lime-sulfur
be
Dotano.py
10
Sulfur Dust
100 be
Eotano-py
Sulfur dust
10
75 lbs /acre
Hotsno-Py
Sulfur Dust # 10
50 lbe/acre
Cheeks
(No Treatment)
15
19
to
2
1§----
13
16
6
4,5,.
7,8,9 and 10,11,12 were combined ih the second
Corvallis Application and dusted respectively with DN Dust, DN dust 1) 4, DN dust D-3,
And Dt Lust D-7. No check rows were allowed to stand between treatments.
16
NoteTreatments 1,2,3
2
3
4
5
Code to Ind endenee Treatments
eatment
DN Dust Applied with Experimental duster
MT Dust D-4 applied with experimental duster
DN Dust applied with Horst apIlis duster
DN Duet D.4 applied with Horst aphis duster
Check. No Treatment
75
75
75
75
lbs acre
lbs/acre
lbs/acre
lbs/acre
EXPERIMENTAL PLOTS
1940
TtlY"r"r%rITtITT itTrr
V
14
II
Iv
14
V
IL
II
10 16 9 8
V
7
18,
5 4 '16.
2. CORVALLIS
I
1. EUGENE
11
III
iii
III
III
II
I ;
II
ill
II
II
:;
Ij
1'T
3
it
11
ii
5. GRANTS PASS
4. CANDY
XIII.' VI
7. SALEM
6. BUENA VISTA
Fig.
13
The materials used in these testa consisted of:
1.
ON dust (1% Dinitro-o-cyclohexyl phenol) in Frianite. Frianite
as a carrier had not been tried on hops, but it was very successful on citrus in California. Previous to this time all DN dusting had been carried on with walnut shell flour.
The cost of
walnut shell flour was more than twice the cost of Frianite.
2.
DN dust - D-4 (2% dioyclohexalamine salt of 1% dinitro-o-cyclohexyl phenol in frianite). This was an entirely new material,
but reportedly safer on foliage than the proprietary DN dust
product.
3.
DN dust flour).
4.
EN dust - D-7 (1% dicyclohexyl amine salt of i% dinitro-o-cyclohexyl phenol in Frianite).
5.
Nicotine sulfate - hydrated lime - sulfur dust (10-40-50) was
used as standard check.
6.
pyrethrum- sulfur dust (Botano-py sulfUr dust No. 10) consisted
of 8.5% pyrethrum flowers and extract; 37% sulfur and 54.6%
talc. This was purchased by the grower and used as an additional treatment at Grants Pass, Oregon.
(i% Dinitro-o-oyelohexyl phenol in walnut shell
With the exception of the trials at the Horst Hop Ranch, at Independence, Oregon, all materials were applied at rates of 50-75 and 100
pounds per acre.
Diagrams of the experimental designs are given in figure 4.
plots were used in all instances.
between each treated plot.
Two row
Check or untreated plots were interspaced
At Grants Pass, Oregon, three check rows were
used between each treated plot.
It was learned later that one to two check
rows were sufficient and this policy was adopted for the remainder of the
season.
The method of measuring biological efficiency VW carried on as
follows;
Five plants were selected at random from each treatment.
25
leaves were taken from each of these plants and 5 leaves from this group
were selected at random and scored according to the living and dead red
spiders.
This was accomplished by the use of binocular microscopes.
The
seasonis work was quite exhaustive and nearly 750,000 spiders were scored
in this manner.
The percentage of dead red spiders was computed from
these figures and used as a measure of acaricidal efficiency.
The scoring
was done by two individuals, each one counting either 2 or 3 replicates
from each plot in order to reduce errors due to the personal equation.
Attempts were made to study the rate of red spider build-up after
dusting at each location.
Harvesting of the crop and other factors inter-
fered with this study to a considerable extent but certain indications
were obtained.
General comment concerning the field experimental program by locality is given as follows:
Grants Peas
I r.
Oregon. Cooperators:Mr. Ben Hull, Mr. Ben Hilton and
George Hilton.
Dusts were applied July 12, 1940, and data were collected July lit.
Temperatures reached a meTtenm of 93 degrees Fahrenheit July 13.
Exceed-
ingly heavy deposits (500 lbs. acre approximation) were noted on several
plants adjacent to the area in which the duster was cleaned.
of injury were noted.
No signs
Very satisfactory control was obtained with DM
dust, DM dust D-4, and DM dust D-3 when applied at rates of 50, 75, and
100 pounds per acre.
DM dust D-7 was generally unsatisfactory, but super-
ior to the nicotine sulfur and pyrethrum duets.
Mr. Hull later purchased sufficient material for dusting his entire
yard of 90 acres.
In the absence of a suitable dusting machine, the Ex-
periment Station cooperated and assisted in the dusting of this yard.
Very satisfactory control of the hop red spider was obtained.
15
Mr. Ben Hilton and Mr. George Hilton later modified their old hop
duster and dusted 100 acres of hops for hop red spider control.
Satis-
factory control was noted and later checks in the Hilton and Hull hop
yards showed that the control was effective over a long period of time.
Corvallis, Oregon.
Cooperator, Mr. H. L. Pankalla.
It was first believed that red spiders would develop more rapidly
in Grants Pass and that work in this section would have been completed
before the red spiders became a pest in the Willamette Valley.
This did
not occur and populations of red spider developed simultaneously at Corvallis and Grants Pass.
The Corvallis plots were dusted July 10 and
operations were then moved to Grants Pass where dusts were applied on
July 12.
It was not possible to collect data on the Corvallis experiment
before July 18.
Mr. Pankallats hop yard was not suckered and all suckers
were heavily infested with red spiders.
The suckers could not be dusted
because of their prostrate habit of growth.
The heavy population on these
suckers was apparently responsible for reinfestation of the treated plots
and control figures in this experimental layout were poor for all treatments.
Mr. Pankalla had these suckers removed and the entire layout was
redusted July 22 at the rate of 75 pounds per acre for each material.
Very satisfactory control resulted from these second treatments and no
plant injury resulted from these two applications.
Later in the season the entire yard of Ur. Pankalla became heavily
infested with red spiders and an attempt was made to control some of them
with DN dust - D-L in a spray combination.
This was used at the rate of
5 pounds per hundred gallons with 1/2 pint of SS -3 used as a wetting agent.
16
Fair control resulted from this trial and the limiting factor was attributed
to the inability to effect proper contact of red spiders on heavily webbed
leaves.
Eugene, Oregon.
Cooperator, Mr. L. S. Christofferson.
The
Red spider populations in this area were comparatively light.
experimental section of the yard was dusted July 16 and data were taken
July 21.
The results were similar to those obtained at Grants Pass, Oregon.
No plant injury was noted.
Salem, Oregon.
Cooperator, Mr. R. E. Chittenden.
This yard of English Red Vines developed a very heavy population of
red spiders.
July 25.
A portion of it was dusted on July 23 and data were collected
Results were similar to those obtained at Grants Pass, Oregon,
and no plant injury was noted.
LT. Chittenden later attempted to modify
a local hop aphid duster, and dusted his entire yard with DN dust.
The
remodeled unit was not efficient and only fair control was obtained.
Canby, Oregon.
Cooperator, Mx. John Nordenhausen.
Certain portions of the experimental section of the hop yard were
very heavily infested with red spider.
were taken on August 2.
It was dusted on July 31 and data
No plant injury was noted and the control obtained
was similar to that of other areas.
Buena Vista, Oregon.
Cooperator, Mr. Dane Purvine.
This yard developed a moderate infestation of red spiders late in
the season and was dusted August 16.
Data were collected August 23.
This
was the last experimental trial of the season and the supply of DN dust 1>-7 was exhausted.
plots.
This material was accordingly not applied to these
Temperature rose to 105 degrees on August 17 (the day following
17
application) and very slight foliage and cone injury VAS observed with
ON dust, LW dust D4 and DN dust D-3.
The rows in this yard ran east and
west and the yard was located low with steep banks forming an amphitheater
about it.
All burning was confined to the south side of the row (that
portion of the raw which was exposed to direct rays of the afternoon sun).
The injury was slight and no economic damage resulted.
The controls ob-
tained were similar to those obtained in other yards.
Independence, Oregon. Cooperator, Mr. Frank Kennedy, Manager of the
Forst Hop hanoh.
The purpose of this experimental setup was different than in other
The efficiency of the experimental duster was tested against the
yards.
efficiency of the Horst hop duster which was commonly used for hop aphis
control.
DN dust and DM dust D-1 were applied at the rate of 75 pounds
to the acre with each unit.
collected August 21.
Dusts were applied on August 15 and data were
The results shoved that the experimental duster was
considerably more efficient and again indicated that satisfactory control
of red spider by dusts could be accomplished only by efficient dusting
equipment.
Two days after application (on August 17) temperatures rose
to 105 degrees Fahrenheit.
No burning resulted on arr of the plants in
the Horst yard.
Albany, Oregon.
Cooperator, Mr. C. A. Eloper.
No experiment was made in this yard.
Ur. Sloper requested the aid
of the experimental duster for application of DN dusts to his heavily infested hop yard.
The Experiment Station accordingly cooperated to this
extent and assisted in application of the dusts.
The dusting of the yard
(August 25) was timed too late for effective results.
Red spiders were
Already in the hop cones and had caused decided discoloration.
It was
Fig.5
Inspection of Experimental Hop Duster
19/40 Hop Field Day, Corvallis, Oregon
18
evident from these results that satisfactory control could not be expected
with any type of equipment after red spiders had once entered the cones.
Discussion of Treatments
1.
Three materials, namely DM dust, DM dust D.4 and DN dust D-3,
gave very satisfactory control of the hop red spider at rates of 50, 75
and 100 pounds per acre.
There was but one exception to this instance
and this occurred in the Corvallis plots.
This has already been discussed
and the low measured kill was attributed to reinfestation of the dusted
plants from heavily infested hop suckers.
2.
DN dust D-7 in all instances was significantly inferior to the
other DN dusts.
3.
All DN materials were in all instances significantly superior
to the nicotine-sulfur plots and in the one instance the pyrethrum- sulfur
plots.
4.
Frianite was used as a carrier in DN dust, DN dust D-14 and
DN dust D-7 while walnut shell flour was used in all DN dust D-3 applications.
General inspection in the field seemed to indicate that better
deposit of the toxicant was effected with walnut shell flour.
This was
somewhat difficult to verify because of the difference in color between
Frianite and walnut shell flour.
Leaves were accordingly selected at ran-
dom from a number of the experimental areas and chemical analysis of the
deposit was made by Dr. R. H. Robinson of the Chemistry Department.
Con-
siderable variation was noted between treatments and this was probably due
to varieties, climatic conditions at time of application and other factors.
One striking feature of the analysis was that DM dust D-3 (1/2% DN in walnut
shell flour) gave a better comparative deposit of dinitro-o-cyclohexyl
19
phenol than did DN dust (1% DN in Frianite).
This is borne out by the
following sursnax7.
Concentration Amount
per acre
of DNOCHP
Type of
Dust
Deposit or
micrograms sq.cm.
Carrier
DK Dust D-3
DK Dust D-3
DN Dust D-3
0.5%
0.5%
0.5%
50
75
100
Walnut Shell Flour
Walnut Shell Flour
Walnut Shell Flour
DN Dust
DV Dust
DN Dust
1.0%
1.0%
1.0%
50
75
100
Frianite
Frianite
Frianite
.8825
.9700
1.0700
.6600
.61400
1.11450
It could be accordingly assumed that a 1% DN dust in walnut shell
flour should produce twice the deposit of the toxicant as a 1/2% dust.
This being true a deposit of 1.7650, 1.9400, and 2.11400 micrograms per
square centimeter could be expected of a 1% DN dust in walnut shell flour
at the rates of 50, 75 and 100 pounds respectively.
This 1% duet in
Frianite gave only .6600, .6400 and 1.1450 micrograms per square centimeter at these rates.
Walnut shell flour may be therefore rated as aver-
aging 58 percent more efficient than Frianite in depositing the toxicant
on hop foliage.
(Chemical analysis data are found on page
of appendix.)
Satisfactory analysis of DN dust D-14 and DN dust D-7 could not be
made because the solvent used in extracting the toxicant also extracted
the chlorophyll and prvented colorimetric determinations.
5.
