Stay in Control With Pre-Emergents

Effective control throughout the growing season isn’t too much to ask of your herbicide. But it requires precise, consistent applications on your part. Follow these guidelines for success with pre-emergent herbicides this year.

Choose an herbicide with a long-lasting active ingredient, such as prodiamine, dithiopyr, or oxadiazon. These products provide control for up to 16 weeks. Dithiopyr also provides post-emergent control of crabgrass to the first tiller (fifth leaf) stage of growth. Oxadiazon is generally only used on Bermudagrass; only the granular form can be used on cool-season turf. The established rate recommendations for each of these common pre-emergent herbicides are as follows:

• Prodiamine: 0.65–0.75 lb/acre
• Dithiopyr: 0.25–0.50 lb/acre
• Oxadiazon: 3.0–6.0 lb/acre

Staying within label limits, be sure to apply a sufficient amount of herbicide. The duration of control is directly related to the application rate. The more product you apply, the longer the control will last. 

Split applications are a way to apply higher rates while increasing application safety and minimizing applicator error. Put down the first application at half-rate, then follow it with a repeat application four to six weeks later.

Accurate, uniform application is critical for optimum control. Set rotary spreaders at the right setting and ensure proper spacing for uniform coverage. Also, make sure your application speed is consistent. A difference of just 0.5 mph is equivalent to a 16.7% change in rate.

Lastly, be sure to start your application at the correct time. The first week of April can be used as a target date, but it may need to be sooner or later depending on the weather conditions.

Reach out to your sales representative to plan a pre-emergent program that will give you the control you need this year.