This proposed research will take the next step in understanding weed management in early-planted soybean by investigating soybean injury potential from several commercially-available PRE herbicides.

Field research will be conducted for two growing seasons at the Crop Sciences Research and Education Center. Treatments will include 12 commercially-available herbicide premixes that span 10 herbicide active ingredients encompassing five site-of-action groups. Each herbicide will be applied at its respective 1x rate according to label directions for soil type and organic matter content. All treatments will be applied immediately after soybean planting in late March or early April each season. The experiment will be located on an area with an historically low weed density to reduce a potentially confounding effect on soybean yield. A nontreated control will be included for comparison. Data to be collected includes:
1) Soil temperature at planting
2) Days until soybean emergence
3) Visual assessment of soybean injury (multiple assessments throughout the season)
4) Soybean stand counts (counts early-, mid-, and late-season)
5) Soybean plant height
6) Soybean yield

Herbicides to be evaluated (1x rate according to soil type and organic matter content)
Product Active Ingredients
Authority Edge pyroxasulfone + sulfentrazone
Authority First cloransulam + sulfentrazone
Boundary S-metolachlor + metribuzin
Broadaxe SC S-metolachlor + sulfentrazone
Fierce EZ pyroxasulfone + flumioxazin
Kyber pyroxasulfone + flumioxazin + metribuzin
Moccasin MTZ S-metolachlor + metribuzin
Preview 2.1SC metribuzin + sulfentrazone
Tendovo S-metolachlor + metribuzin + cloransulam
Tripzin ZC pendimethalin + metribuzin
Zidua Pro pyroxasulfone + imazethapyr + saflufenacil
Prefix fomesafen + S-metolachlor

Active ingredients evaluated (10):
pyroxasulfone
sulfentrazone
cloransulam
S-metolachlor
metribuzin
flumioxazin
pendimethalin
imazethapyr
saflufenacil
fomesafen

This research will generate data necessary to formulate herbicide-specific recommendations in very early-planted soybean. Treatments in our previous experiment were designed more to test research concepts than individual product performance against weeds. This research will build upon our experiences with early-planted soybean and provide us with the ability to make research-based herbicide recommendations that minimize the potential for soybean injury. The experience gained from this research project will guide future research in very early-planted soybean, such as including a cover crop, soybean row spacing for optimal weed control, etc.

Results of this research will better inform soybean producers about which herbicides or herbicide classes they might want to avoid in early-planted soybean scenarios.