NC State Textile Cover Lifts Strawberry Yield 3.56-Fold in Tunnel Tests

A three-dimensional textile crop cover developed at North Carolina State University increased harvestable strawberry production by 3.56 times in tunnel field tests, according to research published in the journal Agriculture. The result is unusually large, but the researchers are also clear that broader on-farm testing is still needed before the technology’s performance can be generalized across crops, regions or commercial systems.

The material, called Plant Armor, is a porous knitted fabric placed over plants. Its structure is designed to make it difficult for insects to reach the crop while still allowing light, rain and airflow through the cover. In the strawberry trials, covered plants produced significantly more fruit by number and weight without a significant increase in vegetative biomass.

The cover changed temperature without blocking light

Researchers initially expected the apparently opaque fabric might reduce light and trigger a shade-avoidance response, pushing plants toward stems and leaves rather than fruit. The field results did not show that effect. NC State reported that light access and relative humidity were not negatively affected, while the cover consistently increased temperature around the plants.

That warming effect may have helped the strawberries accumulate growing degree-days more quickly and move through developmental stages toward fruiting. The researchers reported no difference in vegetative biomass between covered and uncovered plants, suggesting that the higher harvestable yield was not simply the result of larger plants.

Insect exclusion is a second part of the technology

In laboratory bioassays, the fabric provided complete aphid exclusion. That creates a second potential value proposition beyond yield: a physical barrier that could reduce reliance on some insecticide applications. The study did not establish a universal pesticide-reduction rate, however, and commercial pest pressure varies widely by crop, season and location.

Plant Armor grew out of earlier textile research aimed at making military clothing more resistant to mosquito bites and more comfortable under body armor. The strawberry version is patented by NC State and licensed for commercial development, illustrating how a material developed for one use can move into crop protection through applied research.

The next stage is the important one for growers. The authors say on-farm testing is needed across different crops and geographies. Commercial adoption will depend not only on yield response, but also on fabric cost, installation and removal labor, durability, compatibility with irrigation and harvest operations, pest complexes and whether the cover produces repeatable gains outside the experimental tunnel system.