DN dusts as applied were of no value for hop aphis control.
6.
Tests to determine the efficiency of the experimental duster
in comparison to present growers' equipment showed that the former duster
averaged 96 percent kill of the hop red spider as compared with 52 percent
kill with the growers' duster.
7.
The DN dusts showed no evidence of burn to hop plants at tempera-
tures below 100° F.
Slight burning was noted at the Purvine Ranch when
Fig.6 Growers' Examination of DN Dusted Hop Leaves
1940 Hop Field Day, Corvallis, Oregon
Fig,7 Experimental Hop Red Spider Control.
Pankalla Hop Ranch, Corvallis, Oregon - 1940
temperatures reached 105° F. the day following applications.
8.
Red spider population studies showed that one dusting with
I dust) tJ duet D-4 and DR dust D-3 was sufficient) and that there was
little tendency for spiders to increase rapidly on hops which had been
treated with these materials.
The method of studying these trends was
not entirely satisfactory and additional work of this nature should be
continued.
A summary of the figures obtained in these experiments is submitted
on the following pages and complete data on each experiment is included
in pages 62-227
of the appendix.*
data.
* See Department of Entomology report for original
Hull Experiment a Grants Pass
Data collected 7/14/40
ed 7/12/140
Varlet fir
98.4
100.0
99.1
94.2
100.0
99.8
99.4
98.3
98.9
86.1
69.9
66.6
78.5
51.4
48.1
9.9
8.1
96.3
2,5
2
3
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
2.8
11.8
18.0
6.1
97.5
100.0
98.1
96.7
99.0
99.9
100.0
98.0
95.0
90.9
95,3
81.6
72.2
32.8
49.4
16.5
12.2
86.1
4.9
4.3
3.7
6.7
8.4
Crust
5.5
6.4
8.4
98.8
99.8
100.0
96.3
99.9
100.0
99.5
97.6
95.1
100.0
70.1
81.6
52.3
34.7
51.8
28.9
17.5
7.0
1.7
2.8
13.9
5.7
2.9
2.7
95.4
99.7
99.8
97.0
99.5
99.9
99.4
99.2
65.4
52.6
57.4
57.1
63.6
40.1
35.7
25.8
14.7
7.3
7.9
98.2
99.8
96.6
99.6
99.3
99.4
99.7
98.3
99.5
95.3
76.5
44.0
51.2
31.0
38.3
42.2
13.9
5.0
2.5
2.0
18.0
8.1
4.0
97.7
99.9
98.7
96.7
99.5
99.8
99.6
98.3
90.8
85.0
73.8
66.2
63.6
38.0
44.7
24.7
13.3
40.3
3.9
3.5
10.8
9.4
4.8
OS wefts
Treatments
(1-24 inclusive)
At odds of 19-1.... 17.7
49-1.... 22.2
99-1..
Code to
Treatment
Prianite
DNOCHP
DNOCHP - Frianite
DNOCHP - Frianite
No.
1
2
3
25.8
Treatments
(1-12 inclusive)
At odds of 19-1.... 10.88
49-1.... 13.66
99-1.... 15.82
DN Dust
DN Duet
DN Dust
nts
(1-9 inclusive)
At odds of 19-1.... 1.5
49-1.... 1.8
99-1.... 2.1
Treatments
(1-99)
(1-99)
(1-99)
MOM
Frianite
4 DN Dust D-4 DCHA salt of DNOCHP
DNOCHP
Frianite
ON
Duet
D-4
DCHA
salt
of
=CIF
5
Frianite
DN
Dust
D-4
DCHA
salt
of
DNOCHP
DNOCHP
6
7
8
9
10
11
12
13
14
15
16
17
18
19
(2-1-97)
(2-1-97)
(2-1-97)
lbs/acre
100
75
50
100
75
50
100
DNOCHP - Walnut shell flour (0.5-99.5)
75
DNOCHP - Walnut shell flour (0.5-99.5)
50
DVOCHP - Walnut shell flour (0.5-99.5)
100
Frianite
(1-0.5-98.5)
DNOCHP
DNOCHP
DCHA salt of
75
Frianite (1-0.5-98.5)
DNOCHP
DCHA salt of DNOCHP
50
Frianite
(1-0.5-98.5)
DNOCHP
DNOCHP
ON Dust Oq DCHA salt of
Pyrethrum
f1over&extract-eu1fetalc(8.5-37-54.5)
100
Botano-Py Sulfur Dast#10
75
Pyrethrum
flowerecextract-su1
tp-talc(8.5-37-54.5)
Botano-Py Sulfur Dust#10
Botano-Py Sulfur Dust#10 Pyrethrum flowerftextractsulfrtalc(8.5-37-54.5) 50
100
Nicotine sulfate (40%) - Lime- Sulfur
10-40-50
75
Lime- Sulfur
Nicotine sulfate r%)
50
10-40-50
Nicotine sulfate 40%) - Lime- Sulfur
to 24 inclusive - Checks - No treatment
DN
DN
DN
DN
DN
Dust
Dust
Dust
Dust
Dust
D-3
D-3
D-3
D-7
D-7
22
Pankalla Experiment, First Application
Dust applied 7/10/40
Data collected 7/18/140
Variety Fugglea
Percent dead red spiders
Treatment
Replications
Number
2
1
Mean
3
4
5
2
3
14
5
6
7
8
9
23.14
2.3
96.8
28.6
19.2
97.2
214.14
11
63.5
71.7
52.4
12
22.14
13
8.4
17.5
9.1
0.2
10
14
15
16
36.5
1.8
63.9
145.2
15.8
78.9
32.9
91.7
1414.8
149.3
12.7
3.3
5.7
3.7
1.7
25.7
0.4
914.2
25.6
45.3
75.7
76.6
80.8
31.1
62.5
15.2
2.8
15.8
21.7
1.5
16.2
20.0
61.4
40.4
36.3
96.5
15.1
68.8
58.2
44.3
54.8
1.3
9.4
0.8
1403
32.1
3.9
87.9
26.8
5.7
80.8
20.3
32.0
814.2
140.2
88.5
6.4
53.7
77.1
15.9
14.2
1.3
4.6
5.9
5.6
87.14
31.1
71.7
56.6
1414.9
23.9
3.4
10.6
8.2
2.7
Differences necessary for significance at odds of
19.1
21.96
27.57
49-1
99-1
31.914
Code to Treatments
No.
1
2
3
14
5
6
7
8
9
10
11
12
13
114
15
Treatment
DN Dust
DHOCHP- Frianite (1-99)
ON Dust
DNOCHP- Frianite (1-99)
DN Duet
DNOCHP- Frianite (1-99)
ON Dust D-14 DCHA salt of DNOCHP-DNOCHP- Frianite (2-1-97)
DN Dust Di-4 DCHA salt of DNOCHP-DNOCHP- Frianite (2-1,-97)
DN Dust D'-14 DCHA salt of DNOCHP-ONOCH- Frianite (2-1-97)
ON Dust D-3 DNOCHP- Walnut shell flour (0.5-99.5)
DN Dust n6.3 DNOCHP- walnut then flour (0.5-99.5)
DN Dust 1:0-3 DNOCHP- Walnut shell flour (0.5-99.5)
ON Dust D-7 DCHA salt of DNOCHP-DNOCHP- Frianite 1-0.5-98.
DN Dust D-7 DCHA salt of DNOCHP- DNOCHP- Frianite 1-0.5-98.5
DN Dust D0-7 DCHA salt of DNOCW'- DNOCHP- Frianite { 1-0.5-98.5
Nicotine sulfate (40%) - Line - Sul Air (10-40-50)
Nicotine sulfate (140%) - Lime - Sulfur (10- 140 -50)
Nicotine sulfate (140%) - LiMe - Sulfur (10-40-50)
......._216C2211(TIArteet4)
DCHA designates Dicyclohexylamine
DNOCHP designates Dinitro-ortho-c yclohexyl phenol
lbs /acre
100
75
50
100
75
50
100
75
50
100
75
50
100
75
50
Pankalla Experiment
Second Application
Data Collected
7/24/40
Dust applied 7/22/40
es
icati
Treatment
Number
Mean
97.9
99.2
99.9
97.2
0.5
1
2
3
4
5
97.9
98.7
96.7
94.0
1.0
97.8
99.8
99.9
92,5
0.7
99.0
99.6
99.8
93.5
1.3
99.4
99.7
98.3
93.8
0.7
98.4
99.4
98.9
94.2
0.8
Differences necessary for significance at odds of
19-1..... 1.6
49-1..... 2.0
99- 1..... 2.4
Code to Treatments
Treatment
No.
1
2
3
4
5
DN Dust
TM Dust
DN Dust
DN Dust
Check.
DNOCHP- Frianite (1-99)
D-4 DCHA salt of DNOCHP-DNOCFP- Frianite (2-1-97)
D-3 DNOCTiP- 'Walnut shell flour (0*5-99.5)
D-7 rCHA salt of DNOCHP- DNOCHP- Frianite (1.0.5 -98.5)
No treatment
DCHA designates Dicyclohexylamine
DNOCHP designates Dinitro-ortho-cyclohexyl phenol
lbs/acre
75
75
75
75
214
Christofferson Experiment, Eugene, Oregon
Data collected 7/21/40
Dust applied 7/16/130
as
Variety
Treatment
Replications
Number
2
co
2
98.14
3
98.8
14
914.3
5
6
100.0
96.7
99.8
91.1
7449
87.1
90.0
82.3
35.6
67.3
6.8
5.6
7
8
9
10
12
33
14
15
16
3
vio)
14
1111
100.0
100.0
98. 14
99.5
99.3
100.0
96.7
80. 8
99.0
95.1
100.0
100.0
100.0
99. 3
98.7
100.0
99.6
98.7
99. 7
99.14
100. 0
100.0
100.0
99.7
99.3
100.0
99.2
99.6
98.8
97.7
99. 2
96.9
96.5
98.7
96.5
96.2
89.1
76.5
98.0
99. 7
100. 0
96.0
97.6
100.0
96.1
83. 9
82.0
149.0
93.0
914.1
68.14
66.7
100.0
82.9
97. 2
1413.2
141.0
32. 6
43.4
149.2
66.1
56.6
78. 14
62.9
66.3
17. 4
26.6
14.1
14.2
5.3
19.14
9.6
5. 14
5.7
9.1
necessary for signiticanee
Treatments
Treatments
(1-12 inclusive)
(1-9 inclusive)
Iifiereneee
Treatments
(1-16 inclusive
At odds of 19-1... 12.2 At odds of 19-1... 12.5 At odds of 19-1... 7.14
149 -1...
49-1... 15.7
49-1... 15.3
9.3
99 -1... 17.7
99-1... 18.2
99-1... 10.8
Code to Treatments
No.
1
2
3
14
5
6
7
8
9
10
11
12
13
114
Treatment
DN Dust
DNOCHP- Frianite (1-99)
DN Dust
DNOCHP- Frianite (1-99)
DNOCHP- Frianite (1-99)
AN Dust
DM Dust DP-4 DCHA salt of DNOCHP-DNOCHP- Frianite (2-1-97)
fiN Dust D-4 DCHA salt of DNOCHP-DNOCHP- Frianite (2-1-97)
DM Dust D-4 DCHA salt of DNOCHP -DP HP- Frianite (2-1-97)
DN Dust D-3 DNOCHP- Walnut shell flour (0.5-99.5)
DN Dust
DNOCHP- walnut shell flour (0.5-99.5)
J
Dust D-3 DNOCHP- Walnut shall flour (0.5-9905)
DM Dust D-7 DCHA salt of DNOCHP-I:NOCHP-Friautte (1-0.5 -98.5)
fiN Dust D-7 DCHA salt of 1110CHP-DNOCHP-Frianite (1-0.5-98.5)
I
Dust D-7 DCHA salt of DNOCHP-DNOCHP-Frianite (1-0.5-98.5)
Nicotine sulfate (140%) - Lime - sulfur (10-40-50)
Nicotine sulfate (40%) - Lime - sulfur (10-40-50)
Nicotine sulfate (10) - Lime - Sulfur (10-40-50)
15
16 Check - No treatment
DCHA designates Dicyclohexylamine
DNOCHP designates Dinitro-ortho-cyolohexyl phenol
'be/acre
100
75
100
5o
loo
75
5o
100
75
100
75
50
25
Chittenden Experiment
Salem, Oregon
Dust applied 7/23/140
Data Collected 7/25/140
Variety Red Vines
Percent dead red spiders
Treatment
Replications
1
2
Number
Mean
5
3
6
100.0
1
99.5
100.0
99.5
99.2
99.6
2
97.7
97.8
98.9
914.2
98.9
97.5
100.0
100.0
98.5
3
96.7
98.2
95.9
98.5
92.7
98.5
14
97.3
99.0
97.2
99.1
98.5
5
99.4
914.2
99.5
98.1
6
95.6
96.2
98.1
99.1
97.1
97.2
100.0
100.0
99.7
99.9
99.5
99.8
7
8
99.2
98.8
99.3
98.14
98.14
98.8
9
98.9
97.5
99.2
98.1
99.2
98.6
10
85.5
82.2
63.5
95.5
92.9
93.5
97.6
88.2
914.8
95.4
90.14
75.9
12
68.14
59.2
79.5
614.7
59.14
79.0
68.7
62.2
65.14
13
714.0
83.6
58.5
114
17.14
12.6
62.5
10.0
114.0
8.2
15
27.8
17.1
32.2
46.0
34.4
31.5
16
0.5
5.5
8.2
5.1
5.8
5.14
Differences necessary for significance
Treatments
Treatments
(1 to 16 inclusive)
(1 to 9 inclustve)
At odds of 19-1....
