Full LED lighting system helps produce high-quality lettuce

Located in Burton, Ohio, Great Lakes Growers has grown the lettuce growing business he started in 2011 into more than 85,000 square feet of production greenhouses in just six years.

Bonner started Great Lakes Growers after recognizing the growing customer demand for locally grown, pesticide-free produce. The initial planting area was only 300 square feet, but after rapid development, the company can now produce about 1.4 million head lettuces per year.

At the beginning of Bonner's business, traditional high-pressure sodium lamps were used to meet the needs of crop supplementary light, and the prospect of LED supplementary light aroused Bonner's interest. After spending a lot of time learning and researching LEDs, Bonner decided to experiment in-house.

During an expansion in 2016, Bonner designated an LED supplemental light test area so that he could carry out field supplementary light research by himself. Bonner designed a supplementary light control experiment to track and compare the growth difference of lettuce under 600W high pressure sodium lamp and LED supplementary light. With the support of Signify's LED plant lighting partner AgriNomix and Signify's senior plant expert Dr. Abhay Thosar, Bonne installed Philips LED toplight modules in the lettuce test area.

Bonner explained his trial process in an interview with Greenhouse Management, "Three days a week we collect data about plant growth, such as size, color, spacing and growth time, and import it into a data sheet for evaluation."

Bonner observed that lettuce showed some quantitative growth advantages under LED supplemental light, such as faster production speed, increased yield and increased dry weight. At the same time, it also showed many qualitative improvements, such as better coloration and reduced risk of dry heartburn. Bonner said: "After using LED fill light, the lettuce leaves are more green, more saturated, and the taste is better." Replaced with Philips LED top light module.

Bonner then decided to experiment with LED lighting on spice plants. Due to the very good results in the early stage of the experiment, Bonner installed Philips LED toplight modules in the entire spice planting area before the whole experiment was over. At present, the Great Lakes Growers greenhouse has all applied the Philips LED supplementary lighting system.

Bonner expects the greenhouse to increase production by about 30% with the new lighting system.