Evaluation of Insect Repellents and Barriers as Methods to Control
Transcript of Evaluation of Insect Repellents and Barriers as Methods to Control
Evaluation of Insect Repellents and Barriers as Methods to Control
Cucumber Mosaic Virus of Bell Peppers
Joe NunezVegetable/Plant Pathology Advisor
UC Cooperative Extension-Kern
Cucumber Mosaic Virus
• CMV has been afflicting peppers in Kern County for 5 years.
• Appears most heavily in the southern end of the county near Mettler.
• Some years worst than others. • The earlier it appears in the season, the
more damage occurs. • Is aphid transmitted.
Control of CMV• Essentially none-remove weeds around field
and reflective mulches
• Plants are treated with imidacloprid as seedlings in greenhouses.
• Imidacloprid treatments continue through season.
• Organic fields treated with biologicals.– Lady bug release– Lacewing, etc
Control of CMV
●Even with insecticide treatments, aphids will probe and transmit the virus before it is killed.
•Must prevent aphids from landing on plants.
2008 Trial
1.Control2.Citronella Oil3.Citronella/Clove/Geranium4.Clove/Rosemary5.Garlic Oil6.Garlic/Citronella7.Floating Row Cover8.Silver Reflective Mulch
2009 & 2010 Trial
1. Control2. Black3. Silver reflective4. Silver5. White6. Green7. Red8. Surround Canopy9. Surround Soil
0
100
200
300
400
500
600
700
800
gram
s
1. Control 2. Black 3. Silverreflective
4. Silver 5. White 6. Green 7. Red 8. SurroundCanopy
9. SurroundSoil
Total Fresh Weight
cdabc
d
abbc
a ab
d cd
2010
0
10
20
30
40
50
60
70
80
gram
s
1. Control 2. Black 3. Silverreflective
4. Silver 5. White 6. Green 7. Red 8. SurroundCanopy
9. SurroundSoil
Total Dry Weight
Series3
cdab
d
abc
a a
d cd
2010
Aphid Trap Counts
0.0
10.0
20.0
30.0
40.0
50.0
60.0
70.0
80.0
3/29/2010
4/5/2010
4/12/2010
4/19/2010
4/26/2010
5/3/2010
5/10/2010
5/17/2010
5/24/2010
5/31/2010
Num
ber o
f Aph
ids
1. Control2. Black3. Silver reflective4. Silver5. White6. Green7. Red8. Surround Canopy9. Surround Soil
2010
0.0
20.0
40.0
60.0
80.0
100.0
120.0
140.0
Num
ber o
f Aph
ids
1. Control 2. Black 3. Silverreflective
4. Silver 5. White 6. Green 7. Red 8. SurroundCanopy
9. SurroundSoil
Total Aphids for Season
a
bcdd d
bccd cd
bcd
2010
Weekly Aphid Counts 2009
0
1
2
3
4
5
6
7
8
4/21/2
0094/2
3/2009
4/25/2
0094/2
7/2009
4/29/2
0095/1
/2009
5/3/20
095/5
/2009
5/7/20
095/9
/2009
5/11/2
0095/1
3/2009
5/15/2
0095/1
7/2009
5/19/2
0095/2
1/2009
5/23/2
0095/2
5/2009
Num
ber A
phid
s pe
r Tra
p
ControlFloating coverReflective mulchGreen mulchRed MulchBlack MulchSilver MulchSurround/GroundSurround/CanopyWhite Mulch
0
10
20
30
40
50
60
70
80
3/13/2
0083/2
0/2008
3/27/2
0084/3
/2008
4/10/2
0084/1
7/2008
4/24/2
0085/1
/2008
Wee
kly
Aphi
d Co
unt
1. Control
2. Citronella
3. Citronella/CloveOil/Geranium4. Clove oil/Rosemary oil
5. Garlic oil
6. Garlic oil/Citronella oil
7. Floating Row Cover
8. Reflective Mulch
2008 Aphid Counts
Thrip Counts
0.0
500.0
1000.0
1500.0
2000.0
2500.0
3000.0
3500.0
4000.0
3/29/2
010
4/5/20
10
4/12/2
010
4/19/2
010
4/26/2
010
5/3/20
10
5/10/2
010
5/17/2
010
5/24/2
010
5/31/2
010
Num
ber T
hrip
s
1. Control2. Black3. Silver reflective4. Silver5. White6. Green7. Red8. Surround Canopy9. Surround Soil
2010
0.0
1000.0
2000.0
3000.0
4000.0
5000.0
6000.0
7000.0
8000.0
9000.0
10000.0
Num
ber o
f Thr
ips
1. Control 2. Black 3. Silverreflective
4. Silver 5. White 6. Green 7. Red 8. SurroundCanopy
9. SurroundSoil
Total Thrips for Season
bbcde cde de
a
bcd bcdee
bc
2010
Weekly Thrip Counts 2009
0
200
400
600
800
1000
1200
1400
1600
1800
4/21/2
0094/2
3/2009
4/25/2
