NC State Extension Publications

Introduction

Trade Name: Dimension Common Name: dithiopyr Formulations: 2 EW, 40 WP

Uses

Preemergence control of summer annual grasses in turf, including bentgrass, landscape beds, container and field nurseries. Postemergence control of crabgrass is possible when applied before crabgrass has tillered.

Amount of Active Ingredient Amount by Formulation
2 EW 40 WP
Per Acre 0.5 lb 2 pt 1.25 lb
Per 1,000 sq. ft. 0.73 oz 0.46 oz
Note: Different rates of application are recommended for turfgrass applications. In NY, max application rate is 0.25 lb ai/A.

Major Weeds Controlled

Preemergence control of crabgrasses, goosegrass, other summer annual grasses, annual bluegrass, lespedeza, bittercress, chickweed, oxalis, henbit and parsley-piert. Higher rates are needed for goosegrass and broadleaf weeds. Partial control of spurge, longstalked phyllanthus, and rice flat sedge. Postemergence control of smooth and large crabgrass if applied before tillering.

Major Weeds Not Controlled

Weak on many broadleaf weeds including groundsel, eclipta, chamberbitter, spurge, pigweed, and prostrate knotweed. Does not control nutsedge or perennial weeds from rhizomes or stolons. Does not control goosegrass postemergently.

For Best Results

Follow label directions and local Extension guidelines for recommended rates for your area. Apply before weeds have emerged. Irrigate after application to incorporate the herbicide. Two applications are generally necessary for full-season grass control. An emulsifiable concentrate (EC) formulation is also labeled but is generally not recommended for landscape uses due to volatility and odor concerns.

Cautions and Precautions

In landscape beds, apply Dimension as a directed application, avoiding contact with the foliage of ornamental plants. Over the top applications when plants are in active growth will injure the foliage of many ornamentals. Over the top applications to some annual bedding plants has reduced or delayed flowering.

Residual Activity

Up to 12 weeks of residual annual grass control is observed in turf or field soil. Length of residual weed control is less in containers. Two applications are necessary for full-season grass control.

Volatility and Leaching Potential

Moderately-high volatility, especially with the EC formulation. Incorporation via irrigation is necessary. Leaching is negligible.

Symptoms and Mode of Action

Inhibits root growth by blocking cell division in a manner similar to the dinitroanaline herbicides, but the exact site of action is different. Symptoms include swollen root tips. HRAC Group K1; WSSA Group 3.

Additional Information

Worker Protection Standards REI: 12 hours
PPE: long sleeves, long pants, chemical resistant gloves, shoes plus socks
Manufacturer: DowAgroSciences EPA Reg. # 62719-542 (EW) 62719-445 (WP)

Author

Professor of Weed Science and Extension Specialist
Horticultural Science

Publication date: Feb. 20, 2015

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