Arable
Spot sprayer being trialled in the field.
Dramatic reduction in crop damage using targeted spray technology Targeted spraying technology for herbicide applications in onions and other root crops could be the way forward to help growers to keep input costs down while minimising both crop and environmental damage. Heather Briggs reports. Technology which has been combined so growers can keep on top of the weed burden without damaging the crop is showing great promise in onion crops, reports Tom Neat of Techneat Engineering. “One of the key benefits of this technology is the reduction in crop damage; normally the herbicide knocks the crop development back by four or five days but with targeted spraying this is dramatically reduced,” says Mr Neat. “This means that in a season that lasts from March to September, with fortnightly passes to spray herbicides using conventional spray methods, growers can lose
around 24 growing days.” Developed by Dr Nick Tillett and his colleagues at Tillett & Hague Technology, who were previously based at Silsoe Research, the tech comprises a computer vision-based weed detection system that uses a combined nozzle and valve system capable of switching on and off very quickly to apply herbicide with precision to the centimetre. Key to preventing dripping has been a small dead volume in the valve, explains Dr Tillett, adding that his sprinkler nozzles produce large droplets to reduce the threat from spray drift. Nozzles are typically
Prototype spot sprayer developed at Lincoln University.
placed every 10cm or so to provide high resolution. Dr Tillett, who also designs control systems for mechanical weeders, highlights a connection with this technology because both use interrow guidance, and points to the growing interest and popularity of such technologies because of fewer herbicides available in the plant protection tool box.
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work to be done. Mr Neat says: “We are still at an early stage of trialling the applicator in the field, carrying out tests on various planting arrangements to ensure the technology effectively identifies misplaced broad-leaved weeds between crop rows, and applies the herbicide safely.” Interrow guidance can also be used for band spraying, and although
If you have ten people hand hoeing in the field, there is a huge labour cost – and it can take up to two weeks to do just one field, whereas with a spot sprayer you can cover the same area in less than a day. “Weeds are different from the crop in their position, size, shape and small degree colour, so these are the key criteria for identification.” He was also a key player in previous work commissioned by AHDB Horticulture, working with the Silsoe Spray Application Unit, and explored control of volunteer potatoes in onion, leek and carrot crops. At the time, the work was more of an insurance policy for growers, as there were mixes of herbicides to control the volunteers – but the withdrawal of some of these has changed some grower priorities, and there is now renewed interest in the technology. However, there is still
the herbicide being used with the technology is Starane (fluroxypyr), it would also be capable of using a different product over the crop and between the rows, he adds. “As need grows, the cost benefit from these systems starts to really make sense to growers.”
Spot sprayer shows massive potential On-farm trials on onion crops have shown a 93 per cent reduction in chemistry use thanks to this spot spraying technology, reveals Matt Starling, assistant farm manager at Waldersey Farms. The farms, which are based on the continued over…
16 www.farmersguide.co.uk September 2021
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