Insect
Management
and Pesticide
Evaluations
2012
Silvia I. Rondon
Associate Professor, Extension Entomologist Specialist
Oregon State University
Hermiston Agricultural Research and Extension Center
Irrigated Agricultural Entomology Program
2121 South First Street
Hermiston, Oregon 97838
Email: [email protected]
Phone: (541) 567-8321 ext 108
Cell phone: (541) 314-3181
1 | OSU-HAREC-IAEP (Rondon’s Program)
Chemicals are not being endorsed by Oregon State University. If some of the products
presented in this report are not yet registered for the uses discussed herein their use outside
of an experimental context is therefore illegal
Acknowledgements
Special thanks to Alexzandra F. Murphy, Post-doctoral scholar, OSU-HAREC-IAEP for statistical
analysis
Faculty Research Assistant: Ruben Marchosky, OSU-HAREC-IAEP for field setting and
organization of the crew
Plots preparation and establishment: Tim Weinke and Phil Rogers, OSU-HAREC
Student assistants: OSU-HAREC-IAEP Tanner Keys, Mary Adams, Dale Wilkerson, Jonathan
Macias, Brandy White, Treve Moffit, Abbye McDonough
Cooperating company
Nap-Chem
Brandt Monterrey
MGK
BASF
RMS
Bayer
Chemtura
UPI
Syngenta
Chemtura
Nichino
2 | OSU-HAREC-IAEP (Rondon’s Program)
Potato psyllids control
Zebra chip (ZC) is a destructive disease of potatoes emerging in North America and other parts
of the world. Zebra Chip was first recorded in the Columbia Basin of Washington and Oregon
late in the 2011 growing season. This area produces more than 50% of the potatoes grown in
the United States, so the presence of ZC in the region has the potential to be economically
devastating. The pathogen associated with ZC is the bacterium Candidatus Liberibacter
solanacearum (a.k.a. Ca. L. psyllaurous), vectored to potato by the potato psyllid, Bactericera
cockerelli (Šulc) (Hemiptera: Triozidae). In potatoes, the bacterium affects the phloem tissue,
causing foliar and tuber symptoms. Because these insects are so small, damage to potatoes
frequently occurs before the problem is detected. A number of chemical control options are
available for potato psyllids control but this is the first year that pesticides are being tested in
the field in Oregon.
More information can be found at
http://ir.library.oewgonstate.edu/xmlui/bitstream/handle/1957/30058/pnw633.pedf
3 | OSU-HAREC-IAEP (Rondon’s Program)
Efficacy of selected organic pesticides on potato psyllid control-Part I
Objectives
To compare the efficacy of selected registered and experimental pesticides against the potato
psyllid in Oregon
Plots information
Study location
OSU-HAREC-IAEP, Hermiston, Oregon
Planting date
19 May 2012
Variety
Russet Rangers
Application dates
Two applications were made seven days apart on 25 July 2012 and 2 August 2012.
Environmental conditions at application
Temperature 54.15-92.7070F (7/25); 62.52-89.200F (8/2); full sun, winds calm.
Application equipment
Foliar applications were applied with a tractor-mounted boom sprayer using AI11002VS nozzles
spaced at 20” at 30 psi and a ground speed of 2.5 mph. Chemigation treatment was applied
with a tractor-drawn chemigation simulator. All insecticides were applied in 0.10 acre inch of
water.
Plot characteristics
Plots were 4-rows wide × 30 feet long. The experimental design was a randomized complete
block with 4 replications per treatment. Normal commercial production practices were
followed throughout the season.
Fertilizer
20 March 2012
4 June 2012
11 June 2012
18 June 2012
25 June 2012
2 July 2012
9 July 2012
Pre-plant fertilizer -63N-300P-200K-20S-5Zn-1B
30 N
30 N
30 N
30 N
30 N
40N
Herbicides
4 | OSU-HAREC-IAEP (Rondon’s Program)
12 June 2012
20 June 2012
25 June 2012
4 July 2012
10 July 2012
17 July 2012
24 July 2012
31 July 2012
7 August 2012
14 August 2012
Dithane -1 lb
Echo - 1.5 pts
Dithane -1.5 pts
Echo - 1.5 pts
Dithane -1.5 pts
Echo - 1.5 pts
Dithane -1.5 pts
Echo - 1.5 pts
Dithane -1.5 pts
Echo - 1.5 pts
Treatments
All treatments for foliar application and chemigation are shown in Table 1.
Methods
Sampling started after plant emergence (4 June 2012). Un-baited yellow sticky cards and DVAC
(inverted leaf blower) were used to detect the first occurrence of psyllid adults in the research
plots. Sampling occurred only in the two center rows targeting the middle to the bottom of the
plants. Also, 10 leaves from the center and bottom part of the plants from the central two rows
were sampled. DVAC was used to sample adults, while leaves were sampled to look for psyllid
eggs or nymphs. No action threshold exists for psyllids in potato, thus the action threshold was
detection of potato psyllids at any life stage. As season progressed, and plants started showing
typical ZC symptoms, plants were selected for PCR analysis to confirm the disease (Crosslin, JM.,
H Lin, JE Munyaneza. 2011. Detection of “Candidatus Liberibacter solanacearum” in the potato
psyllid by conventional and real-time PCR. Southwestern Entomologist 36(2): 125-135).
Data analyses
Data were analyzed by using a randomized block ANOVA of arthropod densities followed by
Tukey’s multiple comparisons (p < 0.05). All data was transformed using Box-Cox or Johnson
transformations prior to analysis because normality assumptions were not satisfied with the
original data. If data failed to meet the necessary assumptions, a Kruskal-Wallis was used as an
alternative to ANOVA. Samples of adults (DVAC samples) or nymphs and eggs (leaf samples)
were analyzed separately. Each sampling date, following insecticide treatments, was also
analyzed separately. The mean psyllid numbers for Azera foliar and Azera chemigation from 1, 8
and 15 August were pooled and compared as appropriate using a two-sample t-test after
transformation with a Box-Cox transformation. If normality assumptions were not met a MannWhitney was used in place of a t-test. Comparisons were made for adults, nymphs, eggs, and
total psyllids. All analyses were performed using Minitab 16.2.1.
