How to properly prepare stone and pome fruits for sowing. Stratification of seeds of fruit crops, harvesting cuttings for grafting - November work in the garden and vegetable garden
Storage and preparation for sowing stone fruit and pome fruits.
Seeds of stone fruits and pome breeds are living organisms. Where metabolism takes place throughout life.
I.V. Michurin wrote: “... in the body of each seed that is at rest, that is, in a dry form, the process of life does not stop, a constant, albeit slow, metabolism takes place that supports the life of the germ cell, and the correct course of such an exchange depends entirely on those conditions. the environment in which the seed is located until the plant germinates from it. The process of exchange can be faster or slower…”. Most gardeners are sure that the harvesting of seeds and seeds is carried out according to the principle (plucked, eaten, spat out). Elite varietal seeds are collected by the expeditionary method in the taiga from under ancient trees.
The collected fruits are taken out of the taiga and stand in boxes for a certain time until the pulp rots.
Manually, on sieves and screens, the bones are freed from the pulp ...
And thoroughly washed with clean, running cold water.
After a short drying, the bones are lowered for half an hour into a red solution of potassium permanganate for disinfection ...
And then they are thoroughly washed with warm running water and dipped for 20 minutes in a two percent solution of boric acid and again thoroughly washed. Wet seeds are mixed with dry sand and rubbed for 20-30 minutes (scarification)...
Then the seeds laid out on small sieves are dried for 2-3 weeks for outdoors in a place protected from the sun. This completes the process of harvesting seeds for storage. During storage, the seeds do not receive nutrition from the outside, but use the ready supply of nutrients accumulated by the mother plant and intended to feed the future new plant.
The main task in storing seeds is to protect them from the loss of nutrient reserves, that is, to maintain seed germination. During storage, factors such as air oxygen and water play an important role, while the seed breathes intensively, releasing carbon dioxide. Containers in which seeds are stored must not be hermetically sealed. Seed viability is preserved only when certain temperature. You need to know that at a temperature of +55 ... +65 degrees, protein coagulation occurs, and cells die. Optimum temperature for storage of seeds of stone fruit and pome breeds, the temperature was from 0 to +5 degrees. Moreover, the seeds of agricultural crops are stored at a temperature of +3 to +8 degrees. Preferably store only in INCINED, DISINFECTED sand, and not in peat, polystyrene, foam rubber and other achievements of civilization. With prolonged improper storage, due to the evaporation of moisture from the seeds, their weight decreases. Seeds of various plant species, even under ideal storage conditions, retain their viability for an unequally long time. For example, in fruits of hazel and walnut - during the year, in legumes - 7-10 years, in stone fruit - up to 5 years. Freshly harvested seeds have the highest germination rate.
Humidity plays an important role in seed storage. With high humidity, mold and the smell of alcohol appear, such seeds sharply lose their germination capacity and die after three to four months of such storage. Relative humidity in the storage (in the basement) should be maintained within 50-70%. For example, apricot seeds with a dense shell after 120 days of storage at an initial humidity of 12% and air humidity of 75% absorbed only 1.5% of water, and at 87% relative humidity almost 5%. If the air temperature at the storage place drops from -2 to -10 degrees, and even in an open container, at a humidity of 65%, the seeds practically die.
To accelerate the germination of seeds and get friendly seedlings, it is necessary to subject them to pre-sowing treatment. Seeds are soaked in water or moistened in sand until they peck. If there is still some time before planting, growth can be restrained by keeping at low temperatures (0 degrees) or by snowing. If a fungus is found, they should be pickled. Stone fruits are soaked in water with a temperature of +30 .. + 35 degrees for 2-2.5 days, it is desirable to subject it to constant bubbling, that is, to pass air through living water in which the bones are soaked. At the same time, most of the seeds sink to the bottom of the vessel, only after that they are laid out in layers in wet, calcined sand, and when seedlings appear, they are planted.
Stratified seeds are planted in well-moistened soil to a depth of 3 cm. Very large stone fruits (peach, nectarine, plum) are subjected to scarification - mechanical action in which the shell is erased or scratched, after which air access to the embryo is facilitated.
Thus, all seeds must go through a state of dormancy (forced and deep), seeds go through deep dormancy during stratification, that is, when they are kept at low temperatures for a long time. Different plants have different periods of stratification. For example, apricot and hazel need a temperature of +1..+4.5 degrees for 3-4 months. Manchurian nuts are stratified in wet calcined sand before sowing at a temperature of 0..+5 degrees. Without stratification, they are sown late, one to two weeks before frost. Seeds of stone fruits can be sown in the fall without prior stratification or be laid for stratification after pre-training: for Siberia - at the beginning of January, for Primorye from January 20.
The duration of stratification for individual stone fruit species is as follows:
Apricot ordinary 80-90 days.
Apricot Manchurian 55-60 days.
Cherry plum and prunes 120-150 days
Sweet cherry 100-120 days
Turn 150-170 days.
Cherry felt 160-170 days.
Steppe cherry 120-160 days
Cherry steppe stratified immediately after collecting seeds, it is necessary to sow immediately, in the fall. The thick shell of the seeds - endocarp, serves as a mechanical obstacle during seed germination. Best Temperature for germination +18..+27 degrees. At low temperatures, it is advisable to plant the planting with a wet sheet and cover with lutrasil. Watering with warm water is done through lutrasil.
