Cereal rye can help suppress problematic weeds like waterhemp, as well as provide soil health benefits. The question becomes, what is the optimum cereal rye rate to best suppress waterhemp? Beck’s Practical Farm Research (PFR)® conducted studies in 2021 to see what the optimum rate might be. The cereal rye was terminated with crimping or chemical termination the following spring. To evaluate the benefit of a cover crop, no chemical but glyphosate was applied to terminate the cover crop.

SEEDING RATE

Cereal rye was effective on waterhemp, but the seeding rate played a large role in the waterhemp suppression. By increasing the cereal rye rate from 30 lb. to 60 lb./A., the number of waterhemp plants was r educed by 64%. However, increasing from 60 lb. to 90 lb./A. of cereal rye did not increase waterhemp control. Though cereal rye can have soil benefits at 30 lb./A., it should be applied at 60 to 9 0 lb./A. for optimum weed suppression. The cereal rye in this study was planted with a drill; therefore, broadcast rates may be higher for similar results.

CONCLUSION:

For soil conservation, apply at 30 lb./A. For weed control, apply at 60 to 90 lb./A. Increasing the rate from 30 to 60 lb./A. reduced the number of waterhemp plants by 64%. Cereal rye at 90 lb./A. was not enough for full-season weed control; however, cereal rye did significantly decrease the amount of waterhemp. Higher broadcast rates may be needed for similar control. Cereal rye can also help reduce selection pressure on current herbicide technology.