Signify has been delving into the effects of Philips GreenPower LED lighting, specifically the impact of far-red light on June bearing strawberries since 2019. Initial results were inconclusive regarding production enhancement, making it challenging to determine the tangible benefits for growers. Factors like plant data, variety, and cultivation sites added complexity. This prompted further research to understand the potential role of far-red light in cultivating June bearers.
Research Parameters: The study was conducted at Botany Group, focusing on two prominent strawberry varieties for winter production under artificial lighting: ‘Sonsation’ and ‘Sonata’. The setup involved six rows with varying far-red light levels, ranging from 1% to 9%. This design aimed to assess the impact on plant development, fruit appearance, and overall production. A strategic planting date in mid-October was chosen to maximize the effect of far-red lighting, given that this period typically has minimal natural light, amplifying the spectrum’s impact.
The strawberries received a total light intensity of 195 micromole/s/m2, including far-red. The lighting was maintained for a maximum of 16 hours daily, totaling around 1800 hours.
Key Findings: While the research confirmed that adding far-red light boosted overall growth (considering stem and leaf mass, both in dry and fresh weight), it didn’t enhance production in kg/m2. However, benefits were observed in stem elongation. Some strawberry varieties under full LED tend to be compact, which can result in a suboptimal microclimate around the plant. This can lead to issues like reduced crop activity, excessive moisture around fruits, and heightened root pressure, all potentially detrimental to fruit and crop quality.
Far-red light exposure can promote elongation in leaf stalks, and truss stems, mitigating these challenges. This offers more flexibility in cultivation and improved climate control. The effect was more pronounced in ‘Sensation’ compared to ‘Sonata’, emphasizing the role of variety selection. This can potentially enhance picking performance, reduce labor costs, and even decrease chemical usage.
However, the decision to use far-red light remains complex for growers. While omitting it is the most energy-efficient route, the aforementioned benefits often lead growers to incorporate 5-6% far-red light as a precautionary measure. Recognizing this, Signify has included an option for a specific percentage of far-red for June bearers in its standard recipes for several years.
Looking Ahead: The realm of full LED is rapidly evolving. Signify remains committed to staying updated, especially concerning strawberries. A notable advancement is the dynamic light module, offering color-adjustable products. This allows growers more flexibility without necessarily increasing energy consumption. Future research will further elucidate the implications for growers.
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