Results and discussion
No phytotoxicity was noted.
Seasonal trends
5 | OSU-HAREC-IAEP (Rondon’s Program)
Potato psyllid populations increased as the season progressed, with the highest populations
building toward the end of the season (Fig. 1).
Seven days after first application (1 August)
The results for psyllid adults, nymphs, and eggs seven days after first application are shown in
Table 2. Mean number of adult psyllids, nymphs and eggs were not significantly different
among treatments a week after application. Numbers of adults were greater than nymphs and
eggs at this time of the season. The greatest difference was observed analyzing the adult data.
The lowest numbers of psyllid adults were observed in the Agri-Trap and Azera foliar
treatments. The greatest numbers of adults compared to the control were observed in the
Azera chemigation treatment, followed by the Fast Trac EC treatment. The lowest numbers of
psyllid nymphs were observed in the Pyganic + Tri-Tek oil, Fast Trac EC and the standard
Leverage. The greatest numbers of nymphs compared to the control were observed in the Agritrap treatment.
Seven days after second application (8 August)
The results for psyllid adults, nymphs, and eggs seven days after second application are shown
in Table 3. There were no significant differences among treatments for psyllid adults, nymphs,
or eggs. However, mean adult psyllids were lowest in the Agri-Trap treatment when compared
to the control. The lowest mean numbers of nymphs were observed in the Fast Trac EC and
Leverage treatments when compared to the control. The highest mean number of eggs was
observed in the Azera chemigation treatment, even though this treatment had lower numbers
of nymphs. Numbers of potato psyllids eggs on this trial were too low for statistical
comparisons.
Fourteen days after second application (15 August)
The results for psyllid adults, nymphs, and eggs fourteen days after second application are
shown in Table 4. There were no significant differences between treatments for psyllid adults
nymphs, or eggs. However, the mean number of adult psyllids was low in the Azera foliar
treatment, followed by the Azera chemigation treatment. Pyganic + Tri-Tek oil and Azera
chemigation had the lowest (zero) psyllid nymphs compared to the control while Azera foliar
had the highest nymph counts. Egg counts in the Pyganic + Tri-Tec oil, Leverage and Azera
chemigation treatments were relatively low compared to the other treatments. The highest
number of eggs was observed in the Agri-trap treatment.
Foliar and Chemigation application of Azera
There were no significant differences between application methods based on psyllid adults,
nymphs, eggs or total psyllids. However, there was almost a tenfold difference between the
mean number of potato psyllid nymphs found in foliar applications compared to chemigation.
Conclusions
 Psyllids in the entire region increased as season progressed.
 In experimental plots, high number of psyllids (adults, nymphs and eggs) was present in
control plots by the end of the season. Less than 1% were positive for Liberibacter.
6 | OSU-HAREC-IAEP (Rondon’s Program)






Growers in the region were proactively spraying fields to control psyllids throughout the
season. It was decided to terminate plots when psyllid counts in control plots were high.
This decision was reached in order to reduce the risk of psyllid infestation in the area.
Although there were no significant differences among treatments seven days after first
treatment, low mean numbers of potato psyllid adults were observed in the Agri-Trap
and Azera foliar treatment as compared to the other treatments. After a second
application, Agri-Trap lost its residual effect. After fourteen days of application, only the
Azera treatment had a slightly better residual effect.
Azera, which is reported to have multiple modes of action (contact, ingestion and IGR),
should have had a positive effect on all instars of the potato psyllid. However, the foliar
treatment of Azera performed better than the chemigation treatment, controlling
adults; control of potato psyllid eggs and nymphs was inconsistent. The foliar
application appeared to be more effective than using chemigation controlling adults and
eggs but no for nymphs. This experiment should be repeated. Growers in the area rely
on chemigation applications and this data is surprising.
Agri-Trap, responded well controlling nymphs fourteen days after application and a
second application did positively reduce potato psyllid nymphs in the treatment plots.
Agri-Trap did show some activity against adults seven days after treatment, but did not
hold out well at fourteen days. There were some difficulties mixing and handling the
product because precipitation issues.
Pyganic + Tri-Tec oil, a contact insecticide, reduced the number of potato psyllid eggs
and nymphs in treatment plots fourteen days after treatment. It did not appear to have
an effect on adults.
Leverage controlled adults better at fourteen days after treatment than at seven days
after treatment. This data was consistent with other trials where Leverage was used as a
standard. A second application was needed to control adults. On the other hand,
Leverage showed great potato psyllid nymph and egg control.
Fast Trac did not appear to have an effect on psyllid adults, nymphs or eggs as the mean
numbers were consistently higher than the control.
Conclusions
Some of the insecticides tested proved to have a good activity against potato psyllid in the adult
and/or immature stages. Although this was an efficacy trial, this preliminary data suggest
promising “Old” and new chemistry against this pests. Al least one more year data is needed to
make conclusive recommendations in favor or against any of these products.
7 | OSU-HAREC-IAEP (Rondon’s Program)
Table 1. List of treatments, rate, mode of application and total area sprayed.
