In a favourable year, pre-emergence herbicides can deliver high levels of control, but inefficient delivery and the 97% control required to manage black-grass populations, makes this very difficult to achieve.
At the pre-/peri-emergence spray timing the target is the soil. The aim is to maximise coverage with the herbicide spray and retain it in the top 5cm of the soil to control flushes of germinating weeds that may emerge over time. However, coverage can often be compromised by drift and herbicide retention can be affected by soil moisture and leaching potential of the herbicide. The adjuvant Backrow is designed to optimise the placement of residual herbicides by reducing drift and increasing herbicide retention, leading to more effective weed control.
Designed purely to reduce drift and maximise coverage
Key situations in which to use Backrow
With all pre-/peri-emergence herbicides to optimise early weed control
To prevent drift, thereby increasing herbicide dose and coverage on the target
With drift reducing nozzles to improve coverage
Where soil:herbicide contact can be hard to achieve and better coverage is needed
To retain herbicide in the top 5cm of the soil to kill germinating weeds
On light soils to prevent leaching (except pure sand)
With herbicides such as metazachlor which are prone to leaching
To optimise herbicide performance in dry soils
Powering effective weed control
Improves soil coverage with herbicide spray
At the pre-emergence spray timing (i.e. herbicide applications applied to the soil before the weed has emerged), effective coverage of the soil with the applied herbicide is essential to ensure all germinating weeds “pick up” the herbicide as they emerge to prevent them establishing. Poor coverage can occur as a result of spray drift. Backrow reduces spray drift and improves coverage.
Increases the longevity of weed control by up to 8 weeks
Weeds typically germinate from the top 5cm of soil in the soil profile. Residual herbicides (soil acting herbicides) need to be retained in the top 5cm of soil to control weeds as they germinate – weeds pick up herbicide through their roots and shoots – mainly shoots). However, some herbicides will leach down through the soil profile as they are “prone to leaching” or due to light soils which lack organic matter to bind to. Backrow helps retain residual herbicides for up to 8 weeks, increasing the longevity of weed control.
Improves herbicide performance in dry soils
Residual herbicides (soil acting herbicides) typically require some moisture to work. However, often soils can become dry due to the lack of rain or where light soils “leach” the water easily. Backrow retains soil moisture increasing the performance of residual herbicides.
Reduces leaching of crop protection products to groundwater and crop roots
Some herbicides have a tendency to leach, particularly in light soils which lack organic matter to bind to. Backrow helps retain residual herbicides in the soil profile which prevent the leaching to groundwater and the root zone of the crop.
Value in use
Increases the number of weeds coming into contact with the herbicide at germination
Backrow increases the number of weeds coming into contact with the herbicide at germination. This increases the number of weeds that will be controlled, both reducing seed return and improving crop competition and overall yield.
Helps to control flushes of weeds pre-emergence, reducing reliance on follow up treatment post-emergence
The removal of as many weeds possible pre-emergence reduces the reliance on having to make a follow up herbicide application post-emergence. This can often be costly and certainly in Spring crops, the numbers of herbicides available is becoming few and far between. Controlling weeds pre-emergence will help to ensure crops establish free from weed competition.
Improves weed control in dry conditions
Whilst it is not advisable to apply residual herbicides in dry conditions, sometimes there's no other option due to the risk of not getting the spray on at all. In other situations, it may just be that the herbicide went on in good conditions and suddenly soils have become dry due to prolonged, hot dry days. Backrow will improve weed control in these situations.
Improves crops safety and water stewardship
By keeping herbicides and other crop protection products away from the crop root zone, Backrow improves crop safety, which can sometimes be a concern in very wet soils in autumn. Backrow is also a valuable water stewardship measure for herbicides and other crop protection products that may have a tendency to leach through the soil.
How Backrow works
Reduces spray drift
Backrow reduces spray drift significantly by reducing the number of droplets <100 microns which are prone to drift. It also improves deposition and coverage by improving spraying uniformity at the nozzle. This improvement in coverage maximises the number of weeds coming into contact with the herbicide at germination, leading to an increase in the number of weeds controlled.
Retains herbicide and moisture in top 5cm of soil
Backrow improves herbicide and moisture retention in the top 5cm of the soil. This increases the longevity of weed control by up to 8 weeks and increases herbicide performance in dry soils. By retaining the herbicide in the top 5cm of the soil, away from the root zone of the crop, Backrow also improves crop safety and helps to prevent the leaching of all subsequent crop protection inputs to groundwater.
Powering effective weed control
+9% increase in Black-grass control
+13% increase in broadleaved weed control
Improved efficacy in dry conditions
Improved crop safety
Case Study | Adjuvant
Backrow improves herbicide performance
Agrii agronomist, Matthew Clark, believes the addition of adjuvant Backrow to the residual mix of herbicides has an important role to play in improving herbicide performance.