Today I want to draw your attention to the effect of temperature on plants. It is no secret that each type of plant is adapted to a certain climatic zone, which is characterized by certain temperatures. The temperature changes throughout the year and day, somewhere in the tropics it is insignificant, and in our middle zone - from 40 degrees in summer to -30 in winter. Temperature changes have become part of the plant's life cycle: it got warmer - the buds started, autumn colds - we shed the leaves. Temperature often deceives even the biological clock of plants.

The main problem of apartments is excess heat... The temperature is often stable in the apartment, and any fluctuations in the microclimate of the room do not at all coincide with the atmospheric ones outside the window.

Let's look at each season and see how we can help our garden grasses adapt to the microclimate of our apartments.

Summer

Let's first consider the option without air conditioning. It would seem that the room temperature in summer is close to the conditions of open ground. But it turns out that in fact the temperature in the apartment is slightly higher than the outside temperature - we close the windows when we go to work, the glass creates a greenhouse effect, there is not the slightest draft ... Here are just the greenhouse effect against the background of dry air, not high humidity. In the evening, when the plants become half asleep, we arrange ventilators for them.

Air conditioning in the house also dries the air a little, so spray the plants in the morning and evening, put in cups of water. You can get a decorative mini-waterfall. The air flow from the air conditioner should not shake the leaves of the plants - the draft is poorly tolerated not only by ornamental indoor plants, but also by herbs.

Solution: place cups of water between the pots. Moisture will help plants survive the summer heat. Shade the plants, for example, by attaching sheets of white paper or reflective sheeting to the glass (in case the windows face south and southeast).

You can help the plant adapt a little to the heat with phytohormones. For example Epin or Zircon. These preparations increase the plant's resistance to dryness, heat, soil changes and lack of light.

Autumn and winter

From October, most of our perennial spices gradually go into a dormant stage, wither away and wait for the moment when we find a cool, dark place for them. Such conditions are needed, for example, oregano (oregano). It can be a glazed loggia, where the temperature does not drop below 5 degrees in winter. Wintering herbs in an apartment deserves a separate article.

In winter, in our average apartment, the temperature did not rise above 18 degrees. The windowsill, on which the plants stand, heats up more, drying out the soil.

Solution: I do this - I roll up a bath towel and put it between the windowsill and the radiator, thereby dissipating the heat. However, this is true for plants that do not fall asleep, such as rosemary and thyme. Although they should be sent to a cooler (10-12 degrees), but bright place.

Spring

In the spring, our grasses begin a phase of intensive growth, we transplant the plants - it is during this period that the plants need a little more heat. Spring does not always come according to the calendar, so a little heating may be needed.

Solution: I practice warm watering, about 30 degrees.

Air out rooms in the evenings, regardless of the season. This is useful not only for plants, but also for us.

Plant growth is highly temperature dependent and can occur from zero to 35 °.

The growth rate at temperatures above 35-40 ° decreases, and with a further increase it transforms.

Different plants have different attitudes to temperature. Some plants are thermophilic and require a higher temperature to grow. Other plants are more tolerant to cold temperatures and are susceptible to excessive temperatures.

By regulating the temperature regime in conjunction with other living conditions, it is possible to control growth, that is, to suspend it or bring it to an optimal level. It should be borne in mind that it is impossible to act with heat to accelerate or slow down growth without providing the plant with light and moisture.

To get stocky plants quickly, you need more light, heat and moisture (to optimal sizes).

The effect of temperature on the plant is very often used in greenhouses. For accelerated growth, plants are provided with an elevated temperature from the early stages of development to flowering. This method accelerates the growth and development of a plant, but it is not always taken into account that plants grown at a higher temperature turn out to be weaker in vitality than those developed at a lower temperature. Plants grown in greenhouses at higher temperatures in living quarters quickly lose their decorative effect.

When cultivating plants in greenhouses, you need to pay attention to this and not release products for sale that quickly die in rooms.

An example of an erroneous temperature effect on plants is the cultivation of summer seedlings at elevated temperatures. The seedlings are good in appearance, but poorly adapted to the adversity of open ground (short-lived).

If the plant finishes its growth earlier than planned, it is placed in a room with a low temperature to retard growth. If the plant is not squat, but somewhat elongated, it is placed in a cooler room overnight. For greater decorativeness of plants, it is always necessary to reduce the temperature in the premises at night. A gradual and temporary decrease in temperature, repeated several times, increases the resistance of thermophilic plants to low temperatures.