9.0
At odds of 19-1.... 2.2
2.8
149 -1....
149 -1....
11.3
13.1
99-1....
99-1.... 3.3
Code to Treatments
No.
1
2
3
14
5
6
7
8
9
10
11
12
13
114
15
16
Treatment
lbs/acre
DNOCHP- Frianite (1-99)
DNOCHP- Frianite (1-99)
DNOCHP- Frianite (1-99)
DCHA salt of DNOCHP-DNOCHP- Frianite (2-1-97)
DCHA salt of DNOCHP-DNOCHP- Frianite (2-1-97)
DN Dust D-14 DCHA salt of DNOCHP-DNOCHP- Frianite (2-1-97)
DN Dust D-3 DNOCHP- Walnut shell flour (0.5-99.5)
DN Dust D-3 DNOCHP- Walnut shell flour (0.5-99.5)
DN Dust D-3 DNOCHP- Walnut shell flour (0.5-99.5)
DN Dust D-7 DCHA salt of DNOCHP-DNOCHP- Frianite (1-005-98.5)
DN Dust D-7 DCHA salt of DNOCHP-DNOCHP- Frianite (1-0.5-98.5)
DN Dust D-7 DCHA salt of DNOCHP-DNOCHP- Frianite (1-0.5-98.5)
Nicotine sulfate (140%) - Lime - Sulfur (10-40-50)
Nicotine sulfate (401) - Lime - Sulfur (10-40-50)
DN
DN
DN
DN
DN
Dust
Dust
Dust
Dust D-4
Dust D-4
Nicotine sulfate (40%) - Lime - Sulfur (10- 140 -50)
Check - No treatment
DCHA designates Dicycloherflamine
DNOCHP designates Dinitro-ortho-cyclohexyl phenol
100
75
50
100
75
50
100
75
50
100
75
50
100
75
50
26
Nordhausen Experiment
Canby, Oregon
Dust applied 7/31/40
Data Collected 8/2/140
Variety Late Clusters
Percent dead red spiders
lications
Treatment
Number
an
;
97.0
96.8
99.8
93.7
*;
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
98.2
96.3
97.1
97.7
95.6
95.3
95.8
97.9
98.5
96.5
100.0
100.0
100.0
100.0
99.2
82.6
95.1
94.7
97.5
98.5
89.5
84.2
86.3
86.5
95.5
100.0
99.4
99.1
99.7
99.2
87.8
97.8
99.5
99.2
99.1
98.3
90.5
99.1
95.3
95.0
65.7
83.9
94.0
95.7
99.3
86.1
61.9
74.0
61.9
34.6
92.1
62.0
59.1
44.2
90.7
25.9
13.4
24.1
19.3
142.8
23.7
44.0
20.3
26.8
32.3
17,1
15.4
4.7
10.0
6.7
1.6
2.6
3.9
3.0
7.0
erences necessary or s
(lance
12.9
at odds of 19-1
16.2
49-1
18.8
99-1
88.14
99.5
96.7
95.6
87.7
63.7
69.6
25.1
29.4
10.8
3.6
Code to Treatments
No,
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
Treatment
lbs /acre
DN Dust
DNOCHP- Frianite (1-99)
EM Dust
DNOCHP- Frianite (1-99)
DN Dust
DNOCHP- Frianite (1-99)
DN Dust D-4 DCHA salt of DNOCHP-DNOCHP- Prianite (2-1-97)
DN Dust D-4 DOHA salt of DNOCHP-DNOCHP- Frianite (2-1-97)
DN Dust D..4 DCHA salt of DNOCHP-DNOCHP- Frianite (2-1-97)
DN Dust D-3 DNOCHP- Walnut shell flour (0.5 -99.5)
DN Dust D-3 DUMP- Walnut shell flour (0.5-99.5)
ON Dust 0-3 DNOCHP- Walnut shell flour (0.5- 99.5)
DK Dust 1:67 DOHA salt of DNOCHP-DNOCHP- Frianite (1-0.5-98.5)
ON Dust 0-7 DCHA salt of DNOCHP-DNOCM0- Frianite (1-0.5-98.5)
DN Dust D-7 DCHA salt of DNOCHP-DNOCHP- Frianite (1-0.5-98.5)
Nicotine sulfate (40%) - Lime - sulfur (10-40-50)
Nicotine sulfate (40%) - Lime - sulfur (10-4440)
Nicotine sulfate (40%) - Lime - Sulfur (10-40-50)
Check - No treatment
DCHA designates Dicyclohexylamine
DNOCHP designates Dinitro-ortho-cycloheva phenol
100
75
50
100
75
50
100
75
50
100
75
50
100
75
50
27
Purvine Weriment
Buena Vista, Oregon
Data collected 8/23/40
Dusted 8/16/40
Variety Late Clusters
Treatment
Percent dead red spiders
ReOlicationa
5
3
4
Number
1
2
1
100.0
97.4
98.8
99.5
100.0
99.7
98.6
98.9
88.3
82.2
97.8
98.3
99.2
99.8
99.6
98.3
94.5
97.6
98.2
84.2
7.8
15.9
0.7
2
3
It
5
6
7
8
9
10
11
12
13
23.7
14.2
0.6
99.7
98.3
90.0
100.0
92.8
97.3
97.7
91.7
92.0
38.5
7.4
14.7
1.3
100.0
71.2
99.1
99.9
93.6
95.6
99.0
99.5
65.1
10.4
10.4
99.9
94.2
97.1
100.0
99.9
97.6
98.2
88.9
86.4
82.7
18.6
9.3
3.6
3.2
99.14
Mean
99.5
91.3
96.8
99.7
98.4
97.3
96.9
95.2
92.9
70.5
13.6
12.9
1.9
Differences necessary for significance
Treatments
Treatments
Treatments
(1-9 inclusive)
(1-10 inclusive)
(1-13 inclusive)
At odds of 19-1... 32.2 At odds of 191... 11.1 At odds of 19-1... 7.4
49-1... 9.3
49-1... 13.9
149 -1... 40.5
99-1... 10.8
99-1... 16.2
99-1... 46.9
Code to Treatments
No.
1
2
3
4
5
6
7
8
9
10
11
12
13
Treatment
DNOCHP- Frianite (1-99)
DN Dust
DNOCHP- Frianite (1-99)
DN Dust
DNOCHP- Frianite (1-99)
DN Dust
DN Dust D-4 DCHA salt of DNOCHP-DNOCHP- Frianite (2-1-97)
rr Dust D-4 DCHA salt of DNOCHP-DNOCHP- Frianite (2-1-97)
DN Dust D-4 DCHA salt of DNOCHP-DNOCHP- Frianite (2-1-97)
DN Dust D-3 DNOCHP- Walnut shell flour (0.5-99.5)
DN Dust t1-3 DNOCHP- Walnut shell flour (0.5-99.5)
DN Dust D-3 DNOCHP- Walnut shell flour (0.5-99.5)
Nicotine sulfate (40%) - Lime - Sulfur (10-40-50)
Nicotine sulfate (40%) - Lime - Sulfur (10-4040)
Nicotine sulfate (40%) - Lime - Sulfur (10-40-50)
Check - No treatment
DCHA designates Dicyclohalylamane
DNOCHP designates Dinitro- ortho- cyclohexyl phenol
lbs/acre
100
75
50
100
75
50
100
75
50
100
75
50
28
Horst D.
wZ.lete
Herat Hop Ranch
Independence, Oregon
Dust applied 8/15/140
Data collected 8/21/40
Variety Late Clusters
Treatment
Number
1
2
3
14
5
1
95.5
91.0
18.1
92.3
1.2
2
Percent dead red spiders
Replications
3
4
5
99.1
90.5
58.4
60.6
6.6
98.4
98.9
21.9
66,1
4.3
98.2
90.3
64,0
61.2
2.5
97.6
96.5
mean
76.4
57.0
97.8
93.4
47.8
67.4
2.2
3.4
Differences necessary for significance
Treatments
Treatments
(1 to 5 inclusive)
(1 to 4 inclusive)
At odds of 19-1.... 21.5
At odds of 19-1.... 24.5
49-1.... 26.9
49-1.... 30.76
99-1.... 31.2
99-1.... 35.6
Note- Ten leaves populated with 1948 red spiders were counted from
another part of this yard. This had been dusted with Niagara
sulfur and resulted in 21 percent kill. Dusts were applied
with the Horst duster.
Code to Treatments
No.
1
2
3
4
5
Treatment
lbs/acre
EN Dust
Applied with Experimental duster
DN Dust D-4
Applied with D4 ..., mental duster
DN Dust
Applied with Horst aphis duster
DU Dust D-4
Applied with Horst aphis duster
Check - No treatment
DN Dust designates Dinitro-ortho-cyclohexyl phenol
and Frianite (1-99)
75
75
75
75
DN Duct D-4 designates Dicyclohe4rlamine salt of Dinitroortho-cyclohexyl phenol (2%)
Dinitro-ortho-cyclohexyl
phenol (1%) and Frianite (97%)
29
Summary of 1940 Experimental Plots
Percentage of Dead Spiders (Weighted-Mean of Treatment)
Replications
/lean Mean
2
6
1
5
3
4
2
1
acre
Treatment
100 0.9 100.0 99.6 99.0 99.1 95.5'
95.0 Wa)
bk -bust
DN Dust
75 97.7 99.2 97,0 97.2 88.4 32.1 98.3 85.3 95.9
81.2 96.6
3.9
-I Dust
50 99.8 91.6 97.6 97.1 97.1
100 98.7 98.0 97.6 99.9 99.7 84.4
96.4 98.8
D' Dust D-4
-87.2 97.8
34.2
99,4
98.5
DN Dust D-4
99.6
97,1
94,0
75 99,6
-DN Duet D-4
50 99.5 99.2 97.1 90.6 97.7 40.8
87.5 96.8
96.1 99.2
100 99.8 99.2 99.9 99.4 97.5 80.9
L1 Dust D-3
-84.h 97.9
16.7
DN Dust D-3
95.3
98.9
75 99.8 97.3 98.8 98.4
89.8 94.5
50 98.3 86.3 98.5 96.0 93.6 66.3
DN Dust D-3
-81.8 88.1
56.6
--DN Dust D-7
100 93.4 96.0 84.5 78.6
-34.8 94.2 70.6 79.6
DN Dust L1-7
75 88.4 77.8 87.6 64.6
30.2
-50 75.9 83.2 67.2 65.8
-64.5 73.0
DN Dust D-7
100
3.8
-41.4 48.9
Nicotine sulfur
45.3 41.3 69.0 24.3 614.8
-25.8 28.5
75
20.4
67.8
12.9 27.5 13.9 12.3
Nicotine sulfur
50 12.5 16.0 29.4 U.S 10.9
14.9 16.1
Nicotine sulfur
-9.3
100 64.3
Botano-Py #10
75 66.5
Botano-Py #10
Botano -Py #10
50 37.7
4.6
1.6
6.2
2.4
Check
9.6 10.3
4.8
0.7
5.5
Mean 1 includes first and excludes second Corvallis
applications
!lean 2 excludes both Corvallis applications
lbs/
Locetons
1.