With short periods of stratification up to one and a half months, it reduces their germination by a quarter. Accelerated methods of stratification 15-20 days do not provide high seed germination. The seeds of the wild Manchurian apricot germinate within four years - this is protective device species to survive.
Seeds of pome species (wild apple, Kitaika, Sibirka and Amur pear) should preferably be stratified in sifted peat. From a cold room in winter, the seeds are brought in for three to four days into a warm room with a temperature of +18..+20 degrees. They are poured onto burlap, mixed, increasing air access to the seeds. This technique enhances the energy of germination. Then the seeds are kept at a temperature of + 3 + 5 degrees with the following terms:
Chinese apple tree 70 days,
Siberian apple tree 30 days,
half-cultivated pears - 90 days,
Ussuri pear 60 days.
During stratification, the seeds should not dry out and not freeze slightly.
Summer residents who wrote out the seeds safely lay them for stratification in a crowd, not taking into account the timing of stratification. The timing of stratification for all types of stone fruits and pome fruits is different .......
In sufficient quantity, seeds of stone fruits and pome fruits of the Far Eastern flora, you can write out after getting acquainted with the site biologobrodsky.rf
Brodsky Yuri Vasilievich,
biologist, amateur gardener.
692135, Primorsky Territory, Dalnerechensk, st. Mira, 32
Description of the seed stratification procedure. Stratification means sprouting. Seed stratification will achieve high level sprout seedlings. Many people wonder how they stratify the seeds of lemongrass, black raspberry, Japanese quince, apple trees, apricots, etc.
I invite you to the group on Subscribe.ru for summer residents, gardeners:
"Country hobbies"
Seed stratification
Features of seed stratification
All fruit crops have one feature: seeds that are obtained from ripened fruits, and then sown in autumn, germinate normally in spring; but during spring sowing they do not sprout, and if they do sprout, it is very bad.
The period of stratification in different cultures is different. For example, for seeds of apple, quince, pear, up to 3 months is needed; cherries, peach cherries, cherry plums, thorns and blackthorn up to 5.5 months. In this case, humidity up to 60% is needed, at a temperature of +1 - +6 and oxygen access.
In the conditions of the regions Russian Federation, where snow often falls on the ground frozen up to 1.5-2 meters, the seeds of such heat-loving crops as cherry plum, peach, Japanese and common quince, sown in autumn, either do not germinate completely in spring, or give 5% of germination.
If, in the refrigerator or in the cellar, the seeds of pear, quince, peach, apricot, cherry plum, sweet cherry underwent stratification - in just 2 months - then, sown at the end of April in open ground, they sprout 80%.
How to stratify seeds of fruit crops
Before the stratification procedure, stone seeds: peach, apricot, plum, etc. - must be soaked in water at room temperature for 3-4 days. Soak pear seeds, apple trees in water for 20-30 minutes. All non-drowned seeds are thrown away (they are underweight); to prevent the seeds from rotting, it is necessary to change the water every other day.
Note: it is advisable to soak the seeds in rain or snow water. Upon completion of soaking, drain the water, mix the seeds with sand. Sand is pre-calcined on fire.
Stone seeds are mixed with sawdust, pickled the day before with a solution of potassium permanganate in a ratio of 1: 10, and poured into old nylon stockings. Then the seed bags are placed in a box with sand and more sand is added so that the seeds are covered with a layer of 6-8 cm on top.
Labels indicating the variety - metal numbers - are placed in the bag. They are small and will not harm the seeds. Numbers are put in the journal and an entry is made. For example: No. 6 - apricot and the date of the beginning of ripening.
The dates for laying seeds for stratification begin in February. 1-2 times / month, the seeds are mixed, enriched with air, and, if the sand is dry, moistened. Rotting or molding in calcined sand, as a rule, is not observed, since the seeds are in a sterile environment.
For those who do not have a cellar, seeds can be stratified in the refrigerator. In this case, the dishes ( wooden box) should be reduced to a minimum, which means that the sand should be replenished more often with moisture. Do not forget to place the box in a plastic bag to keep moisture longer.
It is necessary to observe the following rule: the temperature in the lower chamber should be + 1-6 °.
By the way, if we talk about the stratification of the apple tree, it is recommended to choose a variety suitable for your garden, read. And if about plums, then you might be interested.
Features of stratification of seeds of berry crops
With the stratification of stone fruits and pome fruits, everything is clear, but what about the small seeds of berries? These seeds also need to ripen.
They can be "sanded", as in the first case. But it will be difficult to choose from the sand. Therefore, they are sown, like carrots or parsley, that is, they make grooves in a box (these crops are grown by seedlings) and, together with sand, which even helps to put seeds in the grooves less often, they are sown in a box, the size of which depends on the number of seeds: the more seeds , the larger the box.
Then it is well watered and put in the cellar until the onset of warm days.
During the winter look through; if there is little moisture, water moderately so that the earth does not acidify, otherwise the seeds will die. It is necessary to sow seeds in a box so that ripening ends before warm days - no more than 2 months. True, it is possible and more, it will not get worse from this. But minimum term- not less than a month. It has already been said about the optimal humidity and temperature in the basement, cellar, refrigerator.
