The temperature of the soil or artificial growth medium is of great importance when growing plants. Both high and low temperatures are unfavorable for the vital activity of the root. At low temperatures, the respiration of the roots is weakened, as a result of which the absorption of water and nutrient salts is reduced. This leads to wilting and stopping the growth of the plant.
Cucumbers are especially sensitive to a decrease in temperature – a decrease in temperature to 5 ° C destroys cucumber seedlings. Leaves of adult plants wither and get burned at low temperatures of the nutrient solution in sunny weather. For this culture, the temperature of the nutrient solution should not be reduced below 12 ° C. Usually, when growing plants in greenhouses in winter, the nutrient solution stored in the tanks is at a low temperature and should be warmed up to at least the ambient temperature. The most favorable temperature for the solution used for growing cucumbers should be considered 25-30 ° C, for tomatoes, onions and other plants – 22-25 ° C.
If in winter it is necessary to warm up the substrate on which the cultivation is taking place, then in the summer, on the contrary, the plants may suffer due to its high temperature. Already at 38-40 ° C, the absorption of water and nutrients is suspended, the plants wither and may die. It is impossible to allow the heating of solutions and substrate to such a temperature. The roots of young seedlings are especially affected by high temperatures. For many crops, the temperature of 28-30 ° is already destructive.
If there is a danger of overheating, it is useful to moisten the surface of the soil with water, when it evaporates the temperature decreases. In the summer, in the practice of greenhouse farming, spraying of glass with a lime solution is widely used, which scatters the direct rays of the sun and saves the plants from overheating.
