- PLANTATION OF A VINEYARD

- CLIMATOLOGY IN GRAPE GROWING



PLANTATION OF A VINEYARD

A series of factors important exists to have present when it is going away to establish a commercial plantation of grapevines, which will throughout influence the period of development and production of a culture.

The investment to establish one hectare of grapevines enough is lifted and any error that is committed in the plantation can bring about problems that later would go in decline of the production.

Therefore, it is necessary to consider at any moment that an investment of this type is long term, reason why is necessary to consider the best elements for the success in the establishment of a parronal.

CLIMATE

For a optimum development of the grapevine, a dry climate is adapted, with moderate temperatures to warm by a period of long time and with invier to us cold. The humid summers, besides affecting the maturity and quality of the grape, favor the development of plagues and diseases.

The previous thing, therefore, is a obstacle the development of grape growing in many areas particularly coastal zones. The local variations affect the election of the varieties, you practice cultural and the quality of the product.

Other factors to consider are: strong frosts, winds, pluviometry under conditions of dry land, etc.

ELECTION OF THE LAND


A land destined to the commercial plantation of grapevines must meet certain conditions so that, once in production, this it stays uniformly in the possible maximum.

The serious ideal to choose a land that have not had grapevines in the last 10 years, nor that have not either been used with susceptible cultures to nematodes and/or diseases radiculares, like for example, tomato, pepper, red pepper, etc.

In case of having a ground infested with nematodes, he is highly recommendable to fumigate the hole of plantation (3 m2), before carrying out it, with the intention of reducing to the risks of problems radiculares.

The factors most important to consider in the election of the land are:

Water availability.


In the zone of irrigation, the availability must be permanent, or within a security rank so that before a period of drought the plantation is not in danger.

This factor is vitally important, where the cycles of drought can last several years in some valleys or sectors. In the zone of dry land, the water availability has a direct relation with the depth of the ground, texture, content of organic matter, handling of the ground and topographic location.


For example, in low lands (fertile valleys) there is an originating water availability to a large extent, of the superficial lifted land draining but.

Depth of the ground.

The grapevine is a plant of deep arraigamiento, that develops an ample system to radicular; of, that most advisable is to select deep grounds, (here greater to 1.5 mts.): In zones where it is not had this type of grounds, a ground could be considered thinner whenever it does not have drainage problems.

Jointly with the depth, the fertility of the ground is important, since fertile and deep grounds favor a greater harvest reducing the production costs. Also it is important to worry about the salinity of the ground and high concentrations of some elements.

Topography.

The flat lands or of very little slope are those that produce less problems for the general handling of the vineyard, nevertheless, is possible to use grounds with pronounced slopes, controlling the erosion by means of plantations in contours.

Also the relief of the terrain, that is to say, those depressions will have to be considered or knolls of small surfaces. The depth of the ground would determine in this case the type of machinery that will be able to be used to make level or to match the microrelief. If the profile is very thin and with topography as well injured, it will only allow to one slight emparejadura and one plantation in contour.

In zones of dry land, the uneven topography is not objectionable and until it can be advantageous.

The topography of the land also will be determining the system of conduction of the vineyard.

Drainage.

Most of the worked plants cannot survive or they are seen very limited in its development if their roots remain for a long time without I oxygenate.

In a saturated ground, the water moves the air of the spaces between particles and therefore the content is limited of I oxygenate, bringing about an asphyxia by the roots. That's why it is important to consider this factor since the grapevine by its deep arraigamiento needs a good drainage. For this reason, those lands of low position that can have been fertile valleys in years of abundant precipitation, do not have to be considered for a future plantation unless it is qualified to them with a good system of drainage. This same one is been worth for those lands that have a superficial subsurface layer.

Also they present/display disadvantages to be planted, the grounds that have an impermeable estrata of the type “hard bread” or “tufa” which would prevent the development by the roots, like also, the circulation of the water in depth.

Exhibition to the sun.

In relation to this aspect, generally there are no problems in warm areas, but in colder areas he is advisable to realise the plantation with North exhibition.

