Rezilon® Herbicide

Sandbur Management

Developing a Sandbur Management Program

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While Rezilon^® herbicide is a key component for a successful sandbur management program, there are many other factors to consider. The following topics will help you develop a program: education, identification, scouting and elimination.

Education

What is sandbur?

Sandbur (Cenchrus spp.) is a grassy weed typically viewed as being an annual species, although some species are actually classified as perennial or short-lived perennial. Learn how to identify which growth cycle of sandbur can infest your field in the section below.

When does sandbur occur?

Sandbur seeds begin to germinate when soil temperatures reach approximately 52° F and continue to germinate throughout the growing season. Perennial vegetative regrowth occurs in the early spring from the crown of old plants.

How long is a sandbur management program?

A successful sandbur management program will likely take many years as sandbur seed can remain dormant in the soil for many years. Although one can drastically reduce their sandbur infestation during one or two seasons of Rezilon use, continued scouting and management should be observed to maintain long-term sandbur control.

Identification

How do I spot sandbur?

Sandbur can be identified by the inflorescence that forms spiny burs when mature. This is where the weed gets its name. These burs decrease bermudagrass quality on grazed and hay production sites.

Newly emerging sandbur seedlings can be identified by digging them up, making sure to keep the entire root system intact because the bur will still be connected to the young root system. To differentiate perennial versus annual sandbur species, mark plants in the fall when seedheads are still attached. Revisit and dig up some of those marked plants over the winter (December and January) and on the cusp of spring (February and March) to check for living vegetation near the crown and underneath the plants. Perennial species can be identified when new growth emerges from the previous year’s crowns or stems. Plants that do not have green vegetation and whose crowns crumble apart easily are annual sandbur species.

Scouting

Why is scouting so important?

To run a successful sandbur program, you should scout for emerging, established or perennial plants to know what you’re dealing with.

When should I scout?

There are three main times to scout:

1. The early part of the year (January through March): Check for perennial plants and develop an approach to control these perennial plants in April or May.
2. Three to four weeks after each Rezilon application: Check for escaped seedlings.
3. Several weeks to a month after any postemergence application (i.e., Pastora^® herbicide or Pastora + Roundup^® Technology): Check the effectiveness of the application.

Elimination

Why do soil disturbances make it hard to eliminate sandbur?

When soil is disturbed, sandbur seeds can germinate much deeper from within the soil profile where it’s harder for Rezilon to reach. Also, soil disturbances can bury and bring up sandbur seeds within the soil profile. Avoid mechanical disturbances when possible, and quickly address the presence of any burrowing animals.

How do I identify annual sandbur from perennial sandbur?

When scouting in the late fall or winter, mark where sandbur grows in your fields, then you can inspect those sites throughout the winter and early spring to determine if you have annual and/or perennial sandburs. In the late winter/early spring (January through March), dig up plants and look specifically at where the plant’s stem connects to the crown. Cut the stems and crowns open. If they are brown and dry, they are likely annual. If they are green or show signs of moisture, they are likely perennial.

How do I prepare for spring application?

Once you know what type of sandburs you have, you can develop your application strategy. Rezilon is a great solution for sandburs germinating from seed regardless if those seeds are from an annual species or a perennial species. Regardless of sandbur species, Rezilon (3 fluid ounces per acre) should be applied in late January or very early February and applied again (3 fluid ounces per acre) immediately after a harvest in June to early July. If you have perennial sandbur plants in your field, an additional postemergence application of Pastora + a glyphosate + a surfactant in at least a 10% UAN carrier is needed immediately following the first or second harvest.

What do I need to know about preparing equipment?

Winter is an ideal time to perform necessary maintenance or upgrade your spray system before spring application. Rezilon requires a boomed sprayer with flat fan nozzles, which helps for an even application and consistent control. When everything is in working order, spray your affected areas in the winter (late January through early February), then make a sequential Rezilon application after the first or second harvest (June through early July).

Prescriptive Solutions
and Further Reading

A successful program uses integrated pest management and combines cultural, biological and chemical measures. While this guide is a useful overview, our Sandbur Solutions brochure has more in-depth information and prescriptive solutions.