Do your PLANTS suffer too HOT in SUMMER?
Thermal stress in plants.
Plants need water and mild temperatures to live and grow. High temperatures can be a problem because they decrease the amount of water available for evaporation from the soil and cause thermal stress to the plants. If there is not additional input of water, plants also suffer from water stress, thereby reducing the surface of the leaves to lose less water. If you also have an excess of light intensity may suffer oxidative damage.
- Reduction of leaf area.
- Inhibition of photosynthesis and respiration.
- Irreversible cytoplasmic dehydration.
- Premature aging and abscission processes.
- Reduction of growth.
Regulation of the temperature in greenhouses.
Greenhouses get very mild daytime temperatures in winter thanks the solar radiation through the walls (plastic or glass) hots the indoor and same walls does not let the heat escape. Greenhouse effect.
But in summer, although best natural ventilation systems, heat inside the greenhouse can exceed the limits permitted by plants, especially at noon. In addition, an excess of light intensity can also damage the crop productivity.
Parasol with inclined plates above the greenhouse.
If you put a support structure on the greenhouse with some umbrellas oriented “up”, you will get all the sun in winter and partial shade in summer. Enhances the production of your crops.
Below I explain how. You can first consult the links at the bottom of this post for better understanding.
Parasol in winter.
The most important thing is to determine the angle of the blades relative to the ground so you can get all the sun on the greenhouse in winter. This angle is determined by the following formula:
90 ° – latitude of the location in degrees – 23 degrees.
The Latitude where you are on land are the degrees to equator. The value of -23 ° are the degrees of the sun when is lower in winter compared to the equinoxes.
If the plates are white on the bottom, you will get an additional reflection of light and radiation on the greenhouse in the morning and evening, increasing production in winter.
Parasol in summer.
The goal the hood is to lower insolation in the central hours of the day in summer, the most critical for plants. The tilt can be locked, according to the winter formula above. What matters here is the distance between the sheets you leave to enter more or less solar radiation between the sun visors.
The space between plates must take into account the inclination of the sun on the summer solstice: 90 º – Latitudeº +23º . If you leave important openings, more direct light will enter the greenhouse.
If you leave almost no separation, there will be a semi-darkness at noon, but there will still radiation at dawn and dusk, on the wings. If you want even more shade, that umbrellas structure can be extended to the sides, east and west.
You’ll find the profitability of the hood if you can do it with very cheap materials, resistant to sun, wind and weather. Also, if you really have a problem of thermal stress, water stress and excess light intensity in your summer crops that hurt your sales and your income.
What do you think? Do you see feasible to do a test area? Your critical opinions interest us.
- Sun and Shadow in your Rural Building (I). Equinox and Solstice.
- Use Sun and Shadow in your Rural Building (II) Solar Parasol (albertcampi.me)
- Sun and Shadow in Rural Building (and III) DIY Solar Parasol (albertcampi.me)
- Sun and Shadow in your Cellar.
- DIY Greenhouse made using recycled windows (mybigearth.com)
- Build a Better Greenhouse (green-trust.org)
- Start your seeds in the MHS greenhouse this spring! (growingfoodandsustainability.wordpress.com)