General Information


This product is not recommended for use by homeowners.

Note: In the state of New York, this product may be applied only by commercial applicators.

For control of crabgrass and other annual grasses and broadleaf weeds,

use Quali-Pro Dithiopyr 40 WSB specialty herbicide in the following sites:

- established lawns

- commercial sod farms

- non cropland and industrial sites

- ornamental turf (including golf course fairways, roughs, tee boxes)

- landscape ornamentals, field grown and container nursery ornamentals. Quali-Pro Dithiopyr 40 WSB only controls crabgrass up to initiation of tillering, that is, when seedlings are first visible in established turfgrasses. Quali- Pro Dithiopyr 40 WSB will not control emerged weeds. For optimum effectiveness, apply Quali-Pro Dithiopyr 40 WSB prior to initiation of tillering, and make all other applications before germination of target weeds.

Quali-Pro Dithiopyr 40 WSB must be activated to be effective. Activation is achieved by watering-in from rainfall or irrigation (1/2 inch or more). Time applications to ensure that activation occurs before the tillering stage of crabgrass development or prior to germination of all other weeds.

Limitations, Restrictions, and Exceptions

SOUTH STATES (Program 1)

14,520: sq ft per water-soluble pouch per treatment

Control of Crabgrass

Preemergence and Early Postemergence Control

Quali-Pro Dithiopyr 40 WSB controls crabgrass, including the large, smooth and southern species, when applied preemergence (prior to the emergence of crabgrass) in established lawns and ornamental turfs. Some early postemergence control of crabgrass is obtained from applications of Quali-Pro Dithiopyr 40 WSB but only in the early stages of crabgrass growth after the crabgrass has emerged. Because of the difficulty in detecting the very small, early stages of crabgrass in well-established lawns and ornamental turfs, apply Quali-Pro Dithiopyr 40 WSB for early post-emergence crabgrass control only before the tillering of crabgrass. This phase of crabgrass growth is typically the time when you can first easily see the crabgrass in the lawn turf. This early post-emergence activity of Quali-Pro Dithiopyr 40 WSB gives the user an additional 2-8 weeks longer period of time to make applications while still controlling crabgrass. The exact amount of additional time will depend on the weather and how fast the crabgrass grows.

Application Frequency and Timing

Use Quali-Pro Dithiopyr 40 WSB as a single application, as a split application, or as a sequential application for crabgrass control in the spring, summer, or fall.

Spring Applications

Apply Quali-Pro Dithiopyr 40 WSB in the spring or early summer at the appropriate rate from one of the three control programs listed in the table “Programs for Crabgrass Control.” The program selected will depend on the user’s location, the mowing height of the turfgrass, and whether the application is considered to be preemergence or early postemergence. The total rate applied will impact the duration of residual weed control. This length of control may vary somewhat and is dependent on a number of factors such as weather, weed pressure, turfgrass competitiveness, and the user’s location within a region.

Program 1 can be used for preemergence control at sites where turfgrass is cut relatively high such as homeowner lawns and will provide 3- 5 months of preemergence crabgrass control. Early postemergence control of crabgrass up to the 3-leaf stage can be expected at sites where turfgrass is cut relatively high such as homeowner lawns.

Restricted Entry Interval

12 hours