Multiple factors can affect the quality as well as the duration of both prodiamine and dithiopyr applications. Human error aside, irrigation and thatch are two of the biggest reasons for failure. Whether you intend to spread your pre-emergent on a fertilizer carrier or spray it, the use of a quality penetrant will greatly enhance your results.
If you’re going to invest the time to apply control products, the use of Hydro-Pak Command will help to get your chemical to the soil/thatch interface by breaking the surface tension of organic matter.
We have all seen crabgrass pop up on slopes or other areas that we know were treated. Typically, most of the pre-emergent never made it to the soil. Instead, it washed down the slope carried by the hydrophobic thatch. This is a quality that makes thatch useful as roofing material, but a serious hindrance in the turf when applying pre-emergent.
Command as a tank mix partner adds less than $10 an acre to your treatment but greatly increases your chances for success. It should also be used when your grub prevention products are applied to enhance results.