Terrain preparation

According to the land that has been chosen to make the plantation, several possibilities as far as their topographic, previous improvement exist to the plantation. It is as well as it can be necessary some of the following workings:

Clearing, destronque and/or despedradura.

According to the amount and type of trunks or trees that exist, this work can be made by hand, with light machinery or can be necessary to use machinery of heavy type (bulldozer). Anyone of these possibilities is going to be, in any case, determined by the terrain conditionses and of the existing vegetation.

Earthwork.

Work that allow to cover some hole, drains, etc. Like also, to make an improvement crude of the topography (to improve microrelief).

Subsolación.

Although this practices is recommendable in all the cases, must become in little uniform grounds or that in this way have problems of an impermeable estrata to certain depth, improving the drainage of those grounds and assuring therefore a good implantation the new vineyard.

Deep plowing.

By means of this operation it is tried to loosen the land before the possible compaction of the bulldozer, or, if no has become him of the previous workings, to begin the terrain preparation. By means of it also it is possible to be removing to roots and stones that were in depth.


- Rastraje.

With the rastraje one is able to mullir the free ground being left it of lumps and weeds, facilitating itself therefore the drawn up one, staked, and later hoyadura. It also allows to leave the land in conditions to make the emparejamiento of microrelief, or, the leveling if it were the case.

Emparejamiento and/or leveling.

This operation leaves the land in conditions to carry out an in line straight plantation that allows the irrigation through straight furrows as well reducing the speed of the water, since otherwise bad advantage of her would take place, as also it would bring about erosion.

The emparejamiento is advisable to make it when they allow it to the conditions, enclosed for plantations in contours. This allows to diminish he I number of “twin” like also maintaining a similar distance between the rows. In a land disparejo, when doing the drawn up one, the rows approaches or separates of others with much facility, being many short or “twin “rows, that make the handling more difficult.

The terrain preparation, must become enters the months of July and August of the year of plantation.



Drawing up and Staked

One is due to realise once finished to the preparation of the ground between the months of January and February being able extending itself, for the case of the zone of the dry land, until August and September; following the pluviometry of the year, which conditions the time of plantation.

This work is of special importance, mainly in those cases in that the plantation is previous to postacion and wire fenced. Any error in the drawn up one, will bring plantation errors, that later they will prevent or you would complicaran the post positioning and stretched of wires.

In order to carry out the drawn up one, two forms exist:

By means of the level use,

By means of the wire use.

Whatever the used system, it must be had ways around the future parronal or 4 vine from 2 to mts. of width, that allows the turn of the tractor with their implementos, or, he transit of vehicles.

Also it is necessary to draw up streets, that they delimit the quarters and that they facilitate the harvest. The width of these streets can vary between 2y 4mts. for example, if is to separate two quarters of parronal each of 3 you have. , mts is advisable to leave a way of approximately 6. of width. The size of the quarters will depend on the system of conduction, the topography and the surface of the chosen land to plant.

Another aspect that is common in both systems of drawing up, is to square the land and it has relation with drawn up of parent mass peaks of reference, whom not necessarily they must comprise of the plantation. In order to draw up them, one takes like reference a way, pirca, builds drains, woods or any other point that by some flank this delimiting future plantation.

For the drawn up one stakes are used, that indicate the location of the plants and posts. The stakes must be but right the possible thing, of a diameter of 2 to 4 cm. and of a length of 40 to 50 cm.


Drawing up with level.

With the level the lines of quadrature, parent mass peaks and teachers rows of stakes that are placed each certain distance and in both senses of the plantation draw up those that serve to orient; the spaces without stakes or quadrants fill up by means of the use of a wire, linen cloth or cord, tightened well, placed enters two teachers the required distance, those that indicated the alignment of stakes. According to the frame the distances oscillate between the 33 cm and 1 meter

The separation between rows will be determined by means of a small board, huincha or in the case of using wire, to mark of weld or painting the desirable distance. The important thing is that the wire, strip of cloth or cord or are tightened and that is not prevented by stones or lumps to the extended being, since it distorts the measurement and the alignment.

