Dynamic Stink Bug Thresholds

1
Dynamic Stink Bug Thresholds in the Southeast
Conception to Delivery
Bacheler J., P. Roberts, J. Greene, D. Mott,
D. Morrison, J. Ruberson, T. Pegram, D.
Robinson, E. Blinka, J. Van Duyn
NCSU Clemson UGA
2
Stink bug insecticide sprays on cotton Georgia,
1996 - 2006
insecticide sprays
(93)
(81)
(70)
(48)
( Bt cotton)
Source Proceedings Beltwide Cotton Conferences
3
Bollgard vs. conventional cottonstink bug
damage to bolls in NC, 1996 - 2006
stink bug damaged bolls
Year
4
Graduated protection tests 14
o
NC
o
o
o
o
o
o
o
SC
GA
o
o
O 2006 O 2005 O 2004
o
o
o
o
5
Progressive bug protection test diagram
Number of applications / plot
6
Examples of data taken () Number of tests
data taken
Square retention (11) Dirty blooms (13) Beat
cloth samples (13) Cadaver counts (8) Quarter
sized boll internal damage (13) Boll diam. _at_ 3.5
wks. 1, 3, 5 weeks gt anthesis (6) Weekly
profile- total bolls/acre and their size. (13)
Year end boll damage (13) Final adjusted yields
(Microgin) (14)
7
Examples of data taken () Number of tests
data taken
Square retention (11) Dirty blooms (13) Beat
cloth samples (13) Cadaver counts (8) Quarter
sized boll internal damage (13) Boll diam. _at_ 3.5
wks. 1, 3, 5 weeks gt anthesis (6) Weekly
profile- total bolls/acre and their size. (13)
Year end boll damage (13) Final adjusted yields
(Microgin) (14)
8
Examples of data taken () Number of tests
data taken
Square retention (11) Dirty blooms (13) Beat
cloth samples (13) Cadaver counts (8) Quarter
sized boll internal damage (13) Boll diam. _at_ 3.5
wks. 1, 3, 5 weeks gt anthesis (6) Weekly
profile- total bolls/acre and their size. (13)
Year end boll damage (13) Final adjusted yields
(Microgin) (14)
9
Examples of data taken () Number of tests
data taken
Square retention (11) Dirty blooms (13) Beat
cloth samples (13) Cadaver counts (8) Quarter
sized boll internal damage (13) Boll diam. _at_ 3.5
wks. 1, 3, 5 weeks gt anthesis (6) Weekly
profile- total bolls/acre and their size. (13)
Year end boll damage (13) Final adjusted yields
(Microgin) (14)
10
Examples of data taken () Number of tests
data taken
Square retention (11) Dirty blooms (13) Beat
cloth samples (13) Cadaver counts (8) Quarter
sized boll internal damage (13) Boll diam. _at_ 3.5
wks. 1, 3, 5 weeks gt anthesis (6) Weekly
profile- total bolls/acre and their size. (13)
Year end boll damage (13) Final adjusted yields
(Microgin) (14)
11
Examples of data taken () Number of tests
data taken
Square retention (11) Dirty blooms (13) Beat
cloth samples (13) Cadaver counts (8) Quarter
sized boll internal damage (13) Boll diam. _at_ 3.5
wks. 1, 3, 5 weeks gt anthesis (6) Weekly
profile- total bolls/acre and their size. (13)
Year end boll damage (13) Final adjusted yields
(Microgin) (14)
12
Examples of data taken () Number of tests
data taken
Square retention (11) Dirty blooms (13) Beat
cloth samples (13) Cadaver counts (8) Quarter
sized boll internal damage (13) Boll diam. _at_ 3.5
wks. 1, 3, 5 weeks gt anthesis (6) Weekly
profile- total bolls/acre and their size. (13)
Year end boll damage (13) Final adjusted yields
(Microgin) (14)
13
Examples of data taken () Number of tests
data taken
Square retention (11) Dirty blooms (13) Beat
cloth samples (13) Cadaver counts (8) Quarter
sized boll internal damage (13) Boll diam. _at_ 3.5
wks. 1, 3, 5 weeks gt anthesis (6) Weekly
profile- total bolls/acre and their size. (13)
Year end boll damage (13) Final adjusted yields
(Microgin) (14)
14
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Proportion of green, brown and southern green
stink bugs at selected test locations, 2004-2006
Southern Green
Green
Brown
NC 04
NC 05
NC 05
NC 05
NC 05
NC 05
GA 05
SC 06
SC 06
GA 06
GA 06
NC 06
NC 06
17
Seasonal mean number of plant bugs/ 6 row ft. in
check, 2005-2006 (adults nymphs)
of plant bugs / 6 ft.
NC 05
NC 05
NC 05
NC 05
NC 05
GA 05
SC 06
SC 06
GA 06
GA 06
NC 06
NC 06
18
Retention of upper squares means for 1st five
wks of blooming in check, 2005-2006
square retention
NC 05
NC 05
NC 05
NC 05
NC 05
GA 05
SC 06
GA 06
GA 06
NC 06
NC 06
19
Percent dirty blooms means for 1st five wks of
blooming in check, 2004-2006
Average dirty blooms
NC 04
NC 05
NC 05
NC 05
NC 05
NC 05
GA 05
GA 06
GA 06
NC 06
NC 06
SC 06
20
Boll age and size vs. yield loss
3.5 weeks bug-safe (approx. 1.25 diameter)
21
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Percentage of bolls with diameters gt 1.25 inches
per week of blooming, Wayne Co., NC, 2005
bolls gt 1.25
Weeks past 1st bloom
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Percentage of bolls with diameters gt 1.25 inches
per week of blooming, Scotland Co., NC, 2005
bolls gt 1.25
Weeks past 1st bloom
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Percentage of bolls with diameters gt 1.25 inches
per week of blooming, Wayne Co., NC, 2004
bolls gt 1.25
Week of bloom
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Percentage of bolls with diameters gt 1.25 inches
per week of blooming, Barnwell Co., SC, 2006
bolls gt 1.25
Week of bloom
26
Bug damage to bolls extreme variability
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Relationship between bollworm and stink bug
damage to bolls and yield loss in NC (n 10
13 tests)
28
Relationship between stink bug damage to
quarter-sized bolls and yield loss, 2005 - 2006
(Yield difference treated vs. UT)
(479)
(8)
(762)
(-15)
(106)
Union, NC 2005
GA 2005
Wayne, NC 2004
Scot., NC 2006
SC 2006
29
Stink bug damage to bolls vs. yield in Bollgard
II cotton, Wayne Co., 2004
Pounds of lint cotton / acre
y -7.076 x 1870.7 R2 0.895
Boll damage
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Yield change from spray at designated weeks of
bloom, NC GA, 2004 - 2006 (n 14 tests)
62.2
Lb. lint / acre
17.1
15.3
-7.0
-9.2
-21.9
1-2
2-3
3-4
4-5
5-6
6-7
Week of bloom
31
Dynamic threshold rationale
Bolls gt 1.25
Percent boll sizes gt 1.25
1
2
3
4
5
6
7
8
9
Week of bloom
32
Observations

