A sharp drop in temperatures across the UK, along with a lack of moisture in some regions, has left growers facing a weed control headache.
With weeds stressed by the cold and dry conditions and not actively growing, herbicide efficacy could be compromised, leaving growers with a decision as to whether to delay the herbicide application or to go ahead and spray.
Weeds under stress are even more difficult to control, according to ADAS because the lack of soil moisture prevents uptake of herbicides through the roots. If foliage has hardened, this can slow foliar uptake as well.
One option is to wait for conditions to improve and for plants to start growing away before applying a herbicide, however as weeds get bigger, they become more difficult to kill, warn ADAS. Moreover, weeds may exceed the cut off point for herbicide application.
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Alternatively, growers can maximise the efficacy of herbicides by using high rates, avoiding coarse quality sprays and by using a combination of actives.
Given crops are also under stress, ADAS warn against over-mixing herbicides with fungicides, PGRs and insecticides, in order to minimise crop damage.
According to Dow agronomist, Stuart Jackson, cleaver control should be a priority for cereal growers. “Cleavers are a top target for growers at this time of year when they are making a decision about what to put in the sprayer.
“Failing to take them out will lead to a yield penalty and leave a problem in the field for next season. Temperatures are all over the place but growers don’t have time to wait until the warmer weather returns.
“The worst case scenario would be growers applying their traditional chemistry now, only for it to be ineffective and then having to endure the expense of repeating the job.”
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He suggests Dow’s new herbicide products – Pixxaro (Arylex + fluroxypyr) and Zypar (Arylex + florasulam) are suited to cold-weather application.
“Performance in cold and variable weather conditions is the hallmark of Arylex Active products and will be a vital tool for any growers who need to get on with spring applications without worrying about the temperature.”
Or spray now and maximise spray efficacy by…