2.
3.
4.
Grants Pass
Eugene
Salem
Canby
).
6.
7.
Vista
First Corvallis application
Second Corvallis application
DN Dust
DN Dust D-4
DN Dust D-3
DN Dust D-7
Nicotine-sulfur
Code to Treatments
DNOCHP - Frianite
DCHA salt of DNOCHP-DNOCHP-Frianite
DNOCHP-Walnut shell flour
DCHA salt of DNOCHP-DNOCHP-Frianite
Nicotine sulfate (40%) -- Lime - Sulfur
Botano -Py #10
Pyrethrum flowers and extract - sulfur -talc. (10- 40-50)
(1-99)
(2-1-97)
(1-0.5-98.5)
(0.5-99.5)
(1-0.5-98.5)
(8.5-37-54.5)
Differences necessary for significance
(inaluaing first CorvallIe application)
Excluding Botano-Py,
Excluding Botano-Py', Check,
Excluding Botano-Py Dust Chck and Nicotine dusts nicotine and D-7 dusts
At odds of 19-1... 36.5 At odds of 19-1... 15.1 At odds of 19-1,0. 16.9
49-1... 45.8
49-1... 20.9
49-1... 18.0
99 -1... 53.1
99-1... 24.1
99-1... 20.7
(excluding Corvallis applications)
Excluding Botano -Py,
Excluding Botano-Py, Check,
Excluding Botano-Py Dust Check and Nicotine dusts Nicotine and D-'7 dusts
At odds of 04... 17.5 At odds of 19-1...
At odds of 19-1... 4;1
49-1... 21.7
49-1... 7.7
49-1... 5.2
99-1... 24.9
99-1... 8.9
99-1... 6.0
30
Studies on Population Build-up after Dusting.
Hull Experiment, Grants Pass, Oregon
Populations ordfroWrrrr-Z-reserlk4tre
Dusting
lbs/acre
Treatment
DN Dust
DN Dust
DN Dust
106
DN Dust D-44
DU Dust D-.4
DN Dust Dm4
DN Dust E-3
75
50
100
75
102.2
193.9
183.9
104.1
Observed
17 days
after
Dusting
1,4
22.1
4.6
3.3
18.3
177V
gxpected*
17 days
after
Dusting
Percent
Control**
120.6
Itf.tr
228,8
217.0
122.8
90.0
87.6
205.6
93.4
91.3
98.6
100
208,2
176.4
2.9
75
211.6
1
10.14
249.7
Ix Dust D-3
114.3
50
274.5
323.9
100
DK Dust D-7
160.3
189.2
39i:i
DN Duet D-7
82.8
181.4
153.7
75
50
DU Dust D-7
219.3
258.8
88.5
i...i
Check- No treatment
-221.0
261.6
261.6
00.0
Nicotine sulfate-sUlfur and Botano-Py plots redusted by groner because of
poor control.
* Computed from the rate of(ncrease of the check /untreated plots)
according to the original (mean) population of the individual plots.
** Computed from the formula.
DN Dust D-,3
Expected population minus observed population
Expected population
X 100
Summary of Mr. Hull's red spider control using the
Station Experimental duster and DU Dust at 50
lbs/acre. 22 days after application.
Mean spiders per leaf
(mean of 600 leaves)
before dusting
198.0
Mean spiders per leaf
after dusting
3.2
Percent
Reduction
98.4
Summary of Mr. Ultonfs red spider control using his
converted hop aphis duster and DN Dust at 50 lbs.
per acre. 114 days after application.
Mean spiders per leaf
(mean of 100 leaves)
befbre dusting
200.0
Mean spiders per leaf
after dusting
0.6
Percent
Reduction
99.7
31
Studies on Build-Up of Red Spider Populations after Dusting.
Pankalla Experiment, Corvallis, Oregon.
Mean popUlation of entire block
before
dusting.
Treatment
of red
dere per leaf
a- Expected populaObservedrpo
tion of dusted
tion on dusted
plots 27 days
plots 27 days
after second
after second
dusting. 39 clays dusting. 39 days
after first
after first
dusting.
dusting. *
Percent
Control**
Mean of all
DN treated plots
462
33
554
93.7
Check No treatment
540
647
647
0.0
* Computed from the rate of increase of average population per leaf of
entire block before dusting and the population per leaf of the check
(untreated plot) after the second dusting.
* Computed from the formula
Expected
ulation minus observed population
100
al119
(toted population
Note- All plots with the exception of the check were treated with DN Dust,
DU Dust D-4, De Dust D-3 and DM Dust D-7 at the rate of 75 pounds to
the acre. Only a few rows were allowed to stand untreated.
Summary of spray treatments at the Panic-ale Ranch
Number of
leaves
counted
Treatment
water
5 lbs.
2/3 pt.
100 gal.
Dry lime
sulfur
water
5 ibs.
100 gal.
DN Dust D-14
SS-3
Percent
Mean population
per leaf
Date
applied
dead
spiders
20
1609
8/18/140
85
25
2147
7/18/40
63
The lime sulfur treatment was applied early in the season by Mi. Pankalla.
A portion of this same yardman used one month later to test the effectiveness of DN Dust D-14 as a spray. The increase in population of red spiders
which averaged 63 percent kill is interesting.
32
Studies on Build -Up of Red Spider Populations after Dusting.
Christofferson Experiment, Eugene, Oregon
a ons o r
of ore
Dusting
Treatment
Ms/acre
DN Dust
DN Dust
DN Dust
DN Dust D-4
DN Dust D-4
DN Dust D-4
DN Dust D-3
DN Dust D-3
ON Dust D-3
DN Dust D-7
Check- No treatment
100
75
50
100
75
50
100
75
50
100
63
88
101
90
64
68
87
101
110
77
73
s rs per
observe
35 cWys
after
Dusting
1
3
3
1
1
2
3
1
4
19
245
e
Expect-1mi
35 dare
after
Dusting
211
295
339
302
215
228
292
339
369
258
245
Percent
Control
99.5
99.0
99.1
99.7
99.5
99,1
99.0
99.7
98.9
92.6
0.0
Note- All remaining treatments had been harvested at time of this survey.
* Computed from the rate of increase of the check (untreated plots)
according to the original (mean) population of the individual plots.
** Computed from the formula
Expected population minus observed population
Expected population
100
33
Studies on Build-Up of Red Spider Populations after Dusting.
Chittenden Experiment, Salem, Oregon
lbsjacre
Treatment
DN
DN
DN
EU
Dust
Dust
Dust
Dust D-4
DN Dust 13-4
DN Dust D-4
DN Dust EI-3
DN Dust D-3
100
75
50
100
75
50
100
75
Population of red spiders per leaf
Population 24 days
Original
after dusting
population
238
12
17
23
29
23
75
34
714
95
22
96
106
158
104
55
Percent
reduction
87.5
83.9
85.4
72.1
90.3
54.7
98.7
42.1
All other treatments and all checks were redusted by the grower
with DN Dust at rate of 50 pounds per acre.
The following data is a summary of counts made on hops which had been
dusted by the favorer. The dusting unit was converted from a hap aphis
duster to be used far red spider dusting. In general it was not efficient in giving adequate coverage on the undersides of the hop foliage.
The different counts show a slight increase in kill which resulted from
minor mechanical changes of the duster.
Date applied
Material
No. of spiders
per leaf
'Percent
dead
ti Met 0 lbs/acre
8/10/140
92
81.4
50 lbs/acre
8/11/40
314
87.4
DN Dust
311
Studies on Population Build -Up after Dusting
Nordenhausen Experiment, Canby, Oregon
a
913
before
Dusting
Treatment
DN
DN
DN
DN
DN
DN
DN
DN
DN
Dust
Dust
Dust
Dust
Dust
Dust
Dust
Dust
Dust
D-4
D-4
D-4
D-3
D-3
D-3
DN Dust D.-7
DN Dust D-7
IV Dust Dar
Nicotine-sulfur
Nicotine-sulfur
Nicotine-sulfur
Check
Ms/acre
100
75
50
100
75
50
100
75
50
100
75
50
loo
75
50
.
o re
.
Observed
28 days
after dusting
248
137
82
82
23
26
26
17
514
19
29
194
90
236
65
103
50
99
53
69
86
814
5 per
Expected *
28 days
after dusting
726
401
2140
26
240
158
586
264
691
190
64
302
73
114
122
1146
3
16
185
224
246
,
290
155
202
251
246
Percent**
Control
96.8
93.5
89.0
92.9
83.0
95.0
98.9
97.8
86.3
78.8
50,0
60.6
21.3
8.4
10,4
0.0
* Computed according to rate of increase of check (untreated plots)
according to original (mean) population of individual plots.
** Computed according to the formula
Expected population minus observed population
Expected population
X 100
35
b.
Investi ations on the Effect DN Dusted Hops
an Chemical
arff651 TIECIMITTWWW
ht Have on the Physical
Quin-flee Uf-Heer.
It was thought advisable to carry on tests in order to ascertain
the effect DN dusted hops might have on the physical and chemical properties
of hops and on the brewing quality of beer.
A number of hop plants (Late
Cluster variety) were accordingly dusted with DN dust and DN dust D-1 at
the excessive rate of approximately 200 pounds per acre.
Undusted rows
were interspaced between the treated rows in order to prevent contamination
due to drift.
Hops were picked and dried the day after dusting.
Samples
of these hops were submitted to the Farm Crops Department and Chemistry
Department of Oregon State College for physical and chemical analyses.
Samples were also submitted to the Wahl-Henius Institute for brewing
studies.
There was no difference in chemical analysis between dusted and
undusted hops as is indicated by the figures for preservative values.
The
undusted hops had somewhat better color as is indicated by their hue.
This, however, offers no serious objection because color has not been
correlated with hop quality.
There was no difference between dusted and
undusted hops with respect to brewing qualities of beer.
The dusted and
undusted hops show no other differences as shown by physical measurements.
Several remarks in the report by the Wahl-Henius Institute require explanaption,
The ring-like dark spots which were present in the undusted sample
and which are mentioned by the Wahl-Henius report are probably due to an
excess of oil in the small baler which was used for pressing the samples.
The undusted hops were baled first and probably absorbed this excess oil.
Sample 3 (DN dusted hops) were reported somewhat redder than the
36
other samples and apparently subjected to a greater extent of wind damage.
The dusted plots were located on the southeastern portion of the yard and
subjected to severe wind damage.
It is probable that one sample may have
shown this damage to a greater extent than the other samples.
62- 64
The couplet!. data on this study are given on pages / of the appendix.
5.
Continued Compatibility Studies of DN and Other Insecticides
Investigations were continued in the small plots of the Entomology
section of the experimental hop yard.
These tests were delayed until after
the extensive field work had been completed.
Reliable results on the
pesticidal and phytocidal action of tested materials may not have been
obtained because of the cool weather during the latter part of August.
The method employed and diagram of experimental layout were similar to
that reported in Journal of Economic Entomology 33, No. 1, P. 70, 1940.
The following materials and combination of materials were tested during
1940.
Treatment
No.
1
2
3
14
Treatment
Check - No treatment
Dinitro-ortho-cresol
Walnut shell flour
1.00
99.00
Dinitro-ortho-cresol
Walnut shell flour
2.00
98.00
Dicyclohexyl amine salt of dinitro-orthocyclohexyl phenol
Dusting sulfur
Frianite
1.00
0.50
49.00
49.50
Dicylcohexyl .amine salt of dinitro-orthocyclohexyl phenol
Dinitro-ortho-cyclohexyl phenol
Dusting sulfur
Frianite
2.00
1.00
49.00
48.00
Dinitro- ortho- cyclohexyl phenol
5
37
Treatments - Continued
Treatment
No.
