More and more wide application in vegetable growing is received by hotbed constructions from synthetic films and fibreglass. At gardeners the polyethylene film, and that is why uses special popularity. First, it is much cheaper some glass, and in the qualities many times over surpasses it. It is known that ordinary glass does not pass infra-red beams without which plants cannot normally develop. The polyethylene film perfectly passes light, ultra-violet and long-wave infra-red beams. Secondly, the film freely passes oxygen and carbonic acid. Without these gases the plant cannot live. Thirdly, frost resistance of a polyethylene film reaches 70°. At svarivanii coverings it is possible to apply sources of so-called open fire to hotbeds: electrosoldering irons, candles, spirit-lamps, oil lamps and even electroirons.
From other kinds of synthetic films in vegetable growing it is recommended to use polyamide, polihlorvinilovuju and atsetobutilovuju films - they differ rigidity.
Of rigid synthetic materials do simple, convenient and cheap adaptations - protective caps. They make active growth and development of various plants because in the top part of a cap warm and damp atmosphere is formed, and through a small aperture oxygen arrives together with fresh air. Such protective caps preserve not only against sharp temperature drops, but also from wreckers who are especially dangerous in the spring.
Skeletons concern number of the elementary constructions from a synthetic film stationary, portable or as them still name, film tunnels. In such constructions it is possible to receive very early crops of vegetable cultures, especially if them to land sprouts.
However to each vegetable grower before to start installation of these constructions, it is necessary to consider all "чр" and "яЁю=шт". We give this council because behind film constructions of this kind (the same as and behind any hotbeds) constant supervision is necessary. Without daily airing, poliva and blackouts (at strong solar illumination) it will be difficult to receive good results.
the Elementary skeleton under its recommendation becomes from rods of an osier-bed, a poplar, leshchiny, willows and if there is a possibility, from a wire section 6 - 8 mm which should be protected from a rust (to paint or wind with film scraps). The handles made of a wire or rods, form a skeleton on which the film hardly stretches. The ends of wire handles need to be adhered to the wooden splittings hammered into the earth on depth no more 30 the Wire skeleton see it is possible to make portable. For this purpose handles below krepjat to wooden bruskam or weld, if the skeleton is planted on a metal pipe.
Vegetable growers-fans use for a skeleton flexible synthetic pipes (for example, polihlorvinilovye) diameter from 13 to 15 mm. These pipes on distance about 1 m from each other stick in soil on depth to 30 sm in the form of arches and fit a film. The film should be hardly tense, for this purpose it from both parties needs to be reeled up on wooden rejki which then follows prikopat the earth or to fix hooks along all skeleton.
Portable skeletons - very convenient constructions in operation which some seasons will serve. They can be established in any place of a garden site. The portable skeleton as follows is constructed: from two longitudinal reek section 4X5 sm and length 4 - 5 m and three cross-section reek in the length 1,6 m, two of which fasten along the edges and one in the middle, make a wooden skeleton. It is possible above instead of wooden reek to fix a wire. For this purpose in longitudinal frameworks drill apertures on diameter of a wire - 6, 8, 10 mm depth 2,5 - 3 see In these apertures insert the ends of arches from an iron wire with which it is necessary to paint for the purpose of protection from a rust.
For durability the skeleton in two-three places should be connected a cord or an aluminium wire, and the ends it to attach to extreme cross-section rejkam.
Hothouses with film shelters concern more, difficult constructions, suitable for long use. In them it is possible to grow up vegetables practically all year long. The candidate of agricultural sciences V.D.Davidov recommends one of designs of such construction. The hothouse the area 2 can be made of 24 m from wooden reek and to cover with a film.
The Hothouse needs to be built on well shined solntsezashchishchennom from a wind a place. In a direction from the north on the south mark a rectangle in the size 6X4 m. On its line pull out a trench depth 30 - 50 sm and do the base (i.e. Fill with its stone, rubble or other materials). On rectangle corners drive vertical racks and from above rigidly strengthen longitudinal and cross-section bars (crossbars). On cross-section crossbars establish podkosy, rejki tension, lateral and internal basic struts. After a skeleton establishment cover its film. It needs to be strengthened so that it was not blown up anywhere, differently the film long will not serve.
At operation of all kinds of constructions with a film covering it is necessary to remember the following:
- during hot time a film slightly open or completely remove, that plants have not overheated;
- all film constructions it is necessary to have on length from the north on the south is improves their light exposure, progrevaemost and raises a crop of plants;
- the film covering on each square metre should have from 150 to 500 apertures (distance between apertures from 5 to 8 sm). Apertures can be made by means of a drill directly in a roll (diameter of a drill from 10 to 12 mm). The film punched thus facilitates air access, does not interfere with penetration of rain water to plants.
To Punch a film it is possible and in another way: to combine it in some layers and to punch apertures a metal pipe with the pointed ends, diameter of a tube 5 - 6 mm, the distance between apertures can be from 25 to 30 see
Very important correctly to find a film for a skeleton covering. For durability it is necessary, that the length of the cut off piece of a film was on 130 smbolshe lengths of the skeleton that it was possible to cover well the face parties, the width also should be more on ' 30 smshiriny a skeleton. It will simplify fastening of a film from sides.
In all cases the film should be strong and is densely strengthened on a skeleton. Do it by means of tetrahedral or round reek. In 2 - 3 coils wind film edge on one rejku, and then on it beat another rejku.
That the strong and equal seam has turned out at a fastening of two panels, two take metal rejki, put between them the stuck together ends so that they spoke on behalf of edges reek on 2 sm and, slowly spending a source of fire along film edge, weld it, receiving thus a strong and equal seam.
The Old film which was in the use badly gives in to restoration. To rivet holes it is possible only a piece of a new film not were in the use. Thus from below it is necessary to enclose a board upholstered with rubber or several layers of a fabric (any, except silk and synthetics), and from above on a film to put cellophane or any paper. For pasting usually use an iron.
Often a film buy in rolls on metres or on weight. Thus it is necessary to know that at a thickness of a film (for example, polyethylene) 0,05 mm in 1 kg contain 20 m 2 , and at a thickness of 0,1 mm in 1 kg - 10 m 2 .
Many vegetable growers use a polyamide film perfol (PC). It is colourless, steklovidna. Through it well passes ultra-violet light.
The Sizes of a film considerably vary under the influence of temperature and humidity. At cooling and humidifying the length of a film increases to 15%, width to 8%, at rise in temperature these sizes accordingly decrease. Therefore at a film tension on a skeleton do an allowance on each linear metre 12 - 15 sm on length and 8 - 9 sm on width, stacking a film oblong folds.
At use of this film it is necessary to remember that it absorbs a moisture considerable quantity (to 12%), bulking up, forms bags with water. Water needs to be shaken from a film after a rain. The angle of slope of the skeleton covered by a polyamide film, should be 27 - 30°.
Stick together a film glue "¤--5". A thin layer of glue put on an edge of one of cloths, on it impose an edge of the second cloth, and a joint warm up a hot iron.
In film constructions the height of any skeleton should be not less than 40 see Then plants will not adjoin to a film. It will protect them from obmerzanija in a cold season and solar burns in the spring.