Based on a recent customer survey, weed control for strawberries and raspberries continues to be an important topic, particularly weed management in strawberries during the planting year and bramble weed management on an established field.
Strawberry Planting Year Weed Control
By selecting the site in the fall prior to planting, you have the opportunity to identify and observe what weed species will be a problem, and to treat the site accordingly to remove those weeds. Identification is important as several of the most prominent weeds have specific herbicides and application timing necessary for control to work effectively. There are several weed identification references available that are very helpful including the MyIPM phone app, as well as the Cornell University (cornell.edu/weedid) and University of Wisconsin (wisc.edu/weedid) websites.
Suggested options for weed control planting year:
• Roundup 30 days before planting. After weeds die, till to prepare for planting.
• For pre-emergent broadleaf control, two ounces of Sinbar per acre within 24 hours after planting. Water ½-1” after to wash the Sinbar off the strawberry plants. Irrigate in ½ - 1” inch of water.
• Devrinol for pre-emergent grass control. Must be watered in with at least 1 inch of moisture to activate. You can use Devrinol throughout the growing season provided you have a good irrigation program after application. At least an inch of water not only activates the product, but regular irrigation works it deeper into the soil, allowing runners to set properly.
• Poast or Selectmax for post emergent grass control. Both are effective on small, actively growing grasses. Select has shown improved activity over Poast on cool-season and perennial grasses. To improve activity on perennial grasses, add 2.5lb/acre ammonium sulfate and repeat application at 14 days. Leaf burn can occur with Poast if applied on hot and humid days.
• In some states, Stinger is labelled for use for post emergent control of broadleaves.
• Dacthal may be an option, is an excellent pre-emergent, specifically for oxalis.
• Check out our Fall 2021 Newsletter in the Commercial Growers section at noursefarms.com, where we give a comprehensive review of late fall weed control options.
Weed Control in Established Bramble Fields
We have found that many perennial weeds can be reduced or eradicated with a Casaron 4G application, after dormancy during winter. This is a great herbicide, but growers must be very careful with application timing and rates. Use of a full rate of Casaron 4G will show yellowing of leaves in the spring and can severely hurt the plants if not applied properly. As it’s a granular, calibration and testing of the granular spreader you are using is critical. We recommend doing a test run of the spreader, along the edge of the field, to doublecheck the output is consistent throughout the row, at the labeled rate. We do not recommend the application of Casoron 4G in the spring.
For spring applications, in our spring newsletter, we noted Trellis SC as a pre-emergent herbicide option to control grasses, as a replacement for Surflan, which will no longer be available. Like our experience with the broadleaf pre-emergent herbicide Princep, damage can be seen using the full rate, particularly on light, sandy soil. Other options to consider would be Sinbar for broadleaves and Devrinol for annual grasses. Based on grower feedback, calibration when using Sinbar, is critical here as above the low end of the label rate can cause plant damage. Devrinol must be watered in to be effective. Summer post-emergent weed control options include Poast or Select.
PLEASE NOTE – Not all of these herbicides are labeled in every state. Consult your state recommendations for labelling and the weeds controlled.