The indicated thing previously is for a flat or semiflat land plantation, that is to say, drawing up in squaring.

For the case that the plantation is in curves at level, it will have to look for the lines of equal level or slope later to do the staked one.

Nevertheless, when one is small surfaces, “homemade levels “can be used (hose) or an angle with carpenter level.

For the drawn up one in curves at level, a major is due to leave I number of samples, because otherwise, the rows that fill up later can be with a falsified slope.

The filling of the rows takes control of plow thrown by horse or with a tractor with surcadores that are following the curve indicated by stakes mothers put in the land.

The proximity between rows allows to better execution or copy of the drawn up one. Once I throw this, is come to indicate the place of each plant on the row.

The staked one can be done starting off of an end and following the curve either drawn up, or, be drawn up to parallels to the parent mass peak to the plantation distance on the row. This completes, implies only an aesthetic aspect in the plantation then in the first case, being easier to execute, are the disorderly plants, however in the other case, it happens the inverse one.

Drawing up and staked using huincha and wire fences.

This system is more homemade and usable in it is only drawn up of little extension where it is possible to reduce some errors that can be committed with this system, like for example, little precision in the angles or faults in the spacing between a stake and another one due to a bad tension of the wire. For this reason, this system is recommendable when it is plantations of great extension.


Hoyadura to plant


This work is due to realise in the months of June to August like maximum date, of way to carry out the plantation with the plant in receso.

The hole must have the following dimensions: 10x40 cm.

Another method exists to make the hole of plantation and that is used exclusively for vines, as a plow is to happen through the row, soon to be planting to the wished distance.


Plantation


One is due to do between the months of January to April since otherwise the loss of plants by dehydration will be high, as also the loss of initial vigor by death of new buds.

The bearded plants, must take from the breeding ground prior to the plantation place and stay in fallow land or in a covered new warehouse in humid coats. The ideal is that it passes the smaller possible time between the starting of the breeding ground and the plantation.

The plant must come disinfected from the breeding ground, thus, previous to planting it are only due to review the roots in search of modules that indicate the presence of nematodes or nutgalls that could have escaped to the selection throws by the nurseryman. to be observed some of these problems, the plant must be eliminated.

For greater security he is recommendable to make a small pruning of roots and to deal with them by immersion in a 0.25% solution about hipoclorito Na by a minute.

Before planting, in some regions it is recommended to apply a basic fertilization of P, K, to the hole of consistent plantation approximately in 400 gr. Of a mixture of Triple Superphosphate and Sulphate of K in equal parts. Once applied the fertilizer, a earth shovelful is added, to object of not leaving the installment in direct bonding with the roots.

Once finished the fertilization, it is come to plant, for necessary it that each planter has his own table planter. This is made agree in its lateral notches with existing auxiliary stakes to both sides of the plantation. The plant is placed in the notch of the center, soon is begun to cover the hole, firstly in the originating ground of the first 20 cm. Of the ground, that is to say, of the layer superior it is tamped strongly and dá a smooth pull upwards to the plant as a form to locate it and to verify well if the neighboring Earth to its trunk were tightened. After this it is possible to retire the table planter and to finish filling to the hole with the originating ground of half inferior.

When it has been finished planting a row draws up a furrow throughout row and one double rate in each one of the plants becomes, soon it is watered avoiding that the water arrives at the trunk. For the conditions of dry land each plant takes a rate to water them individually.



Handling.


Subsequent to the plantation and until first winter s must be the following careful in the handling:

Irrigations.

These must be frequent following the texture of the ground. Generally, in sandy grounds the frequency must be the major that in argillaceous grounds, which retain more humidity.

Control of weeds:

The cleanings must be periodic, of way to maintain the ground and especially the rate, free of weeds that compete by light, water, and nutrients with the plant that is settling down.

Fertilization:

In the middle of the growth station, November to December, gr. is recommendable to make a fertilization nitrogen of 300. Of Saltpeter or 100 gr. Of Urea by plant, before an irrigation. This fertilization can repeat every 30 or 40 days until season aim.

