NC State's knitted Plant Armor cover lifted tunnel strawberry yields as much as 3.56-fold

"As much as 3.56 times" is the best result in the trials, and the comparison is with strawberry plants grown with no cover at all ^[2]. In that best case, covered plants gave 256% more fruit than bare ones ^[1]. The university's release does not give the average gain across the three growing seasons ^[5] or a price for the fabric.

The comparator matters more than the multiple. A cover changes at least two things at once. The knit keeps insects off the plants ^[1], and it also warmed them steadily through all three seasons ^[5]. Gabriel Olawuyi, a graduate research assistant at NC State and the paper's lead author ^[14], said that warmth brought the covered plants to fruiting sooner ^[5]. A bare plot differs on both counts. As described, the trial cannot split the extra fruit between insect exclusion and heat.

Olawuyi's own explanation leans on heat. "Plants require a certain amount of accumulated heat, calculated as 'growing degree-days,' to progress through developmental stages including fruiting. Our plant cover has proven to enhance these," he said ^[6].

The best moment in the study is a prediction the team got wrong. "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," Olawuyi said ^[4]. Then the measurements came in. "However, we found the fabric did not impede access to light at all, and fruit production increased significantly," he said ^[15].

The pesticide case comes from the design. Olawuyi said that because the fabric physically stops insects from feeding, it could reduce the conventional pesticides fields need ^[7]. The researchers say it may also cut water use ^[8]. The results the release reports are yield, light, humidity, plant health and warmth ^[2][3][5]. I think the light result is the firm finding. The 3.56 multiple is a best case against the weakest comparator available.

Co-author R. Michael Roe, William Neal Reynolds Distinguished Professor at NC State ^[16], said the work led to "a product which could triple the output of strawberry farms here in North Carolina" ^[10]. The trials behind that statement were run in tunnels ^[2]. The North Carolina Agricultural Foundation and the USDA's National Institute of Food and Agriculture funded the work ^[12], and the paper appears in the journal Agriculture ^[13].