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


29,040: 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.

- In New York State, do not apply more than 2 water-soluble pouches per acre or 0.23 oz/1,000 sq ft (0.625 lb/acre) per year.

- Do not open the water-soluble bag. The entire water-soluble bag must be used and not measured out or broken open. Prepare tank mixes using whole numbers of bags to treat the appropriate number of acres.

Restricted Entry Interval

12 hours

The material and content contained in the Greenbook label database is for general use information only. Agworld and Greenbook do not provide any guarantee or assurance that the information obtained through this service is accurate, current or correct, and are therefore not liable for any loss resulting, directly or indirectly, from reliance upon this service. This label database does not replace the official manufacture issued label. Users of this database must read and follow the actual product label affixed to the container before use of the product.