CO₂ is necessary for photosynthesis and is consequently essential for the growth of plants. Efficient CO₂ monitoring can optimize the growing period and increase profits. Different plants need different levels of CO₂ concentration to maximize development.

Why measure CO2 in greenhouses?

It is essential to monitor the COvalue in greenhouses at all times, since different plants have different needs. For example, C3 plants cannot store and transpire CO at the same time, because their stomata are permanently open. On the other hand, C4 plants can store COin their environment, so they do not need to keep their stomata open. A third type of plant, the CAM-plant, can only absorb COat night, since their stomata are closed during the day. 

In order to utilize COto maximum effect without risking damage, it is important to have effective control of the ventilation when growing plants. Generally, the best effect is to distribute COto young plants and parent plants regularly, and to all plants for a short period during spring. If the plant is sensitive, it is extremely important to have pure COto prevent damage. 

A good level of COis estimated to be up to 1,000 ppm. If the levels of COare too high in the greenhouse, plants can be damaged because they close their stomata more than normal. This can result in damage to the plant during warm periods. 

The concentration of COvaries considerably over the course of 24 hours. The reason for levels as high as 500 to 1,000 ppm is due to plant respiration, which is usually higher during the night, regardless of the type of plant. 

How does it work?

If all plants grow in the same conditions (including the CO level), it increases the likelihood that they can be harvested at the same time with similar results. The annual consumption of CO in a greenhouse is about 5 - 10 kg/m2, and only in exceptional cases is this exceeded. 

The positive effects of CO can vary considerably. For example, tomatoes and cucumbers can obtain a 8-10% higher return. 

In a study done by Crookshanks, Taylor, and Dolan (1998), results showed that CO enriched plants produced more biomass than other plants. These fortified plants put their new biomass into the root, to be able to develop faster, become stronger specimens, and contribute to the plant’s reproduction.


Key Benefits:

  • Higher profits
  • Less damage on the plants
  • Shorter growing period