Anti-mosquito fabric: 3.56 times more strawberries in lab tests

Strawberry plants under a fabric made to keep mosquitoes off soldiers produced 3.56 times as many fruits as plants left bare. The test took place in a laboratory, and the plants did not grow larger to do it.

The fabric is called Plant Armor. It came out of a research project aimed at making military uniforms more resistant to mosquito bites and more comfortable to wear. At North Carolina State University, researchers then had an idea that looked almost random: cover strawberry plants with the same knitted material. Strawberries are not an easy crop. Weather, pests and water all change how much fruit a plant gives, and growers already use fine mesh nets against insects on crops such as tomatoes, cucumbers and cabbage. The problem with those nets is that the mesh has to be fine enough to stop insects, but not so fine that it blocks light and airflow.

Plant Armor is a porous, three-dimensional knit. Stretched over a hoop of plastic pipes (PVC) about one metre tall, it forms a dome over the plants. Unlike a plastic greenhouse, it does not seal the plants into a closed space. According to the researchers, its 3D structure lets sunlight, air and rainwater through while keeping pests out. In laboratory tests, aphids, tiny sap-sucking insects, could not get through the fabric at all. The cover also kept temperatures consistently higher during the growing season. Plants need a certain accumulated amount of warmth to develop, and the covered plants reached the fruiting stage sooner.

The result that surprised the team came at harvest. The covered plants did not grow bigger and did not produce more leaves. They simply produced far more fruit. Gabriel Olawuyi, lead author of the paper published in the journal Agriculture, had expected the opposite: "We expected that Plant Armor's seemingly opaque fabric would lead to an increase in vegetative biomass at the expense of fruiting," he says. "However, we found the fabric did not impede access to light at all, and fruit production increased significantly."

For a farmer, the question is when and for whom this could matter. The answer is not yet known. These are laboratory results, and the team says the next step is to test Plant Armor on commercial farms, in different places and with other crops. If the gain holds in real growing conditions, the researchers see a path to bigger harvests arriving sooner, with fewer chemical pesticides and less additional watering. Until those field trials are done, the 3.56 figure remains a result from the lab, not a promise for growers.