Corn Replanting - Herbicide Replant Restrictions

As farmers consider replanting corn, the herbicides already applied may limit the options for replant. The following table is an updated version of the table 8 in AGR-195 Replanting Options for Corn. The table below lists corn herbicides and the potential risk associated with replanting corn, grain sorghum or soybean. This table is not exhaustive, and the herbicide label should be consulted for more details on crop rotation limitations.



Table 1. Risk to crops replanted following use of corn herbicides. (This table is a guideline. Consult the herbicide label for additional details. This table is adapted from AGR-6 2016 Weed Control Recommendations for Kentucky Grain Crops)

Herbicide	Risk Potential and Minimum Waiting Period Before Replanting 1
	Corn	Grain Sorghum	Soybean
Accent [nicosulfuron]	No risk to field corn	High: 10 months; 18 months if soil pH >7.5	Slight: 14 days
Acuron	No risk	High: 10 months	High: 10 months
Anthem Maxx	No risk	High: 11 months	No risk
Anthem ATZ	No risk	High: 18 months	Moderate: some conditions may prohibit planting until after 18 months
Anthem Flex	No risk	High: 18 months	No risk
Armezon	No risk	High:  9 months	High:  9 months
Atrazine	No risk	No risk	Moderate; Slight in river bottom soils following a flood.
Balance Flexx	No risk	High:  6 months	High:  6 months
Bicep II Magnum, Cinch ATZ, etc	No risk	Plant sorghum treated with a seed safener.	Moderate
Callisto; Callisto GT	No risk	No risk	High: 10 months
Callisto Xtra	No risk	No risk	High: 18 months
Capreno	No risk (yellow dent corn); 10 months (white corn, popcorn)	High: 10 months, may be longer with some conditions	High: 10 months
Corvus	No risk	High: 17 months	High: 9 months
Degree Xtra, Harness Xtra, FulTime, Keystone	No risk	Plant sorghum treated with a seed safener	Moderate
Dicamba [Clarity, Banvel, etc.]	No risk	Slight to Moderate: 15 days to 4 months depending on rate.	Slight to Moderate: 15 days to 4 months depending on specific product, use rate, and rainfall.
2,4-D	Slight: 7 days	Slight to Moderate: 3 months	Slight: 7 to 30 days depending on amount used
Expert	No risk	Plant sorghum treated with a seed safener.	Moderate
Glyphosate (Roundup and other products)	No risk	No risk	No risk
Gramoxone [paraquat]	No risk	No risk	No risk
Guardsman Max	No risk	Plant sorghum treated with a seed safener	Moderate
Halex GT	No risk	Plant sorghum treated with a seed safener	High: 10 months
Impact	No risk	High: 9 months	High: 9 months
Laudis	No risk	High: 10 months	High: 8 months
LeadOff	No risk	High: 10 months	Low to Moderate: Replant interval depends on rate applied
Lexar, Lumax	No risk	Moderate to High	High
Liberty (LL-corn only)	No risk	Slight: 6 months	No risk
Permit	Slight: 1 month	Moderate: 2 months	High: 9 months
Princep	No risk	Moderate	High
Prowl	High	High: 10 months	No risk
Realm Q	No risk	High: 10 months	High: 10 months
Resolve Q	No risk	High: 10 months	Slight: 1 month
Sharpen	No risk	No risk	Slight, 2 months with corn use rate; When applied at 1 oz/A rotation interval 0 months.
Spirit	Slight: 1 month	High: 10 months	High: 10 months, STS soybean varieties have more tolerance.
Status	Slight: 7 days	Moderate: 4 months	Moderate to High: 4 months
Steadfast Q	No risk	High: 10 months, wait 18 months if soil pH >7.5.	Slight: 15 days
SureStart, TripleFlexx	No risk	High: 12 months	High: wait until next growing season
Verdict	No risk	No risk	Slight:  Consult label for additional restrictions relative to rate or soil type
Zemax	No risk	No risk	High: wait until next growing season
Zidua	No risk	Moderate to High: wait 6 months when applied at 1 to 2 oz/A; wait 10 months when applied at 3 oz/A	No risk
1 Waiting period is defined as the time between herbicide application and replanting.