Mooring cable:

The vegetation can leave itself frees to that a good system forms to radicular at the expense of a greater foliar surface.

For the case that does not have the first wire or rodrigón, it is necessary to put a tutor and to moor all the existing vegetation like lettuce to him. It is counted on the structure, moor these buds wing pegs.












Climatology in the vineyard


Factors of the Climate: latitude, altitude and the proximity of the sea

The Climate of a place is the set of times atmospherics that occur throughout the years



The different places, have different climates, because they depend on several elements.
The most important elements are: the latitude, the altitude and the proximity of the sea


The Latitude

The latitude is the distance that there is from a concrete place to Ecuador and it is moderate in degrees. One will always say if the place is in the North hemisphere or the south.
The climate depends on the distance that there is from a point to Ecuador. The more far from Ecuador it is that point, the more cold does.


The Altitude

The altitude of a place is the height of that place with respect to the sea.
Whatever more altitude, the temperature falls that is that is more cold



The proximity of the sea

The rays of the sun warm up the Earth the same and the sea. Nevertheless the sea cools off and the Earth is warmed up more slowly than, reason why if the Earth is cold (in winter) the sea is hotter and if he is hot (in summer) the sea is fresher. This smooths out to much the temperatures of the places near the sea.

When we are in a place, in a while determined, we can feel the temperature (cold or heat), precipitations (if it rains or if there is dry time), and if is wind.
The temperature, the precipitations and the wind are what we called weather.

Weather = temperature + precipitations + wind.


In a place they change the temperatures, the precipitations and the wind throughout the months and the years. Not always it is warm, not always it rains and not always there is wind.

The weather in a place, changes throughout the year and it is not equal year either after year.



TEMPERATURE: Degree or thermal level of the bodies, related to the kinetic energy of molecules of the same. The room temperature, the one of the atmosphere that surrounds to a body. Temperatures maximum and minimum, the heat major or the smaller degree than is observed in the atmosphere or a body during a determined period of observation.
In order to measure it, it is used the thermometer and in degrees Celsius (ºC).


PRECIPITATION: Water coming from the atmosphere that in solid form (snow or hail) or liquid is deposited on the Earth surface. Usually one is moderate in liters by meter squared with the rain gauge.

EVAPORATION: it is a process which a liquid or a solid becomes gas gradually, considering that in this process the water warms up when absorbing caloric energy of the sun taking into account that this, the power plant of the sun and that this allows to culminate the phase. The necessary energy so that a gram of water becomes steam is of 540 100 calories to ºC value well-known how evaporation heat. When happening the evaporation the temperature of the low air, to the being taken the heat from the surface by the evaporation originatingly is transported at other levels by means of the inverse process of condensation, this then before a mechanism of much importance, with regard to the transference and distribution of the heat in the atmosphere in the Orb.



WIND: Airflow produced in the atmosphere by natural causes. Atmospheric air. We measure its velicidad with the anemometer and observed his I gave

SOLAR RADIACCIÓN: The radiation that comes from the sun comes being the power plant of the terrestrial surface, by his effect on the organic life of our planet and by its importance in the understanding of other meteorological phenomena it is the element of the time and the climate that must study under the cause approach - effect.

Without the radiation the thermal differences could not exist, the evaporation, nor the variations in the diversity of the air, that are as well causes of diverse movements within the atmosphere.

By its nature the solar radiation emits 2 types of very different radiations: the undulatory or electromagnetic radiation (solar radiation) constituted by visible radiations, infrared and ultraviolet at speed of 300,000 light km/seg., the temperature approximated in the 6,000 sun surface is of ºC, with this temperature the sun radiates 56 xs 1026 cal/gr/min, in all directions.

These radiations cover radios and zones every time majors as they move away of the sun. The distance of the sun to the Earth is of 190 million km.


MEASUREMENT ELEMENTS

In order to know the weather that does, the climate of a place, we needed certain instruments that they indicate to us how much heat does, how much rain or snow has fallen, how the wind blows of fort, and in what direction.

