A pre-emergent herbicide that is effective in dry-sowing conditions
Finding a pre-emergent herbicide that works effectively in a dry-sowing condition can be tricky.
BOXER GOLD® provides growers with greater flexibility and convenience by allowing up to seven days between the time of application and the requirement for incorporation via the sowing operation.
The active ingredients in BOXER GOLD have very low volatility and do not readily photodegrade, meaning less product loss in the vapour phase and breakdown in sunlight. This is a major advantage over other pre-emergent products including trifluralin (TriflurX®), pendimethalin (Stomp®) and triallate (Avadex® Xtra).
Mechanical incorporation of BOXER GOLD minimises the reliance on rainfall to wash the product into the weed seed zone and increases the reliability of performance.
Although no significant reduction in weed control is likely when leaving the product for seven days prior to incorporation, incorporation as soon as possible after application is always preferred.
Some points to consider when using BOXER GOLD in dry sowing situations:
- When applied under dry sowing conditions, BOXER GOLD will experience minimal breakdown when incorporated, until activated by moisture (rainfall). - Any moisture in the soil will begin the degradation process and must be taken into account when applying BOXER GOLD in this situation, as the length of residual control will be affected.
- Sufficient soil moisture and rainfall during weed emergence is the single most important climatic factor influencing BOXER GOLD performance. - As with most pre-emergent herbicides, if sufficient rainfall is not received to fully activate BOXER GOLD the level of weed control may be reduced.
- Differences between how the various pre-emergent products are taken up by emerging weeds will also influence the level of weed control under dry or marginal moisture conditions. BOXER GOLD is absorbed primarily through the mesocotyl of the plant; the first section of the coleoptile above the seed. Trifluralin acts on the coleoptile itself, stopping the emerging weed seed from reaching the surface. In contrast, pyroxasulfone (sakura®) is principally absorbed through the roots. This raises a challenge if the weed germinates and the herbicide isn’t below the seed as uptake will be limited. In contrast, BOXER GOLD and trifluralin work on the seed as it grows through the treated herbicide layer of the soil, stopping it from reaching the surface.
- Where BOXER GOLD is being applied in a dry sowing situation and rain is not forecast within 3-4 weeks, it is recommended (where soil pH, rainfall, resistance status is known and cropping rotations are suitable) that a mix with LOGRAN® B-POWER is applied to maximise ryegrass efficacy and to broaden the weed spectrum.
- Although BOXER GOLD has a higher relative solubility than trifluralin, BOXER GOLD is still likely to bind to organic matter, including existing crop residue.
- Areas with greater than 40-50% soil cover with stubble are likely to reduce the level of weed control.
- In stubble situations, use higher water volumes (>70L/ha) to maximise the amount of herbicide reaching the soil.
- Consider the weed pressure likely in each paddock being treated. Areas with high weed populations would be better treated after a germinating rain with a knockdown herbicide (eg SPRAY.SEED® or GRAMOXONE® 360 PRO) to reduce the weed pressure on the pre-emergent herbicide. Additionally, for paddocks with high weed burdens growers should look to adopt other IWM tactics including crop competition and harvest weed seed control measures to manage weed seed population numbers.
- If heavy rainfall occurs after BOXER GOLD has been applied to dry soil, there may be an increased risk of active ingredient washing into the crop seed zone and therefore increased risk of crop damage.
Whilst BOXER GOLD can be used successfully in a dry sowing situation, the above points need to be considered and discussed carefully by the advisor with the client in order to make an appropriately informed decision.
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*Sakura is a registered product of Bayer.