Bees vs drones: How tech is tackling crop pollination

TWO WELLS, Australia/MERU NATIONAL PARK, Kenya: In towering glasshouses at a tomato farm in South Australia, everything from the temperature to the ultraviolet radiation levels is tightly controlled. But despite the farm’s scientific approach, pollinating the crops can still be hit or miss.

The Perfection Fresh farm in Two Wells currently relies on workers who zip between the rows of vines on trolleys, tapping strings tied to the frames to gently shake the plants so pollen drops onto the stigmas to ensure pollination – or so they hope.

“It is largely a manual process, and this is a challenge,” said Troy Topp, general manager at Perfection Two Wells. “Eight years into this job, I’m still trying to find the most effective way to pollinate.”

With about 190 million tons produced annually, tomatoes are among the world’s most valuable crops, and are increasingly grown in protected environments as farmers face more extreme weather linked to climate change, pests and land shortages.

But pollination is a big challenge in covered environments such as glasshouses, where bees are not as effective, and mechanical methods such as tapping, brushing by hand, or using blowers and vibrating devices are labour-intensive and unreliable, growers say.

So Perfection Fresh, one of Australia’s largest tomato producers, is trying out a new technology – drones.

Turbulence from the drones’ propellers helps to maximise the vibration of the flower’s reproductive parts and disperse the pollen – leading to higher crop yields.

“Drones can solve challenges with labour availability, and be quicker and more consistent. Together with pollination, the drones can also be used for crop forecasting and disease monitoring,” Topp told the Thomson Reuters Foundation.

Alternative to nature?

As nature losses grow and many species decline globally, some researchers are investigating whether tech solutions like drones could help fill the gap, and protect global food systems.

Agriculture is among the top users of drones worldwide.

Their growing use in pollination – both in covered farming and in fields – is driven by declines in bee populations because of warmer temperatures, pesticide use, diminishing habitats and other human impacts.

Honeybees struggle in covered environments because they can become disorientated, and in Australia, which has no native bumblebees, the need for different types of pollinators is even more pressing, said Katja Hogendoorn, a research fellow at the University of Adelaide.

“We can do a lot with technology, and drones are a viable option for pollination,” said Hogendoorn, who studies native bees and pollination.

“We can’t solve for every risk with technology, but if drones can be used for mitigating risk in pollination, why not,” she said, warning that widespread drone use might allow the global horticultural industry to resume insecticide use.

But technology is often a poor replacement for the diverse benefits of natural systems, others warn.

Honeybees in Kenya, for instance, provide not just pollination services but an additional income from honey harvesting for farmers who increasingly lose crops to more extreme weather.

And in a country where human settlements are encroaching on traditional wildlife habitats – pushing elephants to raid and destroy farms, bees are being harnessed as “living fences” to protect crops by keeping the animals at bay.

“Drones cannot perform all the duties that the bees are doing in the environment, they can’t compete to that level,” said Newton Simiyu, a project manager at the Born Free Foundation, the conservation charity that first developed the beehive fences.

Farmers turn to drones, AI

The trend towards data-based precision agriculture – such as the use of drones or other tools based on artificial intelligence (AI) – is driven by demographic changes, technological advances and climate change impacts on productivity, the Food and Agriculture Organization (FAO) says.

For Siddharth Jadhav, an engineer who researched drones in Singapore, their use in aerodynamically controlled pollination – using the drone’s downward draft to enable pollen dispersal – is a logical application.

They are particularly suited for self-pollinating crops such as strawberries and tomatoes, said Jadhav, who is founder and chief executive of Singapore-based tech firm Polybee, which uses off-the-shelf mini drones and its own software applications.

To be effective, the technology needs to be “robust and scalable, and easy enough for farm workers to use with minimal training”, Jadhav said.

After promising experiments in vertical farms in Singapore, Australia’s Hort Innovation – a horticulture non-profit – funded a year-long trial of Polybee’s drones to pollinate strawberries and tomatoes in covered farms.