Treatment
Dinitro- ortho- cyclohexyl phenol
6
Dusting sulfur
Frianite
7
No application made
8
9
5% rotenone from Cube root
Inert rotenone filler
1N-834-A-7 (*)
Soapstone
Diatomaceous earth
0.75
15.75
2.00
71.50
10.00
Check - No treatment
Dinitro-ortho-cyclohexyl phenol
5% rotenone from Cube root
Inert rotenone filler
Frianite
0.85
0.75
14.25
84.15
Dicyclohexyl amine. salt of dinitro-orthocyclohexyl phenol
Dinitro-ortha.cyclohexyl phenol
5% rotenone from Cube root
Inert rotenone filler
Frianite
0.85
0.425
0.75
14.25
83.725
12
Dinitro-ortho-cyclohexyl phenol
Nicotine sulfate from 40% nicotine sulfate
Frianite
0.875
5.000
94.125
13
Dicyclohexyl amine salt of dinitro-orthocyclohexyl phenol
Dinitro-ortho-cyclohexyl phenol
Nicotine sulfate from 40% nicotine sulfate
Frianite
0.875
0.4375
5.0000
93.6875
14
Dinitro-ortho-cyclohexyl phenol
Nicotine (Free) from 95% Nicofume
Frianite
0.875
5.000
94.125
15
Dicyclohexyl amine salt of dinitro-orthocyclohexyl phenol
Dinitro-ortho-cyclohexyl phenol
Nicotine (Free) from 95% Nicofume
Frianite
0.875
0.4375
5.0000
93.6875
10
11
16
Dicyclohexyl amine salt of Dinitro-orthocyclohexyl phenol
Dinitro-ortho-cyclohexyl phenol
Loro (rainy]. thiocyanate)
Frianite
(*)
1.00
49.00
50.00
An undisclosed activator manufactured by DuPont.
0.875
0.4375
5.000
93.6875
38
Discussion of Results
1.
A very high mortality was measured in all of the treatments
excepting treatment 8 (Rotenone .75%).
This material was significantly
poorer than any of the other treatments but decidedly better than the
check.
2.
Treatment 16 (DN-Loro combination) was the only treatment to
give foliage injury.
3.
This injury was considered as very severe.
The dusts which contained nicotine and Loro (Nos. 12, 13, 14,
15 and 16) were very heavy and difficulty was experienced in handling them
in the duster.
4.
The addition of rotenone, nicotine sulfate, free nicotine and
Loro did not add or detract from the toxic properties of the proprietary
dusts.
These mixtures were used immediately after mixing and it is pos-
sible that aging might alter the toxic properties to some extent.
5.
The dinitro-o-cresol dusts were equally as toxic as the regular
DN dusts under the conditions of these testa.
The weather was quits cool
at the time of application and the true phytocidal action of these materials
may not have been experienced.
6.
Hop aphis populations were not sufficiently high during 1940 and
the aphicidal properties of these mixtures could not be fully evaluated.
The summary of these data are given on the following pages while
complete data are given on pagea2)12-371 of the appendix.*
* See Department of Entomology for original data.
39
Summary of Small Plot Dusting Trials
Applied 8/11/40
Data collected 8/15/40
East Farm, Corvallis, Oregon
Treatment
Number
1
1
5
6
3.7
99.6
96.5
100.0
100.0
99.8
7
8
48.4
2
3
4
Percentage of dead= i&twiders
Replication number
5
6
2
4
3
4.4
0.9
3.7
5.9
98.6
99.0
99.8 100.0
99.3 100.0
99.1
99.8
99.7
99.9
99.7 100.0
100.0 100.0 100.0 100.0
100.0 100.0
99.7
99.7
NO TREATMENT APPLIED
58.4
79.9
32.4
30.9
T
8
Ian
3.9
99.7
98.3
100.0
100.0
99.7
6.8
99.4
99.5
99.0
100.0
100.0
3.2
98.9
97.5
98.9
99.5
100.0
4.06
99.25
98.75
99.65
99.93
99.86
55.9
23.0
43.1
46.50
Differences necessary for significance at odds of
19-1
7.43
9.10
49-1
10.35
99-1
Differences necessary for significance (Treatments 1 and 8 omitted)
(Check and rotenone plots) at odds of
.67
19-1
.82
49-1
99-1
.93
Treatment
Number
1
9
3.3
10
11
12
13
14
15
16
100.0
100.0
100.0
100.0
100.0
100.0
100.0
Percent of dead red spiders
Replication number
6
2
4
3
5.7
98.7
99.8
100.0
100.0
100.0
99.8
100.0
4.3
100.0
100.0
100.0
100.0
100.0
100.0
100.0
6.6
100.0
100.0
100.0
99.7
100.0
99.5
99.3
1.3
99.4
100.0
100.0
100.0
99.7
100.0
100.0
1.3
100.0
100.0
100.0
100.0
100.0
100.0
100.0
7
5.1
100.0
100.0
100.0
100.0
100.0
100.0
100.0
ti
1.0
100.0
100.0
100.0
100.0
100.0
100.0
100.0
Mean
3.58
99.76
99.98
100.00
99.96
99.96
99.91
99.91
Differences necessary for significance treatment 9 (Check) included
at odds of
19-1
49-1
99-1
.88
1.07
1.22
Differences necessary for significance with treatment 9 (Check) excluded
at odds of
0.23
19-1
0.28
49-1
0.32
99-1
140
The Initiation of the Study of Fungicidal Properties of DN Dusts.
DN dusts were found to offer little promise for hop aphis control.
It was noted, however, that in the dusting trials at the Sloper yard near
This
Albany that a few red spiders were killed in the cone by DN dusts.
indicated that some dust could be introduced mechanically into the hop
cone when it was nearing maturity.
It is at this time of the season that
hop aphis enter the cone and secrete honeydew which promotes the growth of
85 percent of all cones examined showed that mold started in
sooty mold.
cones which were infested with either living or dead aphis.
The presence
of this mold lowers the quality of hops.
It was thought advisable to set up preliminary studies in order to
determine the possibility of using DN dusts for sooty mold control.
If
this were possible, both spider and mold control might be controlled by the
same dust.
A number of hop clusters were accordingly brought into the laboratory
and dusted with various DN dusts.
hop aphis.
These clusters were heavily infested with
After dusting they were placed in a bell jar in order to maintain
high humidity which is favorable for both aphis and mold development.
two weeks, these hops were removed and examined for sooty mold.
After
The number
of bracts of each cone which showed presence of mold were recorded.
The
following summary indicates that the DN dust in combination with sulfur had
some promise.
Treatment
Check
DN dust
2% dinitro-o-cresol
DN dust D-14
DN dust D-14 - sulfur
DN dust - sulfur
T0
N
cones examined
45
45
35
4o
45
ho
Percen
e
infested cones
36
27
51
38
38
0
este.
per cone
5
2
11
5
7
o
ac
141
Sooty mold studies were continued in the laboratory by Mr. J. D.
Vertrees, and the following account is taken from his report:
"Two types of media were made up, one with the bodies of the hop
aphid in agar, and the other with a decoction of hop stems, leaves, and
cones in agar.
The mold is reported to grow rather vigorously on the aphis
bodies in the field, and it was thought that an agar containing aphis would
be excellent for growth of the mold in culture.
However, the mold grew no
better than on the hop decoction agar, or even plain potato-dextrose agar.
"The formula for the aphis agar is as follows:
10 grans of sterilised aphis bodies (steamed in autoclave)
17 grams agar
1000 cc. distilled water
"The formula for the hop decoction agar is:
1 lb. hop leaves, cones, stems, etc.
1000 cc. water
Boil for one hour. Strain.
900 cc. water
100 cc. hop decoction
30 grams agar
"The infested hop cones were brought in from the field and the mold
was isolated from this source.
Cultures were finally obtained and were
perpetuated on the hop agar and also on the potato-dextrose agar.
"Tests were first run on the effect of pH on the growth rate of the
hap mold.
It was desired to find the optimum pH for the growth of this
organism.
The following table summarizes the results.
The pH value was
determined by the electrometer methods of pH determination.
42
No.
pH value
1
2
3
2.34
2.71
3.01
3.15
3.42
3.54
3.88
4.23
5.89
6.53
7.33
7.73
4
5
6
7
8
9
10
11
12
Neasurement of mold growth in sq. am.
(six days after inoculation)
Media hydrolyzed - did not solidity
n
n
n
is
n
90
140
99
40
15
6
4
2
No growth
"
"
"On the basis of these results, most of the other media, which
was used for growth purposes in the experiments, was brought to the
approximate pH of 3.20 to 3.15.
"A few preliminary studies on the fungicidal effect of DN dusts
were carried out.
A summary of these are given in the following table.
The tests were carried out in three different portions.
amounts of the dusts were incorporated into the media.
First, small
Second, the agar
plates were dusted before inoculation of the mold organism.
plates were dusted five days after inoculation.
used were 0.1 gram. per 25 cc. of media.
Third, the
The amounts of dusts
(Plates poured in 25 cc. each)
143
SUMMARY OF TESTS ON HOP MOLD
Dusts Incorporated into the Media
Material
DN
D4
DN-S
D4-S
Sulfur
Check
Types of growth
Means of dimensions in mm.
Very slight growth
No growth
2x8
---3x8
6x11
n
"
n
n
Very slight growth
Large growth
Dusted before inoculation
DN
D4
DN-S
D14-8
Sulfur
Check
--
No growth
II
n
n
if
In
It
---
--
Very slight growth
Large growth
2x5
6x14
Dusted after inoculation
DN
D4
DN-S
Very slight increase in growth
Growth killed
11
5x17
14x15
5x17
"
104-s
Sulfur
Check
Measurements
Original
Final
52E17
6x114
Growth increased
6x17
5219
WS
5x17
5x17
7x14
9x19
"A final experiment was conducted on the fungicidal action of the
DN dusts against the black hop mold.
replications of each treatment.
These tests were made with five
The plates of hop agar were inoculated
with the mold from the pure cultures and allowed to develop for five days.
The measurements were then taken of the growth of the mold colonies.
Dust
was then applied to the surface of the cultures and allowed to remain at
room temperature for ten days.
Measurements were then taken, and the dif-
ference in square millimeters of growth was tabulated."
14
It was evident from these laboratory studies that DN dusts had
This was shown
some inhibiting effect on the development of sooty mold.
when the dusts were incorporated into the media or when the dust was
applied either before or after inoculation.
The pH range for optimum mold
development centered between 3.01 and 3.42, and this suggests that the
addition of the dusts which are slightly acid may have sufficiently changed
the pH and prevented mold development.
DN sulfur in these tests did not
parallel the indications of the original laboratory tests.
None of this
work was conclusive but it was believed that the results were sufficiently
favorable, and that preliminary field tests should be attempted.
145
Hop Mold Studies (Complete Data)
Cone No.
1
2
3
4
5
6
7
8
9
10
11
12
E
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
3o
31
32
33
34
35
36
37
38
39
ho
41
42
43
44
45
Number of bracts shaming sooty mold spots*
Treatments
DM DustDMDN Dust
D4 sulfur
cresol
DN
dust
Check
D4
1
0
4
0
29
16
18
12
0
13
18
22
0
0
23
2
10
0
23
3
1
0
1
8
27
0
0
10
0
0
0
0
0
0
0
0
0
0
0
13
0
0
0
h
0
0
0
24
0
0
0
0
25
0
0
0
0
0
0
0
0
0
0
236
Total
Mean per bract
5.24
% cones
infested
35.5
2
0
0
0
6
0
0
0
1
2
0
0
10
0
0
54
0
0
6
42
7
11
0
39
9
49
46
37
5
0
2
11
9
0
0
0
0
8
0
0
0
30
0
0
21
5
0
0
0
0
0
0
0
0
0
0
0
0
0
12
25
At Dust,.
Sulfur
0
3
20
0
0
0
0
0
0
0
0
0
0
0
0
o
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
27
0
0
12
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
26
29
24
9
3
4o
33
5
h
0
o
4
0
0
0
0
0
0
0
0
0
0
16
0
7
1
24
34
15
0
0
0
0
0
0
0
0
0
0
0
0
8
3
21
36
19
0
0
16
h
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
101
2.24
391
11.17
219
5.47
317
7.04
0
0
26.7
51.4
37.5
37.7
0
0
0
2
25
29
0
* There are on an average of 50-55 bracts per cone.
L6
The P tocidal Effect of DN Dusts on Various Craps, and the Associated
Spiders on7Thardrws
Control of
DN dusts have been found very toxic to many species of red spiders
and many of these pests have a wide list of host plants.
Tetranychus
telarius Linn for example is known to attack over 100 different host
plants.
