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RED x Delphy Improvement Centre

RED Horticulture and Delphy improve tomato yields and quality thanks to a more efficient light spectrum.

14 November 2023

"At first, we thought that all crops could grow using only the red and blue spectrum. However, this is not the case. The emphasis is and will increasingly be on the light spectrum."

Lisanne Helmus

10 years of LED testing

For the past fifteen years, Delphy Improvement Centre has been working to improve production techniques, and is now one of the world’s leading experts in fruit, vegetables and flowers. In charge of greenhouse research, Lisanne Helmus focuses on field trials, which are the last step before a grower decides to invest or modify his production system.
Lisanne Helmus has made great strides in the use of LED technology since Delphy’s first greenhouse trials in 2010.

Delphy has carried out trials under LED light on all vegetable crops, including tomatoes, strawberries, cucumbers, peppers and eggplants. The main aim of the research center is to gain a better understanding of the interaction between light and crop development, which also means studying this relationship in relation to climatic conditions and irrigation strategy, in order to define cultivation itineraries for the future.

"We compared a standard Red & Blue spectrum with a broad spectrum based on the RED Horticulture strategy. The Red & Blue spectrum is defined with a strategy specific to the Dutch model. RED's strategy focuses on efficiency. It was very interesting to see RED's vision of growing under LED lighting by focusing on the spectrum."

Lisanne Helmus

2 strategies

The environmental guidelines were defined by Delphy according to the needs of the Red & Bleu spectrum. During the trial, Delphy controls the growing conditions to ensure quality production. They carry out the necessary measurements to observe the differences between the two modalities. Brix, yield and crop development are important indicators.

PPFD: Amount of PAR reaching the plant
DLI : Daily light quantity

The influence of the spectrum proven

The trial was conclusive on both sides. Lisanne was surprised by the difference between the data obtained for each modality during the winter period.

In fact, during the winter, the RED solution produced higher yields and, above all, much higher quality.
By February 8, yield under the broad spectrum was 13% higher. Brix was 8% higher.

"The amount of light was almost equal on both sides. Yet we observed a clear difference between the two modalities, certainly caused by the spectrum. When you put in the same amount of electricity, you want to use it in the most efficient way."

Lisanne Helmus

Being competitive in winter is essential, as selling prices are more advantageous for the grower.
According to Lisanne, there has been a change in mentality in the Netherlands regarding greenhouse lighting. Before, growers thought that the solution to making lighting profitable was to light as much as possible. Today, the concern is when and how to use the light parameter.

+13%

Efficiency

+8%

Brix

"RED Horticulture shows that it's possible to light in a different way, and I think this is a trend that will continue as a result of the energy transition."

Lisanne Helmus

Future of photobiology

Lisanne believes that the future of LED cultivation is based on the search for the optimum, not the maximum. The general interest will increasingly focus on taste and nutritional quality.
“To know how to implement photobiology in crop management is still a work in progress,” concludes Lisanne.

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