0094/2
7/2009
4/29/2
0095/1
/2009
5/3/20
095/5
/2009
5/7/20
095/9
/2009
5/11/2
0095/1
3/2009
5/15/2
0095/1
7/2009
5/19/2
0095/2
1/2009
5/23/2
0095/2
5/2009
Num
ber T
hrip
s pe
r Tra
p
ControlFloating CoverReflective MulchGreen MulchRed MulchBlack MulchSilver MulchSurround/GroundSurround/CanopyWhite Mulch
Totals Treatment Market Process Total 1. Control 6.7 abc 3.4 10.1 2. Black 7.4 ab 3.4 10.7 3. Silver Reflective 5.5 c 3.5 9.0 4. Silver 8.4 a 3.6 12.0 5. White 6.5 bc 3.2 9.7 6. Green 7.5 ab 2.9 10.4 7. Red 7.3 ab 3.8 11.1 8. Surround Canopy 5.6 c 3.6 9.2 9. Surround Soil 6.9 abc 3.4 10.3
P= 0.0425 0.9167 0.2145 %CV= 17.31 24.09 15.06 LSDp=0.05 1.737 NS NS
2010 Harvest Data
0
2
4
6
8
10
12
14
Kg
1. Control 2. Black 3. Silverreflective
4. Silver 5. White 6. Green 7. Red 8. SurroundCanopy
9. SurroundSoil
Harvested Weights of 12 plants
ProcessingMarketableabc ab
c
abc ab ab
c abc
BBBB’’ss MMaarrkkeettaabbllee WWtt CCuullll WWtt TToottaall MMaarrkkeettaabbllee WWtt TToottaall PPrroocceessssiinngg WWtt TToottaall WWtt.. 11.. CCoonnttrrooll 11 ..1144 00..1122 1166..6611 BBCC 55..5533 BBCC 2222..1144 BBCC
22.. RRooww CCoovveerr 11 ..1166 00..0000 44..9911 DD 22..6666 CC 77..5588 DD
33.. SSiillvveerr RReefflleeccttiivvee MMuullcchh 11..1111 00..0000 1166..4499 BBCC 44..5566 CC 2211..0044 CC
44.. GGrreeeenn MMuullcchh 00 ..7766 00..4411 1188..2266 AABBCC 99..6633 AABB 2277..8899 AA
55.. RReedd MMuullcchh 00 ..6699 00..7766 2222..6688 AA 66..4499 AABBCC 2299..1166 AA
66.. BBllaacckk MMuullcchh 11 ..1155 00..5599 2200..3333 AABB 55..0099 BBCC 2255..1111 AABBCC
77.. SSiillvveerr MMuullcchh 00 ..6644 00..1100 1188..6600 AABBCC 55..5511 BBCC 2244..1111 AABBCC
88.. SSuurrrroouunndd MMuullcchh 00..5555 00..3333 1155..2200 BBCC 1100..8811 AA 2266..6666 AABB
99.. SSuurrrroouunndd WWhhiitteewwaasshh 00..8877 00..2266 1177..8800 AABBCC 66..7755 AABBCC 2244..5555 AABBCC
1100.. WWhhiittee MMuullcchh 00..9955 00..2266 1144..7733 CC 77..0088 AABBCC 2211..8800 BBCC
PP==00..0055 00 ..55777722 00..22114422 00..00000011 00..00445544 00..00000000 %% CCVV 5566..1111 114466..5599 2211..9933 4488..8811 1166..4477 LLSSDD,, PP==00..0055 NNSS NNSS 55..229999 44..554477 55..551166
2009 Harvest Weights (lbs)
Harvest Dates
06/04/08 06/17/08 06/25/08 Total 1. Control 9.1 lb 28.3 14.7 52.2 ABC 2. Citronella 4.8 21.7 16.0 42.5 CD 3. Citronella/Clove/Geranium 6.0 27.5 16.4 49.9 ABCD 4. Clove/Rosemary 4.4 27.3 17.1 48.9 BCD 5. Garlic Oil 5.7 30.0 18.2 54.0 AB 6. Garlic/Citronella 7.7 23.1 20.1 50.9 ABC 7. Floating Row Cover 6.5 16.1 17.7 40.4 D 8. Reflective Mulch 9.6 26.6 24.1 60.2 A P=0.05 0.2547 0.1434 0.5756 0.0831 %CV= 47.43 27.01 35.38 17.20 LSD, P=0.05 4.702 9.969 9.402 12.625 LSD, P=0.10 10.450
lb lb
2008
Conclusions from 2010 Trial
• All mulches, plastic or kaolin clay, can reduce aphid flights into peppers.
• Silver reflective, Silver & Kaolin clay on canopy reduce thrips populations in plant canopy.
• Silver, Green & Red mulches increase plant growth of peppers.
• CMV was not a problem in 2010
Summary for the 3 year study
• Reducing aphid flights into pepper fields reduces the incidence of CMV.
• Reducing incidence of CMV increases yields.
• Plastic mulches, especially silver reflective, are very effective at reducing aphid and thrips populations in a field.
• Red and Green plastic mulch increase plant size and pepper yields.
Summary for the 3 year study
• Kaolin clay as a mulch may be less expensive, easier, and more environmentally sound method to reducing aphid populations.
• Botanical oils sold as insect repellents are not effective.