It's time to disembark, and read.
Overview of fruiting apricots that have grown from the stone. Apricot seedlings are full competitors to varietal apricots.
And here is a revolutionary technology that may come in handy ... in principle, even if there is no garden or summer cottage, you can find a wasteland or some kind of inconvenience in the city and sow seeds ... and not throw them away ...
How to grow an apricot from a seed
In the previous article, information was presented on agricultural technology, food and medicinal use of apricot.
In this article, we will talk about the method of apricot propagation by seeds, which is the most common method of apricot propagation in Kazakhstan.
Apricot is one of fruit crops, which retains mainly its hereditary qualities during seed reproduction.
The first question that arises: Where to get the bones?
So …
Where to get bones?
It is best to sow the seeds of local apricots.
1. Take overripe apricot fruits. Apricots usually ripen from late June to late August. For another two or three weeks they lie on the grass overripe.
2. Separate the bones from the fruits.
3. Make the first selection for quality: make a check for buoyancy. Floating bones are dead, they are thrown away.
4. The rest of the bones are dried after washing, put in a jar under a lid and stored until planting or stratification in the refrigerator.
If apricots do not grow in your area, then it is better to take seeds from gardeners-farmers in Siberia and Far East. Severe climatic conditions have formed the most viable apricot population. Therefore, the offspring from them will be the best.
They are also stored in the refrigerator in a jar with a lid.
What time to plant?
There are two ways to plant seeds: autumn (winter) and spring. Each method has its own advantages and disadvantages.
The first sowing option is winter sowing. We sow the seeds in the fall and leave to winter in the cold.
Dry seeds from the refrigerator are sown as late as possible - not earlier than mid-October, before the first frosts. During the winter, the seeds undergo stratification and natural selection. After a favorable winter, 40-50% of the seeds survive (very rarely 70-90%). If the winter is worse - 10% or even less.
This is what real rootstocks are. Not just strong roots, but a source of increased winter hardiness for grafted varieties.
The advantage of autumn sowing: through natural selection, you get the most viable seedlings.
Disadvantage: low percentage of seedlings coming out of seeds.
For an amateur, especially an experienced one, it is better to sow a lot before winter. Overwintering in the ground is an opportunity to select the most winter-hardy seedlings for breeding purposes, to take not in quantity, but in quality.
The second sowing option is spring sowing.
If you sow dry seeds in the spring, then half or even a quarter will sprout - depending on what the summer was like and what germination energy is embedded in the seeds. They may not rise at all this spring.
What should we do in order to get almost 100% yield of seedlings from seeds? How to make the seeds sprout together during spring sowing?
We must provide the seeds with conditions for passing through a dormant period, and carry out artificial seed stratification. This operation is also sometimes called sanding.
Seed stratification involves keeping them moist at low temperatures for certain period(depending on culture).
What should be the timing of stratification?
Each type of seed or seed has its own stratification time.
Let's say for a plum it will be 120-150 days. For apricot 80-100 days
What does this mean? This means that if we lay the seeds for stratification today, put them in a cold place, then after 80 days they will already begin to peck and germinate. We must lay the apricot seeds for stratification 80 days before the moment when we sow them.
If we plant in late April - early May, then the seeds for stratification should be laid in late January - early February.
Apricot kernel stratification
1. At the end of January - beginning of February, we take out dry seeds and soak them in snow water for three days. We change the water daily. At the same time, the seeds swell.
2. Seeds are mixed with loose, wet washed sand. The ratio of sand to seeds should be 1:3 (three parts of sand are taken for one part of the seeds). You can use sphagnum moss, sawdust instead of sand. Recommended washed river sand. It should not contain organic impurities.
3. The mixture is placed in a plastic bag with a label on the outside. To allow air to enter the bag, it is necessary to make holes with a sharp object in several places.
4. Seeds are now ready to be exposed to low temperatures. The bag should be put in the refrigerator, placing as close as possible to the freezer compartment, where the temperature is lowest (but not negative). The mixture should now be at a temperature of + 2-3 ° C and free access to air.
5. Shake and turn the bag weekly: this prevents the mixture from compacting and improves air exchange in it.
6. Be sure to control the moisture content of the mixture. If necessary, add water, stir.
7. If the seeds start to hatch too early, transfer to conditions with a lower temperature: from 0 ° to 1 ° C.
8. Be sure to write down when and what seeds were planted for stratification so as not to forget.
Stratification in apricot lasts 80-100 days - depending on the type, variety, degree of seed ripening.
At the end of the specified period, the bone cracks, the seed begins to germinate. In this state, sowing is carried out, it should be dated for the end of April - the beginning of May.
The advantage of stratification and spring sowing is that you save the most seeds and get the most seedlings.
Disadvantage: the resulting seedlings do not pass natural selection.
How deep should seeds be planted?
Experience has shown that deep planting is one of the reasons for “poor germination”. The literature gives different figures for the sowing depth: 3, 5, 7, even 10 cm. Even 3 cm is a lot! The reason is too deep root collar. She should not be underground at all: later the tree will inevitably swell.
