Fluence by OSRAM released results from its intercanopy lighting research in collaboration with Wageningen University & Research (WUR). Fluence’s research showed that intercanopy lighting treatments at a high intensity combined with top light increased yield in Hi Power and Skyson cucumber cultivars as well as Merlice and Brioso tomato cultivars.
Following Fluence’s multiyear research on the overall effects of broad-spectrum lighting solutions on plant development, Fluence and WUR further investigated the effects of various light distributions and intensities on plant morphology and fruit quality throughout a winter season.
“Growers have used the same benchmarks for vine crop lighting strategies for decades. Those benchmarks were typically derived from crops grown under high-pressure sodium fixtures that limited potential light intensity due to excess heat,” said David Hawley, principal scientist for Fluence. “LEDs virtually eliminate that restriction. As Fluence seeks to explore how to empower growers to be as productive as possible by maximizing their bottom lines, we wanted to investigate not only how higher intensities affect crops, but how crops use energy within the canopy. Our research overwhelmingly showed that intercanopy lighting in tandem with a top light strategy at a higher intensity boosted yields over conventional lighting strategies.”
Fluence and WUR studied cucumbers and tomatoes in the Netherlands under four light treatments: top light only at 250 µmol/m-2/s-1, top light and intercanopy lighting at 250 µmol/m-2/s-1, top light only at 375 µmol/m-2/s-1, and top light and intercanopy lighting at 375 µmol/m-2/s-1. Under the treatments with both top light and intercanopy lighting, two-thirds of the total PPFD were applied to the top of the canopy with Fluence’s VYPR luminaire, with the other third applied through Fluence’s VYNE intercanopy light.
Key findings from the studies include:
- Adding intercanopy lighting at the higher total intensity increased cumulative yield in both cucumber cultivars up to 110% compared to the top light-only treatment at the lower intensity.
- Similarly, adding intercanopy lighting at the higher total intensity enabled a less aggressive pruning strategy that, in combination with the higher light intensity, also increased the cumulative number of cucumber fruits in both cultivars up to 53% compared to the top light-only treatment at the lower intensity.
- Both cucumber cultivars also saw a decrease in total plant height and more compact morphology at the higher intensity treatments.
- Adding intercanopy lighting at the higher total intensity also increased cumulative yield and the total number of fruits up to 62% and 57%, respectively, in both tomato cultivars over the top light-only treatment at the lower intensity.
To ensure high-quality crops year-round, cucumber and tomato greenhouse growers often explore supplemental lighting strategies to adequately light plants during darker fall and winter months. With Fluence and WUR’s latest intercanopy lighting research, growers can now consider additional light distribution options to optimize yield and quality to meet their cultivation goals.