The trial, which concluded last year, showed “drones’ effectiveness in pollinating tomatoes in glasshouses, setting the stage for further exploration and investment”, said Brett Fifield, Hort Innovation’s CEO.

After the trial at Perfection Fresh, two of Polybee’s drones – named Maverick and Goose after characters from the Top Gun film – now cover 10 rows of tomatoes. A single battery charge lasts about 40 minutes, enough to cover two rows.

The drones, which measure about 38cm (15 inches) diagonally, hover over the plants at a fixed speed, covering one side of the row first, and the other side on the return journey.

Their downward draft loosens the pollen more efficiently and consistently than blowers or tapping, Topp said. Reducing workers’ interactions with the plants can also minimise the risk of disease, he added.

“We’re not the first to try and solve pollination in glasshouses, but other methods have failed because they’re challenging to use, or consume too much labour and time, and are not precise,” said Jadhav, adding that the drones have also been tested to pollinate strawberries in Britain.

“Drones are an elegant way to solve the problem – you just programme them, and it’s a big risk off the table for growers who have so many other risks to deal with,” he added.

Not accessible to all

More than a third of the world’s food production depends on bees. Yet bees and other pollinators are declining worldwide in abundance and diversity, according to the FAO, with rising temperatures and other climate change impacts linked to the decline.

That has made alternative pollination methods all the more urgent.

Besides Polybee, others that are experimenting with drones and robots for pollination include California-based Dropcopter that dispenses pollen in almond, apple and cherry orchards, and Harvard University’s robobees that mimic the action of bees.

At Perfection Fresh the aim is to move fully to drone pollination and to use the drones’ high-resolution cameras to gather data for yield forecasting with AI.

“Solving pollination is not enough. Forecasting yield helps farmers get better prices, and also ensure better food security because accurate data is crucial for developing more resilient varietals,” Jadhav said.

Because of these benefits, the technology is also relevant in poorer countries, though cost is a barrier.

“The technology is not accessible to all, just to large companies and investors. Therein lies a threat,” said Hogendoorn.

Meanwhile, from Azerbaijan to Venezuela, attempts are underway to encourage beekeeping to preserve local bees – whose benefits to farmers sometimes go far beyond pollination.

Benefits of bees

In the rural heartlands of central Kenya, farmers living on the edge of the Meru National Park are using honeybees to combat a decades-old problem – marauding elephants that wreak havoc on their crops, sometimes even causing villagers’ deaths and prompting retaliations.

From 2000 to 2020, 1,160 elephants were killed with causes being attributed to either self-defence, or retaliatory killings, data from the ministry of tourism, wildlife and heritage shows.

But over the past year, a more harmonious solution appears to have emerged: rows of beehives are strung together on wires, forming a barrier around fields. When an elephant tries to breach the wire, it triggers the hives, sending the bees buzzing into action and prompting the elephants to flee.

“Before the beehive fences, it felt like a constant battle. The elephants used to come almost every night,” said farmer Alexander Mburung’a, 33, standing next to a large yellow wooden box containing a beehive on his 10-acre (four-hectare) maize farm bordering the national park.

“Now, the elephants keep their distance, and our crops are thriving,” he said at his farm, located 320 km (200 miles) from the capital, Nairobi.

Conservationists from the Born Free Foundation, which began the initiative in January last year, say although the project is still in its initial stages, the results have been promising.

Farmers are noticing some additional benefits, too.

Geofrey Munyua, 35, said not only have the elephants stayed away from his 1.5-acre (0.6-hectare) plot since the beehive fences were constructed, his cowpea and millet yields have increased.

“I haven’t harvested yet, but my crop yields are looking much better and will be higher this year because of the bees pollinating,” said Munyua.

“I am also hoping to harvest the honey from the hives and earn extra income,” he added.

Simiyu from the Born Free Foundation said that while technological advances such as micro-drones in pollination should be welcomed, they were no replacement for bees.

“Technology is advancing, but nature will always remain superior,” he said. – Thomson Reuters Foundation