For stone fruits, it is better to raise the beds above the soil level. It is enough to slightly press the stone into loose soil and sprinkle with a thin layer. Sometimes the bones are washed away by rain. But they rise to the maximum, and then do not die from damping out.
________________________________________
That's all. We examined issues related to the propagation of apricot seeds. Reproduction by seeds of plums, apple trees, pears and other fruit crops is carried out in the same way, only the timing of stratification for each crop will be different.
Next article: "How to get your seedlings from seedlings."
Preparation and storage of seeds. For sowing, high-quality seeds with high viability and germination are used. They ensure uniform germination, vigorous growth and the formation of uniform, healthy and strong rootstocks. To avoid variegation of seed material, seeds should be harvested separately for groups of similar in their characteristics forms of selected slaughter trees.
The degree of fruit ripening also affects seed germination (Kuznetsov, 1966). So, in a number of cases, in late forms and varieties of pome breeds, the ripening of fruits on the tree is delayed, which leads to the formation of seeds with reduced germination. Therefore, to obtain seeds, it is better to use the fruits of early and medium ripening periods. In stone fruits, on the contrary, seeds should be harvested from the middle and late ripening fruits of plant forms, since early ripening fruits give little similar seeds, which is associated with the underdevelopment of their embryo.
It is also necessary to pay attention to the degree of ripeness of the fruit. Experience and practice have established that seeds for sowing should be taken from well-ripened fruits. However, there may be exceptions to this rule. Seeds of antipka, cherry plum and blackthorn should be taken from browned fruits, since in this case they give more friendly seedlings and are more quickly prepared for germination compared to seeds from mature fruits.
When harvesting seeds, preference is given to large, normally developed and well-colored fruits located on the periphery of the tree crown. Small, underdeveloped and ugly fruits produce seeds of poor quality and in smaller quantities.
Ways to get. Harvesting seeds of fruit species should be accompanied by appropriate economic use fruit pulp and creating conditions for obtaining viable seeds with good germination.
The temperature regime at which seeds are harvested is important. The detrimental effect of high temperatures (40 - 50°C) on seeds with high humidity has been established. The germination of seeds that were at high temperatures is reduced to zero. Therefore, it is possible to extract seeds from fruits only in a cold way. Fruits should not be boiled, steamed or sulphated to soften. For the same reason, heating of fruits during storage in heaps and fermentation of pulp with unextracted seeds should not be allowed.
Depending on the nature of the use of the pulp of the fruit, the size and number of harvested seeds, they are extracted from the fruit in different ways. When harvesting small batches of seeds or stones, the fruits are cut by hand. In small-fruited plums and cherries, the seeds are often knocked out with special machines. With a machine, they cut out the core with seeds from large apples and pears, the pulp of which is used for jam or drying.
Mass production of seeds of all fruit species is carried out in fruit processing shops and enterprises. The bulk of the seeds in the factory is obtained during the processing of fruits for juices.
Before processing, the fruits are thoroughly washed and passed through a fruit crusher. The pulp is loaded into a press and the juice is squeezed out of it. Seeds are separated from pomace or pulp by washing with water, or in a dry way, after drying dry particles of pulp are screened. With any of these methods, it is necessary to start separating the seeds immediately after squeezing the juice, since fermentation begins very quickly in the pulp that has come out from under the press.
In the dry method of obtaining seeds, as well as in case of difficulty with the immediate separation of seeds by washing with water, the pulp is dried. To do this, it is laid out in the air in the shade with a thin layer (7 - 10 cm) and systematically mixed. If air drying of the pulp is not possible due to damp, cold weather, the pomace can be dried in special rooms with artificial heating, but at a temperature not exceeding 30 - 35 ° C. To separate the seeds, the well-dried pulp is passed through a winnower.
The seeds are washed from the pulp with water in special wooden troughs and separated into fractions on metal sieves.
Drying. After washing the pulp, the bones of cherries, sweet cherries, antipka, plums, cherry plums, thorns and thorns are not dried, since drying worsens their germination. It is more expedient to immediately stratify them.
Seeds of apple, pear, apricot, peach and sand cherry, requiring less time for stratification, must be dried immediately after washing, otherwise they quickly lose their germination.
For air drying, the seeds are scattered on special sieves, shields or tarpaulin in the shade in the wind: pome seeds in a layer of 0.5 cm, and stone fruits in 1 - 2 layers of seeds. In unfavorable weather, especially in the case of harvesting large batches of seeds, they have to be dried in dryers with artificial heating.
The optimum drying temperature for pome seeds is 30 - 35°C, for stone fruits - 20 - 25°C. At lower temperatures, drying slows down, mold may appear and the viability of the seeds will deteriorate. Higher temperatures are dangerous, as they cause the death of the embryo and the seeds lose their germination.
Dried seeds are finally cleaned on winnowers before storage.
Sorting. Seeds of fruit crops are qualitatively heterogeneous. In an ordinary trade lot of seeds, small, medium, large, full-weight and light, full and feeble, and even completely empty seeds are easily found. Weight and size are among the important indicators of seed potential.
Since the germination of seeds and the primary growth of seedlings occur due to the reserve nutrients deposited in the seeds, it is natural that large and full-weight seeds are more complete (Table 14).