Greenhouse plants, nursery plants, vegetables, fruit trees,
brambles, etc. are included in this partial list.
DN dusts are now known
to possess definite toxicity to certain plants and the severity of plant
injury by these varies with climatic factors.
The principal contributing
factor of this phenomenon appears to be temperature.
It was thought advisable to carry on studies on the phytocidal action
of DN dusts on a wide assortment of plants in an effort to learn the tolerance of these plants to DN dusts.
This information would be of special
benefit to subsequent red spider control if and when these controls were
made necessary.
Tests were made by Mr. Joe Schuh, Assistant Entomologist,
of Oregon State College and J. D. Vertrees, Research Fellow, Dow Chemical.
Company, Oregon State College.
The tests made by Mr. Schuh were confined
largely to greenhouse and nursery crops and those of Mr. Vertrees consisted
largely of vegetable and field crops.
Information of similar efforts were
collected from California on nursery, vegetable and tree fruits.
These
tests were made by Professor W. E. Blauvelt and Dr. D. T. Prendergast.
In all, 131 different kinds of plants were subjected to DN dusting
of some kind.
Not all were dusted with the same materials and the carriers
of these dusts probably differed.
There have been some conflicting reports
depending on locality and the subsequent different climatic conditions.
In general, it is indicated that plant tolerance is dependent largely
upon the degree of succulence of the plant, the temperature at which the
47
dust is applied, the concentration of dinitro-o-cyclohezyl phenol in the
These results also suggest that
dust and the rate at which it is applied.
each plant has its own thermal range.
This has been determined on citrus
and hops as approximately 100 degrees F.
It is evident that the proprietary 1% dinitro-o-cyclohexyl phenol
dust (DN dust) is toxic to most plants and the 0 dinitro-o-ayclohexyl
phenol (DN dust D-3) is considerably safer.
The 2% dicyclohexylamine salt of 1% dinitro-o-cyclohezyl phenol
(DN dust D-4) tends to make this dust considerably safer to plants while
the 1% dicyclohexylamine salt of 0 dinitroo-ayclohexyl phenol (DN dust
D-7) slightly improves this margin of safety.
The addition of sulfur to the dicyclohexylamine salts of DN (DN dust
D-4; sulfur and DN dust D-7; sulfur) considerably reduces this margin of
The following is a tabular summary of the plants tested.
safety.
Number of
plants
tested
Type of dust
DN dust
DN dust th-3
DN
DN
DN
DN
dust
dust
dust
dust
D-4
D-7
D-4, sulfur
D-7, sulfur
Number of
plants showing no burn
Percentage of
plants showing
no burn
27
28
64
65
80
99
99
111
106
49
49
89
86
13
16
83
27
Satisfactory control of the common red spider was noted on such
plants as beans, violet (a variety of double violet Princess Charlotte;
which was developed by Nrs. R. H. Dearbor140 and hops.
The successful con-
trol of these pests centers itself about plait tolerance and development
of satisfactory means of application of dusts.
A list of the various
plants tested is included on the following pages, and copies of the complete
work are included in pages375-380 of the appendix.*
* See Department of Entomology report for original data.
48
The following is a list of various plants which were dusted with
various kinds of DM dusts.
Data from Schuh.
See Circular of Information,
Oregon State College, No. 235, 1941.
Hardwood Trees or Shrubs
Variety
Code No.
1.
2.
Acer almatum rubrum disectum (Japanese lace-leaf maple)
3.
4.
Aesoulns hippocastanum (Horse chestnut)
Azalea hex.
5.
UMW EMdigeri
lea molls
6.
sac c
um (SilWragl)
7.
8.
Wan alba (European White Birch)
9.
WEB florida rubra (Pink flowering dogwood)
Cotoneaster gprvhigmpHgalor
oxyii011#1J54FLIRETawthorn seedlings)
Crates
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
31.
truxus Selpervirens (Boxwood)
cneorua
sylvatica purpurea (Copper beech)
o
Maidenhair tree)
eat r sp.
Kerrie
Koelreu
Laburnum
nice, flore-pleno
a paniculata /Rain tree)
are (Golden chain, seedlings)
8
=jeans,
us sp. (Apple seedlings)
Prunus americana (American plum seedlings)
Prunus aviva Otazzard cherry seedlings)
t)runus CiFiiifera (Myrobolan plum seedlings)
Prunus mahaleb (Mahaleb cherry seedlings)
rue, sir."-Tnar seedlings)
uercus rubra (Red oak)
Rosa sp.-TIEStta cuttings)
lirira sp. (Multiflora cuttings)
ISTi sp. (Rugosa cuttings)
americana (American linden)
716iinum tinus (Laurastinus)
trtra
The following dusts have been found safe for use on the above plants
as designated by their code number.
unsafe or questionable.
Plants not listed below are either
149
DN Dust
DN Dust D-3
7.
1.
11.
17.
23.
3.
7.
9.
10.
11.
12.
13.
14.
16.
17.
20.
23.
25.
28.
30.
DN Dust D-4
1.
3.
5.
6.
7.
DN Dust D-7
15.
16.
17.
20.
1.
3.
5
23.
7.
8.
8.
214.
10.
10.
11.
12.
25.
11.
12.
14.
15.
16.
28.
31.
DK Dust D-48
17.
20.
21.
22.
23.
24.
25.
28.
29.
31.
DN Dust D-78
7.
3.
7.
11.
11.
12.
16.
17.
20.
23.
25.
28.
12.
17.
20.
23.
24.
25.
3.
28.
31.
Evergreen Trees or Shrubs
Data from Schuh (See Oregon State College, Circular of Information No. 235, 1941)
Variety
Code No.
Cedrum deodora (Deodar cedar)
Chamaecyparis Lawsoniana alumi (Alumi cypress)
thamaecyparis Lawsoniana EWiTades (Birds' neat cypress)
Juni erus ohinensis femina
perils chinensis Prairiana (Pfitserfs juniper)
Juni rue communis de ressa (Vase juniper)
perus ilaiTiii-s
c
(Spring creek juniper)
32.
33.
34.
35.
36.
37.
38.
39.
40.
41.
42.
43.
44.
45.
46.
47.
48.
49.
junl
rus HUTaate (Irish juniper)
rus proc
ens (Chines® creeping juniper)
rue sabina
Julerus virginiana (Eastern red cedar)
cea conoglauca
lar-ea
ens (Colorado blue spruce)
Pinus
o (Uugho pine)
u a or en
s auras. nana (Berckmants golden dwarf)
u a occidentans pyraraiis (Pyramidal arborvitae)
u a occiddntelis woodwardi (Woodward's arborvitae)
axus baccate ((3ciirMIThhe yew)
The following dusts have been found safe for use on the above designated
plants.
Plants not so listed by their code number were either unsafe or
questionable.
50
DN Dust
DN Dust D..3
None
32.
35.
36.
37.
38.
39.
4o.
41.
44.
45.
46.
47.
DN Dust D-4
32.
33.
35.
36.
37.
38.
40.
hi.
42.
DN Dust D-7
32
45.
46.
47.
48.
49.
33.
35.
36.
37.
38.
DN Dust D-4S
DN Dust D-7S
41.
46.
47.
41.
44.
45.
46.
47.
142.
45.
46.
47
48.
49.
39.
40.
41.
Greenhouse and Nursery Flowering Plants
(Data from Blauvelt and Geary in California; Vertrees in Oregon)
Code Number
5o.
51.
52.
53.
54.
55.
56.
57.
58.
59.
60.
61.
62.
63.
61i.
65.
66.
66A.
67.
68.
69.
70.
71.
72.
73.
74.
75.
76.
77.
78.
79.
79A.
80.
Variety
,..__arbiE.J.z
Aster
Azalea
Begonia
Calendula
California poppy
Carnation (20 common commercial varieties)
Chrysanthemums (50 common varieties)
Coleus
Crassula argentea
Cyclamen
Gardenia
Geranium
Hydrangea
Xalenchoe
Ligustrum lucid=
Morning glory (Wild)
Peony
Peperomia
Pilea macrophylla
of se
Better Times)
Rose (Variety Briarcliff)
Rose (Variety Premier Supreme)
Rose (Variety Talisman)
Rose (Variety Token)
Rose (variety Yellow Gloria)
Rose (wild)
Saintpaulia
Sedum Weinbergia
Sagon
Stock
Violet (Princess Charlotte)
Zinnia
51
The following dusts have been found safe for use on the plants as
designated by their code numbers.
Plants not so designated are either
unsafe or questionable.
DN Dust D-7
DN Dust D-4
50.
52.
53.
71.
72.
73.
74.
75.
76.
77.
78.
79.
79A.
62.
50.
52.
53.
54.
56.
58.
59.
60.
61.
63.
64.
65.
66.
66A.
67.
68.
69.
70.
54.
56.
58.
59.
60.
61.
62.
63.
64.
65.
66.
66A.
67.
68.
69.
70.
71.
72.
73.
74.
75.
76.
77.
78.
79.
79A.
Note - DN dust D-4 mixed with water at rate of 1.5 pounds per 100 gallons
of water showed no burn on 31 varieties of Chrysanthemums and
slight burn on 9 varieties Fir Chrysanthemums.
Fruit Trees
Data from Amndergast and Vertrees
Variety
Code Number
Code Number;
89.
90.
Almond*
Apple
Apricot*
Cherry*
Fig*
Filbert*
Grapefruit
Lemon
81.
82.
83.
84.
85.
86.
87.
88.
91.
92.
93.
94.
95.
96.
Variety
Olive*
Orange
Peach*
Pear*
Pecan*
Plum*
Prune*
Walnut (Persian)
The following dusts have been found safe for use on the above plants
as designated by the following code number.
Plants not so listed are either
unsafe or questionable.
DN Dust
81.
87.
88.
89.
90.
95.
96.
DN Dust D-3
81.
82.
85.
86.
87.
88.
89.
90.
93.
94.
95.
96.
DN Dust D-4
82.
87.
88.
90.
96.
* Note - This dust
not applied to
the remainder of
the above plants
52
Hardwood and Evergreen Shade Trees
(Data from Prendergast)
Varlet?'
Code Number
Elm
97.
98.
99.
100.
Maple (Norway)
Pine
3 care
The following plants have been found safe for dusting with the
dusts as designated below.
ON Dust
Alai
97.
99.
100.
Dust D-3
97.
99.
100.
Berries and Small Fruit
(Data from Prendergast and Vertrees)
Variety
Code Number
Blackberry
Grape*
Raspberry
Strawberry
101.
102.
103.
104.
The following plants as listed by their code number are safe for
application of the following dusts.
DN Dust
DN Dust D-3
DN Dust D-4
ON Dust 0-7
None
None
101.
103.
101.
103.
* Grapes not dusted with LW dust D-4 or DN dust D-7.
53
Field Crops
(Data from Prendergast and Vertrees)
Variety
Code Nubber
Alfalfa
Barley
Clover
Corn
Flax
Hops
Rye
Vetch (Hairy)
Wheat
105.
106.
107.
108.
109.
110.
111.
112.
113.
The following plants as listed by their code number are safe for
application of the following duets.
DN Duet
108.
111.
112.
113.
DN Dust D-3
103.
105.
108.
110.
111.
112.
113.
DN Dust D-4
103.
104.
105.
108.
109.
110.
111.
112.
113.
DN Dust D-7
103.
10L.
105.
108.
109.
110.
111.
112.
113.
54
Vegetable Crops
(Data by Vortrees and Pandergast)
Code Number
Variety
Artichoke (Jerusalem)*
Asparagus*
Bean
Beets (Garden)
Cabbage
Celery
Cucumbers
Eggplant
Muskmelon
Onion*
Peas
Peppers (Bell)
Potatoes
Rhubarb*
Squash
Tomato
Watermelon
114.
115.
116.
117.
118.
119.
120.
121.
122.
123.
124.
125.
126.
127.
128.
129.
130.
The following plants as listed by their code number are safe for
application of the following dusts.
DN Dust
DN rust D-3
114.
119.
120.
122.
123.
124.
127.
128.
130.
114.
116.
118.
119.
120.
121.
122.
123.
124.
126.
127.
128.
130.
DN Dust D-4
116.
117.
118.
119.
120.
121.
122.
124.
125.
126.
128.
130.
