This section of the web site features Management Updates written by the turf specialists of the UMass Extension Turf Program. The messages cover local problems, are geared toward local conditions, and are posted frequently during the growing season. The most current message appears below; click into the archive at the right to see previous messages. Join our free e-mail list to receive notification whenever an update is posted.

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Latest Message

Date: July 3, 2009
Category: Weeds
Subject: Crabgrass, Broadleaf Weeds, Paspalum, Yellow Nutsedge

The cool and weather of the last few weeks has resulted in slower than normal annual grassy weed growth.  Depending on site location and condition of turf, crabgrass generally ranges from the 1 to 5-6 tiller growth stage.  A wide range of growth stages will require turf managers to carefully monitor a specific turf site in order to select the best postemergence crabgrass herbicide. Fenoxaprop (Acclaim Extra™) is best used on crabgrass up to the two-tiller stage of growth.  Quinclorac (Drive™) can be used on a wider range of crabgrass growth stages but is often weak on crabgrass in the 2 to 4-tiller growth stage.  Follow label instructions for the addition of surfactants.

As a result of cool weather and adequate moisture, herbicide applications for broadleaf weeds can continue.  White clover remains in flower and applications of broadleaf herbicide products that contain dicamba, clopyralid, fluroxypyr and quinclorac are good choices.  Clopyralid is not labeled for use on residential turf.  Herbicide products that contain triclopyr and/or dicamba are good choices for ground ivy , sheep sorrel and wild violets .  Amine formulations of broadleaf herbicides are preferred over ester formulations for areas around ornamental plantings.

Paspalum is rearing it's ugly head.  This species is a crabgrass look-alike and a close relative of dallisgrass which is found much farther to our south.  Management strategies that are effective for crabgrass, including both cultural practices and herbicides, are not effective on this species.  Applications of MSMA are the best choice and applications should not be made when cool-season turfgrasses are experiencing moisture and/or heat stress.  Repeat application may be required at 14 to 21 days following initial treatment and some temporary discoloration is likely to occur.  If the population is small, digging and reseeding can be used as a non-chemical management strategy.

Yellow nutsedge is becoming apparent.  Postemergence applications for yellow nutsedge should be occurring now and should be completed by the second week in July.

Submitted by: Randy Prostak

DISCLAIMER - As always, it is the responsibility of the applicator to verify the registration status of any pesticide BEFORE applying it. Different states have different regulations as well. Trade names of materials are provided for informational purposes only and do not substitute for a thorough and careful reading of the label and application according to label instructions. The author and the University of Massachusetts are not liable for any consequences of any pesticide recommendations. Mention of any trade name is not to be considered endorsement of a product.

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