Arable
Top tips for getting the most out of herbicides Heavy reliance is often placed on herbicides to target a wide range of weeds, so it is important to maximise their performance in order to get the most out of applications this spring. At this time in the arable season, many farmers across the country will be planning their spring herbicide programmes and will be hoping to achieve smooth and effective weed control in the most efficient way. Adam Espir (pictured), commercial technical manager at FMC, says growers can achieve successful knock down of weeds this spring if they take into consideration the four key factors which can impact the performance of herbicides.
Working around weather conditions Mr Espir explains that weather is a factor that can greatly help or hinder weed control during the spring, so it is important not to take it for granted. “Weeds thrive in warm and wet weather, so after a prolonged period of these conditions a welldeveloped canopy of weeds can quickly appear. “This means it’s important to pay attention to the weather conditions throughout the spring, but particularly when you’re getting to the stage of making applications,” he says. Herbicide applications are best made when weeds are small and actively growing, but Mr Espir points out that sometimes this early growth stage, which is ideal for herbicide activity, doesn’t always coincide with ideal spraying conditions. “If conditions are particularly dry, weeds can develop waxy leaves and stems which help the plant to retain water. However, these can then make it difficult for the plant to take up herbicides, potentially reducing efficacy. “In these circumstances, delaying application until after a period of wet weather and allowing weeds to begin actively growing again can achieve better success,” he recommends. On the other hand, if there is a prolonged period of heavy wet weather, it may be hard to travel on the fields – meaning spraying plans may need to be postponed until the ground is drier. “Weather is important whichever way you look
at it, so growers need to plan their applications in consideration of the weather and understand how it can impact herbicide performance, as best as possible,” he says.
Reducing resistance pressures with a tank mix partner Mr Espir explains the use of a tank mix partner is also important when applying herbicides, but especially when using sulfonylurea (SU) herbicides. SU herbicides have been a mainstay of the arable grower’s armoury for over 30 years and, due to their reliability, remain an important part of a grower’s toolkit in the spring. “A tank mix partner is a second herbicide that’s used alongside the originally chosen product. Tank mix partners help to prolong the life of SU herbicides such as Ally Max SX by reducing the risk of resistance, so I would always encourage growers to use another herbicide with a different mode of action in tandem with their chosen SU herbicide. “By bringing in a different mode of action, growers can increase the speed of kill on weeds, with visible results seen much sooner. They will also be able to broaden the spectrum of weeds targeted with just one application.” “Currently, very few broadleaf weeds have been confirmed as resistant to SU herbicides. A small number of mayweed, chickweed, and poppy populations have been identified as resistant, but thanks to tank mixing, this resistance is manageable and is unlikely to become a big issue,” he explains. Mr Espir advises any growers concerned about resistance or looking to learn more about potential tank mix partners to speak to their agronomist.
Using the correct equipment for good coverage Ensuring adequate herbicide coverage of the target is key to successfully eradicating weeds.
“Coverage is determined by the equipment used and the application rate of both herbicide and water, so growers need to thoroughly plan this before applications,” says Mr Espir. “For example, if the crop is particularly dense, applications should be made with a high-water volume, up to 300 litres/ha. “Using sprayer nozzles which are appropriate for the specific target species can also help to ensure the weeds are well covered by any applications. “Always check the herbicide label before use to ensure you’re applying it at the correct rate and with the right equipment,” he adds.
Sprayer hygiene The final step to consider is sprayer hygiene, arguably one of the most important practices farmers should undertake when it comes to spraying. “If sprayers aren’t properly cleaned out, it could cause devastating impacts to crops and leave growers out of pocket,” warns Mr Espir. Residues from herbicides can linger in sprayers after use, which can cause blockages and reduce the efficacy of the sprayer. There is also a heightened risk of contamination, as residues can wash out in subsequent applications, potentially causing damage to sensitive crops. “Following good hygiene practices is critical. Thoroughly wash out sprayers soon after each use to avoid any issues,” he says. The use of a liquid sprayer cleaner, such as All Clear Extra, specifically formulated for SU herbicides, can help to wash out any remaining residues. Mr Espir adds that it is particularly important for growers to use a tank cleaner and carry out a full washout procedure on sprayers if they are moving on from a cereal to a broad-leaved crop such as sugar beet, OSR or potatoes, as residues could cause significant damage. “By taking the weather into consideration, using a tank mix partner with suitable equipment and carrying out proper sprayer hygiene, growers should be able to successfully control emerging spring weeds and get the most out of their investment this spring,” he concludes. FG
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