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How to Manage Pests
UC Pest Management Guidelines
Cole Crops
Other Aphids
Scientific Names:
Green peach aphid: Myzus persicae
Turnip aphid: Lipaphis erysimi
(Reviewed 6/07,
updated 6/07)
In this Guideline:
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Several other aphids may occur on cole crops. The most common is the
green peach aphid,
which is a yellow-green aphid with prominent
tubercles at the base of the antennae. None of the other aphids occurring in cole crops
have the waxy coating that characterizes the cabbage aphid. Green peach aphid
and turnip aphid also tend to be more randomly dispersed around the plants than
the dense colonies of the cabbage aphid. The turnip aphid, a species that is a
worldwide foliar aphid pest, occasionally infests the roots of cole crops in
coastal California. These aphids are dark to olive green and unlike other root
aphids, have visible cornicles.
When populations are heavy, green peach aphid can stunt seedlings;
however, economic damage rarely occurs on older plants because green peach
aphids tend to feed on older
leaves and rarely enter heads of broccoli, cauliflower, cabbage, or Brussels sprouts.
Turnip aphids on the roots of cole crops can seriously stunt and even kill
plants.
These aphids rarely require treatment in cole crops. Because they
remain mostly on the older, nonmarketable leaves of cole crops, low-to-moderate
populations can be tolerated on older plants. High numbers of green peach aphid
can kill young seedlings or transplants, so treat infested young plants if they
show stress from feeding by this aphid. The same general predators and
parasites that attach cabbage aphids also attack these aphids.
Biological Control
Many predators and parasites attack aphids, especially in fields that
are not sprayed or sprayed with less toxic materials. These natural enemies,
including general aphid predators and the parasites Lysiphlebus testaceipes, Aphidius matricariae, Aphelinussemiflavus, and Diaeretiella rapae, may
provide adequate control under certain circumstances.
Cultural Control
Remove infested culls and weedy species around fields that may harbor the aphid
between crops. Turnip aphid problems tend to recur in the same fields. Long
term rotation to other crops may be advised.
Organically Acceptable Methods
Biological and cultural controls as well as sprays of insecticidal soap,
which can give partial control of aphids, are organically acceptable methods.
Insecticidal soap sprays, however, may be phytotoxic under some conditions and
rates, especially in Brussels sprouts and cabbage.
Monitoring and Treatment Decisions
No special monitoring is needed for green peach or turnip aphids in cole
crops; keep notes on them as you monitor the cabbage aphid. Treat seedling
plants if they appear to be stressed by aphid populations. Older plants can
tolerate low to moderate populations. If applications are made for cabbage
aphid just before heading, other foliar aphid species will be controlled as
well.
| Common name |
Amount/Acre |
R.E.I.+ |
P.H.I.+ |
| (trade name) |
|
(hours) |
(days) |
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| When choosing a pesticide, consider information relating
to the impact
on natural enemies and honey bees and environmental impact.
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| Note: Resistance to
some insecticides has been reported in some aphid populations. Rotating
pesticide materials with different mode of action group numbers may effectively help slow the development of resistance. |
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| A. |
ACEPHATE |
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(Orthene) 75S |
0.66–1.33 lb |
24 |
14 |
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MODE OF ACTION GROUP NUMBER1: 1B |
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COMMENTS: For Brussels sprouts, cauliflower. |
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| B. |
ACETAMIPRID |
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(Assail) 70WP |
0.8–1.2 oz |
12 |
7 |
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MODE OF ACTION GROUP NUMBER1: 4A |
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COMMENTS: Do not apply more than once every 7 days or make more than 5 applications/season. |
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| C. |
CHLORPYRIFOS |
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(Lorsban) 50W |
2 lb |
24 |
21 |
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MODE OF ACTION GROUP NUMBER1: 1B |
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COMMENTS: For broccoli, Brussels sprouts, cabbage, cauliflower. Avoid drift and tailwater runoff into surface waters. |
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| D. |
DIAZINON* |
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(Diazinon) 50W |
0.5–1 lb |
24 |
see comments |
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(Diazinon) AG 500 |
0.5–1 pt |
24 |
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MODE OF ACTION GROUP NUMBER1: 1B |
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COMMENTS: Avoid drift and tailwater runoff into surface
waters. Preharvest interval is 7 days for broccoli, Brussels sprouts, and cauliflower and 21 days for cabbage. See label for other cole crops. |
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| E. |
DIMETHOATE |
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(Dimethoate) 4EC |
0.5 pt |
48 |
see comments |
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(Dimethoate) 2.67EC |
0.75 pt |
48 |
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MODE OF ACTION GROUP NUMBER1: 1B |
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COMMENTS. Preharvest interval is 7 days for broccoli and cauliflower and 10 days for Brussels sprouts. See label for other cole crops. |
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| F. |
INSECTICIDAL SOAP# |
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(M-Pede) |
1–2% solution |
12 |
0 |
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MODE OF ACTION: A contact fungicide with smothering and barrier effects. |
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COMMENTS: For broccoli, cabbage, cauliflower, Brussels
sprouts. Only partial control. May be phytotoxic on Brussels sprouts and cabbage. |
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| G. |
OXYDEMETON-METHYL* |
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(MSR Spray Concentrate) 2SC |
1.5–2 pt |
48 |
see comments |
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MODE OF ACTION GROUP NUMBER1: 1B |
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COMMENTS: Preharvest interval is 7 days for broccoli, cabbage,
and cauliflower and 10 days for Brussels sprouts. See label for other cole crops. |
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| H. |
PYMETROZINE |
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(Fulfill) |
2.75 oz |
12 |
7 |
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MODE OF ACTION GROUP NUMBER1: 9B |
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COMMENTS: Best used in a tank mix with another insecticide
registered for aphids. Do not apply more than 2 applications/crop/season. Make applications at least 7 days apart. |
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UC IPM Pest Management Guidelines: Cole Crops
UC ANR Publication 3442
Insects
W. E. Chaney, UC Cooperative Extension, Monterey Co.
E. T. Natwick, UC Cooperative Extension, Imperial Co.
Acknowledgments for contributions to the insects section:
W. J. Bentley, UC IPM Program, Kearney Agricultural Center, Parlier
N. C. Toscano, Entomology, UC Riverside
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