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Hybrids with Multiple Traits for ECB and CRW Control

Refuge Options for the Following Products:

Agrisure Viptera 3122, Genuity SmartStax, Optimum Intrasect Xtreme, SmartStax

Refuge Options for Agrisure Viptera 3122, Genuity SmartStax, Optimum Intrasect Xtreme, SmartStax

Specific Criteria:

  • 5% of your total corn acreage must be planted to a non-Bt refuge hybrid
  • Strips must be 2 rows or wider
  • Refuge must be planted within or adjacent to the Bt corn field
  • Bt corn and refuge corn must be planted at the same time so that they are equally attractive to ECB

Further Details:


Many field sizes and configurations will make the ‘whole field’ option impossible and require that a specific block or portion of a field be planted as non-Bt refuge. One potential problem in this arrangement is the possibility of having the 5% non-Bt refuge too far away for rootworm adults to mate with those emerging from the Bt planted area.

Alternating Strips

This is considered the best and most effective option for this type of Bt hybrid. It carries the 5% refuge deeper into the field, helping enable rootworm adults emerging from the Bt hybrid area to mate with those emerging from the refuge strips.  This approach eliminates the need to dump planter boxes and switch hybrids over the course of a field or farm, but it is restricted to planters with individual row hoppers. Each refuge strip must be a MINIMUM OF TWO ROWS wide. DO NOT plant less than two rows of refuge and DO NOT mix Bt and non-Bt seed on-farm. This could allow the larva to travel and feed on both Bt and non-Bt hybrid, thus ingesting an insufficient amount of Bt-toxin and increasing the risk of resistance development


Planting headland areas with non-Bt hybrids is another option. Some quick calculations indicate that depending on the dimensions of the field, headlands of 6 to 8 rows in width can generally meet the 5 per cent requirement on fields up to approximately 60 acres (again, depending on shape).