Using rootstock and scion

Using rootstock and scion

In the DREVO system of land restoration, forest creation and sustainable forest gardens

1. General concept

The use of rootstock and scion allows you to combine two different sets of qualities in one plant:

rootstockforms the root system and the lower part of the plant;

scionforms the above-ground part, crown, flowering and fruits.

Thus, one tree can combine:

resistance to local soil;

drought resistance;

frost resistance;

resistance to soil diseases;

the required growth force;

valuable variety;

high quality fruits;

cultural and genetic heritage.

The rootstock largely determines the size and vigor of a tree and can also influence its resistance to soil-borne diseases. The scion preserves the key varietal characteristics of the above-ground portion.

The DREVO project views grafting not only as a gardening technique, but also as a tool:

adaptation of plants to restored lands;

preservation of rare varieties;

accelerated formation of forest gardens;

use of resilient local root systems;

increasing diversity;

gradual modernization of existing plantings.

Basic principle:

The rootstock connects the tree to the ground, and the scion determines its productive and hereditary function.

2. The importance of rootstock

The rootstock is responsible for the interaction of the plant with the soil and the underground part of the ecosystem.

It affects:

depth and spread of roots;

tree resistance to drought;

tolerance to waterlogging;

adaptability to acidity or alkalinity;

resistance to salinization;

ability to grow on poor soils;

resistance to individual soil diseases and pests;

growth force;

final height of the tree;

fruiting period;

wind resistance;

durability of wood;

need for support and care.

Therefore, the choice of rootstock should begin not with the desired fruit variety, but with an analysis of the site.

First, the following are studied:

climate;

soil depth;

type of regolith or andosol;

humidity;

drainage;

pH;

salt content;

pollutants;

frosty depressions;

wind load;

expected lifespan of the tree.

After this, a rootstock is selected that can survive stably in the given conditions.

3. The importance of scion

The scion determines the main properties of the above-ground part of the plant:

variety;

shape and quality of fruits;

flowering time;

ripening periods;

productivity;

taste properties;

color and shape of fruits;

crown features;

quality of wood of young shoots;

part of resistance to crown diseases;

cultural and historical value.

Grafting allows for precise propagation of a variety, as trees grown from seed usually don't fully replicate the characteristics of the parent plant. To preserve a specific variety, vegetative material—a scion or bud—is used.

In the DREVO project, the scion can perform one or more functions:

food;

seminal;

cultural;

selection;

educational;

collectible;

adaptive;

experimental.

4. The main goals of vaccination in the project

4.1. Adaptation of varieties to local soil

A valuable variety may grow poorly on:

dry;

rocky;

heavy;

sour;

alkaline;

waterlogged;

poorly developed soil.

In this case, it is grafted onto a rootstock that is better suited to the local soil profile.

This is especially important when mastering:

restored regolith;

disturbed andosols;

slopes;

arid lands;

areas with uneven soil depth;

areas with limited irrigation.

4.2. Preservation of old and local varieties

Grafting allows you to preserve the variety even when the old mother tree:

dies;

becomes emergency;

damaged by fire;

affected by disease;

is located on the territory of future construction;

loses productivity.

Before a valuable tree is removed or dies, the following is collected from it:

cuttings;

kidneys;

seeds;

samples for the genetic archive.

The scions are placed on several rootstocks and in different natural zones so that one accidental death does not destroy the varietal line.

4.3. Acceleration of forest garden creation

A fruit tree seedling can remain in a juvenile state for a long time and produce unpredictable fruits.

A grafted tree usually allows:

to obtain a known variety earlier;

plan the harvest more accurately;

control the size of the crown;

form productive zones faster;

maintain proven qualities.

However, rapid fruiting should not be put above the formation of a healthy root system.

4.4 Re-grafting of existing trees

Healthy but low-value or unsuitable trees can be re-grafted rather than uprooted.

Saved:

developed root system;

formed soil zone;

mycorrhizal relationships;

tree stability in place;

part of the trunk and skeletal branches.

