Updated May 4, 2006
by Gary Hein and John Thomas
by Gary Hein and John Thomas
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Treatment guidelines based on number of grasshoppers (nymphs and adults) per square yard can be used through the season. Moderate to abundant grasshopper populations can cause considerable damage to headed wheat by clipping the stems resulting in dropped heads. |
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| Grasshopper Population | Within Field | Field Margin | Treat? |
|---|---|---|---|
| Non-Economic | 0 - 2 | 5 - 10 | No |
| Light | 3 - 7 | 11 - 20 | Questionable; depends on size, species, type of crop. |
| Moderate | 8 - 14 | 20 - 40 | Probably |
| Abundant | 15 or more | 41 or more | Yes |
| In the fall, the thresholds above need to be modified for grasshopper control in winter wheat because only a minimal amount of leaf material is available for the grasshoppers to eat. Adult grasshoppers can consume a great deal of plant material in a short time. Due to the low amount of vegetation available and the large size of the grasshoppers, light to moderate infestations in the field and borders can cause stand reduction or loss along borders. | |||
This list is not inclusive. See http://www.greenbook.net
or other resources for additional registrations.
This information is presented in abbreviated form. Be sure to consult the label for additional information and restrictions.
This information is presented in abbreviated form. Be sure to consult the label for additional information and restrictions.
| IRAC Mode of Action Classification: | ||||
|
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| R = Restricted-Use Product | * = Suitable for chemigation | ai = active ingredient | REI = Re-Entry Interval | |
| Mode of Action |
Product Name |
Common Name |
Rate | Restrictions/Comments |
|---|---|---|---|---|
| 1B R | Methyl 4EC | methyl parathion | 0.375 - 0.5 lb ai/A | Do not apply within 15 days of harvest. REI 5 days. |
| 1B | Dimethoate, Dimate |
dimethoate | Up to 0.375 lb ai/A | Do not apply within 35 days of harvest. REI 48 days. |
| 1B R | Di-Syston 15% G | disulfoton | 1.67 oz/1000 ft, Up to 6.7 lb/A |
Apply by drilling or broadcast at planting time. REI 72 hrs. |
| 1B R | Lorsban 4E*, Nufos 4E* |
chlorpyrifos | 0.5 - 1.0 pt/A | Do not apply within 28 days of harvest. REI 24 hrs. |
| 1B | Malathion (Multiple Products) |
malathion | Up to 1.25 lbs ai/A | Do not apply within 7 days of harvest. REI 12 hrs. |
| 3 R | Mustang Max | zeta-cypermethrin | 3.2 - 4.0 oz/A | Do not apply within 14 days of harvest. REI 12 hrs. |
| 1B R | Penncap-M | methyl parathion | 2 - 3 pts/A | Do not apply within 15 days of grazing or harvest. REI 5 days. |
| 3 R | Proaxis | gamma-cyhalothrin | 2.56 - 3.84 oz/A | Do not apply within 30 days of harvest. REI 24 hrs. |
| 3 R | Warrior,* generics |
lambda-cyhalothrin | 2.56 - 3.84 oz/A | Do not apply within 30 days of harvest. REI 24 hrs. |
