4 Steps to Season-Long Weed Control

Launch a more proactive plan for your orchard.

Over the last few years, seasonal weather patterns have become less predictable on the West Coast. But one thing you can count on when fall or winter rains arrive is that weeds will quickly follow.

Avoid the challenges of controlling late-winter and early-spring weed flushes in your orchard by taking a more proactive approach to weed control starting this fall, recommends Jeff Pacheco, technical sales agronomist, DuPont Crop Protection. “Stopping weeds before they emerge is key to staying ahead of weeds throughout the year.”

He offers these strategies for effective season-long weed control in orchards.

1. Start clean after harvest.
Two weeds that often germinate again in the fall, marestail and fleabane, are becoming more challenging to control because they have developed increased resistance to contact herbicides such as glyphosate and paraquat, notes Pacheco. “DuPont™ Matrix® SG herbicide is a good alternative for control of these two tough broadleaf weeds, and it can be tank mixed with a variety of other herbicide modes of action to achieve customized weed control with resistance management.”

Matrix® SG can be applied as a single broadcast application in fall or early winter, or as sequential applications in fall and spring, depending on weed pressures and moisture patterns, he adds.

2. Get ahead of winter weed growth cycle.
Most orchards are plagued by a healthy crop of young weeds when fall or winter moisture is plentiful and soils begin to warm in the spring. A preemergence, residual herbicide applied in late fall, prior to a rain event, can provide effective control through the winter and early spring months, says Pacheco. “Following that with a sequential herbicide treatment in the spring, usually in mid to late March, will allow growers to get consistent and extended weed control while taking advantage of California’s typical rainfall patterns.”

In field studies, sequential applications in the fall and spring that included Matrix® SG as the foundational residual herbicide achieved excellent preemergence weed control in those seasons, and extended residual control into late spring and summer, he says. “Applying Matrix® SG in a sequential treatment program – one 50 percent or less banded treatment in the fall and a second 50 percent or less banded treatment in the spring – will reduce the need to use multiple applications of burndown herbicides during the busy late spring and summer months.”

3. Aim for broadspectrum control.
Choosing a foundational herbicide that controls a wide range of broadleaf and grass weeds will save you time and money, adds Pacheco. Matrix® SG controls 10 tough grass species and 37 common broadleaf weeds, including fleabane and marestail.

“A sequential program also allows growers to tailor a tank mix to control the orchard’s most important weed problems in the late fall, winter, spring and early summer months,” he says. “Using Matrix® SG in a tank mix with DNA herbicides, such as Prowl and Surflan or Alion have provided the most effective and extended summer grass control when applied in the spring,” he says.

4. Maintain flexibility.
A herbicide that offers both preemergence and early postemergence control of difficult weeds can also provide application flexibility. Matrix® SG has several key benefits:

  • Commercially proven crop tolerance
  • No application restrictions during dormant or nondormant periods
  • No soil restrictions
  • Low labeled use rate
  • Water-soluble granule formulation that dissolves faster and goes into complete solution for more consistent weed control

A well-planned preemergence weed control program is more effective and provides a good return on a grower’s investment, says Pacheco. “By achieving more consistent control, growers can avoid the cost and hassle of follow-up or rescue treatments and working around unpredictable weather conditions during the fall and winter season. It’s the best way to stay ahead of weeds and improve orchard productivity.”


Always read and follow all label directions and precautions for use. DuPont™ Matrix® is not registered in all states. Contact your DuPont representative for details and availability in your state.

®™ Trademark of The Dow Chemical Company (“Dow”) or E. I. du Pont de Nemours and Company (“DuPont”) or affiliated companies of Dow or DuPont.

Alion® (Bayer); Prowl® (BASF Corporation); Surflan® (United Phosphorus Limited).