The increase in cold resistance of plants is achieved by sowing seeds directly into open ground. In this case, the seedlings can withstand frosts of 2-3 °. Seedlings of many plants grown in greenhouses and hotbeds die in the ground at -1, -2 °.

Increasing plant resistance to low temperatures can be achieved by breeding cold-resistant varieties, "cooling" the seeds, etc.

Temperature conditions also affect the release of seeds from dormancy (stratification), as well as their subsequent germination. This mode is also important for the passage of the rest period. Plants that come from northern latitudes need organic rest. Without going through dormancy at low temperatures, they will not grow and develop well in the future. To accelerate the passage of organic dormancy, you need to provide the plant with a low temperature.

If it is necessary to postpone the onset of dormancy or to prolong its period, conditions are created for the plant that are unfavorable for the passage of organic dormancy, that is, they do not give an appropriate low temperature.

If the organic dormancy has passed, in order to retard growth or prolong the forced dormancy, the plants are again placed in conditions of low temperatures.

An increase in temperature during forced rest reduces the latter.

To delay the germination of some tubers, bulbs and seeds, snow is used or trenches with frozen soil are used to keep them.

Keeping seeds in early spring at a temperature of 5-20 °, especially in sunlight, ensures their ripening within 7-10 days; at temperatures around 0, this process is very slow. The increased temperature in August favors the ripening of the bulbs.

The retardation of plant growth in open ground in spring is affected by trampling of snow and covering it with manure around the plant.

The air temperature also affects the respiration of plants, which becomes more intense at elevated temperatures.

In winter, when there is almost no accumulation of organic matter under insufficient lighting, it is necessary, by providing the plant with a slightly lower temperature, to reduce the intensity of respiration. This also applies to bulbs, tubers and rhizomes preserved in winter.

plant needs

Air temperature significantly affects indoor plants, like any other living organisms on Earth. Most houseplants are native to the tropics or subtropics. In our latitudes, they are kept in greenhouses, where a special microclimate is maintained. These facts may lead to the mistaken belief that all indoor flowers need to maintain a high air temperature.

In fact, only a small part of the plants can grow in our apartments at elevated temperatures (over 24 ° C). This is due to the fact that our conditions are noticeably different from the natural habitat in greater dryness, as well as less intensity and duration of illumination. Therefore, for the comfortable growth of indoor plants at home, you need to make an amendment to the air temperature, which should be lower than in their homeland.

1. Thermal conditions for indoor plants

How does temperature affect plants?

The temperature regime is measured by the amount of heat and the duration of exposure to a certain temperature. For indoor plants, there are minimum and maximum temperature limits within which their normal development occurs (the so-called temperature range).

Cold air slows down physiological and biochemical processes - a decrease in the intensity of photosynthesis, respiration, production and distribution of organic matter. With an increase in temperature, these processes are activated.

Natural temperature fluctuations

Rhythmic changes in the amount of heat occur both during the day (change of day and night) and throughout the year (change of seasons). Plants have adapted to similar fluctuations that exist in their natural habitats. So, the inhabitants of the tropics react negatively to sudden changes in temperature, and the inhabitants of temperate latitudes can tolerate their significant fluctuations. Moreover, during the cold period, they have a period of rest, which is necessary for their further active development.

With a large difference between summer and winter, day and night temperatures (wide temperature range), it is best to grow ficuses, aloe, clivia, sansevier and aspidistra.

General rule: it should be 2-3 ° C cooler at night than during the day.

Optimum temperature

For the normal growth of tropical flowering and decorative deciduous plants, a temperature of 20-25 ° C is required (for all aroids, begonias, bromeliads, mulberries, etc.). Plants of the genus Peperomia, Coleus, Sanchecia, etc. develop best at 18-20 ° C. Residents of the subtropics (zebrina, fatsia, ivy, aucuba, tetrastigma, etc.) will feel comfortable at 15-18 ° C.

The most demanding for heat are tropical variegated plants - cordilina, codieum, caladium, etc.

Winter temperatures and dormant periods

In winter, some plants need coolness because their growth process is slowed down or they are dormant. For example, for eucalyptus and rhododendrons in winter, a temperature of 5-8 ° C is desirable, for hydrangea, primrose, cyclamen and pelargonium - about 10-15 ° C.

Another example. To force plants such as Scherzer's anthurium, Sprenger's asparagus and Wallis spathiphyllum to bloom even more intensely, during the dormant period in the fall, the air temperature is lowered to 15-18 ° C, and in January it is raised to 20-22 ° C.

A common reason for the lack of flowering is non-observance of the natural rhythm of plant life - their dormant period.