Treatment
#
1
2
3
4
5
6
7
Product
Untreated Control
Pyganic Acid
Tri-Tek oil
FastTrac EC
Leverage 360
Agri-Trap
Azera
Azera
Rate
(fl oz/a)
18
64 fl oz/100 gal
1.4
2.80
33
32
32
Mode of
Application
Foliar/ground
(tank mix)
Foliar/ground
Foliar/ground
Foliar/ground
Foliar/ground
Chemigation
Total area sprayed
(acres)
0.0312213
0.0312213
0.0312213
0.0312213
0.0312213
0.0312213
Table 2. Mean potato psyllid (±SE) counts seven days after first application of foliar insecticides,
Hermiston, Oregon 2012.*
Treatment
Adults
Nymphs
Eggs
Untreated Control
Pyganic + Tri-Tek oil
Fast Trac EC
Leverage 360
Agri-trap
Azera Foliar
Azera Chemigation
0.00 ± 0.00a
0.25 ± 0.25a
0.50 ± 0.29a
0.25 ± 0.25a
0.00 ± 0.00a
0.00 ± 0.00a
0.75 ± 0.48a
0.00 ± 0.00a
0.00 ± 0.00a
0.00 ± 0.00a
0.00 ± 0.00a
1.00 ± 1.00a
0.25 ± 0.25a
0.25 ± 0.25a
0.00 ± 0.00a
1.00 ± 0.71a
0.00 ± 0.00a
0.00 ± 0.00a
0.00 ± 0.00a
0.00 ± 0.00a
0.00 ± 0.00a
*Adults were sampled with a DVAC and nymphs and eggs were sampled collecting leaves. Means within the same column that share the same
letter are not significantly different.
8 | OSU-HAREC-IAEP (Rondon’s Program)
Table 3. Mean potato psyllid (±SE) counts seven days after the second application of foliar
insecticides, Hermiston, OR 2012.*
Treatment
Adults
Nymphs
Eggs
Untreated Control
Pyganic + Tri-Tek oil
Fast Trac EC
Leverage 360
Agri-trap
Azera Foliar
Azera Chemigation
1.00 ± 0.58a
1.50 ± 0.65a
1.25 ± 0.95a
2.25 ± 1.11a
0.75 ± 0.25a
1.50 ± 0.87a
1.75 ± 0.63a
0.00 ± 0.00a
0.50 ± 0.29a
0.00 ± 0.00a
0.00 ± 0.00a
0.75 ± 0.75a
1.00 ± 0.58a
0.25 ± 0.25a
0.50 ± 0.50a
1.50 ± 0.96a
0.00 ± 0.00a
0.00 ± 0.00a
0.25 ± 0.25a
0.00 ± 0.00a
6.75 ± 6.42a
*Adults were sampled with a DVAC and nymphs and eggs were sampled collecting leaves. Means within the same column that share the same
letter are not significantly different.
Table 4. Mean potato psyllid (±SE) counts fourteen days after the second application of foliar
insecticides*, Hermiston, OR 2012.*
Treatment
Adults
Nymphs
Eggs
Untreated Control
Pyganic + Tri-Tek oil
Fast Trac EC
Leverage 360
Agri-trap
Azera Foliar
Azera Chemigation
5.25 ± 0.85a
5.25 ± 1.38a
7.00 ± 1.68a
7.00 ± 2.12a
6.00 ± 2.04a
2.75 ± 0.48a
3.50 ± 1.32a
0.25 ± 0.25a
0.00 ± 0.00a
0.75 ± 0.48a
0.50 ± 0.29a
0.25 ± 0.25a
2.75 ± 2.14a
0.00 ± 0.00a
0.00 ± 0.00a
0.00 ± 0.00a
3.75 ± 2.17a
0.50 ± 0.29a
4.25 ± 4.25a
1.25 ± 0.75a
0.50 ± 0.50a
*Adults were sampled with a DVAC and nymphs and eggs were sampled collecting leaves. Means within the same column that share the same
letter are not significantly different.
9 | OSU-HAREC-IAEP (Rondon’s Program)
Efficacy of selected pesticides on potato psyllid control-Part II
Objectives
To compare the efficacy of selected registered and experimental pesticides against the potato
psyllid in Oregon.
Plots information (same as in Part I)
Treatments
All treatments received Maxim®4FS in furrow at planting at a rate of 0.08 fl oz/100lbs seed
(Table 1). Maxim®4FS seed treatment fungicide has become the standard in early-season
disease protection against key plant pathogens, including Fusarium and Rhizoctonia.
Methods
Sampling started after plant emergence (4 June 2012). Un-baited yellow sticky cards and DVAC
(inverted leaf blower) were used to detect the first occurrence of psyllid adults in the research
plots. Sampling occurred only in the two center rows targeting the middle to the bottom of the
plants. Also, 10 leaves from the center and bottom part of the plants from the central two rows
were sampled. DVAC was used to sample adults, while leaves were sampled to look for psyllid
eggs or nymphs. No action threshold exists for psyllids in potato, thus the action threshold was
detection of potato psyllids at any life stage. As season progressed, and plants started showing
typical ZC symptoms, plants were selected for PCR analysis to confirm the disease (Crosslin, JM.,
H. Lin, JE Munyaneza. 2011. Detection of “Candidatus Liberibacter solanacearum” in the potato
psyllid by conventional and real-time PCR. Southwestern Entomologist 36(2): 125-135).
Data Analyses
Analyses were performed using randomized block ANOVA of arthropod densities and Least
Significant Differences (LSD) Multiple Range Test (p < 0.05). Samples of adults (DVAC samples)
or nymphs and eggs (leaf samples) were analyzed separately. Each sampling date, following
insecticide treatments, was also analyzed separately. All analyses were performed using JMP
10.
Results
No phytotoxicity was noted.
Seven days after first application (30 July)
The results for psyllid adults, nymphs, and eggs seven days after first application are shown in
Table 2. Mean number of psyllids and nymphs were not significantly different among
treatments. Numbers of nymphs were greater than adults and eggs at this time of the season
and the greatest difference was observed analyzing the nymph data. The lowest number of
psyllid nymphs per sample compared to the control was observed in the Sivanto treatment,
followed by Movento, Rimon, Assail 1.1 oz and Assail 1.7 oz. There were significant differences
among treatments for psyllid eggs. A significantly greater number of eggs compared to the
10 | OSU-HAREC-IAEP (Rondon’s Program)
control were observed in the Rimon treatment; all other treatments were statistically similar to
the control.
Fourteen days after first application (6 August)
The results for psyllid adults, nymphs, and eggs fourteen days after first application are shown
in Table 3. There were no significant differences among treatments for psyllid adults, nymphs,
or eggs. However, mean adult psyllids were lower in the Movento, Sivanto and Rimon
treatments. The lowest mean number of nymphs were observed in the Leverage and Sivanto
treatments when compared to the control.
