BIOBARRIER®
Product Information

Discover how BIOBARRIER® works to protect your property from tree root damage

How BIOBARRIER® works

BIOBARRIER® consists of composite nodules injection-moulded through Tekton®, a spun bonded polypropylene geotextile fabric. The through injection moulding technique ensures permanent nodule attachment. Impregnated with trifluralin, the nodules function as a protective reservoir. The nodule composition is designed to slowly release trifluralin vapours, which adsorb in the soil.

Outside the nodule, the trifluralin degrades but is continuously replaced by new material, building and maintaining a root inhibition zone. Accurate nodule spacing ensures the individual nodule zones overlap and reinforce each other. At equilibrium, the inhibition zone becomes contiguous, enveloping the BIOBARRIER® fabric.

When roots enter the inhibition zone, root tip cells cannot divide, preventing growth in that direction. Trifluralin is not systemic; therefore, it is not taken into the plant. As a result, the root system is diverted away from the BIOBARRIER®-protected structure without adversely affecting the desirable plants or trees. Root branches outside of the zone are not affected.

By utilising a technology that combines a proven geotextile drainage fabric with an effective pre-emergence herbicide, BIOBARRIER® also marketed as a pre-emergence weed control fabric for landscaping, prevents grass and weed growth without affecting desirable plants. When covered with 50 mm (2”) of mulch, stone, or other medium, the trifluralin inhibition zone both above and below the plane of the fabric blocks grass and weeds from establishing a viable root system needed to support growth. Additional protection is provided by the 136 g/sq. m (4 oz./sq.yd.) geotextile fabric, which blocks existing grass, and weeds from coming up through the fabric. New plants or desirable existing plants that have roots below the 50 mm (2”) inhibition zone are not adversely affected.

 

How trifluralin works

The root inhibition zone is created and maintained by the trifluralin released from the nodules. Consequently, the highest trifluralin concentration in the soil is at the plane of the barrier, with concentration levels diminishing as distance from the barrier increases. The concentration level effective for all roots measured is less than 7.6 ppm. Plant species vary in resistance to trifluralin. This concentration level at zone equilibrium, based on field and laboratory measurements, occurs approximately 25 mm (1”) from the barrier. Some root branch elongation may occur after the root tip meets the effective concentration level, pushing the tip within the 25 mm (1”) zone.

With a water solubility of 0.3 ppm, trifluralin does not present a significant leaching problem. Additionally, trifluralin has a high soil adsorption and short half-life.

Toxicity level of trifluralin

With a U.S. EPA Class IV rating and an Oral LD50 of 10,000, technical grade trifluralin is considered practically non-toxic, ranking it between sugar (29,700) and salt (3,000). Since only a minute amount of trifluralin is emitted from the Biobarrier nodules at any point in time, the hazard is minimized.

The active ingredient in BioBarrier is trifluralin, which is commonly used in weed control. The trifluralin is released in a gaseous form into the soil and creates a small (about 2 inch) zone where roots wont grow. The product is non-systemic, meaning it wont harm the roots or rest of the tree, it will just prevent it from growing in that area. The US FDA rates trifluralin in toxicity somewhere between table salt and sugar. We actually used to have an engineer with our company that would eat the nodules at trade shows as a way to show people they weren’t harmful. I understand there is usually a concern with putting ‘chemicals’ into the ground, but we like to remind customers that this chemical isn’t going out into the soil and spreading, it is staying in a gas form within a couple inches of where the material is laid.

Technical data

The hemispherical shaped nodules on Biobarrier contain one active ingredient (trifluralin) and two inactive ingredients (polyethylene and carbon black). Biobarrier is engineered to release the trifluralin very slowly in vapour form and establish a narrow (see chart below) protective chemical zone in soil adjacent to the fabric. This unique delivery method, combined with the chemical characteristics of trifluralin detailed below, ensure that the chemical zone remains very near the fabric and does not present a significant leaching problem. Trifluralin has been used extensively in commercial applications for over 40 years and widely recognised as a leading pre-emergence herbicide. See EPA Toxicity Rating for trifluralin below.

Environmental Rate of Trifluralin

Solubility in Water<0.3ppm @ 25 degrees C
Vapor Pressure1x 10^-4
Degradation in Soil1 to 6 months
Half Life
Air Photolysis42 minutes
Water Photolysis9 Hours
Soil Photolysis (Dark)41 Days
Soil Photolysis (Light)66 Days

EPA Toxicity Ratings

Classification (mg. Kg.)
1. Extremely Toxic50
2. Highly Toxic50 to 500
3. Moderately Toxic500 to 5,000
Practically Non-Toxic5,000 to 15,000
Toxicity Examples (mg. Kg.)
1. Nicotine32
2. Aspirin1,000
3. Salt3,000
4. Triflurin10,000

 Protect your property

Here’s what our clients have to say about BIOBARRIER®

  • "This is the best product I have seen come into the industry in the 42 years I've been working in landscaping."

    Stan Hoglund
    HOGLUND
    Fargo, ND, USA

  • "BIOBARRIER® has proved to be an effective tool against root invasion, bamboo spray, and weed control techniques."

    Tony Colon
    ACADEMY LANDSCAPES
    Titirangi, Auckland, NZ

  • "Completed several product installations, very easy to use and really helps control damage caused by roots."

    David Todd
    DAVID TODD LANDSCAPE
    Drury, Auckland, NZ

  • "It's a great product and backup service is excellent."

    Neven Millar
    TOTAL LANDSCAPE CREATIONS
    East Auckland, NZ

  • "BIOBARRIER® has proven to be an excellent product for a timber planter and has performed admirably and proved itself to be fit for purpose."

    Bill Holden
    DESIGN & LANDSCAPE LTD
    Warworth, Auckland, NZ