When the first day of the apple harvest rolled around in Washington State last year, the fruit was ripe and the pickers were ready – but the weather had other ideas.
“It was like 38C… it’s not safe for people to work in that heat,” recalls Joel Carter at Okanagan Specialty Fruits. “We had to stop at 10 o’clock in the morning.”
He says that artificial intelligence (AI) models that forecast ideal harvest dates, taking into account the weather, would be useful. “You need to know more than just when your fruit is going to be ripe. How long do you have to pick it?” he says. “That’s where these models are really helpful.”
Carter’s company has more than 1,250 acres of apple orchards in Washington, and the fruit is grown for sliced apple portions – often sold to hotels and schools, for example. The firm is investing in technology with the hope of maximising productivity. Even the apples are genetically engineered so that they don’t brown easily once cut.
But planning a harvest is tricky. New tools that count and analyse fruit on the tree or vine, and predict when crops will ripen, are emerging. It matters because prices for fruit, especially high-value berries such as strawberries or blueberries can fluctuate wildly. Getting the harvest date wrong means you book seasonal workers when you don’t actually need them, and risk missing out on the biggest profits.
Okanagan Specialty Fruits is already experimenting with cameras from a Canadian firm called Vivid Machines. The cameras are mounted atop tractors and they scoop up imagery of the apple trees as the tractor trundles by. AI identifies buds, flowers or fruit in that footage.
“Right now, Vivid is telling us crop estimates and harvest dates,” says Carter. He notes that the system is good at picking out very tiny flower buds, which are hard to see at a glance with the naked eye.
But the accuracy of forecasts is noticeably dependent on the quality of historical information fed in to the system, adds Carter. “This isn’t something where an AI can scrape the internet and figure out what’s the average [yield] for Granny Smith,” he explains. “It’s going to be bespoke to your farm.”
Apples are at least somewhat forgiving – the harvest window for those Granny Smiths is three weeks long, says Carter. For other fruit, such as berries, you might only have a few days.
“If a strawberry crop is on, you have to harvest it – otherwise your entire crop gets diseased very, very quickly,” says Raymond Martin, co-founder and chief operating officer of FruitCast, a UK company that offers harvest forecasts to fruit growers here.
His firm offers growers crop predictions for strawberries and also raspberries, blackberries, blueberries and tomatoes. “We’re moving on to grapes next year,” adds Martin.
Don’t experienced farmers know when their fruit will be ripe, I ask? Martin says they generally do – but not necessarily across their entire farm, which might be many acres in size, or have both outdoor and indoor growing areas. “We do exactly what the farmers could do but we just do it on a scale that they can’t.”
The system analyses footage of ripening fruit that can be captured by drones, someone walking up and down a field with a smartphone, or a camera mounted on a farm vehicle.
This year has been challenging, notes Martin, with hot weather and severe drought hitting much of the UK. This has stressed many fruit plants, putting them into thermal dormancy and slowing down fruit production.