The picking of seedlings from large seeds ensured the yield of 91.3% of rootstocks, from medium seeds - 79.8%, and seeds not sorted by size gave 77.1% of rootstocks from the number of picked plants (Kirkinskaya, 1953). All this indicates the need to select larger and full-weight seeds of fruit species.
Seeds are sorted by size on metal sieves with oblong holes for apple and pear and round holes for cherries.
exit rules. The yield of seeds depends primarily on the breed from the fruits of which they are obtained. Of great importance are the shape and variety of the fruit species, the size of the fruit, the number and weight of seeds in them. Seed yield is usually expressed as a percentage of the mass of processed fruits (Table 15).
condition and quality. The condition and good quality of the seeds determine their purity and viability. Standard seeds of fruit species should have a purity in the range of 86 - 96%. Seed viability is the most important indicator their goodness. Clogged seeds can be improved by clearing them of debris. It is impossible to increase their viability. The viability of seeds of class I should be within 85 - 90%, class II - 70 - 80%, class III - 50 - 65%. Methods for determining seed viability are discussed in the Fruit Growing Workshop.
Storage. Bad years in fruit growing, associated with the frequency of fruiting and adverse weather conditions, lead to a shortage of seeds of fruit trees. This forces nurseries to create the necessary reserves of seeds and organize their rational storage.
The viability of seeds is supported by the reserves of nutrients deposited in them. These reserves are gradually depleted, and the seeds lose their germination, and the more unfavorable the storage conditions, the faster. The degree of humidity of the seeds, as well as the relative humidity of the air in the room where they are stored, is of decisive importance. An increase in seed moisture and relative air humidity in the storage reduces the germination of stored seeds, as their respiration is activated, as a result of which the consumption of nutrients and the activity of microorganisms increase. This is clearly shown by the experiments of M. A. Solovieva (1960). When storing apple and pear seeds with a humidity of 8.5 - 10% indoors at an air temperature of 16 - 20 ° C and a relative humidity of 50 - 70%, their germination in the second year of storage decreased by only 1 - 6%, and apricot and cherry plum seeds - by 0.5%. When seeds were stored under conditions of 80–90% relative air humidity in a room where the air temperature varied from 2 to 12°C, the humidity of apple seeds increased from 10.1 to 15.5%, pear seeds - from 9.4 to 15.5%, in the second year of storage, the germination of seeds decreased by 57.4 and 34.8%, respectively. It is no coincidence that it is believed that the seeds of fruit species during normal storage retain high germination only in the year of their harvest.
From the foregoing, it follows that the seeds of fruit species during long-term storage until the stratification period should remain dry, with a moisture content of not more than 10 - 11% of their total mass. Therefore, it is better to store reserve seeds in a dry room with a constant, but low temperature (2 - 10 ° C) and low (50 - 70%) relative humidity. In this case, they retain high germination for 2-3 years.
Seeds are placed in bags or boxes with a capacity of 15 - 20 kg for pome and 50 - 60 kg for stone fruits or in glass bottles closed with a cork through which a tube filled with calcium chloride is passed. During storage, care must be taken to ensure that there are no dangerous seed pests, especially mice, in the storage.
Preparing seeds for sowing.post-harvest maturation. The seeds of most fruit species, in contrast to the seeds of many field and vegetable crops do not germinate without prior preparation. This biologically useful property for plants was the result of evolutionary development. In a natural setting in middle lane the period of deep and relative dormancy in pome fruits lasts 6 - 7 months, in stone fruits - 8 - 9 months.
In plants that have developed in areas with a harsh continental climate, characterized by sharp transitions from autumn to winter and from spring to dry and hot summer, this period is much shorter.
For example, the duration of the period for preparing seeds for germination of a forest pear from the Voronezh region is 90 - 100 days, Ussuri pear - 50 - 60, forest apple - 90 - 100, Siberian apple - 25 - 30, ordinary apricot - 100, Siberian apricot - only 50 - 60 days. Post-harvest ripening normally takes place with sufficient aeration, required humidity and low, but positive temperature. All these conditions in a natural setting are observed in the autumn months, before the soil freezes, and in early spring, after it thaws.
Preparation of seeds for the passage of the dormant period begins when they are formed in the fruit. It comes down to the formation of dense seeds and shells that protect the seeds from drying out and slow down the penetration of moisture and air into them. Great changes are also observed in the biochemical processes of the protoplasm of the cells of the developing seeds. The starch contained in them initially in large quantities disappears (Oknina and Barskaya, 1962). There is an accumulation of proteins, phosphatides, nucleic substances, storage carbohydrates, fatty oils and other substances, as well as various enzymes that determine respiration and other vital processes of dormant seeds (Blagoveshchensky, 1958).
The transition of seeds to a dormant state by P. A. Genkel and E. Z. Oknina (1964) is explained by the formation of lipoid substances and hydrophobic colloids on the surface of the protoplasm of their cells, leading to dehydration and isolation of the protoplasm from the cell walls and disruption of the plasma connection between individual cells. All this weakens the intensity of the physiological and biochemical processes of the protoplasm of seed cells.
Being at rest, seeds more successfully withstand long-term adverse conditions in which they fall before germination, while maintaining high vitality and germination.
