Trade name(s) Poast, Poast Plus, Prestige, Vantage
Manufacturer(s) BASF, Nufarm
Formulation(s) 1, 1.3, and 1.5 lb/gal emulsifiable concentrate.
Remarks A selective, postemergence herbicide to control most annual and perennial grasses. A crop oil concentrate enhances activity.
Water solubility 4,700 ppm at pH 7
Storage conditions Store between -4°F and 86°F in sealed containers.
Acute toxicity LD50 - 4,900 mg/kg
Action in plant Inhibits growing points of grasses.
Site of action Group 1: acetyl CoA carboxylase (ACCase) inhibitor
Chemical family Cyclohexanedione
Koc Average is 100 mL/g (estimates) at pH 7
Rick Boydston
Revised March 2013
ASPARAGUS—Seedbeds and Early Establishment
See Section N. Vegetable Crops: Site Preparation, Stale Seedbeds, and Selective Postemergence Applications for additional options for weed control during asparagus establishment.
clethodim (several trade names)
Rate 0.07 to 0.12 lb ai/A
Ed Peachey
Revised June 2012
Multiply rate by 0.023 for amount per 1,000 sq ft
LARGE FOOD GARDENS—Preemergence, Soil-applied Treatments
napropamide (Devrinol 2G Ornamental)
Fruits and nuts
Rate 4 to 6 lb ai/A
Time Apply to weed-free soil any time of year, although fall and winter applications are preferred.
Ed Peachey
Revised June 2012
Multiply rate by 0.023 for amount per 1,000 sq ft
BULB AND FLOWER BEDS—Preemergence, Soil-applied Treatments
dithiopyr (Dimension 2EW)
Iris, tulip and lily
Rate 0.375 to 0.5 lb ai/A (0.75 to 1 quarts/A)
Time Apply preemergence around bases of bulbs in landscape.
Ed Peachey
Revised June 2012
Multiply rate by 0.023 for amount per 1,000 sq ft
geo-textiles
Available at agricultural and garden supply stores
Spun-bonded fabrics (non-woven) lightweight, extruded polypropylene fibers; requires mulch cover due to moderate UV light sensitivity; weed roots and rhizomes can penetrate fabric unless removed before establishment; cheapest option.
Tim Miller
Revised September 2012
Daffodil, dahlia, gladiolus, iris, lily, narcissus, tulip, and peony
Ed Peachey
Revised June 2012
Conifer seedlings are extremely poor competitors during the first 2 years in a seedbed. Consequently, it is imperative to select a site that contains few weeds, or weeds that can be controlled with current technologies. Complete elimination of all perennial weeds and proper seedbed preparation is essential. Constant surveillance coupled with regular and timely weed control practices is required to maintain weed-free seedbeds and nurseries. Consult labels for tolerant crops.
CONIFER SEEDBEDS—Preemergence Control before Conifers Germinate
Ed Peachey
Revised June 2012
Weeds compete with newly planted nursery stock. Deep-rooted perennial weeds can reduce vigor and render a mature product unmarketable due to laws on transporting noxious weeds. Consequently, weeds are controlled with herbicides either broadcast-applied in closely spaced crops, or within the tree or shrub row for wider spaced crops, with alleys being mowed or flailed.
Ed Peachey
Revised June 2012
Sanitation The first step to effective weed management is sanitation. Start with potting mixes that are free from weed seeds. Control weeds that have wind-dispersed seeds around the perimeter of the site. If weeds emerge in containers, remove them before they produce seeds. The more weed seed allowed to contaminate containers, the higher the probability that the weeds will germinate in areas where the herbicide barrier has been weakened or disrupted.
Ed Peachey
Revised March 2013
TOMATOES, PEPPERS, AND EGGPLANTS—General Weed Management Strategy
Ed Peachey
Revised March 2013
RHUBARB
glyphosate (many products)
Rate Consult label
Time Broadcast before crop emerges; after crop emerges use hooded and shielded sprayers in row middles, and wiper application in row middles.
