Feb 29, 2016

New(er) berry crop herbicides

Some new herbicides, or in some cases, new formulations, have become available for use in berry crops in the last few years. Here is a summary of these additions.

Devrinol

Devrinol (napropamide) is a pre-emergent herbicide that has been around for a long time, but one drawback was that it needed to be incorporated quickly after application to prevent it from breaking down in sunlight. It is available in two new formulations, Devrinol 2XT and Devrinol DF-XT. Both contain an additive that makes the active ingredient more resistant to breakdown in sunlight, so the recommended time for incorporation is now given as a range from 24 to 72 hours. It still has the same spectrum of activity, being strongest on annual grasses, but also is effective in preventing some broadleaf weeds including pigweeds, purslane, and chickweed. It’s labeled for use in strawberries, raspberries, blackberries, and blueberries. It is typically used for spring or fall applications.

Trellis

Trellis (isoxaben) is a pre-emergence material with the same active ingredient as the one in Gallery. Like Gallery, Trellis is effective for prevention of broadleaf weeds including some troublesome ones such as ragweed and nightshade. It can be used only in nonbearing (i.e., at least one year to harvest) plantings of raspberries and blackberries, blueberries, currants, gooseberries and elderberries.

Callisto

Callisto (mesotrione) is labeled for pre-bloom use on raspberries, blackberries, highbush blueberries and red and black currants. It can be used on lowbush blueberries only in non-bearing years. It has pre-emergence activity, and also post-emergence activity as long as the weeds are small (< 5” tall). It is effective against many broadleaf weeds including marestail, black nightshade and pigweeds, but has little activity on grasses. Casoron CS Casoron CS (diclobenil) is a liquid formulation of an older product that was challenging to apply as a granular formulation. It can be used in established (more than a year old) raspberry, blackberry, and blueberry fields, preferably during late fall and early spring when conditions are cool and moist. If applied under conditions that are warm (> 70 degrees) and dry, the material converts to a gaseous form and is not bound to the soil, so control is reduced. It has preemergence activity against a wide range of annual broadleaves and some grasses, and also suppresses some perennials. It has kickback activity on young weeds whose root systems are not already growing below the herbicide layer (i.e., generally weeds that are less than 2” tall).

Zeus XC

Zeus XC (sulfentrazone) is labeled for use on healthy blueberry plants that have been in the ground for at least three years. It is in the same chemical class as Chateau and has a similar spectrum of activity. It is primarily a preemergence material with some postemergence activity on emerging annual grasses and certain broadleaves. It also can help control sedges postemergence.

Zeus Prime XC

Zeus Prime XC is a combination of two active ingredients (carfentrazone-ethyl and sulfentrazone) and has both post-emergence burndown activity and pre-emergence activity. It is labeled for use on bushberries (highbush blueberries, currants, gooseberries, and elderberries) and caneberries (raspberries, blackberries, etc.) and controls a wide range of broadleaf weeds including emerged nutsedge. It should only be applied to established plants that have been in the ground for at least two years.

Matrix SG and Solida

Matrix SG and Solida (both contain rimsulfuron as the active ingredient) are labeled for use on highbush blueberries, raspberries, blackberries, and lowbush blueberries during their vegetative year when managed to have one. These products have both preemergence and early postemergence activity and control primarily annual grasses and a limited variety of broadleaves. Raspberries must have been in the ground at least one year, and blackberries at least two years before these materials can be used on them. The active ingredient has the same mode of action as Sandea, and so these materials cannot be used in the same year as Sandea.

Sandea

Sandea (halosulfuron-methyl) is labeled for use on highbush blueberries. It has both preemergence and postemergence activity and is useful for control of broadleaf weeds including marestail, and also nutsedge. The label recommends one or two applications to nutsedge in late June; however, with a 14-day PHI, timing of application could be problematic for early and mid-season blueberry varieties.

Prowl H2O

Prowl H2O (pendimethalin) is now labeled for use on highbush blueberries, red and black raspberries, blackberries, and aronia, in addition to strawberries for which it has been labeled for some time. It is a preemergence material that is effective mostly on grasses, with control of certain broadleaves (lambsquarters, purslane, pigweeds).

As always, the label is the law — pesticides can only be used in the manner consistent with the product label. Products must be registered for use in the state in which they are applied.

— Kathy Demchak, Penn State University