Stratification. The nature of post-harvest ripening of seeds of fruit crops is complex and has not yet been fully elucidated. AT in general terms changes in the seeds are reduced to the fact that during the period of preparation for germination they swell, their shells soften, the intensity of metabolism increases. The energy of respiration increases sharply due to the oxidation of reserve fats and carbohydrates by enzymes. Complex reserve substances break down into simpler, low-molecular compounds that are easily accessible for assimilation by the embryo. As a result of the entry of more water into the cells, their membranes are stretched, the movement of nutrients is enhanced. All this creates favorable conditions for faster division and growth of young seed cells.
Seeds of fruit plants have a dual mechanism of inhibition of germination: dormancy is determined by the special state of the embryo by the action of its integuments. The integuments act mechanically (bones, nut shells), but the main importance is the low permeability of the internal integuments for gases and the resulting disruption of the gas exchange of the embryo. Surrounding tissues may also contain growth inhibitors.
To overcome the dormancy of seeds and prepare them for germination, long-term exposure to low positive temperatures in a humid environment with sufficient air access is used. This is the so-called stratification. It comes down to layering, more often mixing seeds with a substrate (stratification technology is given in the "Workshop on Fruit Growing").
Moisture activates the ripening of seeds and helps prepare them for germination. Its excess is harmful, as it causes loss of germination, and sometimes the death of seeds. Drying is also dangerous. This delays the ripening of seeds, and in more late dates stratification reduces the germination of seeds, since the growth points of their primary roots die off (Chepikov, 1953).
3. K. Shumilina (1966) established the ways of penetration to the seed embryo of moisture, which initially enters the seeds through special passages - tubules, and then, as the walls of the shells soften, through them.
In stone fruit seeds, the water-supplying canal begins at the base of the stone, runs along the suture, and opens at the seed germ. In pome breeds, this tubule is located at the base of the seed.
The temperature regime of seeds is of great importance in the stratifying complex of conditions. Dried, non-stratified seeds do not respond to the effects of low and high temperatures (up to certain limits). Stratified seeds become more sensitive to temperature changes. Freezing seeds at a not particularly low temperature at best delays their post-harvest ripening. With a significant decrease in temperature (up to - 17, - 22 ° C), the seeds lose their germination.
Heating stratified seeds to room temperature, according to S. N. Stepanov (1963), not only slows down their preparation for germination, but also at certain stages, before acquiring the ability to germinate, "removes" stratification. This kind of heating of seeds (up to 20 - 25°C) can be used to accelerate their germination only when they are already prepared for germination.
The process of post-harvest ripening of seeds of fruit species proceeds faster at low positive temperatures (ranging from 1 to 10 ° C, depending on the species). V. Croker (1955) explains this by the fact that in the living tissues of seeds it is at these temperatures that the most significant metabolic processes occur, associated with the intensive transformation of insoluble high-molecular substances into soluble low-molecular compounds. According to A. V. Poptsov (1960), this ensures a more efficient supply of the seeds with oxygen necessary for respiration, which enters them together with water. The solubility of oxygen increases with decreasing temperature, while its consumption by the embryo decreases.
The process of post-harvest seed ripening depends not only on the assistance of environmental factors, but also on the covers and the state of the embryo and reserve nutrients in them. Thus, according to V. I. Piskarez (1940), seeds of pome species without stratification, not freed from covers or with only the seed peel removed, do not germinate.
Gives great effect mechanical removal bones (splitting). This technique can greatly increase the germination of seeds of cherries, apricots and cherry plums.
Studies by E. 3. Oknina (1948) show that the cells of the cone of growth of the primary root come out of dormancy first. Then the cells of the primary kidney and cotyledons begin to awaken. All this is accompanied by the disintegration of the lipid layer and the gradual weakening of the isolation of the protoplasm of the seed cells. These processes are completed in seeds of different breeds and varieties not in same time. For example, in the seeds of the Chinese apple tree, the golden initial dormancy stage is removed on the 30th day of stratification, and the transition to germination occurs on the 36th - 40th day, while in the seeds of the cherry plum and the wild forest apple tree this is observed after 48 days of stratification. Therefore, the duration of stratification in seeds of fruit trees is different. For the stratification of seeds of pear, apple, quince, apricot, 80 - 100 days are required, peach - 100 - 120 days, cherries, cherry plums, thorns, cherries and blackthorns - 120 - 180 days.
Growing seedlings in the breeding department. The technology of growing rootstocks by seed is diverse in technique and depends on biological features propagated crops, the level of agricultural technology, organizational, economic and soil climatic conditions nursery location.
All the variety of existing in practice ways of preparing rootstocks and laying the next fields of the nursery can be divided into two groups:
planting in the next field of standard rootstocks grown in the breeding department (seedling school);
direct method, when the process of preparing rootstocks and growing seedlings is carried out on the same field (combined culture of rootstocks and seedlings).
A distinctive feature of growing seedlings in the breeding department is that the rootstocks are preliminarily grown in special breeding areas (sowing department, seedling school) "and then planted in the next field of the nursery (field of formation), where they are ennobled and cultivated seedlings are formed.