THERMOMETER: Instrument that serves to measure the temperature of a body or an atmosphere.

RAIN GAUGE: Apparatus that serves to measure the amount of rain that falls in a certain place and a given time.

EVAPORIMETRO: (of micrometric screw) this apparatus this constituted by a metal drum magazine of 200 cm2 that rests on a tripod and by a micrometric screw of fine end. The screw takes a graduated scale in mm, increases of above downwards and the part superior of the screw takes a circular graduation in tenth of millimeters.

EVAPORIMETROS: (of tanks outdoors) these tanks are placed directly to the sun and are exhibited to precipitations. These vary in size and forms and installation but the principle is the same, the measurement of the evaporante power of the water

VANE: Movable plate around a vertical axis that is placed at the top of a building to indicate the wind direction.

ANEMOMETER: Instrument to measure the wind speed.

PIRANÓMETRO: it measures the solar radiation that emanates of a whole hemisphere.

PORHELIÓMETRO: It is an instrument for the measurements of the direct solar radiation and normal incidence to global celestial radiation and radiation spectra



AS IT AFFECTS THE CLIMATE TO THE FRUITGROWING.


PLUVIOMETRY AND ENVIRONMENTAL HUMIDITY.

Although the temperature is important is not the most important factor. The trees need a certain level humidity in the ground to survive and to grow. These needs depend on the zone and if there is shortage or flood arises problems.

If there is lack of water:

The number of buds falls and the buds are shorter. The tree can die of thirst if there is drought.

Also one is affected the floral induction (a smaller percentage of yolks to flower yolks is induced).

The size of the fruit is reduced if lack water. Also one is affected the quality of the fruit (as far as color and other organoleptic qualities).

Normally, the species of temperate zone could be cultivated with 700 mm For that reason, the problem is not really the lack of water, but there is a high irregularity in the distribution of rains. Thus, if the tree lives with the water of rain, it is cultivated in dry land and, if it needs irrigations, it is cultivated in irrigated land.

The species of temperate zone (with precipitations of 500 mm) can be:

Resistant to the drought that can be cultivated in dry land.

Less resistant to the drought and for which an irrigation of support is recommended.

Sensible to the drought and that needs irrigation.

Rain can bring about damages according to his ocaasionalidd:

During the flowering:

- The bees do not fly if it rains.

- The pollen grains can be dragged to the ground.

- Losses of flowers.

- Washing of pollen that already was in the stigmata.

During the development of the fruits:

- Cracked or boasted of fruits: One occurs by an excessive water accumulation by the fruit after a period of drought (via epidermis and radicular) and, as the epidermis is not elastic, cracks.

- If there is high and continued environmental humidity, russeting” or potato skin takes place “: microscopic cracks that suberifican giving pinto brown and amarronado color that condition the consumer. Also it is possible to be produced due to a fitotoxicidad process.

- Massive Fall of fruits or fall of maturity: The problem is greater in fruits of greater weight and species of delayed maturation.

- Rains also affect to the appearance of fungi and criptogámicas diseases. In the dry zones this is not so serious (only something in spring and autumn), but, however, since there is no high humidity, the problem is the acaruses (red spiders).

During the period of vegetative activity: It can bring about asphyxia if there is much encharcamiento during several days, since lack oxygen for the seeds.


INSOLATION.

All the species need her to survive because it affects the photosynthesis. The needs even vary between species and varieties being different according to the times from the year.

The fruit trees are better in sunny zones than in zones of shade and its production is greater.


Damages caused by one lower insolation.

Diminution of the intensity of the photosynthesis: The tree produces less hydrocarbon substances what brings about the diminution of the vegetative growth (there are less buds and are shorter) and than the leaves they are smaller of the normal thing.

As the tree grows, the vegetation is more abundant in the outer zones, that give shade to the inner primary branches, that remain naked. This fact is independent of the insolation that there is in the zone and it indicates a bad accomplishment of the pruning.

There is minor floral induction, since less carbohydrates form.

