Maximizing Herbicide Performance

As we approach the intense post-emergent spray window for many crops, here are a few tips to consider to maximize herbicide performance:

1) Match the most effective herbicide for the most difficult weeds to control in the field

• positively identify your weeds

• understand how your herbicide works, to better manage application parameters and herbicide resistance

2) Use tank-mixes whenever possible

• this will allow for the use of multiple modes of action and target weeds with a one, two punch

3) Spray when weeds are small and at early leaf stages for the most effective control

4) Use full-labelled rates to maximize control and reduce chances of weed escapes which can lead to weed resistance

5) Use the most effective adjuvants when one is recommended with your herbicide and/or when water quality is a concern e.g. hardness

• remember this could be a non-ionic surfactant, oil adjuvant or AMS depending on the product

6) Use the correct spray volume

• contact herbicides work best at higher water volumes e.g. 10-15 gpa

• systemic herbicides can be applied at 5-10 gpa

7) Choose the correct nozzle

• contact herbicides are best applied with finer to medium spray droplets, be cognizant of drift

• systemics are best with coarse to ultra coarse nozzles

8) Reduce speed of travel to ensure better coverage and to reduce drift

9) Apply during good weather conditions

• the ideal is warm, humid and sunny

• temperature and moisture extremes detract from herbicide performance

10) Apply herbicides from 8 am to 8 pm, herbicide efficacy is enhanced during daylight hours

11) Remember to do a post-spray follow-up to evaluate herbicide performance and address any touch-up spraying required.

Please visit with your Shur-Gro agronomist for more advice on choosing the best product and fine-tuning your weed control application.