Seven days after second treatment (13 August)
The results for psyllid adults, nymphs, and eggs seven days after second treatment are shown in
Table 4. There were no significant differences between treatments for psyllid adults or eggs.
However, the mean number of adult psyllids was low in the Movento treatment. Movento and
Leverage had the lowest (zero) psyllid eggs compared to the control. There were significant
differences for the mean number of psyllid nymphs per sample. Nymph counts in the Movento,
Leverage and Sivanto treatments were low compared to the control. The highest number of
nymphs was observed in the Assail (1.7oz) treatments.
No further data was collected beyond this point since psyllid numbers were increasing
tremendously in the experimental plots and there were concerns about the spread of the issue
in the region. Experimental plots for this efficacy trial were immediately terminated.
Discussion
 Psyllids in the entire region increased as season progressed.
 In experimental plots, high number of psyllids (adults, nymphs and eggs) was present in
control plots. Less than 1% of psyllids tested were positive for Liberibacter however, at
least 20% percentage of plants in control plots showed classic ZC. Few tubers rated on
this trial (Texas 1-3- scale) confirmed this observation. Growers in the region were
proactively spraying fields to control psyllids throughout the season. It was decided to
terminate plots when psyllid counts in control plots were high. This decision was
reached in order to reduce the risk of psyllid infestation in the area.
 Although there were no significant differences among treatments seven days after first
treatment, low mean numbers of potato psyllid nymphs were observed in the Sivanto
treatment as compared to the other treatments. Low mean numbers of potato psyllid
nymphs in the Rimon, Movento, Assail (low and high) rate treatments were also
observed.
 The residual effect of Sivanto, Rimon, Movento and Leverage treatments on nymphs
was observed at fourteen days after first application.
 Sivanto, that affects the insect central nervous system, performed well controlling
nymphs seven and fourteen days after first application. It also performed well
controlling adults. Results of the application of Movento were comparable to the results
of the Sivanto treatment for controling adults.
11 | OSU-HAREC-IAEP (Rondon’s Program)




Rimon responded well controlling nymphs seven days after application. It did not hold
out well beyond fourteen days after application. A second application at fourteen day
did positively reduce potato psyllid nymphs in the treatment plots. Since Rimon acts by
inhibiting chitin formation, it was not expected to affect adults. Table 3 shows the
positive effect of Rimon controlling psyllid eggs.
Oberon, an insecticide/miticide, reduced the number of potato psyllid eggs and nymphs
in treatment plots fourteen days after treatment. As expected, it did not have an effect
on adults.
Leverage, controlled adults at seven days after treatment better than at fourteen days
after treatment. A second application was needed to control adults. On the other hand,
Leverage showed great potato psyllid nymph and egg control only after the second
application.
Assail, a systemic and translaminar neonicotinoid, treats both the leaf surface and the
underside of the leaf, and should have had a good effect on psyllids, however,
performed best controlling nymphs fourteen days after treatment at a lower rate. Assail
at a higher rate (1.7oz) was outperformed by Assail at a lower rate (1.10oz).
Conclusions
Some of the insecticides tested proved to have good activity against potato psyllids in the adult
and/or immature stages. Although this was an efficacy trial, this preliminary data suggest
promising “old” and new chemistry against this pest. At least one more year data is needed to
make conclusive recommendations in favor or against any on these products.
12 | OSU-HAREC-IAEP (Rondon’s Program)
Table 1. List of treatments, rate, mode of application and total area sprayed.
Treatment
#
1
2
3
4
5
6
7
8
Product
Untreated Control
Movento
Oberon 4
Leverage 360
Sivanto
Rimon
Assail
Assail
Rate
(fl oz/a)
5.00
8.00
2.80
14.00
12.00
1.10
1.70
Mode of
Application
Foliar/ground
Foliar/ground
Foliar/ground
Foliar/ground
Foliar/ground
Foliar/ground
Foliar/ground
Total area sprayed (acres)
0.0312213
0.0312213
0.0312213
0.0312213
0.0312213
0.0312213
0.0312213
Table 2. Mean potato psyllid (±SE) counts seven days after first application of foliar insecticides,
Hermiston, Oregon 2012.
Treatment
Untreated Control
Movento
Oberon 4
Leverage 360
Sivanto
Rimon
Assail (1.10 oz)
Assail (1.70 oz)
Adults
0.25 ± 0.25a
0.00 ± 0.00a
0.00 ± 0.00a
0.25 ± 0.25a
0.25 ± 0.25a
0.00 ± 0.00a
0.50 ± 0.29a
0.00 ± 0.00a
Nymphs
5.00 ± 3.08a
1.00 ± 0.58a
4.00 ± 3.34a
4.00 ± 2.27a
0.25 ± 0.25a
1.25 ± 0.63a
1.00 ± 1.00a
1.50 ± 1.50a
Eggs
0.50 ± 0.29c
1.00 ± 0.41bc
1.75 ± 0.75abc
0.50 ± 0.29c
0.00 ± 0.00c
3.50 ± 1.44a
0.50 ± 0.29c
0.75 ± 0.48c
*Adults were sampled with a DVAC and nymphs and eggs were sampled collecting leaves.
Means within the same column that share the same letter are not significantly different.
13 | OSU-HAREC-IAEP (Rondon’s Program)
Table 3. Mean potato psyllid (±SE) counts fourteen days after the first application of foliar
insecticides, Hermiston, OR 2012.
