Attaining good weed control is essential for maintaining maximum yield potential. Weeds are one of the biggest robbers of yield that we have. Left unchecked, weed competition can cause upwards of 50-80% yield reduction. Even getting 90-95% control of weeds can still cause up to 15% yield reduction, especially if weeds are present in the early developmental stages of the crop.
That is why it is important to take a season-long view of weed control. That starts with utilizing spring burndown herbicides, followed by a robust pre-emerge herbicide program. These are just the foundation to season-long control.
Weed control challenges really start when we need to control escaped weeds, or late emerging weeds – prior to crop canopy. These can be the yield robbing weeds.
Challenges include: Herbicide resistant weeds; potential crop damage; lower crop plant populations or sporadic crop stands; adverse weather or soil conditions; weed size, crop size; to name a few.
What is most important is to make sure we reduce competition early in the crop’s life. Once the crop reaches full canopy, the shade will reduce weed emergence, and those later season weeds that do emerge, although they still cause some yield loss, are not nearly as yield robbing as early season weeds.
Finding the right tank mix to control weeds post-emerge requires a good knowledge of the weed species in the field, the level of herbicide resistant weeds, adding the proper adjuvants to increase efficacy, and layering another residual herbicide on the field for extended control. This is not an easy task since we have limited modes of action available.
Your Crop Quest Agronomist can help you navigate all the factors involved for attaining acceptable weed control. Regardless of the crop, it takes a multi-pronged and multi-pass approach for success.
