Spring Orchard Pre-Emergent Herbicides

Mike Basedow and Janet van Zoeren

If you weren’t able to get pre-emergent herbicides on in the fall, spring still presents a good time to get something out before many annuals start to germinate.  Below are some pre-emergent product recommendations to consider this spring. To help you select materials, have a look at the herbicide selection table available on our website here: https://enych.cce.cornell.edu/submission.php?id=744&crumb=crops|crops|apples|crop*38

For many products, at least ½” rainfall or irrigation is needed within 7 days after application to move (“activate”) the herbicide into the soil solution. Delaying activation may reduce overall performance if some weeds continue to germinate under low soil moisture conditions or if herbicide at the surface of the soil is susceptible to sunlight breakdown.

Remember, if you’ve already got seedlings germinating, you will want to include a post-emergent product as well, such as paraquat, glufosinate (broadleaves and grasses), Aim, or Venue (small broadleaves only).  Pre-emergent products will also have little to no efficacy on your difficult perennial weeds that will emerge from belowground vegetative structures. These will likely need to be controlled later in the season with other well-timed, post-emergent products.

 

Be sure to add a post-emergent product this spring if your weeds have already begun to emerge.

 

Some Specific Product Reminders:

Alion – Group 29 – Annual broadleaves and grasses. Apply to a clean herbicide strip. Do not apply to frozen, snow covered, or saturated ground. No rainfall and do not irrigate within 48 hours of treatment. Rate and use restrictions depending on soil texture and organic matter content. Do not apply to disturbed soils. Apply to trees at least three years after planting in good growing condition. Avoid tree contact, including roots. Rotate and mix with other materials!

Matrix – Group 2 – Annual broadleaves and grasses. Has some post emergence activity (<1” tall). Spray solution pH of 4-8. Best results if soil is moist at application, and ½ of rain or irrigation occurs within 2 weeks of application. Can be used in trees established 1 year+. Avoid direct contact with sensitive tissues.

Sandea – Group 2 – Annual broadleaves and nutsedge. Best results require application with a broad spectrum burndown herbicide, such as paraquat. Nutsedge control is best at 3-5 leaf stage. Can be used in apple and pear 1 year after planting. Not for use in stone fruit.

Chateau SW, Chateau EZ – Group 14 – Annual broadleaves and some grasses. Some post emergent activity, but weeds must be small (<4”). Chateau SW must be applied prior to pink bud in apples and bud break in stone fruit. Chateau EZ must be applied prior to silver tip in apple and bud break in stone fruit. ¼” of rain or irrigation within 3-4 weeks of application needed. Can injure green tissues. Do not apply to stressed plants. Do not apply in or near non-dormant pears. Do not mow treated areas when green tissues are present. Do not apply to trees planted less than 1 year, unless protected.

Goal 2X, Goaltender – Group 14 – Annual broadleaves and some grasses. Some post emergent activity,
but weeds must be small (<4”). Must be applied when trees are dormant post-harvest or prior to bud break. ¼” of rain or irrigation within 3-4 weeks of application needed. Can apply on newly planted trees once soil has settled and no cracks are present. Apply to soil and base of dormant trees.

Diuron 4L, Diuron 80DF, Karmex 80DF – Group 7 – Annual broadleaves and grasses.  Apply early spring before weeds emerge. For apples and pears, do not apply to varieties grafted onto fully dwarfing rootstocks. For peach, only apply to trees 3 full years old or older on some labels. See label for soil texture and organic matter rate limitations. Add paraquat to help control established weeds. Addition of Surflan has improved late season annual grass and broadleaf weed control. Karmex may be applied in apple and pear plantings established at least 1 year, and peach plantings established at least 3 years.

Prowl 3.3 EC and Prowl H2O – Group 3 – Annual grasses and some broadleaves. Should be mixed with a broadleaf herbicide. Rate depends on soil and weed species present. Can be applied year of planting. Do not apply until soil has settled around newly transplanted trees. Do not allow contact with roots or other sensitive tissues. Prowl 3.3 EC non-bearing trees only. H2O may be used in non-bearing and bearing trees.

Surflan – Group 3 – Annual grasses. Should tank mix with a broadleaf material. Apply to weed free soil, or tank mix with a post-emergent product. ½ to 1 inch of rainfall/irrigation for activation. Can be used year of planting.

Simazine 90DF, Princep, other formulations – Group 5 – Annual broadleaves and grasses. Apply early spring before weeds emerge. See soil-texture rate limitations. Add paraquat for already established weeds. Addition of Prowl or Surflan has improved late-season annual grass and broadleaf weed control. Tank mixes will alter PHI. Can be used 1 year after planting. See label for details.

Sinbar 80 WDG – Group 5 – Annual broadleaf weeds, + POST activity on emerged weed seedlings. Tank mix with grass material. Rate varies with tank mix combo, age of tree, soil texture/OM content.  Apply to bearing trees as a directed spray to avoid contact with sensitive tissues. For non-bearing, newly planted trees, make the first application after rainfall or irrigation has settled the soil around the base of the tree. Not for use on bearing stone fruit, except peaches. Reduced rates for non-bearing stone fruit.

Solicam – Group 12 – Annual and perennial grasses. Tank mix with a broadleaf material. Apply early spring before weeds emerge. Do not apply after bud break on sandy loam soils. Rainfall is needed within 4 weeks of application, or worked in with flood or sprinkler irrigation. Trees must be established one year before use. Soil should be settled before application. Do not contact sensitive tissues. See soil texture, rate, and tree age limitations on label. Not recommended for cherry on sandy/loamy sand soils.

While we do our best to be as accurate as possible, remember to always review the label before selecting your materials!

Want to talk more on weed management? Reach out to me at mrb254@cornell.edu or 518 410 6823.

 

 

Changes in pesticide registrations occur constantly and human errors are possible. Read the label before applying any pesticide. The label is the law. No endorsement of companies is made or implied.