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SUGGESTED WEED CONTROL CALENDAR FOR

ST. AUGUSTINEGRASS SOD FIELDS

Prepared by:

Tim R. Murphy, Extension Agronomist - Weed Science

2002

NOTE: ALL HERBICIDE RATES ARE PRODUCT RATES PER ACRE.

MONTH	RECOMMENDED WEED CONTROL PRACTICE¹
November	Apply 1.0 qt of Princep Liquid or Atrazine 4L (or equivalent amount of other simazine or atrazine formulations) to control winter annual weds. Princep and atrazine will control annual bluegrass, common chickweed, henbit and most other winter annual weeds. DO NOT apply to fields overseeded with perennial ryegrass. Princep and atrazine will not control wild garlic, dandelion, plantains and most other perennial weeds.
Late November through December	Use Manor at 0.33 to 0.5 oz./acre + 0.25% v/v nonionic surfactant for wild garlic and winter annual broadleaf control at this time.
January to Mid-February	If winter annual weeds emerge following the November application of Princep or atrazine, apply an additional 1.0 qt. per acre of either herbicide. If field has received applications of Manor for wild garlic control, this application may not be necessary unless annual bluegrass is the predominant weed. Manor at 0.25 to 1.0 oz./acre + 0.25% v/v nonionic surfactant may also be used for wild garlic and winter annual broadleaf control at this time.
Mid-February to March 15	Apply Ronstar 2G at 150.0 lbs. per acre to control summer annual grasses such as crabgrass and goosegrass. This application of Ronstar is highly recommended as the postemergence herbicide control options for annual grass weeds is limited to only Asulox. For bermudagrass suppression in St. Augustinegrass use Prograss 1.5EC at 2.0 gals./acre. Begin applications as bermudagrass initiates spring green-up. Make up to 2 additional applications at intervals of 30 days each. In immature or recently-harvested St. Augustinegrass use Prograss only at 1.0 gal./acre. Atrazine at 2.0 qts./acre tank-mixed with Prograss will improve bermudagrass suppression.
¹Other herbicides may be substituted for many uses discussed in this calendar. Refer to the current issue of the Georgia Pest Control Handbook.
MONTH	RECOMMENDED WEED CONTROL PRACTICE¹
May through June	If emerged crabgrass or goosegrass becomes a problem use Asulox at 5.0 pts./acre. Make only one application per year to St. Augustinegrass and DO NOT add a spray adjuvant. DO NOT apply to St. Augustinegrass that is stressed or freshly mowed Manor may be used during summer months for the control of numerous annual broadleaf weeds such as prostrate spurge, pigweed spp. and 'Pensacola' bahiagrass. Non-typical turfgrass weeds (common ragweed, sicklepod, morningglories, others) will be controlled by repeated mowings. It is usually not necessary to use a herbicide to control this group of weeds.
June through July	If purple or yellow nutsedge becomes a problem, apply Manage at 1 1/3 oz. + 0.5% v/v nonionic surfactant or Image at 2.0 pts./acre. Image will reduce the growth of immature St. Augustinegrass. Use Image only on production fields that have complete soil coverage. Basagran T/O at 3.0 pts. or Prompt at 2.4 pts./acre can be used to control yellow nutsedge and various annual sedges. Repeat the application as directed on the herbicide label. Established St. Augustinegrass has excellent tolerance to Manage.

General guidelines for herbicide use on St. Augustinegrass sod fields.

Use a spray volume of 20 to 40 gpa.

DO NOT apply postemergence herbicides if summer air temperatures are greater than 90⁰ F.

Avoid the use of postemergence herbicides during spring green-up. Herbicide use at this time can temporarily injure the turfgrass (about one month) and retard spring green-up. Use herbicides at this time of year only if there is a severe weed infestation.

Most preemergence herbicides are not generally used on sod production fields as they can inhibit root development from the stolon nodes. Preemergence herbicides should be used only on fields where complete soil coverage has been achieved and the sod will not be cut for transplanting purposes for 6 to 8 weeks after application.

DO NOT use MSMA, Drive, Sencor, Confront, Vantage, Fusilade II, Acclaim Extra and Illoxan on St. Augustinegrass. Also, St. Augustinegrass has a low level of tolerance to 2,4-D and most two-way and three-way that contain 2,4-D and triclopyr. Use two-way or three-way herbicides only if recommended on the specific herbicide label.

READ THE LABEL OF ALL HERBICIDES THAT WILL BE USED.