One or more new varieties are introduced onto an existing tree.

This method is especially useful for the gradual modernization of a forest garden without completely destroying the already formed structure.

4.5. Creating multi-varietal trees

Several varieties of the same or closely related species can be grown on one compatible rootstock.

This allows:

increase varietal diversity in a small area;

ensure cross-pollination;

distribute flowering periods;

extend the harvest period;

preserve rare varieties;

create demonstration and educational trees.

A multi-variety tree requires constant monitoring, since one scion may grow stronger than the others and gradually suppress them.

5. Types of rootstocks

Seed rootstock

Grown from seed.

Usually he:

forms a strong root system;

better secures the wood;

able to develop the soil more deeply;

can be durable;

characterized by genetic diversity;

does not always ensure the same growth force for all trees.

Seed rootstocks are especially important for:

large forest gardens;

dry areas;

forest-steppe;

areas with minimal maintenance;

long-lived trees;

creating genetically diverse populations.

They are suitable where the main goal is not compactness, but stability and durability.

Clonal rootstock

It reproduces vegetatively and therefore retains relatively identical properties.

It allows for more precise control over:

tree height;

growth force;

fruiting periods;

placement density;

Features of the root system.

Clonal rootstocks are useful in:

intensive productive zones;

nurseries;

small forest gardens;

educational gardens;

in places where it is necessary to limit the height of the crown.

Some dwarf rootstocks may require:

permanent support;

regular watering;

more fertile soil;

increased care.

Therefore, they should not be automatically used in remote or poorly controlled areas.

Local wild rootstock

Formed from local wild or naturalized plants that are well adapted to the area.

Its advantages:

adaptation to the local climate;

resistance to soil characteristics;

connection with local biota;

possibility of natural renewal;

genetic diversity.

However, before use, you need to check:

compatibility with scion;

presence of diseases;

invasive potential;

quality of rootstock fruits;

formation of root shoots;

influence on growth force.

Intermediate insert

Sometimes a third component, an intermediate insert or intercalary, is introduced between the rootstock and the scion.

It can be used for:

overcoming partial incompatibility;

regulation of growth force;

creating a certain height of the trunk;

increasing the winter hardiness of the trunk;

a combination of properties of several plants.

In such trees, all components must be certified:

main rootstock → intermediate insert → scion.

6. Rootstocks for different functional zones

Natural forest zones

In natural kernels, grafting is used to a limited extent.

Main priority:

natural reproduction;

local species;

seed diversity;

preservation of natural selection.

Vaccination is permitted for:

preservation of a rare genetic line;

restoration of a historical plant;

scientific observation;

creating a backup copy of a valuable copy.

Natural oaks, lindens, maples, ash trees and cedar pines should primarily develop on their own roots or from seeds.

Transitional forest-steppe zones

Vigorous seed or local rootstocks can be used here.

They must ensure:

deep rooting;

drought resistance;

ability to grow with limited care;

wind resistance;

durability.

Sustainable forest garden

The following combination is used:

seed rootstocks for long-lived trees;

medium-sized rootstocks for the main productive zones;

dwarf rootstocks for intensive care areas;

local rootstocks for experimental adaptation;

multi-varietal trees for preserving collections.

Nursery area

Various combinations are grown and tested in the nursery.

For each combination the following are evaluated:

survival rate;

quality of graft union;

growth force;

winter hardiness;

drought resistance;

disease resistance;

fruit quality;

durability;

need for watering;

suitability for a specific natural zone.

Remediation zone

In contaminated areas, food grafts should not be used unless they have been proven safe.

Even if the scion produces quality fruit, the root system remains connected to contaminated soil.

The following are permitted in such areas:

non-food rootstocks and scions;

decorative forms;

industrial crops;

experimental plants;

seed trees whose material is not introduced into the food cycle.