The most difficult part of this technology is the cultivation of high-quality rootstocks. The main requirement for rootstocks is that they have a well-developed root system. It is known that the thicker the seeds are sown, the more seedlings with a tap root system will be. The picking used earlier in practice, that is, transplanting seedlings into early stage, accompanied by shortening of the main root, gave nice results. Seedlings grown with a pick have a well-branched root system. Picking allows more efficient use of seeds and lengthens the period of growing seedlings due to the "run" in the seedling period, since in nurseries and well-prepared ridges, seeds can be sown 2-3 weeks earlier than in the ground. However, the picking process is very time consuming and expensive. According to V. V. Malinkovsky (1939), M. D. Kuznetsov (1966) and others, the costs associated with the preparation of seedlings in the nursery, their picking and post-planting irrigation, account for more than 60% of all costs for the picking site. In addition, after picking, there is a large death of plants, reaching 30 - 40% or more of the number of picked plants. Therefore, at present, seedlings are not picked in industrial nurseries.
Search new technology rootstock cultivation was carried out in two directions: the possibility of replacing picking with other, less labor-intensive methods that increase the yield of rootstocks with a branched root system from the seedling school, and a comprehensive study of the direct method with a view to its wide application in production conditions.
In the school of seedlings, instead of picking, it was proposed to prune the roots of young seedlings. The first recommendations on the technique and timing of this technique were given by M. V. Rytov (1910). L. M. Ro (1929) and others subsequently engaged in a comprehensive study and development of the technology of this technique.
In terms of its effect on the quality of the root system, pruning gives quite satisfactory results. The disadvantages of this method include the difficulty of obtaining uniform seedlings, which is why some of the seedlings are not pruned, and the death of seedlings (sometimes significant), which is explained by the design flaws of the knives used for pruning.
The experience of nurseries shows that cutting the roots of seedlings is most successful in areas with light, well-cultivated soils, cleared of rhizomes, stones, sticks and weed residues.
Pruning should begin at the time most seedlings form 3-4 true leaves and do it at a depth of 6-8 cm from the soil surface. Pruning can be done in the afternoon with the obligatory compaction of the soil near the rows of plants and watering. Watering should be alternated with loosening until the plants take root.
The data of many authors show that the formation of a certain type of seedling root system when seeds are sown in the soil to a large extent depends on the conditions of water and mineral nutrition in crops. So, A. K. Chepikov (1953) notes that organo- mineral fertilizers introduced into the upper soil layer (up to 20 cm) contributed to increased branching of the roots of apple rootstocks in the seedling school.
According to our data, on the floodplain soils of the Moscow region, foliar feeding (NPK), carried out in the phase of the 5th - 6th leaf, increased the yield of standard seedlings of Antonovka vulgaris by an average of 38.9% over 3 years. A similar effect of organo-mineral fertilizers on the branching of the root system of apple seedlings is also noted by many other authors. Consequently, the creation of a high agricultural background can significantly increase the yield of seedlings with a well-developed root system.
The timing of sowing seeds. The term for sowing seeds in the soil of the school of seedlings depends on the soil and climatic conditions and the type of seeds. For spring sowing, seeds well prepared during the stratification period and tested for germination are usually used. Therefore, spring sowing of seeds of rootstocks of fruit species, carried out in a timely manner and in short time, in all areas of fruit growing give good results.
When sown in autumn, the seeds ripen on the site in naturally developing and more difficult to control external conditions. Therefore, autumn field sowing of seeds is permissible only in those cases when it is known for sure that they will find the necessary conditions for the normal completion of the processes of ripening and germination in early spring. Autumn sowing of seeds will be more effective in the southern regions, which are characterized by structural, moist and long-term non-freezing soils. Stone fruit seeds, with the exception of apricot, peach and almond, even in these favorable conditions due to the long ripening period should be sown after their preparation.
In areas with unstable soil moisture, late snowfall and deep freezing of dense, heavy and easily floating soils, which form a crust that is difficult for seedlings to break through by spring, autumn sowing of seeds should not be used. Much top scores under these conditions will give spring sowing of seeds of rootstocks of fruit plants.
In order to create best conditions for the timely appearance of full-fledged and friendly shoots and the further growth of seedlings, seeds must be sown in carefully and well-prepared soil. In the presence of wireworms and grubs, the soil must be fumigated. autumn sowing seeds are carried out on a well-cultivated fallow and early tilled no later than 20-30 days before the soil freezes (Kuznetsov, 1966).
Spring sowing of seeds, which is carried out as soon as the soil condition allows, should be preceded by deep autumn plowing, as well as spring pre-sowing harrowing and deep (up to 8 - 12 cm) subsurface loosening. Heavily silted and compacted soils should be finely plowed with immediate harrowing, leveling and rolling with a light wooden roller. Methods and techniques for sowing seeds. Depending on climatic conditions and the amount of work, seeds are sown by machines or manually on a flat surface and on raised ridges. When growing rootstocks on large areas, seeds are sown by machines.
Sowing seeds with a seeder is a very responsible job. Especially strictly it is necessary to monitor the preservation of the straightness of the rows.
