Planting Interval of Corn after Previous Year's Soybean Herbicides

Field of soybeans — Figure 1. If a fomesafen-based herbicide (Flexstar/ Flexstar GT/ Marvel/Rumble) was applied in soybean in 2016, maintain 10 months of planting interval to corn this year.

April 21, 2017

Amit Jhala - Extension Weed Management Specialist

Corn-soybean is the most common cropping system in eastern Nebraska. While corn growers are getting ready for planting this season, it is important to pay attention to the planting interval of herbicides applied the previous year in soybean.

Certain soybean herbicides have relatively longer planting intervals for corn, especially if they are applied post-emergence in soybean. This is particularly important because soybean planting was late last year in much of Nebraska due to May rains. This caused post-emergence herbicides to be applied later in the season than they might normally be, making it important that you pay attention to the planting interval.

For example, herbicides with fomesafen (Flexstar/Rumble/Marvel/Flexstar GT) have 10 months of planting interval for corn. When herbicide tank-mixture is applied, consider the longest planting interval mentioned for any tank-mix partner.

Popcorn and sweet corn are more sensitive to herbicides as compared to field corn; therefore, certain herbicides have a longer planting interval for popcorn/sweet corn. For example, Pursuit has a planting interval of 8.5 months for field and seed corn, but 18 months for popcorn and sweet corn.

Resource

For more information on herbicides and planting intervals, check the latest Guide for Weed, Disease, and Insect Management in Nebraska, available to order from the Nebraska Extension Publications website.

**Table 1. Planting interval (in months) of corn after soybean herbicides applied.**
Soybean Herbicide	Planting Interval Field Corn	Planting Interval Seed Corn	Planting Interval Popcorn	Planting Interval Sweet Corn
Enlite	9	9	9	9 to 18^c
Envive	10	10	10	18
FirstRate	9	9	9^d	18
Flexstar/Rhythm/Rumble	10	10	10	10
Flexstar GT	10	10	10	10
Marvel	10	10	10	10
Pursuit	8.5	8.5	18	18
Raptor	8.5	8.5	8.5	8.5
Reflex	10	10	10	4
Rowel	1	1^a	4 to 18^b	3 to 18^b
Rowel FX/Valor XLT	10	10	10	18
Sonic	10	10	10	18
Torment	10	10	40	18
Trivence	10	10	10	18
Valor	1	12	12	4
Warrant Ultra	10	10	12	12
^a With application of Rowel at 3 oz/ac rate and at least one inch of rainfall/irrigation. Check the label if Rowel is applied at a rate of more than 3 oz/ac. ^b Planting interval changes depending on rate of Rowel applied and tillage practice, check the label. ^c Planting interval changes depending on processing sweet corn variety or other sweet corn variety. Check the label of this herbicide. ^d Verify with seed company (supplier) the safety of herbicide on inbred lines or hybrids.