Food vaccinations are only permitted:

on a clean, isolated soil base;

after soil analysis;

after assessing contaminants in fruits;

under constant monitoring.

7. Compatibility of rootstock and scion

Biocompatibility is required for successful vaccination.

The most reliable combinations are:

within one species;

between closely related species of the same genus;

between certain closely related families under confirmed practice.

It cannot be assumed that all woody plants can be connected to each other.

Incompatibility may manifest itself:

immediately after vaccination;

in a few years;

after the beginning of fruiting;

under heavy crop load;

after frost or drought.

Signs of possible incompatibility:

poor healing of the joint;

thickening above or below the graft site;

sharp difference in the thickness of the components;

cracking;

tissue death;

stunted growth;

premature yellowing;

a split in the wood at the junction.

Differences in the growth strength of the rootstock and scion can lead to thickening and destruction of the connection.

In a long-term project, it's not enough to evaluate a graft after just one season. Compatibility must be monitored for decades.

8. Requirements for grafting material

The rootstock should be:

healthy;

correctly defined;

free from dangerous infections;

well rooted;

adapted to the site;

not damaged by frost or drought;

of sufficient thickness for the chosen method.

The scion must be:

taken from a known mother plant;

correctly signed;

free from visible diseases;

collected at the appropriate time;

protected from drying out;

stored at a suitable temperature;

have viable kidneys;

be traced through the passport of origin.

For valuable varieties, it is advisable to collect scions not from one, but from several healthy mother trees of the same confirmed line.

9. Basic methods of grafting

The choice of method depends on:

rootstock diameter;

age of the tree;

time of year;

plant species;

objectives of the operation;

conditions of the cortex;

qualifications of the performer.

Copulation

Used when the rootstock and scion have similar thickness.

Suitable for:

young trees;

nurseries;

tabletop grafting;

creation of new seedlings.

The key is precise alignment of the cambial tissues. Good cambial contact facilitates rapid and strong fusion.

Improved copulation

Additional longitudinal cuts create “tongues” that:

increase the contact area;

better fixation of components;

increase the stability of the connection.

Cleft grafting

Used with thicker rootstock.

Applicable for:

re-grafting of young trees;

modified varieties;

restoration of part of the crown.

Bark grafting

Suitable for grafting thicker branches or trunks when the bark separates well.

It allows the formed root system of an old tree to be used to grow a new variety.

Grafting

Instead of a cutting, one bud is used.

Main options:

T-budding;

kidney vaccination;

chip budding.

Using a single bud allows for economical propagation of rare material.

Bridge grafting

It is used primarily to save trees with ring-shaped bark damage.

Scions create a bypass for the movement of substances between the roots and the crown.

Ablation

Two plants are joined together and retain their own roots until they are completely fused.

The method can be applied:

for complex types;

in the restoration of valuable plants;

to form living structures;

in experimental ecosystem projects.

10. Using grafting on restored regolith

At the early stage of regolith development, grafted fruit trees should not be the first plants.

First, the following are formed:

water regime;

grass cover;

shrubs;

pioneer trees;

organomineral horizon;

protected microclimate.

Once a stable soil-plant system has emerged, grafted trees can be introduced.

Preference is given to rootstocks that:

able to master poor substrate;

resistant to moisture deficiency;

form a strong root system;

do not require constant watering;

approach the depth of the formed soil.

The planting hole shouldn't become an isolated "pot" of rich soil within poor regolith. The roots should gradually migrate into the surrounding substrate.

Therefore, not only a planting hole is created, but also:

extended root zone;

watershed;

transitional soil mixture;

mulched surface;

protective plant guild.

11. Using grafting on Andosols

Andosols can provide good conditions for fruit trees, but it is necessary to consider:

acidity;

phosphorus availability;

humidity;

profile depth;

tendency to erosion;

possibility of over-watering;

altitude above sea level.

Rootstocks are selected taking into account the specific site.

In deep, wet Andosols, an overly vigorous rootstock can form an overly robust crown. On slopes, a weak root system can reduce the tree's stability.

