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Miniature robots could cut pesticide use on farms in future


Robots could also reduce food waste and help harvest crops,but they may not be commercially available for some years to come, say experts

A demonstration of a weeding robot on a farm in Saint-Hilaire-en-Woevre, France

 A demonstration of a weeding robot on a farm in Saint-Hilaire-en-Woevre, France. Photograph: Jean-Christophe Verhaegen/AFP/Getty Images

Miniature robot farmers may be the answer to concerns overchemical use on farms and cutting down on food waste, as well as easing labourshortages, academic farming experts have said.

The drawback is that the machines in question, whiledeveloped in laboratories to an advanced stage, are not yet commerciallyavailable in the UK. In an optimistic scenario, they could become available inas little as three years, but that would be likely to take large investment anda high degree of entrepreneurialism in the private sector, the experts said onMonday.

Robots set to work in the fields would be able to targetpesticides to the plants that need them, in contrast to current practices,dubbed “spray and pray”, which waste 95% to 99% of pesticides and herbicides becausethey are blanketed across entire fields. Most of this is wasted, but itpromotes resistance among pests and weeds, rendering the harsh chemicalsineffective and encouraging farmers to use more. Some pesticides used in thisway are also harmful to pollinators, such as bees, and their blanket use hasbeen banned.

“Farmers have been heavily reliant for decades on the heavyuse of pesticides. Some spraying is very desperate,” said Toby Bruce, professorof insect chemical ecology at Keele University. “Farmers are spraying [chemicals]to which there is resistance. They will not be killing pests as the pests haveevolved resistance. They will be killing other insects [such as pollinators].”

If instead such products were used in tiny quantities anddirected by robots so that 100% of the pesticide was going straight to theplant needed, then it might be possible to resume the use of banned orrestricted pesticides, said Prof Simon Blackmore, head of robotic agricultureat Harper Adams University. Such targeted use would prevent pests from taking ahold on crops, but would be so small it would cause minimal harm to bees, andbe less likely to give rise to resistance.

Robots would also be able to detect when fruit andvegetables were becoming malformed, which gives them a lower market value, andwhen they were too small to be harvested, allowing the harvesting to wait untilthey are ready. This would reduce food waste, said Blackmore.

Robots have the additional advantage that they could, ifthey become available soon, ease the pain of Brexit already being felt by somefarmers, who are concerned about shortages of cheap imported labour needed tobring in their crops from the field.

But Blackmore and Ji Zhou, a project leader at the EarlhamInstitute, noted that while lab development of such technology is now at anadvanced stage, more will be needed to bring it to market. Many farm technologycompanies are wedded to the existing model of large vehicles and blanketspraying, and fear the destruction of their business model from more targetedand higher-tech approaches.

“I think the innovation will come from start-ups,” saidBlackmore. “We need to see more start-ups in this field.”

Bruce added that a complementary approach in reducingpesticide use was for chemicals companies and farmers to work with biotechexperts to use already available technology such as pheromone traps, whichcapture pests without using pesticides and give an indication of whether pestsare present and in quantities that require spraying.

He said experts were also increasingly using plants’ owngenetic qualities to repel pests, citing the example of the orange wheatblossom midge, a pest to which some strains of wheat naturally developed theirown defences. Those strains are now incorporated into 60% of the UK’s wheatcrop, reducing the need for pesticides.