Treatment
Untreated Control
Movento
Oberon 4
Leverage 360
Sivanto
Rimon
Assail (1.10 oz)
Assail (1.70 oz)
Adults
4.50 ± 2.63a
0.75 ± 0.48a
2.00 ± 1.15a
1.00 ± 1.00a
0.75 ± 0.25a
0.75 ± 0.48a
1.75 ± 0.75a
2.00 ± 0.71a
Nymphs
5.00 ± 3.72a
1.25 ± 0.75a
1.25 ± 0.95a
0.50 ± 0.29a
0.50 ± 0.50a
5.25 ± 3.20a
1.00 ± 0.71a
4.25 ± 2.98a
Eggs
2.50 ± 1.19a
4.25 ± 3.61a
0.25 ± 0.25a
0.25 ± 0.25a
0.25 ± 0.25a
1.25 ± 0.75a
2.00 ± 1.68a
2.00 ± 1.08a
*Adults were sampled with a DVAC and nymphs and eggs were sampled collecting leaves.
Means within the same column that share the same letter are not significantly different.
Table 4. Mean potato psyllid (±SE) counts seven days after the second application of foliar
insecticides, Hermiston, OR 2012.
Treatment
Untreated Control
Movento
Oberon 4
Leverage 360
Sivanto
Rimon
Assail (1.10 oz)
Assail (1.70 oz)
Adults
5.75 ± 1.31a
1.75 ± 0.85a
3.50 ± 0.65a
3.75 ± 2.06a
4.50 ± 2.87a
5.25 ± 1.80a
3.75 ± 2.46a
4.50 ± 1.85a
Nymphs
0.50 ± 0.29bcd
0.00 ± 0.00d
0.50 ± 0.29bcd
0.00 ± 0.00d
0.00 ± 0.00d
0.25 ± 0.25 cd
0.25 ± 0.25cd
2.25 ± 0.85a
Eggs
3.25 ± 2.14a
0.00 ± 0.00a
0.25 ± 0.25a
0.00 ± 0.00a
0.25 ± 0.25a
0.25 ± 0.25a
1.25 ± 0.95a
0.50 ± 0.29a
*Adults were sampled with a DVAC and nymphs and eggs were sampled collecting leaves.
Means within the same column that share the same letter are not significantly different.
14 | OSU-HAREC-IAEP (Rondon’s Program)
Efficacy of selected pesticides rotation programs on potato psyllid control and zebra chip
disease incidence – Part III
Objectives
To compare season long chemical control against the potato psyllid in Oregon.
Plots information (same as in Part I and II)
Insecticide Rotation Programs
All programs, EXCEPT program 3, received Maxim 4FS in furrow at planting at a rate of 0.08 fl
oz/100lbs seed (Table 1). All foliar applications were made at a frequency of 7-10 days as
requested by chemical companies otherwise noted (Table 1).
Methods
Sampling started after plant emergence (4 June 2012). Un-baited yellow sticky cards and DVAC
(inverted leaf blower) were used to detect the first occurrence of psyllid adults in the research
plots. Sampling occurred only in the two center rows targeting the middle to the bottom of the
plants. Also, 10 leaves from the center and bottom part of the plants from the central two rows
were sampled. DVAC was used to sample adults, while leaves were sampled to look for psyllid
eggs or nymphs. No action threshold exists for psyllids in potato, thus the action threshold was
detection of potato psyllids at any life stage. As season progressed, and plants started showing
typical ZC symptoms, plants were selected for PCR analysis to confirm the disease (Crosslin, JM.,
H Lin, JE Munyaneza. 2011. Detection of “Candidatus Liberibacter solanacearum” in the potato
psyllid by conventional and real-time PCR. Southwestern Entomologist 36(2): 125-135). Zebra
chip ratings was determined by collecting 100 tubers per plot two weeks after vines were beat
and vine killed. The 0-3 Texas rating scale was used (top and bottom end of each tuber).
Data Analyses. Analyses were performed using randomized block ANOVA of arthropod
densities and Least Significant Differences (LSD) Multiple Range Test (p < 0.05). Samples of
adults (DVAC samples) or nymphs and eggs (leaf samples) were analyzed separately. Each
sampling date, following insecticide treatments, was also analyzed separately. Zebra chip
ratings were analyzed using a one-way ANOVA with treatment as the main factor for each set of
ratings: stolon end and bud end. All analyses were performed using JMP 10.
Results
Phytotoxicity was noted.
Psyllid populations increased as the season progressed, particularly in untreated control plots
(Fig. 1).
Psyllid population on 9 July (one week after first application) was low and not suitable for
trends comparisons or statistical differences. On 16 July and 23 July numbers of psyllids (adults,
eggs and nymphs) were still low in the experimental plots (sentinel plots at the HAREC
suggested that psyllids were colonizing in the area).
15 | OSU-HAREC-IAEP (Rondon’s Program)
Psyllid populations on 30 July
Potato psyllid adults, nymphs, and eggs counts after selected chemical application are shown in
Table 2. There were no significant differences for psyllid adults or nymphs though programs 2
(Movento), 3 (Movento, 4 (Movento), 5 (Rimon) and 7 (Torac 15 EC). However, there were
significant differences for potato psyllid eggs counts. Program 3 (Movento) had significantly
higher numbers of eggs compared to all the other treatments (2.75 ± 1.31 potato psyllid eggs
per plot).
Psyllid populations on 6 August
Potato psyllid adults, nymphs, and eggs counts after selected chemical application are shown in
Table 3. There were no significant differences for potato psyllid adults, nymphs, or eggs.
However, programs 2 (Beleaf), had the lowest numbers of psyllids (eggs, nymphs and adults)
compared to the control. Programs 5 (no application) presented low mean number of potato
psyllid adults and eggs compared to the control; a week earlier that plot was sprayed with
Rimon. Program 7 (Torac 15 EC) also showed low mean number of potato psyllid adults and
eggs compared to the control.
Psyllid populations on 13 August
Potato psyllid adults, nymphs, and eggs counts after selected chemical application are shown in
Table 4. There were no significant differences for psyllid adults or eggs. Programs 4 (Fulfill) and
7 (Torac 15 EC) had the lowest number of psyllid adults compared to the control. Programs 2
(Beleaf) and 6 (No application) had the lowest numbers of eggs compared to the control;
program 6 was previously sprayed with Torac 15 EC. There were significant differences between
programs for potato psyllid nymph counts. Program 6 (no application) had significantly lower
numbers of nymphs compare to program 2 (Beleaf) and 3 (Fulfill). Programs 6 (no application)
and 7 (Torac 15 EC) also showed low numbers of potato psyllid nymphs compared to other
programs.
