Water regime

The conditions of the water regime, implying the supply of moisture to the plants and maintaining the balance of the intake and flow of water by the leaves during the transpiration( moisture evaporation), are of great importance. Insufficient amount of moisture leads to slow growth processes, most stomata on the leaf plate is closed, which reduces transpiration and the intensity of processing of nutrients and synthesis. Obtaining high yields of vegetable crops is impossible without sufficient supply of plants with water. Water is an integral part of all organs of plants, in the productive part of vegetable crops it contains 65-97 %, therefore vegetable crops show increased demand for moisture. Insufficient water supply of plants reduces the commodity and taste qualities of fruits;excess leads to the fact that the vegetables become watery, contain few sugars and salts. Water - one of the elements of plant nutrition, the solvent of all the ash elements, due to which they are available to all organs of the plant in an accessible form. Water is of great importance for the regulation of plant temperature and metabolism.

Water plays an important role in plant life. It supports the necessary metabolism in them, is a part of protoplasm, cell sap and cell membranes, other organs, determines the internal tension of cells( turgor).With a lack of water, the turgor weakens and the plants wilt. With the help of water, nutrients are moved, and due to the evaporation of moisture, the temperature of the plant is regulated.

Distinguish the need and exactingness of plants for water. The need for in water is characterized by the amount of moisture necessary for normal plant growth and crop formation. The demand for water is expressed by the amount of water that the plant consumes to create a unit of dry matter, since it is known that less than 1 % consumes plant water to form various organs, the remaining 99 % are expended by the plant for transpiration. The requirements of plants for water are characterized by the optimum soil moisture level for culture, which is determined by the culture during the growing season. The need and exactingness of plants in water depend on the biological characteristics of plants, the period of their vegetation, the nature of the development of the root system and the structure of the leaf apparatus, from environmental factors such as heat, light, mineral nutrition conditions, soil type, etc.

The root system is onefrom the most important indicators of the demand for vegetable crops to soil moisture: the more powerful the root system, the more it extracts water from the soil, the higher its ability to extract water from deep layers in the dry period. In structure and size, the following types of root system of vegetable plants are distinguished:

a strongly branched root system extending to a depth and width of 2-5 m( pumpkin, beet, horseradish);

medium-branched - 1-2 m long( carrots, parsley, tomato);

highly branched surface root system located in arable layer - 15-20 cm( cabbage, cucumber, pepper, eggplant, radish, spinach);

weakly ligated root system - 10-15 cm long( bows).

According to the requirements for soil moistening conditions, vegetable crops can be divided into the following groups:

1. Plants most in need of high soil moisture, intensively consuming water and characterized by the greatest water consumption. They have a poorly developed root system and the associated weak ability to extract water from the soil and a powerful leaf surface that evaporates a lot of moisture. This is a cucumber, cabbage and cauliflower, kohlrabi, turnip, radish, lettuce, radish. Such plants with a lack of moisture stop in growth and produce a bad crop, they do not tolerate drought and need regular watering.

2. Plants that require high soil moisture, but consume water very economically - onion, turnip, onion, leek, garlic. They have a poorly developed root system and a small evaporating leaf surface.

5 - Plants, content with moderate soil moisture, but spending intensively a year - table beet, pumpkin, squash, squash, pepper, beans, peas. They are characterized by a powerful root system and a powerful leaf surface. They require sufficient moisture, but at its lack are able to extract water from deep soil layers.

4. Plants that require low soil moisture and consume water sparingly - tomato, eggplant, parsley. They have a powerful root system and a small leaf surface.

Vegetable crops should be watered, given their biological characteristics, such as type 9632;the degree of development of the plant, the area of ​​the leaf plate, and the total volume of the deciduous mass, which affects the intensity of evaporation of moisture by the plants. Cucumber, spinach, cabbage, and radish are particularly in need of water, in which the root system is poorly developed and located in the surface horizons of the soil, and the evaporating surface of the leaves is large.

It is not recommended to water plants during daylight hours in sunny weather, as most of the spilled water evaporates quickly. Watering is best done in the evening hours: 2-3 hours before sunset or early in the morning. With cloudy weather, we allow watering in the daytime.

For each growing season, this or that vegetable culture requires optimal soil moisture. The greatest need for moisture plants are tested during the swelling of seeds. During this period, the degree of moistening of the soil should be close to its full saturation. The plants also need a lot of moisture in the period of growth of the main organs, the formation of ovaries and fruits.

Vegetables require frequent watering at a low rate of water consumption. This is due primarily to their biological characteristics. The root system of most vegetable crops is concentrated in a 30-50-cm layer of soil, so there is no need for deep soaking.

It is very important to correctly establish the need for plants in moisture at each of the moments of their development and not miss the timing of watering, give moisture when they need it most. Determination of the irrigation time should be based on the state of the soil at a particular time. Different types of soils, depending on the weather conditions, the amount of precipitation, the frequency of irrigation are saturated to a different degree with moisture. To determine the moisture reserves in the soil and to establish the necessary irrigation time, one should take a handful of earth in the palm of your hand and squeeze it into a ball or roll it into a ball. If the soil moisture is below the critical level, watering is done. Particularly necessary are watering with a lack of precipitation by the middle of summer, when the stocks of spring soil moisture are completely depleted and they need to be filled with irrigation. The need for water in vegetables during the growing season is not the same. Cabbage most needs water in the growth phase of the head, root crops - in the first half of the vegetation, when they do not have the maximum roots, onion - in the phase of leaf growth. Maximum consumption of water from pumpkin, squash, patisson in the second half of July - August, in the phase of fruit formation.

Watering is needed	Watering is not needed
1. Light sandy loamy soil
No ball forming	Soil to the touch
quickly disintegrating	wet leaving
wet marks on the
filter paper
2. Lightweight	i loam
Formed in undefined-	Formed in a coherent
decaying	bead
bead
3. Medium loam
Formed in loose	Formed in a tight
bead, disintegrating	ball, leaves
when pressing	wettrace on
paper
4 - Heavy loam
Formed in a cohesive	Formed in a strong
bead, disintegrating	tight ball, sticky
when pressing	to the touch, leaves
wet trace on the
filter paper

With regular wateringin pumpkin cultures, fruit formation continues to the frosts.

If there is a lack of moisture in vegetable crops, growth stops, product quality decreases, and in the case of excess, root hairs die, as water displaces oxygen, plants affect diseases, tomato, zucchini, pumpkin, and patissoni become less sugary.

The need for vegetable crops in watering can be determined by the appearance of plants. For example, in cabbage, when there is a lack of moisture, the leaves are covered with a bluish-white coating, and their edges are somewhat twisted, the tomato leaves acquire a dark green color, the hairs on them are almost in an upright position. The leaves of cucumber and carrots darken and slightly curl. At the onion with a lack of water, the feather becomes bluish-white, the tip bends and turns yellow, and the beetroot leaves grow smaller and brighten in burgundy and violet colors. Sometimes the general state of wilting plants can be a deceptive sign, as it often occurs in too hot weather with low humidity. Therefore, when determining the timing of irrigation, it is better to be guided not only by the appearance of plants, but also by the state of the soil.

It is important to prevent the moment when watering can no longer save highly dehydrated plants.