The fruit does not form well its pigments (in zones where east problem occurs, varieties of fruit of green color are due to cultivate, where the problem is less serious).

This problem has forced to put conduction systems flat (espaliers).


Damages brought about by a high insolation.

Pigment destruction, that gives rise to darker fruits (it occurs with excessive insolations, but not very high).

Plate of color: The fruit, by the exhibited face more, has a darker color, than sometimes it can give rise to a serious burn that causes that the zone softens much and that loses commercial validity. This phenomenon occurs more in varieties of little color.

Asurado: Buds dehydrate and leaves and fall. The problem comes when the asurado one is repeated during many years.

On the wood burns can be caused, mainly in the South face. In plantations also can be produced these burns (those plants usually come from breeding grounds where the conditions have been very smooth







WIND.

The trees need ventilation in the glass so that oxygen renovation occurs and it renews the wood and the yolks of flower. Nevertheless, if the air is very intense, there is a series of problems:

Mechanics, in whom the wind speed is key:

Leaves can be fallen to necrosar themselves because they are struck.

Smaller leaves of the normal thing.

Mechanical damages in fruits, that depend on the size of the fruit and that they are more important at the most great are the fruits.

Rameo of the fruits (the fruits are struck against the branches and suffer injuries).

Increase of the fall of precocious maturity if the variety has tendency to undergo that fall.

The strong winds with dominant direction cause that the trunks incline and the glasses are become deformed (they grow more by the zone opposed to the wind and glasses in the form of flame occur).

Breakage of branches and descuaje of the tree (started from the root) with winds of more than 30 km/h.

Great wounds that give rise to cárcavas when not healing. Through them fungi can enter, plagues and humidity.

Difficulties in the operations of culture (pulverization, aerosolisation, irrigations by aspersion).

Physiological, in that they concern the characteristics of the wind and not of the speed:

It prevents the flight of the bees if its speed is superior to 10 km/h, which causes that there is not pollination.

Asurado of buds and leaves by warm winds and droughts, although the water contribution is sufficient, since the sweating is very intense.

There are winds karsts in the coastal zones that deposit salt on the leaves, that is phytotoxic. It is not necessary that is very strong winds.




HAIL AND PEDRISCO.

Hail: Spherical ice precipitation, I am transparent and with size between 2 and 5mm of diameter.

Granulated snow or white hail: It has the opaque and whiter faces.

Pedrisco: Irregular pieces, I am not transparent and with diameters majors of 5mm.

Usually they go associate to wind strong and rain (storms). Spring and summer occur more in, in the evening after a warm morning and without wind.

Usually they are erratic phenomena (they do not serve the data as the laboratory) and very located.

The damages that cause are mechanical damages, that are broth of culture for criptogámicas diseases (that can cause damages more serious than those of the own hail). The fundamental ones are:

- Blows in the tree.

- Breakage and defoliation.

- Fall of fruits.

- Damages in the wood.

In order to detect the hailstorm risk it is important to know with certainty if it can have something of risk perhaps (if there is a hailstorm per year is condition not to plant).

The defense measures a posteriori are little useful, reason why more preventive measure cradles are used in which more hail forms but than he is smaller and that falls with less speed:



There is insurance policies combined for frosts, wind and hail.

To install a network of you enmesh of plastic on posts.

The wounded wood can be eliminated leaving more inner wood it grows more. Simultaneously anticriptogámicos treatments occur also.





SNOW.

It is not a factor of most complicated (it contributes humidity to the ground, protects of the cold…). But problems in evergreens arise (occur breakage) or if there is snowed early. If the snow is congealed in the ground, there are problems in the neck of the plant, that is fastened with rings (it is congealed). These snow-covered are dangerous in young shoots. Like prevention measurement:

To prune so that the skeletons do not accumulate much snow.

Supported forms so that the snow does not knock down the tree.

To earth up in vineyard and to graft to more height.

To in center use very resistant landlords to the cold of Europe.



FROSTS.