Psyllid populations on 20 and 23 of August
Potato psyllid adults, nymphs, and eggs counts after selected chemical application are shown in
Table 5. There were no significant differences between treatments for psyllid adults, nymphs,
or eggs. Program 4 (Rimon) had the lowest mean number of psyllid adults. Programs 6 (no
application) and 7 (Torac 15 EC) had low numbers of potato psyllid nymphs. Programs 2
(Oberon) and 6 (no application) had lower numbers of psyllids eggs.
Psyllid populations on 27 August
Potato psyllid adults, nymphs, and eggs counts after selected chemical application are shown in
Table 6. There were no significant differences between treatments for psyllid adults, nymphs,
or eggs. Program 4 (Rimon) had the lowest mean number of psyllid adults. Programs 4 (Rimon)
and 7 (Torac 15 EC) had the lowest numbers of potato psyllid nymphs as compared to the other
treatments. Programs 2 (Oberon), 4 (Rimon), and 7 (Torac 15 EC) performed well regarding
potato psyllid eggs counts, although no significant.
Psyllid populations on 4 September
16 | OSU-HAREC-IAEP (Rondon’s Program)
Potato psyllid adults, nymphs, and eggs counts after selected chemical application are shown in
Table 7. There were significant differences between treatments for psyllid adults and nymphs.
Programs 3 (Warrior) and 4 (Warrior) had significantly lower numbers of psyllid adults
compared to the control. Programs 7 (no application) and 4 (Warrior) had significantly lower
numbers of potato psyllid nymphs compared to the control. There were no significant
differences for psyllid eggs, though both programs 3 (Warrior) and 4 (Warrior) had lower
numbers compared to the control ant Program 7 (no application).
Zebra chip ratings
The results for the ZC ratings are shown in Table 8. There were significant differences for ZC
rating on the solon end and on the bud end of the tuber. Based on ratings on the stolon end,
Program 4 performed significantly better than that control and most of the other programs.
Program 4, with the lowest ZC ratings, was followed by Programs 5 and 2. In program 7 ZC
rating was significantly higher than the control, followed by Program 6. Based on ZC ratings for
the bud end, Program 7 had significantly higher ZC ratings compared to the control and all the
other programs. While differences were not significant, for bud end rating, programs 4, 5, and 2
presented the lowest mean.
Conclusions
 Psyllids in the entire region increased as season progressed.
 In experimental plots, high numbers of psyllids (adults, nymphs and eggs) were present
in control plots. Less than 1% were positive for Liberibacter. Growers in the region were
proactively spraying fields to control psyllids throughout the season. It was decided to
terminate plots when psyllid counts in control plots were high. This decision was
reached in order to reduce the risk of psyllid infestation in the area. The long season
programs were kept until the end.
 On 30 July, only potato psyllid egg counts showed significant differences. Program 3
(Movento) had significantly higher numbers of eggs compared to the other programs.
 On 13 August, though not significant, programs 4 (Fulfill) and 7 (Torac EC) presented the
lowest numbers of potato psyllid adults.
 On 4 September, programs 3 (Warrior) and 4 (Warrior) had significantly lower numbers
of adults compared to the control. A similar trend was seen with potato psyllid eggs.
Program 4 (Warrior) presented significantly lower numbers of potato psyllid nymphs
compared to the control.
 The most accurate assessment of each rotational program is determined by ZC ratings.
 Previous research at the HAREC showed that there are differences in ratings between
the stolon and bud end of the potato tubers. Stolon ends tend to present at the
beginning a higher ZC rate. As season progresses, the bacteria “moves” throughout the
tuber reaching the bud end.
 Based on ZC ratings of the stolon end, program 4 performed significantly better than the
control, and several of the other programs. Programs 2 and 5 also presented relatively
low ratings. Programs 6 and 7 performed under performed. This was expected since
several frequency of application was 14 days or longer.
17 | OSU-HAREC-IAEP (Rondon’s Program)






Program 2 consistently maintained low numbers of psyllids, mainly nymphs and eggs. ZC
ratings support these finding, as program 2 achieved lower mean ratings for both the
stolon and bud ends.
Program 3 maintained only moderate to poor psyllid control through a majority of the
study. Better control was achieved following the application of Warrior at the end of the
season. Zebra chip ratings support this trend, as mean ratings were comparable to the
control for the stolon end, and higher than the control for the bud end.
Program 4 maintained psyllid populations at low, sometimes significantly low, levels,
particularly for adults. This program also had the lowest mean ZC ratings for the stolon
end and low ratings for the stolon end. This program consistently performed well.
Program 5 supplied variable low-moderate control of psyllid populations. At times
psyllid populations were relatively high. However, ZC ratings of the bud and stolon end
were relatively low compared to the control.
Program 6 also supplied variable low to moderate control of psyllid populations through
the season. Most of the time, this program maintained populations lower than the
control. However, the ZC ratings for the stolon end were relatively high, as were the
ratings for the bud end.
Program 7 maintained lower psyllid populations early in the season, but control
appeared to fail later in the season since frequency of application was 14 days or longer.
Conclusions
Some of the insecticides tested proved to have a good activity against potato psyllid in the adult
and/or immature stages. Preliminary data suggest promising rotations against the potato
psyllid. Al least one more year data is needed to make conclusive recommendations in favor of
any of these rotations. Products should be tested in well thought out rotation schemes.
18 | OSU-HAREC-IAEP (Rondon’s Program)
Table 1. Long season control rotation programs for potato psyllids, Hermiston, Oregon 2012.
