When growing vegetable crops, it is necessary to comply with the basic temperature and humidity parameters of the air environment of cultivation facilities. The temperature and relative humidity of the air largely determine not only the yield, but also the development of plants at different stages of the growing season [1–3].

It is known [2] that the air temperature when vegetables grow depends on the considered growing season. Seeds should be sown at a temperature of 25–28 °C, and when planting seedlings — 20–23 °C. During the flowering period, its values should be in the range of 25–28 °С, and during the formation of ovaries — 20–35 °С. The best conditions for abundant fruiting are 25–30 °C. At the same time, at the initial stage, nighttime temperatures should be in the range of 16–18 °С, and then they should be increased by 3–5 °С. It is important to take into account that at temperatures below 15 °C, plant growth slows down, at 10 °C it stops, and at 9 °C and below the plant may die. During fruiting, nighttime temperatures that ensure maximum productivity are in the range of 21–23 °C. However, a long period of this temperature regime can lead to stems weakening. To avoid this, it is recommended to reduce nighttime temperatures to 18 °C for 10–14 days.

The second most important air factor influencing the growth of vegetable crops is the relative humidity of the air. At the seedling stage, its values should be minimal (70–75 %). During the growth period — not less than 90%. From the moment of flowering, humidity is reduced to 75–80 %. Low humidity leads to a slowdown in the growth, death of the ovaries.

Thus, for vegetable crops, it is obviously very important to comply with the specified air parameters at each stage of the plant growing season. Consequently, modern greenhouses must be equipped with equipment that can control and maintain the specified air parameters, taking into account the growing season, time of day, climatic conditions, etc.