Table 6-2: Preplant Herbicide Weed Control Ratings


Pub 75: Guide to Weed Control > Preplant and Postharvest Weed Control > Table 6-2: Preplant Herbicide Weed Control Ratings

Excerpt from 2010-11 Chapter 6, Publication 75, Guide to Weed Control, Order this publication

Cover of Publication 75, Guide to Weed ControlTable of Contentss

  1. Preplant Herbicide Weed Control Ratings (Table 6-2) (PDF - 49 kb)
  2. Other Preplant and Postharvest Weed Control Tables
    • Non-Selective Herbicides Available for Preplant Site Preparation (Table 6-1) (PDF file - 55 kb)
    • Postharvest Weed Control (Table 6-3) (PDF file - 47 kb)
  3. Other Special Methods of Weed Control
  4. Related Links

NOTES: Weed control ratings are given as 0-9 where 0 indicates no control and 9 indicates 90-100% control under ideal conditions. Ratings are subjective values based on best available information and give general comparisons based on use as described in this guide. Under unfavorable conditions (e.g. too dry, too wet, too cold, or poor application) the herbicides may not be as effective as indicated. Ratings may vary with weed and crop stage and with the timing and rates of the product(s) being used. Ratings in BOLD indicate the weed is listed on the product label for control or suppression. Please see product label for more information on registered weed species, product uses and precautions.

Table 6-2. Preplant Herbicide Weed Control Ratings
Preplant Herbicides Annual Grasses Annual Broad-leaves Field Bind-weed Mouse-eared Chickweed Dand-elion Golden-rod

Ground-ivy (creeping charlie)

Horse-
tail
Aim EC 0 ** - - - - - -
Amitrol 240 ** ** a - 9 a - 7
More...
Cleanstart Plus1 ** ** 7a 9 7/8d - 5 0
glyphosate* ** ** 7a 9 7/8d - 5 0
More...
Gramoxone ** ** b b b - b b
More...
Guardian1 ** ** 7a 9 7/8d - 5 0
Ignite ** ** 8c - 8 - - 7c
More...

Table 6-2. Preplant Herbicide Weed Control Ratings
Preplant Herbicides Mallow Milk-weed Nut sedge Plan-
tains		 Poison-ivy Quack-grass Sow-thistle Canada thistle Vetches
Aim EC 8 - - - - - - - -
Amitrol 240 - a a 8 8 7 a 7 -
Cleanstart Plus1 8 a 7 9 8 8/9 a a 5
glyphosate* 5 a 7 9 8 8/9 a a 5
Gramoxone B b 0 b b 5 b 0 b
Guardian1 5 a 8 9 8 8/9 A 7A 5
Ignite - 6c 7c - - 8c 8c 8c -

Table 6-2. Preplant Herbicide Weed Control Ratings
Preplant Herbicides Mallow Milk-weed Nut sedge Plan-
tains		 Poison-ivy Quack-grass Sow-thistle Canada thistle Vetches
Aim EC 8 - - - - - - - -
Amitrol 240 - a a 8 8 7 a 7 -
Cleanstart Plus1 8 a 7 9 8 8/9 a a 5
glyphosate* 5 a 7 9 8 8/9 a a 5
Gramoxone B b 0 b b 5 b 0 b
Guardian1 5 a 8 9 8 8/9 A 7A 5
Ignite - 6c 7c - - 8c 8c 8c -

Table 6-2. Special Notes on Weeds Controlled and Product Rates Associated with Various Glyphosate Concentrations
Glyphosate* Concentration Produce Rate/ac Weeds Controlled & Notes

360 g/L
450 g/L
480 g/L
500 g/L
540 g/L

0.3 - 1.4 L/ac
0.24 - 1.12 L/ac
0.22 - 1.05 L/ac
0.22-1 L/ac
0.2-0.93 L/ac
  • For control of annual weeds.
  • Use 50-100 L/ha (20-40 L/ac) for the low rate, or use surfactant with larger water volumes.
  • The highest rate is required for weeds over 15 cm in height.
  • For weeds smaller than 15 cm in height consult the product label for weed specific rates.
  • For actively growing weeds in the fall, or spring prior to emergence of any crop.
  • Allow 5-7 days translocation time after application before doing any tillage when conditions are good. If cool temperatures follow application, allow additional time for translocation to be completed before disturbing treated weeds.
  • Only weeds emerged at application time will be controlled
360 g/L
450 g/L
480 g/L
500 g/L
540 g/L
 1 - 2.8 L/ac
0.8 - 2.25 L/ac
0.75 - 2.1 L/ac
0.72 - 2 L/ac
0.67 - 1.87 L/ac
  • For dandelions and quackgrass.
  • Apply when quackgrass has 3-4 new leaves.
  • The low rate will provide a minimum of one season control while higher rates will provide longer term control of quackgrass.
  • For dandelions, apply the low rate if smaller than 15 cm in diameter and higher rates if greater than 15 cm in diamete

* - Numerous products exist. Refer to Table 4-1. Herbicides Used in Ontario, on page 23 for a complete list of products.
** - Indicates that most annual weeds will be controlled if emerged.
1 Indicates herbicide sold as a co-pack under this trade name.
- Insufficient information available to make a rating.
a - Optimum growth stages for best control of these weeds will not likely be attained prior to planting in early to mid spring.
b - Top growth only, regrowth can be expected.
c - Repeated applications may be necessary.
d - Use higher rates for plants over 15 cm tall or across.

Related Links

 


For more information:
Toll Free: 1-877-424-1300
Local: (519) 826-4047
E-mail: ag.info.omafra@ontario.ca
Author: OMAFRA Staff
Creation Date: 25 November 2002
Last Reviewed: 30 January 2010