For example, cacti, which in winter, at moderate temperatures and regular watering, give ugly growths and cease to bloom. Hippeastrum ceases to lay buds, and cannot please with anything except green leaves.

Is soil temperature important?

Typically, the temperature of the ground in a pot is 1-2 ° C lower than the ambient air. In winter, care must be taken that the pots with plants are not overcooled and do not place them close to the window glass. When the soil is overcooled, the roots begin to absorb water poorly, which leads to their rotting and the death of the plant. The best solution is a cork mat, wood, foam or cardboard pot holder.

For example, for a plant such as Dieffenbachia, the substrate temperature should be between 24-27 ° C. And such as gardenias, ficuses, eucharis, which love warm soil, you can pour warm water into trays.

2. Plant groups in relation to heat

Plants for cool places (10-16 ° C)

These include plants such as azalea, oleander, pelargonium, aspidistra, ficuses, tradescantia, roses, fuchsia, primroses, aucuba, saxifrage, ivy, cyperus, chlorophytum, araucaria, asparagus, dracaena, begonia, balsam, calanoma coleus, arrowroot, ferns, sheflera, philodendron, hoya, peperomia, spathiphylyum, etc.

Plants for moderately warm places (17-20 ° C)

At moderate temperatures, anthurium, clerodendron, saintpaulia, wax ivy, pandanus, siningia, monstera, Liviston palm, coconut palm, aphelandra, ginura, rheo, pilea will develop well

Heat-loving plants (20-25 ° С)

Feel most comfortable in the warmth: aglaonema, dieffenbachia, calathea, codieum, orchids, caladium, syngonium, dizigoteca, akalifa, etc. (read the information separately for each plant)

Plants that are dormant (5-8 ° C)

A group of plants that need rest and lower temperatures in winter: succulents, laurel, rhododendron, fatsia, chlorophytum, etc.

3. Non-observance of the thermal regime

Temperature jumps

Sudden drops in temperature are very harmful, especially by more than 6 ° C. For example, when the temperature drops to 10 ° C in Dieffenbachia spotted, the leaves begin to turn yellow and die off; at 15 ° C the golden scindapsus stops growing.

As a rule, sudden changes in temperature cause rapid yellowing and leaf fall. Therefore, if you ventilate the room in the winter, try to remove all indoor plants from the windowsill.

Temperature too low

If the temperature is too low, the plants do not bloom for a long time or form underdeveloped flowers, the leaves curl up, acquire a dark color and die off. The only exceptions are succulents, including cacti, which are adapted to high daytime and low nighttime temperatures.

It should be borne in mind that in the cold season, the temperature on the windowsill may be 1-5 ° C lower.

Too high temperature

Hot air in winter with a lack of light also negatively affects tropical plants. Especially if the nighttime temperature is higher than the daytime. In this case, during breathing at night, there is an overexpenditure of nutrients accumulated during photosynthesis during the day. The plant is depleted, shoots become unnaturally long, new leaves become smaller, old ones dry up and fall off.

Completed by: Galimova A.R

Effects of extreme temperatures on plants

In the course of evolution, plants have adapted quite well to the effects of low and high temperatures. However, these adaptations are not so perfect, so extreme extreme temperatures can cause some damage or even death of the plant. The range of temperatures acting on plants in nature is quite wide: from -77 ° C to + 55 ° C, i.e. is 132 ° C. The most favorable temperatures for the life of most terrestrial organisms are +15 - + 30 ° С.

High temperatures

Heat-resistant - mainly lower plants, such as thermophilic bacteria and blue-green algae.

This group of organisms is able to withstand temperatures up to 75-90 ° C;

The resistance of plants to low temperatures is subdivided into:

Cold resistance;

Frost resistance.

Cold resistance of plants

the ability of heat-loving plants to tolerate low positive temperatures. Heat-loving plants suffer greatly at positive low temperatures. The external symptoms of plant suffering are wilting of leaves, the appearance of necrotic spots.

Frost resistance

the ability of plants to tolerate negative temperatures. Biennial and perennial plants growing in the temperate zone are periodically exposed to low negative temperatures. Different plants have unequal resistance to this effect.

Frost-resistant plants

Influence on plants of low temperatures

With a rapid decrease in temperature, ice formation occurs inside the cell. With a gradual decrease in temperature, ice crystals are formed primarily in the intercellular spaces. The death of the cell and the organism as a whole can occur as a result of the fact that the ice crystals formed in the intercellular spaces, drawing water from the cell, cause its dehydration and at the same time exert mechanical pressure on the cytoplasm, damaging the cell structures. This causes a number of consequences - a loss of turgor, an increase in the concentration of cell juice, a sharp decrease in cell volume, a shift in pH values ​​in an unfavorable direction.