Program
Date(s) of
treatment
Product
Rate
(fl oz/a)
Mode of
application
Untreated Control
-
-
2 July
9 July
16 July
23 July
31 July
6 August
13 August
20 August
Platinum
Fullfill
Fullfill
Movento
Movento
Beleaf
Beleaf
Oberon 4
Oberon 4
2.67
5.5
5.5
5
5
2
2
8
8
In furrow at planting
Foliar/ground
Foliar/ground
Foliar/ground
Foliar/ground
Foliar/ground
Foliar/ground
Foliar/ground
Foliar/ground
2 July
9 July
16 July
23 July
31 July
6 August
13 August
20 August
27 August
Cruiser Max
Agrimek + NIS
Agrimek + NIS
Movento
Movento
Fullfill
Fullfill
Rimon
Rimon
Warrior
0.3
16
16
5
5
5.5
5.5
12
12
1.92
Seed treatment
Foliar/ground
Foliar/ground
Foliar/ground
Foliar/ground
Foliar/ground
Foliar/ground
Foliar/ground
Foliar/ground
Foliar/ground
2 July
9 July
16 July
23 July
31 July
6 August
13 August
20 August
27 August
Platinum 75 SG
Agrimek + NIS
Agrimek + NIS
Movento
Movento
Fullfill
Fullfill
Rimon
Rimon
Warrior
2.67
16
16
5
5
5.5
5.5
12
12
1.92
In furrow at planting
Foliar/ground
Foliar/ground
Foliar/ground
Foliar/ground
Foliar/ground
Foliar/ground
Foliar/ground
Foliar/ground
Foliar/ground
2 July
9 July
16 July
23 July
6 August
13 August
Agrimek + NIS
Movento
Movento
Rimon
Rimon
Warrior
16
5
5
12
12
1.92
Foliar/ground
Foliar/ground
Foliar/ground
Foliar/ground
Foliar/ground
Foliar/ground
1
2
3
4
5
6
19 | OSU-HAREC-IAEP (Rondon’s Program)
2 July
9 July
16 July
31 July
Admire Pro
Torac 15 EC + adj
Movento + adj
Movento + adj
Torac 15 EC + adj
8.7
24
5
5
24
In furrow at planting
Foliar/ground
Foliar/ground
Foliar/ground
Foliar/ground
2 July
9 July
16 July
23 July
31 July
6 August
13 August
20 August
Admire Pro
Torac 15 EC + adj
Torac 15 EC + adj
Torac 15 EC + adj
Torac 15 EC + adj
Torac 15 EC + adj
Torac 15 EC + adj
Torac 15 EC + adj
Torac 15 EC + adj
8.7
24
24
24
24
24
24
24
24
In furrow at planting
Foliar/ground
Foliar/ground
Foliar/ground
Foliar/ground
Foliar/ground
Foliar/ground
Foliar/ground
Foliar/ground
7
20 | OSU-HAREC-IAEP (Rondon’s Program)
Table 2. Mean potato psyllids (±SE) counts on July 30, Hermiston, Oregon 2012.
Treatment #
1
2
3
4
5
6
Treatment
Untreated Control
Movento
Movento
Movento
Rimon
Adults
0.25 ± 0.25a
0.00 ± 0.00a
0.25 ± 0.25a
0.5 ± 0.29a
0.5 ± 0.29a
Nymphs
5.00 ± 3.08a
0.00 ± 0.00a
1.00 ± 0.71a
0.75 ± 0.75a
1.00 ± 0.41a
Eggs
0.50 ± 0.29b
1.50 ± 0.65b
2.75 ± 1.31a
0.50 ± 0.29b
0.50 ± 0.50b
No application
0.00 ± 0.00a
1.00 ± 0.58a
0.75 ± 0.48b
7
Torac 15 EC
0.00 ± 0.00a
0.00 ± 0.00a
0.25 ± 0.25b
*Samples consist of either DVAC samples for adults or leaf samples for nymphs and eggs. Numbers with the same letter within a column are not
significantly different. The foliar insecticide used (July 13) is listed on Table 1.
Table 3. Mean potato psyllids (±SE) counts on 6 August. Hermiston, Oregon 2012.
Treatment #
1
2
3
4
5
6
Treatment
Untreated Control
Beleaf
Fulfill
Fulfill
No application
Adults
4.50 ± 2.63a
0.75 ± 0.25a
1.50 ± 0.65a
2.25 ± 0.48a
0.50 ± 0.50a
Nymphs
5.00 ± 3.72a
0.00 ± 0.00a
1.25 ± 0.48a
0.75 ± 0.48a
2.00 ± 1.22a
Eggs
2.50 ± 1.19a
0.25 ± 0.25a
1.00 ± 0.58a
0.50 ± 0.29a
0.75 ± 0.75a
Torac 15 EC
1.25 ± 0.48a
1.75 ± 1.75a
0.00 ± 0.00a
7
Torac 15 EC
0.75 ± 0.75a
1.00 ± 1.00a
0.75 ± 0.75a
* Samples consist of either DVAC samples for adults or leaf samples for nymphs and eggs. Numbers with the same letter within a column are
not significantly different. The foliar insecticide used (July 31) is listed on Table 1.
21 | OSU-HAREC-IAEP (Rondon’s Program)
Table 4. Mean potato psyllids (±SE) per sample for each treatment on 13 August, Hermiston,
Oregon 2012.
Treatment #
1
2
3
4
5
6
Treatment
Untreated Control
Beleaf
Fulfill
Fulfill
Rimon
Adults
5.75 ± 1.31a
3.50 ± 0.65a
4.00 ± 0.41a
0.75 ± 0.48a
4.00 ± 1.47a
Nymphs
0.50 ± 0.29bcd
1.25 ± 0.63abc
1.50 ± 0.65 abc
0.75 ± 0.48 bcd
0.25 ± 0.25cd
Eggs
3.25 ± 2.14a
0.50 ± 0.50a
1.00 ± 1.00a
0.00 ± 0.00a
1.00 ± 1.00a
No application
2.25 ± 0.48a
0.00 ± 0.00d
0.00 ± 0.00a
7
Torac 15 EC
1.50 ± 0.65a
0.25 ± 0.25cd
0.50 ± 0.50a
* Samples consist of either DVAC samples for adults or leaf samples for nymphs and eggs. Numbers with the same letter within a column are
not significantly different. The foliar insecticide used (6 August) is listed on Table 1.
