Plants show a delayed response to changes in light intensity. Actually they are always a few steps behind and that reduces production. Diffuse light results in fewer changes and therefore to higher production.
If the light intensity in the greenhouse changes greatly, photosynthesis can be one third lower than when the light level stays steady. This is because the plant constantly has to get used to new circumstances.
Yet light changes continuously. Not only can a cloud move in front of the sun, light spots in the crop are constantly moving from place to place. In addition, the leaves themselves move so that they can be in or out of the light spots. The result is that there are always areas where the crop does not function optimally. Elias Kaiser of Wageningen University and Research has figured out which factors play a role and what the grower can do about them.
Stomata
It is well known that stomata need some time before they open to their maximum. This is particularly true at the start of the day. However, this is less important when the changes in light are rapid during the day. Then the stomata simply maintain their original position for a few minutes.
More important is how the enzyme Rubisco functions. This plays a very important role in capturing CO2, one of the first steps in photosynthesis. This enzyme has an active and an inactive form. The switch from inactive to active can take from 5 to 20 minutes. This explains the delay in the plant’s response to changing light conditions.
ReduFuse
A grower can’t do anything about the specific characteristics of the enzyme but can do something about the conditions; these have a lot of influence on the speed of the response.
Firstly, it’s important to prevent the light spots from continuously changing. By using ReduFuse, the light level in the greenhouse is much more uniform. The constant light level is an important explanation as to why a diffuse greenhouse roof leads to higher production. Namely the crop doesn’t constantly experience adjustment problems.
The CO2-level in the greenhouse also plays an important role. At a low level (200 ppm) it takes at least 18 minutes before photosynthesis reaches the maximum. It takes just six minutes when the level is high (800 ppm). This is because the enzyme Rubisco is activated faster at a higher CO2-level, in addition to the fact that the opening of the stomata plays less of a role when the level is high.
Humidity
Finally, humidity is important. This has an effect on the opening of the stomata. They close more at a lower humidity so less CO2 can enter. This slows down photosythesis but also Rubisco is less active at a lower level.
In summary: Prevention of changes in light by using ReduFuse and ReduFuse IR increases production. Furthermore a high CO2-level and good humidity make a positive contribution to the crops ability to respond to changes in light that occur even when a coating is present – after all, a cloud can always pass by.
For more information
Mardenkro The Netherlands
Geerstraat 8
5111 PS Baarle-Nassau
The Netherlands
T: +31 (0)13 507 70 69
Email: sales@redusystems.com
www.redusystems.com

Announcements
Job Offers
- Packing Supervisor
- Head Grower Greenhouse Canada
- Post Entry Quarantine Facility Manager
- Economic Policy Officer Agri-Tech Kentucky
- Licensing Manager North America
- Junior Sales Executive
- Fruit Breeder/Trait Discovery Scientist
- General Manager
- Regional Sales Manager – DACH Region
- Country Manager – Italy
"Tweeting Growers"
Top 5 -yesterday
Top 5 -last week
Top 5 -last month
Receive the daily newsletter in your email for free | Click here
Other news in this sector:
- 2023-01-31 Türkiye exported 145 million USD worth of flowers and plants in 2022
- 2023-01-30 CAN (ON): University of Guelph research makes growing greenhouse industry more efficient
- 2023-01-30 Use of biological control still increasing in Dutch greenhouse
- 2023-01-27 US (NC): Bringing people and plants together: A tour of the Duke Greenhouse
- 2023-01-19 Sculptural greenhouse opens up into a crown
- 2023-01-18 Winter tunnel temperature management
- 2023-01-13 Improving plant production efficiency in controlled environments
- 2023-01-12 US (MI): Keit's Greenhouse in Bay City closing after 167 years of business
- 2023-01-09 Higher light transmission and lower heat demand with double foil greenhouse
- 2023-01-09 US (PA): Beloved greenhouse shuts its doors after 50 years in business
- 2023-01-05 AR glass easy to clean, researchers conclude
- 2023-01-04 Türkiye: A “Smart Garden” system has been developed to grow 105 different plants without soil or sunlight
- 2023-01-03 Happy new year! LED lights instead of fireworks
- 2022-12-23 Ranking greenhouse floors, what is the best for your plants?
- 2022-12-20 Florists kept the prices at the same level for Teacher’s Day in Türkiye
- 2022-12-15 New chairman of Turkish greenhouse association looks ahead with roadmap
- 2022-12-12 Why retro-fitting new materials in a glasshouse can reduce energy use and costs
- 2022-12-08 Arboretum installs quarantine house and filtered rainwater system to further sustainability efforts
- 2022-12-05 US (KY): Hendon's Garden Center grows year-round with a Growspan greenhouse
- 2022-12-01 Understanding basic principles of lighting and its effect on flower crops