* Not dusted with DN Dust D-4 or Di Dust D-7
DN Dust D-7
116.
117.
118.
119.
120.
121.
122.
124.
125.
126.
128.
130.
55
8.
Time Mortality Studies of DN on the pa. Red Spiders
In answer to numerous requests regarding the rate of toxicity,
Mr. J. D. Vertrees undertook to study this problem in some detail.
Dosages
of DN dust were held constant and the time required to kill red spiders was
measured.
The technique and complete data are found in the report of
Mr. Vertrees to the Dow Chemical Company.
A tabular summary of these
results is all that is included at this point.
Percent dead spiders
Average
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
9.
The Leaf Area of a
Time required to kill
spiders. Minutes. Overage)
24
33
43
52
62
71
79
90
100
110 (1 hour 50 minutes)
120
130
139
149
158
167
177
186
195
204 (3 hours 40 minutes)
Plant and. Method of Its Estimation
Gross (Hops in their Botanical and Commercial Aspect, page 16,
Scott Greenwood and Company, London, 1900) reports Fleischmann as stating
the total superficial leaf area of a hop plant is about 120 square feet.
There was no mention of the method of obtaining this figure.
The writer searched literature for some rapid and inexpensive
56
means of evaluating the total leaf surface of a hop plant and finally
adopted the following procedure.
Thirty different hop leaves were taken from several hap plants of
the Late Cluster variety.
square centimeters.
These leaves varied in size from 10 to 400
An outline of each leaf was traced on paper and this
model was carefully cut out with scissors.
Various known areas of the
paper were weighed and paper area was computed in terms of square centi
meters per gram.
The thirty leaf models were then computed for area on
the basis of their weight.
The thirty leaves were dried thoroughly and individual dry weight
measurements were made for each leaf.
The regression coefficient was then
computed between the area of each leaf (as determined from paper models)
and the dry weight of each leaf.
Three hop plants of the Late Cluster variety (two female and one
male) were then selected and every leaf was removed.
The leaves of each
plant were kept separate and their dry weight determined.
An extension
of the regression coefficient for each plant showed the following results.
Dry weight of
hop plant leaves
Grams
629.50
623.75
702.25
Plant 1 b.
2
" 32
Mean
Leaf surface area of hop plants
sq. centimeters
86169.2750
86382.3875
96125.1125
89225.59
sq. ft.
92.75
91.90
103.47
96.04
It was found that the surface leaf area was not directly proportion,'
al to dry weight of the leaves.
Figures computed on the dry weight of each
leaf on the basis of direct proportion are given as follows.
57
Plant 1 'b
pi
ft
108398.01 sq. cm. or 116.68 sq. ft.
107364.83 sq. cm. or 115.57 sq. ft.
120925.34 sq. cm. or 130.16 sq. ft.
2
3
Mean
112229.39 sq. cm. or 120.80 sq. ft.
The above method is naturally subjected to many sources of variance
(variety irrigation, soil fertility, cultural practices, etc.) but it is
felt that for a reliable approximation it should serve very well.
It will
be noted that the mean value figured from direct proportion is very close
to that mentioned by Gross while the value computed by regression is considerably lower.
The variance between plants is not large and a differ-
ence of 10 to 20 of the largest leaves could easily account for this difference.
Complete data of this work with a table for rapid estimation of
leaf area of hops from dry weight are given on the following pages.
Boyce et al. (J.E.E. Vol. 32, No. 3, pp. 450.4467, 1939) conducted
laboratory studies with dinitro-o-cyclohexyl phenol on the Citrus Red Mite,
Paratetranychus citri McG.vand found that .356 micrograms per square
centimeter of this material was necessary for satisfactory control.
They
also stated that Tetranychus telarius was somewhat easier to control.
There are normally 680 hop hills per acre which when mature would
approximate 65,307 square feet (60,673.400 square centimeters). of leaf surface.
From those figures an estimated 5 pounds of complete 1 percent dust
would be necessary to adequate coverage of leaf surface for an acre of hops.
The amount of DN dust found necessary for satisfactory control during
the 1940 season was 50 pounds per acre.
This represents a difference in
material costs of $4.50 per acre, and indicates that considerable value could
be achieved by continued investigations into more efficient dusting equipment.
58
Leaf Area-Dry Weight Study on Hop Leaves
Dry Freight of
Leaf No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
leaf, grams
2.875
.815
.655
.265
.395
.045
.110
.715
.170
.225
.100
.505
.330
.410
.745
.320
1.535
1.205
.640
.420
2.045
.180
.280
.740
.145
.315
.250
.040
1.200
1.155
Weight of paper
replica, grams
1.675
.580
.505
.180
.390
.040
.110
.555
.170
.195
.100
.335
.265
.290
.505
.285
.795
.705
.505
.280
.875
.175
.235
.415
.135
.215
.185
.040
.710
.695
1 gram of paper averaged 267.11 square centimeters.
Area of paper replica
Square centimeters
447.4
154.9
134.9
48.1
104.2
10.7
29.4
148.3
45.4
52.1
26.7
89.5
70.8
77.5
134.9
76.1
212.4
188.3
134.9
74.8
233.7
46.7
62.8
110.9
36.1
57.4
49.4
10.7
189.7
185.6
59
Calculation of Regression Line of Hop Leaf Area
from Leaf Weight (x) and Leaf Area (y)
Weight of
leaf (x)
grams
Area of leaf (y)
Square
centimeters
447.4
154.9
134.9
48.1
104.2
10.7
29.4
148.3
lo
11
12
13
2.875
.815
.655
.265
.395
.045
.110
.715
.170
.225
.100
.505
.330
114
.1410
15
16
17
.745
.320
1.535
1.205
.640
.420
2.045
.180
.280
.740
.145
.315
.250
.040
1.200
1.155
18.83
.628
Leaf
No.
1
2
3
4
5
6
7
8
9
18
19
20
21
22
23
24
25
26
27
28
29
30
Total
Mean
Correlation coefficient 121.55 - 67.91
r=
(1/.786 - .394) (- (L9399.93 - 11694.25)
or
53.64
or
.976
145.11
52.1
26.7
89.5
70.8
77.5
134.9
76.1
212.4
188.3
134.9
74.8
233.7
46.7
62.8
110.9
36.1
57.4
49.4
10.7
189.7
185.6
3241.3
108.14
Regression coefficient -
Y = a
plus bx
b
Standard deviation y
Standard deviation x
or 87.78
r
976 = 136.85
.626
a= Mean y - b Mean x or
108.1h - (136.85) (.628)
or 22.20
= 22.20 plus 136.85 x
1.000 Then Y - 159.05
295.90
2.000
432.75
3.000
Total (e) 581997.79
108.14
.628
Mean (y4)
19399.93
86169.275(92.75
sq.ft
Plant 1 Male .... 629.500
Total (14)
23.5825
85382.3875(91.90
Plant 2 Female... 623.75
Mean (x2)
.786
96125.1125(103.47 "
.626 Plant 3 Female .. 702.25
Standard deviation (x)
Mean
Standard deviation (y) 87.78
Mean (x2)
.394
11694.25
Mean (y2)
Total (xy)
Mean (xy)
3646.5949
121.55
Let x
The above leaf areas if computed from the
would give the following results:
116.68
Plant 1 Male
115.57
Plant 2 Female
130.16
Plant 3 Female
120.80
Mean
mean on basis of direct proportion
sq.
sq.
sq.
sq.
ft.
ft.
ft.
ft.
60
Table for Computing Surface Area of Hop Leaves
from Dry Weight of Leaves (Variety Late Clusters)
Dry weight Leaf area
Dry weight
Dry weight
Leaf area
sq. cm.
grams
eq. am,
grams
grams
23.57
.di
1.13
100.20
.57
101.57
.02
24.94
.58
1.14
102.94
.03
26.31
1.15
.59
27.67
.60
104.31
1.16
.04
29.04
.61
1.17
105.68
.05
.06
.62
107.05
1.18
30.41
.63
108.42
1.19
.07
31.78
08
.64
109.78
1.20
33.15
.65
.09
111.15
1.21
34.52
.10
112.52
.66
1.22
35.88
.67
113.89
1.23
.11
37.25
.12
.68
115.26
1.24
38.62
.69
116.63
.13
1.25
40.00
118.00
1.26
.70
.14
41.36
.15
119.36
1.27
.71
42.73
.72
120.73
.16
1.28
44.10
122.10
1.29
.17
45.46
.73
.18
46.83
123.47
1.30
.74
124.84
.19
.75
1.31
48.20
.20
126.21
1.32
.76
49.57
50.94
.21
127.57
1.33
.77
.22
.78
128.94
1.34
52.31
.23
130.31
1.35
53.68
.79
.80
131.68
1.36
.24
55.04
.25
.81
1.37
133.05
56.41
.26
.82
1.38
134.42
57.78
135.79
59.15
1.39
.27
.83
60.52
.28
1.40
.84
137.15
.29
61.88
138.52
.85
.30
.86
1.42
63.26
139.89
.31
64.62
141.26
.87
1.143
66.00
.88
142.63
1.44
.32
67.36
1.45
.89
144.00
.33
68.73
.145.37
1.46
.34
.90
1146.74
1.47
70.10
.91
.35
.36
.92
148.10
71.47
1.48
72.83
1.49
149.47
.37
.93
.38
150.83
1.50
74.20
.94
152.21
1.51
.39
75.57
.95
.40
76.94
.96
153.57
1.52
.41
1.53
78.30
154.94
.97
.42
156.31
1.54
79.68
.98
81.05
1.55
.43
157.68
.99
82.41
1.00
1.56
.44
159.05
.45
83.78
1.01
1.57
160.42
161.79
.46
85.15
1.02
1.58
86.52
1.03
163.15
1.59
.47
.48
87.89
1.04
164.52
1.60
89.26
165.89
1.05
1.61
.49
.50
1.62
90.63
1.06
167.26
168.63
1.63
.51
1.07
92.00
170.00
1.08
1.64
.52
93.36
1.09
171.37
1.65
94.73
.53
96.10
1.10
172.74
1.66
.54
1.67
1.11
174.10
97.47
.55
.56
98.83
1.12
175.47
La
Leaf area
eq. am.
176.83
178.21
179.57
180.94
182.31
183.68
185.05
186.42
187.78
189.15
190.52
191.89
193.26
194.63
196.00
197.36
198.73
200.10
201.47
202.84
204.21
205.57
206.94
208.31
209.68
211.05
212.42
213.79
215.15
216.52
217.89
219.26
220.63
222.00
223.37
224.74
226.10
227.47
228.83
230.21
231.57
232.94
234.31
235.68
237.05
238.42
239.78
241.15
242.52
243.89
245.26
246.63
248.00
249.37
250.74
61
Table for Computing Surface Area of Hop Leaves (Continued)
Dry weight
grams
1.68
1.69
1.70
1.71
1.72
1.73
1.74
1.75
1.76
1.77
1.78
1.79
1.80
1.81
1.82
1.83
1.84
1.85
1.86
1.87
1.88
1.89
1.90
1.91
1.92
1.93
1.94
1.95
1.96
1.97
1.98
1.99
2.00
2.01
2.02
2.03
2.04
2.05
2.06
2.07
2.08
2.09
2.10
2.11
2.12
2.13
2.14
2.15
2.16
2.17
2.18
2.19
2.20
Leaf area
sq. cm.
252.10
253.47
254.84
256.21
257.58
258.94
260.31
261.68
263.05
264.42
265.79
267.15
268.52
269.89
271.26
272.63
274.00
275.37
276.73
278.10
249.47
280.84
282.21
283.58
284.94
286.31
287.68
289.05
290.42
291.79
293.16
294.52
295.89
297.26
298.63
300.00
32.37
302.74
304.10
305.47
396.84
308.21
309.58
310.95
312.31
313.68
315.05
316.42
317.79
319.16
320.53
321.89
323.26
Dry weight
grams
2.21
2.22
2.23
2.24
2.25
2.26
2.27
2.28
2.29
2.3o
2.31
2.32
2.33
2.34
2.35
2.36
2.37
2.38
2.39
2.4o
2.41
2.42
2.43
2.44
2.45
2.46
2.47
2.48
2.49
2.50
2.51
2.52
2.53
2.54
2.55
2.56
2.57
2.58
2.59
2.60
2.61
2.62
2.63
2.64
2.65
2.66
2.67
2.68
2.69
2.70
2.71
2.72
2.73
Leaf area
sq. cm.
