Scouting time
Cutworm damage to sorghum is infrequent, but growers should be alert when early season cutworm damage has occurred in neighboring cornfields. The crop is at risk in the two weeks after planting, so scout fields during and shortly after emergence.
Sampling method
None listed.
Thresholds
Rescue treatments should be considered if a majority of larvae are less than 1/2-inch long. Worms of this size can destroy four to six plants each before completing development. Older larvae are harder to kill and less is gained by controlling them because they have already caused most of their damage. Consider the amount of stand reduction that can be tolerated before deciding to treat. If the minimum stand density recommended for a particular hybrid under your management program is 40,000 plants per acre and you have 50,000, then you can tolerate a stand reduction of 20 percent before treatment becomes economically justified, assuming losses will be even across the field. If cutworm damage is localized in certain areas, spot treatments applied to affected areas will be more cost effective than treating the whole field.
Chemical control
|
Cutworm Management Options |
|
|
Insecticide |
Rate |
|
Alpha-cypermethrin (Fastac EC) |
1.3 to 3.8 fl. oz./acre |
|
Beta-cyfluthrin (Baythroid XL) |
0.008 to 0.010 lbs. a.i./acre (1.0 to 1.3 fl. oz.) |
|
Chlorpyrifos (numerous products) |
Check label, but generally 1 to 2 pints/acre. |
|
Chlorpyrifos (Saurus) |
8oz./1,000 row ft. - T-band at planting |
|
Chlorpyrifos plus gamma-cyhalothrin (Cobalt Advanced) |
11 to 38 fl. oz. of product/acre |
|
Chlorpyrifos plus zeta-cypermethrin (Stallion) |
3.75 to 11.75 fl. oz./acre |
|
Deltamethrin (Delta Gold) |
0.012 to 0.018 lb. a.i./acre (1 to 1.5 fl. oz.) |
|
Esfenvalerate (Asana XL 0.66) |
0.03 to 0.05 lb. a.i./acre (5.8 to 9.6 fl. oz.) |
|
Gamma-cyhalothrin (Proaxis) |
0.0075 to 0.01 lb. a.i./acre (1.92 to 2.56 fl. oz.) |
|
Lambda-cyhalothrin (numerous products) |
0.015 to 0.02 lb. of a.i./acre |
|
Zeta-cypermethrin (Mustang MAXX, Respect EC, etc.) |
0.008 to 0.025 lb. a.i./acre (1.28 to 4.0 fl. oz.) |
Non-chemical controls
None listed.
Content authors
Disclaimers
This content may not be suitable for states other than Kansas.