It’s hard to think of two things less related than military uniforms and strawberries. But apparently, they have something in common: a textile called Plant Armor.
Plant Armor is a knitted fabric that grew out of a research project aimed at making military uniforms more resistant to mosquito bites and more comfortable to wear. Somewhere along the way, researchers at North Carolina State University came up with the idea to cover strawberry plants with this fabric to increase the yield. It sounds like a pretty random idea, but it worked!
Strawberries might seem relatively easy to grow compared with some other fruits, but getting a good harvest always depends on multiple factors. Weather, pests, and water management can all affect how much fruit a plant produces. Plant Armor tackles some of these challenges, starting with the pests.
So, how does it work?
The fabric is stretched over a 1-meter-tall (3.3-ft) hoop structure made from PVC pipes, forming a dome around the strawberry plants. The setup looks very similar to a greenhouse, but there’s an important difference. Plant Armor is a porous, three-dimensional knitted fabric that acts as a physical barrier against insects without completely enclosing the plant in a controlled environment like plastic does.
Small mesh nets have been used before to keep insects away from crops such as tomatoes, cucumbers, and cabbage. But here is the issue: the mesh needs to be fine enough to prevent insects from getting through, but also not so fine that it blocks light and airflow. Plant Armor solves this dilemma. Its 3D-knitted structure allows sunlight, air, and rainwater to pass through while keeping pests out. In laboratory tests, aphids were completely unable to get through the fabric.
That said, pest protection isn’t the only advantage of Plant Armor.
Researchers found that temperatures were consistently higher under the fabric during the growing season, and this is very important for a concept called “growing degree-days.” In simple terms, plants need to accumulate a certain amount of warmth to grow and produce fruit. Because the fabric maintains a stable warmer environment and essentially acts like a small climate-control system, covered strawberry plants reached the fruiting stage sooner.
The biggest surprise came at harvest time. Strawberry plants grown under Plant Armor produced 3.56 times as many fruits as plants grown without the cover. And the most interesting part was that they produced much more fruit without growing any bigger in size or producing more leaves.
Gabriel Olawuyi
“We expected that Plant Armor’s seemingly opaque fabric would lead to an increase in vegetative biomass at the expense of fruiting – because reduced sunlight would trigger a ‘shade-avoidance’ response, making the plant divert energy toward stem and leaf growth rather than fruit production," says Gabriel Olawuyi, lead author of an Agriculture paper on the research. "However, we found the fabric did not impede access to light at all, and fruit production increased significantly.”
The next step is to test Plant Armor beyond the laboratory – on commercial farms, in different locations and with different crops. If this success can be repeated in real-world farming conditions, it means that in the future farmers could get bigger harvests sooner while using fewer chemical pesticides and less additional watering.
Source: North Carolina State University