The occurrence of frosts is considered when the temperature of the air, registered in the meteorological shelter (that is to say to 1.50 meters on the level of the ground), is of 0ºC. This form to define the phenomenon was decided by the meteorologists and climatologists, although often, the temperature of the surface of the 3 ground can get to be at 4ºC smaller than the registered one in the meteorological shelter.

From the point of view of the agricultural climatology, frost to the occurrence of a certain temperature cannot be considered, since vegetables exist that undergo the consequences of the low temperatures without this one arrives at zero degrees (for example: the tropical coffee, cacao and other vegetables).

Different types from frosts exist. According to his origin they are classified in:

Advection frosts: they appear in a region when this one “is invaded” by a cold air mass whose temperature is inferior to 0ºC. This type of frosts is characterized by the wind presence with equal speeds or the 15 superiors to km/h and the temperature gradient (variation of the temperature with the height) is negative, without thermal inversion. The affected areas are extensive and the cloudiness does not influence the temperature, that undergoes variations with the hour march. The plants cool off by contact.

Frosts of radiation: They take place by the cooling of the low layers of the atmosphere and the bodies that in them are due to the loss of terrestrial heat by irradiation during the night. A stratification of the air takes place where the lowest layers are colder and the highest layers are warmer (thermal inversion). This type of frosts takes place in conditions of barren or little wind, since the wind absence prevents to mix these layers, and in addition, with cloudless sky that allows a greater loss of heat from the terrestrial surface. The loss of heat is greater when the nights begin to be longer and the moisture content of the air is smaller. In grounds covered with vegetation and at heart with valleys it is more probable that they occur this type of frosts. In the case of the vegetal cover, this acts as insulating between the ground and the atmosphere, avoiding that the heat of the ground is passed on quickly to the air. In addition the entrance of the solar radiation diminishes the heat accumulation in the ground when preventing. The relief of the ground, by its diverse accidents, determines the direction and intensity of the cold air flow nocturne. If the ground has slope, the cold air (denser) will look for lower levels, where it will park and continue cooling off. It is for that reason that the bottom of valleys is a propitious place for the formation of frosts.

Frosts of evaporation: Had to the liquid water evaporation from the vegetal surface. Usually it happens when, due to the diminution of the atmospheric relative humidity, the dew formed on the plants evaporates. The liquid passage of water to its gaseous state requires heat. That heat contributes the plant to it with its consequent cooling.

Mixed frosts: They are denominated in this way to those frosts that simultaneously take place by the cold air upset and the loss of heat of the ground by irradiation.

According to the visual effects that this phenomenon causes:

White frosts: one takes place when the temperature descends below OºC and ice forms on the surface of the plants. This type of frosts takes place with humid air masses. In addition the barren wind and the cloudless skies favor their formation.

Black frosts: In the black frost the reduction below OºC does not go accompanied of icing-up. Its designation responds to the visualization of the coloration that acquires some vegetal organs due to the destruction caused by the cold. This type of frosts takes place when the air mass is dry. The sky overcast or overcast or the turbulence in low layers with the atmosphere favors the formation of this type of frosts.

The frosts are frequent in the winter, but autumn and spring also happen in, knowing themselves the autumnal ones like early frosts and the primaverales like delayed frosts. In these two stations the plants have the great sensitivity to the temperature drops.

FROSTS PRIMAVERALES: The flower, in each of its states during the flowering, is very sensible to the cold. Within her, most sensible they are the ovary with ova and the base of the style. With temperatures of -1°C or -2°C those zones can be burned (it talks about to temperatures in the flower, not in the air). If the covers surround to these zones they protect, them, reason why, as it is developed the yolk, it acquires minor resistance to the cold:

The most sensible state is the mincemeat because the fruit is naked and in addition their walls are thin and they protect neither to the embryo nor to the seed.

Among the fruit species, the vine, the olive tree and the walnut are most sensible to the primaverales frosts (they are defended delaying to his borración and flowering).

The wood buds and yolks are sensible to the primaverales frosts (that burn those buds and make react to the plant, appearing auxiliary yolks below which they were burned, bringing about problems derived from the additional cost of energy).

