Influence of environmental factors on the growth and productivity of vegetable crops

on their impact

The growth and development of plants is a manifestation of the genetic characteristics of a cultivar under specific conditions. In nature, plants are influenced by a complex of environmental factors in various combinations and intensities. All of them are conventionally divided into four groups:

1. climatic factors (including cosmic ones) — light, temperature, atmospheric air composition, its movement, humidity;

2. soil (edaphic) factors — physical state, chemical composition, supply of mineral nutrients, soil moisture level, etc.

Some researchers combine these two groups into one, called abiotic factors;

3. biotic factors — the influence of neighboring plants, microorganisms, and animals;

4. anthropogenic factors — human influence (the use of mechanical and chemical means, surgical intervention, and the creation of high-performance technologies that cause environmental pollution). Climatic and soil factors directly affect the plant, while others act mainly indirectly, through means used in agricultural techniques, as well as substances that pollute the atmosphere and water, worsening conditions for plant growth and development, which sometimes leads to the suppression of grown crops and the accumulation of chemical compounds harmful to humans in the harvest.

All the listed factors are interconnected and interdependent. A lack of sunlight leads to a decrease in temperature. A dry wind leads to a decrease in soil moisture, which negatively affects the mobility of soil nutrients and their absorption by plants. Excessively high temperatures can lead to similar consequences. Therefore, it is necessary to determine which factor (or factors) is in deficit or excess and neutralize them to create favorable conditions that promote active harvest accumulation. But to solve this problem, one must know the plant's reaction to the action of the external environment. The assessment of this reaction is carried out not unambiguously, but according to three indicators that must be taken into account when performing various elements of the cultivation technology of crops: plant requirements, resistance, and responsiveness.

Requirement for environmental conditions — the plant's need for soil moisture, a certain ambient temperature, concentration of soil nutrients, etc., and the duration of these factors' action.

Resistance — the ability to tolerate extreme environmental conditions (minimum and maximum manifestations) under which the plant remains alive, but its metabolism is somewhat disturbed and there is no accumulation of vegetative mass. The more active the growth processes, the more difficult it is for the plant to tolerate extreme conditions; sudden transitions from optimal to extreme are especially dangerous. In unfavorable conditions, plants or their organs in a dormant state are the least vulnerable.

Responsiveness — the plant's reaction to changes in external factors, for example, an increase or decrease in temperature, a change in the concentration of mineral nutrients, etc. The greatest responsiveness is manifested during the period of intense growth and the formation of product organs. It is more pronounced in early-ripening cultivars. But each crop has its own peculiarities of reaction to changes in growing conditions.

Optimization of vegetable crop growing conditions

The ways to solve the problem of creating external conditions that correspond to the genetically determined requirements of vegetable plants for environmental factors are complex, but have long been known. Vegetable growers have determined zones and timing for cultivation, to the conditions of which the vegetable crops common in various regions are adapted.

Increasing plant resistance to unfavorable conditions is achieved by using known techniques to increase plant viability:

• selection and preparation of seed;
• hardening of young plants;
• application of growth stimulants, etc.

But in parallel with this, creative work is underway to improve the genetic potential of vegetable plants' resistance to extreme conditions and diseases by introducing resistant wild species into the breeding process when creating cultivars and heterotic hybrids.

The role of protected soil in vegetable growing

Great importance is attached to protected soil, where it is possible to create an optimal combination of environmental factors and change them in accordance with the level of requirement characteristic of each stage of plant growth and development. But for this, it is necessary to know the reaction of vegetable crops and even cultivars to each of the environmental factors and their mutual influence.