Control
Solo ADV + Clethodim
Baseline treatment used to compare crop response and yield against increasing metribuzin rates.
2025 Metribuzin Tolerance
CDC 6964 CL, CDC 7757 CL and LCS Rush CL were compared under control, 90, 110 and 160 g/ac metribuzin treatments using early and late field observations, crop tolerance and yield response.
Research Question
How does metribuzin rate affect crop tolerance, weed control and yield response across small green, large green and small red lentil varieties under a high-stress activation environment?
Environmental Conditions
Starting CAW
Precipitation
Total CAW
The 2025 lentil trial was intentionally conducted under a difficult activation scenario. Metribuzin was applied late and was followed one day later by 1.5 inches of rainfall. The environment had 6.45 inches of starting Crop Available Water and 5.70 inches of precipitation for a total of 12.15 inches CAW. This environment was used to expose differences in crop tolerance between varieties and herbicide rates.
Treatments
Metribuzin
90 g/ac
Lowest metribuzin rate in the comparison. This rate provided the strongest yield response in the small green and red lentil types.
Metribuzin
110 g/ac
Intermediate metribuzin rate used to compare tolerance and yield response across varieties.
Metribuzin
160 g/ac
Highest metribuzin rate used to expose crop-tolerance differences. Early injury was observed in some varieties while others showed little or no visible injury.
Results
CDC 6964 CL Response
Weed control improved as metribuzin rate increased. The 160 g/ac treatment showed early crop injury.CDC 7757 CL Response
Weed control improved with increasing metribuzin rate. No visible injury was observed at the 160 g/ac rate.LCS Rush CL Response
Slight crop injury was observed early at 160 g/ac, but later evaluation showed no visible injury.Yield Response
Tolerance differences translated into yield response. The 90 g/ac rate produced the strongest yield response in small green and red lentils, while large green lentils maintained yield at higher rates.Management Implication
Metribuzin tolerance is variety dependent and should be interpreted together with application timing, rainfall and Crop Available Water. The 90 g/ac treatment provided the strongest yield response in the small green and red lentil types, while the large green type maintained yield at higher rates. Higher herbicide rates increased the ability to reveal tolerance differences but did not automatically improve yield.