Dithiopyr is a preemergent herbicide for crabgrass control in turf and ornamental grasses.

Its duration of efficacy is approximately 4 months, so lawns should not be reseeded during this time frame following application of the chemical.

Dithiopyr acts primarily as a preemergent herbicide but can also be used in early postemergent control of crabgrass.

It is an ingredient in many products including Dimension from Dow AgroSciences.

Dithiopyr can be obtained through a multi-step process starting from ethyl trifluoroacetoacetate and isovaleraldehyde.