Table 5. Mean potato psyllids (±SE) on 20 and 23 August, Hermiston, Oregon 2012.
Treatment #
1
Treatment
Adults
Nymphs
Eggs
Untreated Control
4.50 ± 0.87a
6.00 ± 3.19a
8.50 ± 5.32a
2
Oberon 4
5.25 ± 2.29a
2.50 ± 0.96a
6.50 ± 3.12a
3
Rimon
4.50 ± 1.94a
1.50 ± 1.19a
1.75 ± 1.11a
4
Rimon
2.25 ± 1.11a
0.75 ± 0.75a
2.50 ± 2.18a
5
Warrior
No application
Torac 15 EC
6.00 ± 1.47a
3.25 ± 1.38a
1.75 ± 0.63a
5.75 ± 5.42a
0.50 ± 0.50a
0.25 ± 0.25a
9.25 ± 4.03a
2.00 ± 1.00a
4.25 ± 2.25a
6
7
* Samples consist of either DVAC samples for adults or leaf samples for nymphs and eggs. Numbers with the same letter within a column are
not significantly different. The foliar insecticide used is listed on Table 1.
22 | OSU-HAREC-IAEP (Rondon’s Program)
Table 6. Mean potato psyllids (±SE) on 27 August, Hermiston, Oregon 2012.
Treatment #
1
2
3
4
5
6
7
Treatment
Untreated control
Oberon 4
Rimon
Rimon
No application
No application
Adults
12.25 ± 2.39a
14.25 ± 3.12a
15.67 ± 4.18a
11.00 ± 4.51a
-
Nymphs
5.00 ± 2.27a
4.25 ± 1.65a
6.00 ± 5.51a
3.50 ± 0.65a
-
Eggs
7.00 ± 4.85a
5.75 ± 3.54a
12.00 ± 3.61a
5.25 ± 4.27a
-
Torac 15 EC
14.75 ± 4.09a
1.00 ± 0.71a
4.50 ± 0.29a
* Samples consist of either DVAC samples for adults or leaf samples for nymphs and eggs. Numbers with the same letter within a column are
not significantly different. The foliar insecticide used (20 August) is listed on Table 1.
Table 7. Mean psyllids (±SE) per sample for each treatment on 4 September, Hermiston, Oregon
2012.
Treatment #
1
Treatment
Adults
Nymphs
Eggs
Untreated Control
7.25 ± 1.11a
14.75 ± 5.50a
16.25 ± 6.80a
2
No application
-
-
-
3
Warrior
3.00 ± 1.08b
8.00 ± 2.48ab
5.25 ± 2.25a
4
Warrior
3.25 ± 1.31b
2.00 ± 0.41b
5.25 ± 2.36a
5
No application
No application
No application
6.75 ± 1.11a
1.25 ± 0.95b
15.25 ± 7.92a
6
7
* Samples consist of either DVAC samples for adults or leaf samples for nymphs and eggs. Numbers with the same letter within a column are
not significantly different. The foliar insecticide used (27 August) is listed on Table 1.
23 | OSU-HAREC-IAEP (Rondon’s Program)
Table 8. Mean zebra chip ratings (±SE), Hermiston, Oregon 2012. Ratings include one
measurement for the stolon and bud end of 100 potato tubers per treatment (Texas 0-3 scale).
Treatment
Untreated Control
2
3
4
5
6
7
Stolon end
0.244 ± 0.012bc
0.203 ± 0.012cd
0.225 ± 0.015bc
0.163 ± 0.013d
0.206 ± 0.010c
0.261 ± 0.013b
0.330 ± 0.025a
* Numbers with the same letter within a column are not significantly different.
24 | OSU-HAREC-IAEP (Rondon’s Program)
Bud end
0.007 ± 0.002b
0.005 ± 0.004b
0.023 ± 0.009b
0.008 ± 0.005b
0.006 ± 0.002b
0.014 ± 0.004b
0.121 ± 0.020a
Figure 1. Mean potato psyllid counts (±SE) in the control over the season, Hermiston, Oregon
2012.*
* Eggs and nymphs were collected in a sample of 10 leaves/plot. Adults were sampled using a DVAC.
25 | OSU-HAREC-IAEP (Rondon’s Program)
Pictures (Photo credits OSU-HAREC-IAEP Rondon’s Lab)
The potato psyllid (top left, eggs; top right, nymph; bottom left, mature adult; bottom right,
“young” adult)
(Photo credits OSU-HAREC-IAEP Rondon’s Lab, Murphy)
Texas scale (0-3)
(Photo credits OSU-HAREC-IAEP (Rondon’s lab)
26 | OSU-HAREC-IAEP (Rondon’s Program)
Sequence of ZC damage; week 1, purple leaves; week 2, few plants start going down; week 3,
potato plants dead.
(Photo credits OSU-HAREC-IAEP Rondon’s Lab)
Zebra chip disease
(Photo credits OSU-HAREC-IAEP Rondon’s Lab)
27 | OSU-HAREC-IAEP (Rondon’s Program)
Using the DVAC (inverted leaf blower) to collect psyllids
(Photo credits OSU-HAREC-IAEP Rondon’s Lab)
Sticky cards in the efficacy trials
(Photo credits OSU-HAREC-IAEP Rondon’s Lab)
28 | OSU-HAREC-IAEP (Rondon’s Program)
Crew sorting samples in the IAEP lab
(Photo credits OSU-HAREC-IAEP Rondon’s Lab)
IAEP (Rondon’s lab) 2012 crew (psyllid scouts!)
29 | OSU-HAREC-IAEP (Rondon’s Program)
Pictures
(Photo credits OSU-HAREC-IAEP Rondon’s Lab)
30 | OSU-HAREC-IAEP (Rondon’s Program)