An Israeli start-up company has developed a mechanical pollination system that it says will help ensure the continued production of nutritious food.
There is concern about the decline of pollinators and its effects on food production. Pollinators play a critical role in moving pollen from male to female parts of the plant that result in the growth of seed distribution mechanisms, like fruit.
Claims of a dire ecological calamity aside, one Guelph environmental sciences professor says mechanical pollination has potential in some instances. There are, however, many practical challenges.
Why it matters: Mechanical pollination technologies might be more useful for specific production needs, not as a total replacement for natural pollinators.
Edete, the Israeli company, is doing commercial field trials of its mechanical pollination system in Australian and Israeli almond orchards. Resembling a beefed-up television antenna, the system shoots pollen at flowering trees as it’s driven down the orchard row.
The system relies on a two-step process.
Edete mechanically harvests flowers, separates, and stores pollen in two separate production facilities. The process ensures pollen remains viable for a considerable period of time, and overcomes “the problem of desynchronization of different cultivars’ blooms.” That is, accounting for the specific pollination needs of different crop species.
At application, the pollen is blown onto trees using the company’s 2B mechanical pollinator unit. Lidar sensors are used to apply the pollen from the most effective distance to each part of the tree. The pollen is applied via electrostatic deposition – where a material is deposited as a liquid but quickly evaporates to form a solid coating.
As described on the company’s website, 2B units can operate day and night. They are also quick in covering any open flower in range, and not limited by low temperatures. Growers also have the ability to match the best pollen to their crops, and at the most optimal time, guaranteeing or potentially increasing yield.
An expensive process
According to Peter Kevan, a University of Guelph researcher specializing in applied ecology, pollination biology, apiculture, plant breeding systems, and other areas of ecology, the prospect of mechanical pollination has potential, but is by no means a new phenomenon.
Early examples include the manual pollination of date trees in the Middle East, and oil palms in Southeast Asia – the former example dating back to prehistoric times. Greenhouse growers used to vibrate plants to release pollen in more recent times, but the practice has since been abandoned in favour of bumble bees.
Though not familiar with Edete’s system, knowledge of similar technologies leads Kevan to suspect it is indeed an effective tool. However, cost is likely the most critical factor hindering wider adoption.
“Costs have to include gathering pollen in order to put it in the machine,” he says. “There’s a whole technology associated with that. Getting it collected for more artificial distribution, that’s been worked out for a few economically important plants. That would include pome fruits and probably almonds.”
A complicating factor is the variability of pollen types, and how long they stay viable. Some pollen is only viable for a few minutes after being released from the plant. If that’s the type of pollen required for a crop, extraction, delivery, and application would be even more challenging.
Despite these costs, Kevan says mechanical pollination could still be a valuable tool for some crops – and not necessarily because of concerns around the decline of pollinating insects.
Like Edete suggests, it could be used to improve yields, timing of harvest, and other production factors for higher value crops. Pollination via bees also doesn’t happen in adverse weather conditions, so mechanical methods could be used during those times. In lower value field crops, such as canola, it might also be useful in the production of hybrids. The machinery used to mechanically pollinate could itself take a variety of forms as well, including drones.
“Again, it comes down to the whole issue of cost. I think there are a lot of problems with mechanical pollination,” says Kevan. “The potential is there. It’s one of these things I think should be tried, but ultimately, whether it’s going to be cost effective, that to me is really what we get down to.”
Potential impacts on quality
Fundamentally, Kevan is unsure if those developing mechanical pollination technologies are asking the right questions, or more specifically, putting enough effort towards understanding the nuances of natural pollination.
He describes the introduction of self-compatible sunflowers as an illustrative example. When the varieties were introduced several decades ago, growers were led to believe they would not need pollinators. Unfortunately, seed quality turned out to be poor compared to those from cross-pollinated plants.
“Basically, the growers were trading honeybee pollination for a 20 per cent reduction in crop…Nobody really calculated that out in terms of what it was worth for the sunflower growers,” says Kevan. He adds a similar challenge occurred with soybeans in Brazil, where growers determined the presence of honeybees helped pods develop more seeds.
“Someone has to do the cost benefit. We haven’t been able to get anywhere with that, not in Canada with the major seed producing companies.”
Honeybees doing well in many areas
Overall, Kevan reiterates many pollinator populations are not declining. Canada’s honeybee population, for example, is doing well, as is Mexico’s. The two countries contrast with the United States, where beekeepers have in fact seen major declines.
Declines in wild pollinators are a concern too. However, Kevan believes there is a large gulf between dropping populations and claims of imminent global food catastrophe.
“It’s a jump from the rusty patch bee is in decline, therefore food prices are going to shoot up 50 per cent. It’s adding two and two, and making 24,” he says.
“We definitely need to be watching our pollinators, and beekeepers have every right to be concerned about losing their bee stocks to diseases and pesticides and various other things…Overall Canada’s beekeepers have done a wonderful job.”