GENERAL INFORMATION ON CULTIVATION OF VEGETABLES
Vegetable plants have specific thermal requirements, luminous, water and soil, which should be taken into account when growing them, to get the results you want. In terms of heat requirements, vegetable plants are divided into three groups:
a) with low thermal requirements, so resistant to cold and frost, on the other hand, it does not tolerate high temperatures well (above 20-25 ° C); this group belongs to: pea, cauliflower, cabbage, radish and radish, for, lettuce, spinach, which grow best at 10-18 ° C;
b) with moderate thermal requirements; this group belongs to: onions, celery, Chinese cabbage, broccoli;
c) with high thermal requirements (the so-called. thermophilic), so sensitive to cold (below 5 ° C) and hating frosts; the optimal temperature for their growth is 16-23 ° C; this group includes: beans, tomato, paprika, cucumber, pumpkin, melon, kawon.
So that some species of vegetables can bloom and bear fruit, they must be subjected to relatively low temperatures for a shorter or longer period, which for many is from 0 do 10°C, for others it is higher. This process is called vernalization. It is undesirable in the cultivation of vegetables for consumption, because premature breakout in flower shoots (the so-called. haste), e.g. cabbage, celery, red beet, it lowers their value or makes them unfit for consumption. Therefore, you should not sow or plant vernalizing plants too early in the spring, and their seedlings should not be tempered by exposure to cold.
Vegetables are generally photophilous plants, therefore they do not grow well in shady places. However, they have different sensitivity to shading: e.g. tomatoes and cucumbers are very sensitive, onion, cabbage and red beets – less, and rhubarb, sorrel and spinach – least. The sensitivity of vegetable plants to light deficiency is particularly high after emergence, what should be borne in mind when producing seedlings. The length of the exposure period during the day is also of great importance, which is the length of the day, because plants can only bloom for a certain day length. In this regard, we divide the plants into three groups:
a) short-day plants, from countries closer to the equator; they bloom on a day of 10 hours or less, e.g. military;
b) long day plants, blooming on a 14-hour day or longer; they include e.g.: radish, lettuce, spinach;
c) plants indifferent to the length of the day; their flowering does not depend on the length of the day; these plants include e.g.: tomato, cucumber, pumpkin, beans.
Knowing how the plants react to the length of the day, we will know, when to sow them; i tak np. long day plants should not be sown in summer, because they will strike the seed shoots. However, you must know, that varieties of one species may differ in day length requirements.
Fresh vegetables contain a lot of water in their tissues and therefore require a lot of water for proper growth. Water shortage causes a loss of delicacy and juiciness (the so-called. ingestion or woodworking), in many vegetables, thus lowering their value.
However, excess water is also undesirable, because the vegetables then become watery, distasteful, not very aromatic, and if heavy rainfall falls after a drought, to np. tomato, cabbage and carrots break easily and then they are poorly preserved.
The main source of water is precipitation, however, the amount of which only in southern Poland may be sufficient for the cultivation of vegetable plants. However, because the distribution of precipitation during the growing season is not always favorable, vegetables grown in our gardens should be watered. Assesses itself, that the vegetable plants on the surface 100 m2 is needed to produce a good yield from 360 do 780 m3 of water, depending on the plant species, type of soil etc.. Calculated, that plants exploit approx 55% rainwater, we need to provide them with the rest by watering them with watering cans, hose or sprinkler, whichever is the case, what source of water do we have.
Air humidity is also important for the growth of vegetables. Vegetables generally have high soil requirements, however, until the soil in our garden is treated to the maximum extent, we can choose the cultivated species and varieties according to the soil conditions, bearing in mind, however, the following principles:
a) the earliest vegetables can only be grown successfully in warm soils, airy, drying out quickly and warming up in spring; these are lighter soils, with a high content of humus, provided by abundant organic fertilization;
b) the highest yields of vegetables are achieved on medium heavy soils, well-fertilized;
c) peat soils are well suited for growing most vegetables, if proper fertilization is applied, however, they are not suitable for thermophilic vegetables.