324.63
326.00
327.37
328.74
330.11
331.47
332.84
334.21
335.58
336.95
338.32
339.68
341.05
342.42
343.79
345.16
346.53
347.90
349.26
250.63
352.00
353.37
354.74
356.11
357.48
358.84
360.21
361.58
362.95
364.32
365.69
367.05
368.42
369.79
371.16
372.53
373.90
375.27
376.63
378.00
379.37
380.74
382.11
383.48
384.85
386.21
387.58
388.95
390.32
391.69
393.06
394.42
395.79
Dry weight
grams
2.74
2.75
2.76
2.77
2.78
2.79
2.80
2.81
2.82
2.83
2.84
2.85
2.86
2.87
2.88
2.89
2.90
2.91
2.92
2.93
2.94
2.95
2.96
2.97
2.98
2.99
3.00
3.01
3.02
3.03
3.04
3.05
3.06
3.07
3.08
3.0
3.10
3.11
3.12
3.13
3.14
3.15
3.16
3.17
3.18
3.19
3.2o
3.21
3.22
3.23
3.24
3.25
3.26
Lea! area
_151.
397.16
398.53
399.90
401.27
402.64
40440
405.37
406.74
408.11
409.48
410.85
412.22
413.58
414.95
416.32
417.69
419.06
420.43
421.79
423.16
424.53
425.90
427.27
428.64
430.00
431.37
432.74
434.11
435.48
436.85
438.22
439.59
440.95
442.32
443.69
445.06
446.43
447.80
449.16
450.53
457.90
453.27
454.64
456.0o
457.37
458.74
460.11
40..48
462.85
464.22
465.58
466.95
468.32
APPENDIX
62
The common red spider, Tetranychus telarius, is the most important
hop pest in the Pacific Northwest.
This tiny mite feeds on the under-
surface of the hop leaf and at harvest time will enter the ripening cone.
General lowering of yields, defoliation and lowering of quality result
when this pest is abundant.
The Oregon Agricultural Experiment Station instituted a research
program for the control of this pest in 1937.
Large scale field tests
were attempted during 1940 and the Division of Drug and Related Crops of
the United States Department of Agriculture, the Dow Chemical Company of
Midland, Michigan, and the Departments of Entomology and Agricultural
Engineering of Oregon State College cooperated in this endeavor.
Two proprietary compounds were found to be satisfactory at the rate
of 50 pounds to the acre, and efficient dusting units were necessary for
their application.
1.
DN dust.
2.
DN dust
D-4
The two materials are given as follows:
Dinitro-ortho-cyclohexyl phenol
Frianite
1%
99%
Dinitro-ortho-cyclohexyl phenol
Dicyclohexyl amine salt of dinitro- orthocyclohezyl phenol
Frianite
1%
2%
99%
The above materials had been approved by the Pure Food and Drug Administrap.
tion but there was some question regarding their possible effect on the
brewing industry and the production of beer.
A number of hop vines (variety
Late Clusters) were selected and dusted heavily (approximately 200 pounds per
acre) with these materials.
An undusted portion of the same variety was set
aside for comparative purposes.
Undusted roes were interspersed between
each dusted row to prevent contamination due to drift.
picked and dried the day after treatment.
The hops were
Physical and chemical tests were
made by the Departments of Farm Crops and Chemistry of Oregon State
College.
The data from these analyses are submitted as follows:
Chemical Analysis
Treatment
Percent by weight
Beta
Alpha
resin
resin
(B)
Moisture
(Al
Hard
resin
Preservative
value
10 (A + i)
11.66
10.17
10.72
1.29
1.05
0.98
98.0
97.6
98.7
DN dust
DN dust D-4
Check (Undusted)
9.32
10.96
10.80
5.91
6.37
5.30
Physical Analysis
Color
Treatment
DN dust
DN dust D-4
Check (Undusted)
Treatment
DN dust D-4
::2:::;Undusted)
Treatment
DN dust
DN dust 5-4
Check (Undusted)
Treatment
DN dust
DN dust D-4
Check (Undusted)
Green
10 gy 7/8
23
27
29
Yellow
10 yr 7/8
16
13
12
Black Gray
N-1
N-7
Hue
Chrome
Brilliance
22
27
21
5.90
5.00
7.07
1.95
1.30
2.05
5.5
5.6
5.5
49
33
38
Foreign Material
Seeds
items ano leaves
Weight
Weight
%
%
0.10
0.08
0.08
0.5
0.4
0.4
3.54
2.40
3.00
Strip,
Weight
9.6
10.7
8.7
1.92
2.14
1.54
16.7
12.0
15.0
Lupulin Examination
Lupulin
Aroma
Evaluation
Evaluatlon
Color
0-10
1-20
Amount
Description
Med. pleas.
"
"
16
16
16
Med.
Good
General Examination
Appearance
General
evaluation
description
Good
Good
Good
9.0
9.5
9.5
8
8
9
n
Condition of
color (1-10)
Cryst.
Trans.
Med. yellow
9
9
9
Seed
color
Seed
density
Pubescence
or strigs
3 tan - 2 purp.
3 tan-2 purple
2 tan-3 purple
2/5
3/5
3/5
Dense-short
Med. - Med.
Med. - short
There was no apparent significance in the chemical properties
(preservative Value) of either treatment on untreated hops.
The check
on untreated sample was somewhat superior to the dusted hops as is
indicated by the hue of these samples.
This offers no serious objection
because color is not correlated with the quality of hops.
Samples of these dusted hops were submitted to the Wahl-Henius
Institute of Chicago, Illinois, for brewing tests.
The results of this
study are submitted in its entirety in the following report.
Two items
of explanation of this report are given at this point.
1.
Sample 1 (Undusted sample), ring-like dark spots which were
not present in any of the other samples.
This resulted from
an excess of oil in the small baler used for pressing the
samples.
2.
Sample 3 (DN dusted sample) was somewhat redder and subject
to apparent wind damage.
This was probably true.
The loca-
tion of the dusting plots was in the southeastern section of
the yard which is subjected to severe wind damage.
DINITRO-ORTHO-CYCLOHEXYLPHENOL DEPOSITS ON DUSTED HOP LEAVES
In cooperation with Ur. Uorrison, of the Entomology Department,
samples of hop leaves that had been dusted with varying amounts and
percentages of dinitro-ortho-cyclohexylphenol were collected and analyzed.
The DN dust was prepared using either walnut flour or Frianite as the
carrier or diluent.
The DN was incorporated to give either a .5 per cent
or a 1.0 per cent DN dust.
The dust was then applied to the hops at the
rate of 50, 75 or 100 pounds to the acre.
About fifteen leaves were then
selected from each plot, from which eight were taken for the chemical
analyses.
From this group, eight leaves were selected that measured by
the planimeter about 1000 square centimeters.
after extraction of the DN by the solvent used.
The leaves were measured
The accompanying table
contains the results obtained.
On the assumption that a 1 per cent DN dust would deposit more
than a .5 per cent dust, and that when used at 100 pounds of the dust to
the acre greater amounts would be deposited than when used at the rate
of 75 or 50 pounds to the acre, the results as a whole are contradictory,
and inconsistent.
For example, at Grants Pass, more DN was deposited
when a .5 per cent dust was used than when a 1.0 per cent dust was used.
Also the Corvallis yard deposited more DN when a .5 per cent dust was used
at 50 pounds to the acre than when it was used at 75 or 100 pounds to the
acre.
There seems to be a fair consistency in the relative amounts
deposited from 50, 75 and 100 pounds to the acre in the Eugene yard, but
there again less dust was deposited when used at the rate of 1.0 per cent
than when used at the rate of .5 per cent DN.
There is a possibility that the quality of the hop leaf surface
or the influence of dew together with mechanical imperfections that might
prevent even distribution of the dust at close range may account for the
inconsistencies of the results.
On the other hand it may be possible
that a .5 per cent DN dust will deposit more of the active ingredients
than a 1.0 per cent dust.
Unquestionably there is a large error of
sampling, since some of the leaves were so thickly covered with the dust
that it was easily visible and imparted a yellowish color to the extract..
ing solvent.
Notations of possible abnormally large amounts of dust were
made before analyses, and these observations usually were found true.
It
is also interesting to note, as were obtained from the Eugene yard, the
results were fairly consistent at 50, 75 and 100 pounds of the DN dust to
the acre.
The fact that a .S per cent dust deposited larger amounts than
1.0 per cent dust may be actually true, and it might be well to test a
concentration even lower than .5 per cent for deposit, especially if the
latter has given as effective control as did the 1.0 per cent dust.
67
19140-14.1
Dinitro-ortho-cyclohegylphenol on dusted hop leaves
...ortrr_s.142.
DN in dust: Lbs. Acre:
ory
Yards
a t ran
ass :
ene
SURE-crograms
tro-0-cy o egy p now sq. cm.
.5
50
1.07
1.13
.44
.89
.5
75
.69
1.38
.58
1.23
.5
10o
.97
1.58
.92
.81
1.0
5o
.96
.6o
.18
.90
1.o
75
.45
.74
.25
1.12
1.0
100
2.30
.70
.30
1.28
Lab. book R -7, p. 224.
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P
OREGON STATE COLLEGE
School of Agriculture
Experiment Station
Extension Service
Corvallis
September 16, 1940
Dean Wa. A. Schoenfeld
Campus
Dear Dean Schoenfeld:
The attached excerpts from letters addressed to Dr. Mote relative
to the hop red spider control program are transmitted herewith for your
information and for any disposition you wish to make of them.
It occurs to me that you may wish to transmit a copy to Mr. Mac
Hoke, Chairman of the Experiment Stations Committee through President
Ballard inasmuch as the work done on the red spider problem was under
the legislative funds.
These letters of commendation from prominent hop growers were,
I believe, unsolicited and speak well for the progress Doctors Morrison
and Mote have made with this problem.
Very truly yours,
R. S. Besse, Asst. Director
Agrfl. Experiment Station
RSBOLH
ccs D. C. Mote
H. E. Morrison
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0
p
Y
Box 366
Eugene, Oregon
August 21, 1940
Doctor Don C. Mote
Oregon State College
Corvallis, Oregon
Dear Doctor Mote:
I want to take this opportunity to thank Oregon State College
for the demonstration of red spider dusting which they performed in
my hop yard. I am well pleased with the results and I know it is a
great benefit to the hop growers in this district to have a dust that
will kill red spider.
Sincerely yours,
/8/
L. S. Christofferson
70
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P
Y
Corvallis, Oregon
August 17, 19140
Dr. Don C. Mote
Agriculture College
Dear Sir:
I wish to thank you for the good work you have done on our hop
ranch, of the control of red spider. The five acres that Mr. Morrison
dusted we picked every hop, and the rest of our forty acres, which we
did not dust, we lost considerable hops, which to my estimation would
amount to around six hundred dollars.
Hoping that you continue this experiment which we appreciate
very much. I also want to thank Mr. Morrison for his prompt cooper*.
tion.
Thanking you again, we remain
Yours respectfully
/3/
H. L. Pankalla
71
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EOLA RANCH, Independence, Oregon
August 21st, 1940.
Dr. Don C. Mote,
c/o Oregon Agricultural College
Corvallis, Oregon
Dear Dr. Motes-
We wish to express our appreciation to you and to Dr. Morrison
for the very thorough experiments you have made this summer with the
D.N. dust in the control of red spider in hops.
Today we had an opportunity to examine leaves which had been
dusted on a check plot in one of our yards and found more dead mites than
we had ever seen after using wet sprays or any of the dusting sulphurs.
As you know, we have tried a great many different combinations of dusting
materials in an effort to control red spider but none of them have been
satisfactory.
Fortunately, there has been a very light infestation of red spider
this season but we have seen several seasons when growers' crops have
been reduced by two or three bales to the acre and the quality of the
crop damaged by red spider. This has cost the growers thousands of
dollars.
We sincerely hope that the experiments can be continued another
We
season in order that growers will be prepared to combat this pest.
believe that within a few years, most growers will use the D.N. dust in
their routine dusting programs, the same as they now use dust or spray
for combating aphis.
Very truly yours,
E. CLAM) NS HOIST CO.
By
DFK
D. F. Kennedy