Many growers ask them self what is the best cultivation temperature day and night?
The culture temperature is a very important determining factor. If the growing temperature is not correct, the plant will grow less or not at all.
It has been discovered in science that the best temperature around the leaf is 24˚C for each crop for maximum growth and flowering day and night.
During the day the plant makes energy to grow (assimilation) and at night the plant uses energy to grow (breathing).
The art of cultivating is to ensure that the plant makes as much energy as possible during the day and uses as little energy as possible at night.
We can stimulate this during the day by adding a little more CO2 and lumen (light) and stimulating the evaporation under the leaves (in adult plants) by using. air circulation. Be careful of course for to high evaporation.
The biggest growth is where the gap between Assimilation and Breathing is the greatest. However, if the temperature were 3˚C higher than optimum during the day (27˚C), to get the same optimum growth at night, the difference could be brought down also with 3˚C to 21˚C.
However, the temperature should never fall below 20˚C day and night, because with temperature lower than 20˚C a Phosphor deficiency will appear.
The colder the temperature under 20˚C will be, the more difficult Phosphorus will be transported.
This also applies to the soil temperature.
When temperature becomes too hot, plants start vaporising more to keep a workable temperature. The plant will need more water.
With hydroponics you often see that the plant has enough water, but with heat it creates large fluffy flowers.
This occurs when the nutritional value (EC) is too high in the water. The plant needs to lose its heat and will therefore create more airy surface near the flower to lose heat.
This can be easily solved by lowering the EC in the water.