• Significant variability boll damage vs. yield
  loss
• (approx. 1/3 that of bollworm).
• Thresholds may need to be increased during
• initial weeks of blooming.
• Degree of damage to quarter sized bolls may be
• important.
• Green (NC) vs. southern green (GA) species may
• have management implications.
• Results preliminary conclusions only suggestive.

33
Observations

• Significant variability boll damage vs. yield
  loss
• (approx. 1/3 that of bollworm).
• Thresholds may need to be increased during
• initial weeks of blooming.
• Degree of damage to quarter sized bolls may be
• important.
• Green (NC) vs. southern green (GA) species may
• have management implications.
• Results preliminary conclusions only suggestive.

34
Observations

• Significant variability boll damage vs. yield
  loss
• (approx. 1/3 that of bollworm).
• Thresholds may need to be increased during
• initial weeks of blooming.
• Degree of damage to quarter sized bolls may be
• important.
• Green (NC) vs. southern green (GA) species may
• have management implications.
• Results preliminary conclusions only suggestive.

35
Observations

• Significant variability boll damage vs. yield
  loss
• (approx. 1/3 that of bollworm).
• Thresholds may need to be increased during
• initial weeks of blooming.
• Degree of damage to quarter sized bolls may be
• important.
• Green (NC) vs. southern green (GA) species may
• have management implications.
• Results preliminary conclusions only suggestive.

36
Observations

• Significant variability boll damage vs. yield
  loss
• (approx. 1/3 that of bollworm).
• Thresholds may need to be increased during
• initial weeks of blooming.
• Degree of damage to quarter sized bolls may be
• important.
• Green (NC) vs. southern green (GA) species may
• have management implications.
• Results preliminary conclusions only suggestive.

37
Identifying Practical Knowledge and Solutions
for Managing The Sucking-Bug Complex In Cotton
Research In The Southeast Region
Southeast State Support Committees