Weed Free Period - Parrish and Heimbecker, Limited

Understanding the Critical Weed Free Period

In weed control, timing — is everything

Like so many aspects of agriculture, the difference between good results and great results for in-crop weed control often comes down to timing. “The critical weed free period” is a specific window in crop development when plants are most susceptible to weed competition for light, water and nutrients. Keeping crops free of weeds during this period can be crucial to maximizing yield potential at harvest.

Critical weed free periods

Each crop varies in its respective critical weed free timing:

  • Spring Cereals: 1 to 3 leaf stage
  • Corn: V3 to V8 (3 to 8 leaf stage)
  • Soybeans: V1 to V3 (1st to 3rd trifoliate)
  • Forages: 4 to 6 weeks after planting
  • Pulses: 2 to 6 leaf stage

 

Choosing the right pre-emergent herbicide

There are a number of herbicide choices that can be used to maintain the critical weed free period for each crop, including options that also offer residual control. Integrated weed management is an important part of maximizing your crop’s success, but with the right strategy, the right herbicide program and the right timing, effective control can be achieved and maintained.


Visit your local retailer and talk to your P&H Representative for more information on the critical weed free period.

P&H is your top choice for effective herbicide strategies, and our team of experts is always ready to help you develop a customized approach that is right for your crop plan and growing conditions.