For the successful operation of seeders, it is necessary that the seeds sown be free from the substrate in which they were located during the stratification period, have the necessary flowability and do not lose their sowing qualities. One of effective ways seed preparation is their drying before sowing with the separation of the substrate on sieves. However, according to Yu. G. Popov (1967), drying apple seeds for 7; 17 and 25 hours has a noticeable negative effect on their germination and germination energy. Short-term drying for 1–3 hours has a positive effect on seeds: their germination capacity increases by 10–15%, germination energy increases, and the period between sowing and germination is reduced (Zakotin, 1967). Further drying up to 6 and especially 12 hours leads to sharp decline their field germination (up to 24% against 50% in control). This is due to the fact that in the first hours, the seed coats lose the largest amount of water (37.8% in 1 hour, 70.4% in the next 2 hours), and not the embryos (only 0.9% in the first 3 hours). Further exposure of the seeds to air for up to 6 hours leads to the loss of 42% of water by the embryo, and after 48 hours - about 90%. Seeds become glassy and not viable.
With spring crops for more exact definition the direction of the rows when loosening the plot, it is advisable to add the seeds of lighthouse crops (for example, lettuce) to the seeds of fruit species.
In the conditions of production, there are various schemes for sowing seeds, developed in relation to the conditions of certain fruit nursery farms: single-line - the distance between the lines is 40 - 80 cm, in the line 8 - 15 cm; tape, consisting of 2 - 3 or more rows with a distance between tapes of 50 - 80 cm, between lines of 15 - 30 cm; wide-line - during sowing, the seeds are evenly scattered over the width of the entire tape (18 - 20 cm), the distance between the tapes is 50 - 80 cm. With the latter method of sowing, the nutritional conditions of the seedlings improve and the cost of manual care is significantly reduced. Shirokostrochnye crops are used in the state farm. Lenin of the Moscow region, in the Shakhtinsky nursery of the Rostov region, in the Kushchevsky fruit-nursery state farm Krasnodar Territory and in other farms.
Seed sowing depth. Seeds germinate normally only with sufficient moisture and aeration of the soil. Small incorporation poorly protects the seeds from possible drying and death. Conversely, sowing in deep furrows makes it difficult to access oxygen, prevents overcoming soil resistance when seedlings emerge, and usually produces weak, late and sparse seedlings.
The establishment of a specific sowing depth of seeds of various species depends on their size, mechanical composition and soil moisture. Larger seeds on light and slightly moist soils are sown deeper, and small seeds on heavy and moist soils are sown smaller. Thus, seeds of pome species on light soils are planted to a depth of 3–7 cm, on heavy soils to a depth of 2–3 cm, and stone fruits, respectively, to 5–8 and 4–5 cm.
Seeding rates set depending on the breed, size, economic suitability and field germination of seeds, as well as the density and timing of sowing (Table 16). The width of the row spacing and the percentage of plant waste in the seedling school during the growing season are also of significant importance.
Soil and seedling care. Seedling care comes down to creating necessary conditions for their fastest, maximum and continuous growth and full maturation. This is achieved by careful tillage, systematic control of weeds, diseases and pests, as well as watering and fertilizing plants. The soil in the seedling school by systematic and repeated loosening and timely weeding should be maintained in a loose and weed-free state. With insufficient precipitation, seedlings should be watered. The number and timing of irrigations depend on local soil and climatic conditions. Usually they start when the soil moisture decreases to 75 - 80% of the full field capacity. In the south, they water more often, 8-10 times or more, in the middle lane less often - it is enough to give 3-4 waterings.
Thinning seedlings with thickened seedlings is an obligatory agricultural technique.
The feeding areas of seedlings have a decisive influence on the vigor of growth and the quality of the rootstock. Experience shows that seedlings need a feeding area of 100 - 120 cm 2 for normal growth.
When tape sowing in two lines with a distance of 20 cm between them, seedlings of pome fruits should be placed in a row 5 - 6 cm from one another, cherries, plums - 3 - 4 cm, apricots, cherry plums - 2 - 3 cm from each other .
Taking into account the positive effect of the density of standing in the first period of the life of seedlings on their growth and development, as well as the weak resistance of immature plants to sparse standing, thinning is recommended in two steps: the first - by 2 - 3 cm during the formation of 1 - 2 true leaves, the second - 15 - 20 days after the first, at a normal distance.
The growth of seedlings and the increase in the yield of high-quality rootstocks, especially on infertile and depleted soils, are effectively affected by top dressing with easily digestible fertilizers. Usually, mineral fertilizers, slurry, bird droppings, etc. are used for this purpose. At the first top dressing, up to 20 kg of nitrogen, phosphorus and potassium are applied per hectare. Then their doses are increased to 30 kg, and the concentration from 0.1 - 0.15% is adjusted to 0.2%. Top dressing should be given only in the first half of the growing season: the first, when the plants reach 8 - 10 cm in height, the second and, if necessary, the third - sequentially after 15 - 20 days. Especially increased the yield of first-class rootstocks (by 22 - 27%) compared with the control at the state farm. Lenin Moscow region foliar top dressing boric acid, ammonium molybdenum acid, and a mixture of microelements against the background of NPK (Potapova, 1976).
At the first time of growth, the wireworm and larvae of the May beetle are dangerous for seedlings. Aphids do great harm. Seedlings are often affected by the black leg, and older plants by scab. To prevent damage to plants, pest and disease control should be organized in advance to prevent their mass occurrence. The output of seedlings from 1 hectare of the sowing department ranges from 150 to 200 thousand pome species and from 150 to 300 thousand stone fruits.