Influence on plants of low temperatures

Plasmalemma loses its semi-permeability. The work of enzymes localized on the membranes of chloroplasts and mitochondria and the processes of oxidative and photosynthetic phosphorylation associated with them are disrupted. The intensity of photosynthesis decreases, the outflow of assimilates decreases. It is the change in the properties of membranes that is the first cause of cell damage. In some cases, membrane damage occurs during thawing. Thus, if the cell has not passed the hardening process, the cytoplasm coagulates due to the combined effect of dehydration and mechanical pressure of ice crystals formed in the intercellular spaces.

Adaptation of plants to negative temperatures

There are two types of devices for the action of negative temperatures:

avoiding the damaging effect of the factor (passive adaptation)

increased survival (active adaptation).

Plant growth is possible over a relatively wide temperature range and is determined by the geographical origin of the species. The plant's temperature requirements change with age, and are different for individual plant organs (leaves, roots, fruit elements, etc.). For the growth of most agricultural plants in Russia, the lower temperature limit corresponds to the freezing point of cell sap (about -1 ...- 3 ° C), and the upper one corresponds to the coagulation of protoplasmic proteins (about 60 "C). Recall that temperature affects the biochemical processes of respiration, photosynthesis and other metabolic systems of plants, and the graphs of the dependence of plant growth and enzyme activity on temperature are similar in shape (bell-shaped curve).

Temperature optima for growth. For emergence of seedlings, a higher temperature is required than for germination of seeds (Table 22).

22. The need for seeds of field crops in biologically minimal temperatures (according to V. N. Stepanov)

Temperature, "С

germination of seeds 1 germination

Mustard, hemp, camelina 0-1 2-3

Rye, wheat, barley, oats, 1-2 4-5

peas, vetch, lentils, rank

Flax, buckwheat, lupine, beans, 3-4 5-6

nougat, beetroot, safflower

Sunflower, perilla 5-6 7-8

Corn, millet, soybeans 8-10 10-11

Beans, castor oil plant, sorghum 10-12 12-15

X-wolf, rice, sesame 12-14 14-15

When analyzing plant growth, three cardinal temperature points are distinguished: minimum (growth is just beginning), optimal (most favorable for growth) and maximum temperature (growth stops).

Distinguish plants that are quiet-loving - with minimum temperatures for growth of more than 10 "C and optimal 30-35" C (corn, cucumber, melon, pumpkin), cold-resistant - with minimum temperatures for growth in the range of 0-5 "C and optimal 25-31" WITH. The maximum temperatures for most plants are 37-44 "C, for southern ones 44-50" C. With an increase in temperature by 10 ° C in the zone of optimal values, the growth rate increases by 2-3 times. An increase in temperature above the optimum slows down growth and shortens its period. The optimum temperature for the growth of root systems is lower than for aboveground organs. The optimum for growth is higher than for photosynthesis.

It can be assumed that at high temperatures, there is a lack of ATP and NADPH, which are necessary for recovery processes, which causes growth inhibition. Optimal temperatures for growth can be unfavorable for plant development. The optimum for growth changes during the growing season and during the day, which is explained by the need for changing temperatures fixed in the plant genome, which took place in the historical homeland of plants. Many plants grow more intensively during the night.

Thermoperiodism. The growth of many plants is favored by a change in temperature during the day: increased during the day, and lowered at night. So, for tomato plants, the optimum temperature_) in the daytime is 26 "C, and at night 17-19 _C. F. Vent (1957) called this phenomenon thermoperiods. Thermoperiods! - the plant's reaction) to a periodic change of high and low temperatures, expressed in a change in growth processes and development! (M. *. Chailakhyan, 1982). Distinguish between daily and seasonal thermoperiods. For tropical plants, the difference between day and night temperatures is 3-6 ° C, for plants of the temperate zone - 5-7 "C. It is important to consider this when growing plants in the field, greenhouses and phytotrons, zoning crops and varieties of agricultural plants.

The alternation of high and low temperatures serves as a regulator? __ of the internal clock of plants, like n photope1_iodism. Relatively low night temperatures increase the humiliation of potatoes (F. Vent. 1959), the sugar content of the root crops of sugar beet, and accelerate the growth of the root system and lateral shoots * of tomato plants (NI Yakushkmna, 1980). Low temperatures possibly increase the activity of enzymes that hydrolyze starch in the leaves, and the resulting soluble forms of carbohydrates move to the roots and lateral shoots.