Late Season Herbicide Application

Late planting, lack of pre-emergence herbicide application, slow canopy development, and ample soil moisture have led to many weed infested fields.

Important considerations prior to late season soybean herbicide application:

Restriction of post-emergence herbicide application on soybeans is based on growth stage listed on herbicide labels, crop rotation or, pre-harvest interval.

The growth stage that is most restrictive should be followed.

• (R1) Stage: At least one flower appears on the plant on any node on the main stem.
• (R2) Stage: The plant is beginning full bloom.
• (R3) Stage: When the first pod on one of the four upper nodes reaches 3/16 inch long.
• (R4) Stage: When the plant reaches the full pod stage.

Most post-emergence soybean herbicides have restrictions up to R3 growth stage.