Combination chemicals tackling weeds
COMBINING preemergence sprays with a residual herbicide adjuvant, such as Backrow Max from Interagro, is recommended to help pulse growers combat yieldreducing weeds eectively before spring, as stated by Interagro’s technical manager, Stuart Sutherland. Given the unpredictable weather which can limit spraying opportunities, utilising this approach is critical, especially since pulse crops are vulnerable to weed competition and can experience yield losses up to 40%.
Unlike more robust cereals and oilseed rape, pulses have limited postemergence herbicide options, making preemergence applications vital. Sutherland emphasises the importance of getting the weed control strategy right from the start to maximise returns, especially a¢er a challenging autumn and winter. He suggests that using a residual herbicide adjuvant like Backrow Max can significantly enhance the eectiveness of these
applications.
Backrow Max is designed to reduce spray dri¢ and increase the coverage and uptake of pre-emergence herbicides, which is crucial for ensuring that applications remain on target. The adjuvant helps in minimising the formation of droplets prone to dri¢ and run-o, thus maintaining a more optimal droplet size for application.
Another significant advantage of Backrow Max is its ability to improve
herbicide retention in the soil’s top 5cm, known as the ‘kill zone’ where weed germination primarily occurs. A¢er wet conditions, as seen in recent seasons, soil moisture can increase herbicide mobility, risking leaching to the crop seeds and potentially harming emerging seedlings. Backrow Max eectively counters this by enhancing the soil’s ability to hold onto the herbicide, particularly in the case of herbicides like imazamox and clomazone, which are more susceptible to being washed away.
In addition to retention, Backrow Max also maximises herbicide uptake, which is particularly beneficial in light soils that may dry out. If conditions become too dry for optimal herbicide action, Stuart advises delaying application until more favourable moisture conditions are forecast. However, for herbicides with a longer half-life, such as pendimethalin, it’s feasible to apply earlier as they will remain active until conditions improve.
Field trials have shown that Backrow Max can increase the eectiveness of herbicide treatments by up to 33% in dry conditions, underscoring its value in enhancing overall weed control ecacy. This makes it an essential part of the strategy for successful pulse cultivation, according to Sutherland, especially as these crops gain prominence in agricultural rotations and face increasing risks from weed competition.