Enjoy Those Strawberries Longer: PhylloLux Innovation Leads the Way

Advances in technology, automation, and remote sensing is a cross-cutting, macro movement in science impacting agriculture outlined in the USDA Science Blueprint (PDF, 2.6 MB). The Science Blueprint guides USDA’s science priorities for the next 5 years, building from past success. Relative to other crops, many specialty crops are more dependent on agricultural labor for production, harvesting, and processing. This is part of a blog series that highlights research investments to advance automation and mechanization for specialty crops.

We’ve all enjoyed some delicious strawberries this summer, but a short-shelf life can limit that enjoyment. One of the biggest challenges in U.S. strawberry production is managing diseases and pests. The fungal pathogen Botrytis cinerea results in gray mold, or the unappetizing gray fuzz that can quickly appear on strawberries all too soon after we get them home. Growers typically apply fungicides on a weekly basis to control gray mold as well as other fungal diseases.

Agricultural Research Service (ARS) researchers developed an alternative technology called PhylloLux, which combines Ultraviolet-C (UV-C) irradiation followed by a specific dark period. UV-C kills microbes by damaging their DNA, but doses required to kill fungal pathogens can also damage plant leaves and fruit. ARS researchers found that including a dark period after irradiation prevents activation of a daylight-induced mechanism that repairs DNA damage in microbes and allows for much shorter UV-C irradiation times. The resulting UV-C/dark (UV-C/d) treatment of strawberry plants twice per week, as suggested for commercial application, did not affect nutritional values of strawberry fruit.

To move the technology to commercial use, ARS scientists first developed a self-propelled, fully automated and programable apparatus that was used for night-time irradiation of strawberries in a high tunnel culture. In 2019, a second robot was developed for autonomous application of UV-C/d in commercial strawberry fields. Preliminary results from two farms in Delaware indicate the UV-C/d application was as good as weekly fungicide sprays.

The combination of innovation in approach to disease management and in application through new technology is a result of close collaboration between plant pathologists, horticulturists, entomologists and engineers. In fall 2020 larger California pilot tests are planned for targeted pests, including aphids, thrips, scale insects, and slugs.

PhylloLux is a prime example of innovation in agriculture production as a solution for farmers, consumers, and the environment in support of the USDA Agriculture Innovation Agenda goal to increase U.S. agricultural production by 40 percent while cutting the environmental footprint of U.S. agriculture in half by 2050. Growers can benefit from the resulting drastic kill of fungal plant pathogens causing gray mold, powdery mildew, and anthracnose. The new method is also an effective control for spider mites, further reducing produce loss to growers. Reducing pesticide use improves environmental outcomes and has potential for organic as well as conventional production. And we’ll all benefit from enjoying those strawberries longer.

This research supports the “value-added innovation” theme outlined in the USDA Science Blueprint and moves us closer to meeting the goals outlined in USDA’s Agriculture Innovation Agenda.