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12. Adjust Planting and Harvesting Dates
to Control Insects


Adjusting your planting and harvesting dates can sometimes help you avoid certain insect infestations, reducing the need for chemical control. But adjusting planting and harvesting dates can backfire if you don't think it out carefully.

Also, other conditions—such as soil temperature early in the season, rainfall, and tillage method—can sometimes reduce the effectiveness of your timing adjustments. Scouting your fields can help you to determine what pest problems you may have and what conditions exist in your fields.

How Early planting affects insects in corn For corn growers, early planting can decrease the damage by black cutworms and second-generation European corn borers. But it can increase damage by corn rootworm larvae and first-generation European corn borers. If seed germination is delayed by cold, wet soils, early planting can also increase seedcorn beetles, seedcorn maggots, and wireworms.
how late planting affects insects in corn Late planting of corn can increase the damage by black cutworms and second-generation European corn borers, but it can decrease damage by first-generation European corn borers, seedcorn beetles, seedcorn maggots, wireworms, and corn rootworm larvae. Be aware, however, that corn rootworm beetles lay more eggs in late-planted corn.
bean leaf beetle For soybean growers, planting dates have only minor impacts on insect and mite pests of soybeans. But it still helps to note which pests are more common in late plantings of soybeans.
how late planting affects insects in soybeans Late planting of soybeans can decrease the damage by seedcorn maggots and overwintered adult bean leaf beetles. But it can increase pod damage by late-summer infestations of bean leaf beetles, grasshoppers, and stink bugs.
wheat field Wheat growers should adjust their planting dates to avoid infestation by the formidable, but easily avoided, Hessian fly. Hessian fly adults lay eggs in wheat seedlings planted in the autumn. But if you wait until these adult flies have died before planting, you can seed wheat in the autumn without the risk of infestation. Destroying volunteer or set-aside wheat in the late summer is also necessary for Hessian fly control.
alfalfa bale Planting dates have little effect on insect infestations in alfalfa, but harvesting dates can be important. An early first cutting can help, as long as it does not reduce yields. It can reduce alfalfa weevil larvae infestations by exposing the larvae to sunlight, dry conditions, and more predators. Many leafhoppers and their eggs can be removed in the second or third cuttings. But fields should then be scouted within a few days after cutting to determine the number of leafhoppers still in the field.

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