Ministry of Agriculture, Food and Rural Affairs

Preemergence herbicide applications in grapes

New Plantings

Herbicide	Herbicide Group	Rate (kg/ha)	Timing	Tank Mix Information
Frontier Max (dimethenamid)	15	0.963 L/ha	PRE - Do NOT apply during bud swell, bud break or first flush of new growth.

Established Plantings

Herbicide	Herbicide Group	Rate	Timing	Tank Mix Information
Alion (indaziflam)	29	0.375 L/ha	PRE - Do NOT apply prior to any soil disturbance.	May be tank mixed with glyphosate and glufosinate ammonium
Casoron (dichlobenil)	20	110-225 kg/ha	PRE - moist, unfrozen ground in fall or spring
Chateau (flumioxazin)	14	0.28-0.42 kg/ha	PRE - 2 applications, 30 days apart. Do NOT apply after budbreak	May be tank mixed with glyphosate
Frontier Max (dimethenamid)	15	0.963 L/ha	PRE - Do NOT apply during bud swell, bud break or first flush of new growth.
Karmex (diuron)	7	2.25-6.7 kg/ha	PRE - spring and / or fall. Applications must be 90 days apart. Do NOT exceed the maximum rate per year or injury could result.
Princep Nine-T (simazine)	5	4-5 kg/ha	PRE - apply after hills are removed but before weed emergence.	May be tank mixed with glyphosate and glufosinate ammonium.

Note: Alion can only be applied to established plantings > 5 years; Casoron and Chateau can only be applied to established plantings > 2 years; Karmex and Princep Nine-T can only be applied to established plantings > 3years.

Tank Mixes

Tank mixes with burn down herbicides (glyphosate, glufosinate ammonium and paraquat) if emerged weeds are present are needed for Alion and Chateau because neither of these herbicides have activity on germinated weeds. Consider tank mixes with other PRE herbicides to both broaden the weed spectrum and manage the selection of herbicide resistant weeds.

Table 1. Selectivity of Weeds to Preemergence Herbicides Registered on Grapes in Ontario - Annual Broadleaves

C = Control, P = Partial control, N = No control,- = No information

	diuron (Karmex)	dichlobenil (Casoron)	dimethenamide (Frontier Max)	flumioxazin (Chateau)	indaziflam (Alion)	napropamide (Devrinol)	simazine (Princep Nine-T)
Canada fleabane	P	N	N	C	-	N	P
Chickweed	P	C	N	C	C	C	C
Clovers	P	N	N	N	-	P	C
Cocklebur	C	N	N	N	-	P	C
Goosefoot	C	N	N	C	-	C	C
Groundsel, common	N	C	N	C	C	P	P
Hairy fleabane	P	N	N	C	-	N	P
Henbit	C	N	N	C	-	P	C
Lamb's-quarters	C	C	N	C	C	C	C
Lady's-thumb	C	P	P	P	C	P	C
Mustard	C	C	N	C	C	P	C
Nightshade	C	N	C	C	-	N	C
Pigweed	C	C	C	C	P	C	C
Prickly lettuce	C	N	N	P	P	C	C
Purslane	C	C	N	C	-	C	C
Shepherd's-purse	C	C	N	C	C	P	C
Sowthistle	C	C	N	P	-	C	C
Spotted spurge	N	C	N	C	C	C	P

Table 1. Selectivity of Weeds to Preemergence Herbicides Registered on Grapes in Ontario - Annual Grasses

C = Control, P = Partial control, N = No control,- = No information

	diuron (Karmex)	dichlobenil (Casoron)	dimethenamide (Frontier Max)	flumioxazin (Chateau)	indaziflam (Alion)	napropamide (Devrinol)	simazine (Princep Nine-T)
Annual bluegrass	C	P	N	C	N	C	C
Barnyard grass	C	P	C	C	C	C	P
Crabgrass, large	P	C	C	C	C	C	N
Fescues	C	P	N	P	N	C	P
Foxtails	P	C	C	C	C	C	C

Table 1. Selectivity of Weeds to Preemergence Herbicides Registered on Grapes in Ontario - Perennials (seedling)

C = Control, P = Partial control, N = No control,- = No information

	diuron (Karmex)	dichlobenil (Casoron)	dimethenamide (Frontier Max)	flumioxazin (Chateau)	indaziflam (Alion)	napropamide (Devrinol)	simazine (Princep Nine-T)
Field bindweed	P	P	N	N	C	N	P

Table 1. Selectivity of Weeds to Preemergence Herbicides Registered on Grapes in Ontario - Perennials (established)

C = Control, P = Partial control, N = No control,- = No information

	diuron (Karmex)	dichlobenil (Casoron)	dimethenamide (Frontier Max)	flumioxazin (Chateau)	indaziflam (Alion)	napropamide (Devrinol)	simazine (Princep Nine-T)
Canada thistle	P	P	N	N	-	-	-
Dandelion	N	P	N	C	-	-	-
Field bindweed	N	P	N	N	P	N	N
Nutsedge, yellow	P	P	P	N	-	N	N