- Christine Law
- business tech reporter
Here’s an elegant and simple solution to an age-old problem: keep your crops safe from harm by covering them.
Nets are commonly used to keep pests at bay in vegetable production, especially in high-value areas like seeds.
However, according to Mirella Aoun, an agronomist and researcher at Bishop’s University in Quebec, Canada, who has studied agricultural nets for more than a decade, the use of nets in fruit production has yet to be explored and tested. I’m here.
Professor Aoun explains that initially, fruit growers put nets on trees mainly to protect them from hail damage. Now they are experimenting with nets that can protect against insects.
The mesh size of the insect net is determined by local conditions, including the nature of the insects.
Of course, that could shut out the insects that farmers really want: pollinators like bees.
One option is to apply the net after the pollination period. Another is to open the net during the day and bring in the beehive.
Tree nets are particularly established in apple orchards in France and Italy. Nets hung on rows of apple trees Restricts codling moth movement and egg laying. This allowed farmers to control persistent pests and reduce the use of costly and environmentally harmful chemical pesticides.
Fruit lovers also benefit. “When we see less pesticide residues from crops under the control net, it is good news for consumers,” says Professor Aoun.
The net is also seen as a way to tackle the effects of climate change. Warming is causing a resurgence of certain insects and diseases.
Some areas are seeing droughts and heavy rains during more severe periods, and nets can help with that.
For example, depending on location, net type, and usage, net systems can prevent solar radiation that leads to heat stress and inhibits photosynthesis in trees.
However, the introduction of nets can result in a more humid environment around the trees. This does not help crops prone to fungal disease in humid climates like the northeastern United States and Canada.
However, some researchers working on hydrophobic netsthe treatment with botanical pesticides makes the net inherently water repellent.
Photoselective (colored) nets can also affect light transmission. A dark, opaque net reduces light intensity but not light quality.
The pearlescent net scatters the light better, allowing it to reach more parts of the plant. On the other hand, the blue, red, and yellow nets filter specific solar wavelengths, so they can stimulate specific plant responses related to fruit quality.
According to Professor Aoun, tweaking net usage often results in more high-caliber fruit.As her research in the Mediterranean It has been shown that trees covered with colored shade nets can produce larger, brighter colored fruits.
The net is not always the answer. May not be suitable for small, diverse orchards. Also, it is not necessary for all climatic conditions.
Also, the nets used for fruit trees are usually made of polyethylene, which is not ideal for a world that is moving away from its dependence on plastic.
One company working on non-plastic nets is Texinov, a French technical textile company. Texinov is researching different types of biodegradable nets, including those made from flax.
The company has already introduced a biodegradable net made from polylactic acid (PLA) produced by fermenting corn. This kind of net requires industrial composting to break down, and sales manager Adrian Etienne says it’s about 10% more expensive than traditional nets.
According to Etienne, biodegradable nets are now more popular in Europe than in North America.This may be linked to European policies aimed at reduction Use insecticide. Etienne says, among cherry farmers in France, for example, “I think mosquito nets will become more prevalent because pesticides are less prevalent.”
Initial costs are a barrier for some farmers. “Mosquito nets, of course, are a little more expensive than insecticides,” admits Etienne.
Texinov’s cheapest net sells for around €0.50 (44 pence) per square meter for personal use in France, according to Etienne. This type of net only lasts one or two seasons, while heavy climate protection nets last much longer. Durability depends on factors such as sun exposure. “The sun makes the nets more fragile,” says Etienne.
Overall, Professor Aoun says prices are dropping as products become more diverse and accessible. “In general, the net’s positive impacts outweigh the negatives,” she summarizes.
Jean-Marc Rochon heads the apple tree nursery Pépinière Rochon in Quebec and keeps an eye on the progress of the net.
“In my eyes, the technology is more in the development and refinement phase than in large-scale applications,” he says.
Net cost isn’t the only factor for Rochon to start using nets on his apple trees. “I see it more as a way to rethink how we do things,” he explains.
To be viable in his nursery, the net must be reliable and not cause overload. It should also be usable in large orchard sections.
Clearly, improvements in technology and communication are needed to convince more fruit growers of the usefulness of the net.
However, Professor Aoun believes that “as we move towards more climate challenges and unpredictable weather, net-based protective cultivation is the way forward.”