The call of the last 10 days continues to be concerns on fomesafen carryover in corn. I had an opportunity to walk a number of these fields this week. The corn was showing the characteristic corn leaf vein chlorosis (picture right) caused by fomesafen carryover. It is not a real surprise as it is well known that fomesafen applied within 10 months of corn planting can carry over into corn. This has not happened often over the last several years because the summers/falls were wet compared to 2011. Wet soils will readily break down fomesafen. Another reason this has not happened in the last several years is due to the wet springs which forced later corn planting dates.
Fortunately, most of the corn fields I visited were recovering well from the fomesafen injury. The new growth from the whorl was showing a healthy green color. Even though most of the corn was recovering, there were hot spots in some of these fields where the fomesafen was obviously doubled (picture lower right).
The corn stand in these areas was greatly reduced, by as much as 70% in some cases. Despite some of these hot spots the corn stand in these fields were keepers and would not be replanted.
All of this points out that in this new world of weed control we have to be mindful of herbicide application dates and that relationship to next year’s crop. This is particularly true for June and July applications of herbicides like fomesafen that can be persistent enough to be an issue in corn or grain sorghum the next year.