Robotics may eventually provide the solution to labour shortages in the soft fruit sector but the breakthrough is five or 10 years away.
AHDB’s recent SmartHort conference at Stratford-upon-Avon heard Dr Michael Stoelen from the University of Plymouth describe a prototype robotic arm which can pick a raspberry without damaging it in 12 seconds, however they believe once the robot is commercialised they can half the time it takes.
Scottish growers harvested 280 ha of raspberries in 2018, nearly all grown under cover, but the area is likely to decline unless the harvesting problem is solved.
Fewer EU nationals are coming to Scotland for seasonal work and the position may become more acute after Brexit.
Dr Stoelen said: “These initial robots will not replace manual labour.
“What we expect is that they will be able to pick the more accessible fruit with human pickers there to pick the fruit which the machine is not yet able to.
“The challenge with designing robots such as these is not just in the delicate nature of the raspberry, but also ensuring they can cope with having people around them, as well as other complicating factors such as poles, sunlight and complex foliage.”
Dr Stoelen’s team has focused on human biology as the inspiration for the robots, developing an arm which mimics a human’s ability to shift between being robust and delicate as required.
“We looked at human muscles, such as the biceps and triceps, and the way humans can flex and stiffen those muscles depending on the situation,” he added.
“We have also been using ‘deep learning’ to build a large database of raspberries which will make it easier for the robot to classify and grade them.”
James Porter, NFU Scotland soft fruit committee chairman and large scale grower, said: “This is interesting but if it will only pick the easiest half of the fruit it will not work. The picker following it up will have to walk just as far to pick a half crop.
“It is the total cost per kilogram picked that is important and this is unlikely to be economical.
“On paper we should have enough pickers for this year but that is provided we are not faced with a no-deal Brexit. That would be disaster.”