In principle, the species of temperate zone are more resistant to the primaverales frosts that those of zones tepid. The degrees are important even, since half degree can affect to some species and another no.

Normally, the primaverales frosts do not affect wing old wood, but to the flowering and the buds in growth. As the fruit is maturing, it increases his resistance to the cold

How they affect the low temperatures to vegetables?

As a result of the low temperatures, in the plant the following steps follow one another:

A weakening of the functional activity takes place among others being reduced to things the enzymatic actions, the respiratory intensity, the photosynthetic activity and the speed of absorption of the water

A displacement of the biological balances exists stopping the breathing, photosynthesis, sweating, water absorption and ascending circulation.

Finally one takes place the cellular death and the destruction of weaves

It is necessary to consider that the sensitivity that a vegetable has to the cold depends on its state of development. The more vulnerable fenológicos states to the cold are the flowering and the mincemeat of fruits.

Many vegetables have created natural resistance to the cold:

By means of concentration of the cellular juice. This way the freezing point descends.

By means of the hardening: when the reduction of the temperatures is realised progressively the vegetable is adapted to the new situation by means of cellular physiological changes.

Methods of defense against frosts

Two types of methods are distinguished to control the frosts in agriculture: the active methods liabilities and methods.

Methods liabilities:

a) To avoid the sensible culture of species or varieties to the low temperatures, in zones where very high probabilities that exist frosts happen.

b) To choose resistant varieties and of greater height, to avoid contact of the flowers with the cold air near the ground.

c) The sensible species, do not have to be implanted in depressions. To prefer, in these the warmest cases, faldeos

d) When a barrier exists, for example a too dense curtain cortaviento, the frost danger is greater towards the side of above of the slope.

f) To avoid seedtime of prairies, cereals, shrubs or breeding grounds in the proximity of a fruit orchard. These act as insulating of the heat flow of the ground, increasing the risks of damage by frosts in low cultures.

g) To avoid the excessive working of the ground. Of being therefore a loose ground layer forms, that acts like insulator of the heat that flows from the deepest layers of the ground towards the surface.

h) As far as possible to maintain the ground free of weeds, without moving it and not leaving to much straw or another material one on the ground.

Active methods: Those applied right when beginning the frost and during her are. The principle of these methods is very simple: the frost must to the cold, therefore we must avoid the cooling. In order to avoid a frost it is sufficient, in theory, to contribute to the surface of the ground an equal energy to that one lost one by this surface, that is what brings about the cooling. Also methods exist that act directly on the temperature of the plants.

Several forms exist to bring about the heating of the air:

a) Land flood, that increases to the caloric capacity of the ground and its thermal conductivity.

b) Air mechanical mixture, consists of mixing, with the help of great helices, the cold air near the ground with the warm air of the atmospheric layers more discharges.

c) Protection by interruption of the radiation, consists of avoiding the radiation losses using some type of “ceiling” on the vegetation.

d) Smoke screens, clouds or fog. Considering that the air has bad thermal conductivity and that the heat transfer through him, to the objects that surrounds, is difficult, one has practiced to directly transfer the heat to the plants.

e) Heating of the air that surrounds to the plant, consists of warming up the cold air that surrounds to the plant, since the one is this one that brings about the cooling of vegetables. One of the used methods more is to ignite burning (jars) of petroleum, 100 to 300 by hectare. Another alternative is the hot air agitators or the burners to gas.

f) Water aspersion: the use of aspersion with water to fight against the frosts, takes advantage of the heat release that takes place when being congealed the water (80 cal/g). When placing a small waterproof cloak on a leaf that is cooling off, the released energy by the water when being congealed is taken advantage of by the leaf. If the aspersion stays constant, during the period of low temperatures, until the ice has been fused by action of the sun, the temperature of the leaf will not descend from OºC. It is important to consider that if it is a culture with fine branches, the weight of the ice can break them. The aspersion must begin at the moment that the temperature lowers of lºC and must stay without interruption until after the exit of the sun, so that the heating of the atmosphere compensates the heat absorption produced by the fusion of the ice. 

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