The following become priorities:

good fixation;

compliance with water regime;

resistance to local diseases;

durability;

moderate dependence on external care.

12. Vaccination as a means of gradual modernization

The project is designed for 150 years, with a 300-year forecast. During this time, the following may change:

climate;

composition of diseases;

taste preferences;

economic tasks;

availability of water;

a set of resistant varieties.

Grafting allows for the modernization of a forest orchard without the complete destruction of mature trees.

Possible actions:

replacement of some varieties;

adding new pollinators;

introduction of later flowering;

adding drought-resistant varieties;

preserving the old variety on separate branches;

re-grafting of the damaged part of the crown;

creating backup copies of valuable lines.

Modernization is carried out gradually, so as not to lose the entire harvest and genetic base at once.

13. Preservation of the natural framework

Grafting should not turn all the trees in the forest into fruit trees.

The project must maintain separation:

Nature-forming trees

Their main function:

forest formation;

soil creation;

water retention;

support for biodiversity;

long-term stability.

They are mostly preserved in their natural form.

Fruit trees of the forest garden

Their function:

food production;

preservation of varieties;

support for pollinators;

educational and economic activities.

They can make extensive use of the rootstock and scion system.

Experimental trees

Used for:

compatibility tests;

evaluation of new rootstocks;

adaptation of varieties;

selections;

long-term sustainability observations.

They are placed in separate controlled areas and should not form the basis of the entire ecosystem until the results are confirmed.

14. Passport of the grafted plant

The passport of a grafted tree must be more detailed than the passport of an own-rooted plant.

It records:

If there are several grafts on a tree, each one receives a separate entry.

15. Passportization after 16 years

After 16 years, not only the condition of the tree is assessed, but also the stability of the entire combination.

The following are checked:

connection strength;

absence of signs of incompatibility;

rootstock health;

root condition;

crown growth balance;

wind resistance;

reaction to droughts and frosts;

regularity of fruiting;

fruit quality;

disease resistance;

formation of shoots;

need for support;

expected durability.

A grafted tree can be assigned one of the following statuses:

G1 - experimental combination;

G2 - Pre-confirmed compatibility;

G3 - a stable productive combination;

G4 - a valuable hereditary combination;

G5 - mother tree for propagation;

G6 - a multi-variety collectible tree;

G7 - a combination with signs of late incompatibility.

A passport doesn't eliminate follow-up care. Some problems may appear decades later.

16. Mother trees and graft bank

As part of the project, a special bank of vaccination material is being created.

It includes:

mother trees;

collection gardens;

reserve nurseries;

refrigerated storage of cuttings;

kidney catalog;

genetic records;

digital photo chronicle;

duplication of material in different places.

For each valuable variety it is desirable to have:

at least several living trees;

plants on different rootstocks;

reserve outside one natural zone;

annually updated vaccination material;

confirmed description of the variety.

This protects the collection from:

fire;

diseases;

droughts;

mechanical damage;

care errors;

loss of one territory.

17. Successor trees and grafting succession

For a particularly valuable tree, two forms of succession are created.

Family succession

The seeds retain some of the genetics, but create a new, unique plant.

It is important for:

adaptations;

natural selection;

genetic diversity;

the emergence of new varieties.

Clonal succession

The scion preserves the varietal line of the mother tree.

It is necessary for:

precise preservation of the variety;

historical trees;

outstanding fruit quality;

rare local forms;

documented heritage.

In the project, both forms should complement each other.

Seeds create future diversity. Scions preserve the plant's proven memory.

18. Risk management

The main risks include:

incompatibility;

introduction of viruses and other pathogens;

incorrect labeling of the variety;

weak connection point;

frost damage;

breakage under the harvest;

formation of rootstock shoots;

excessive deepening of the grafting site;

transition of the scion to its own roots;

dominance of one variety in a multi-varietal tree;

too early crop load.

After vaccination it is necessary:

protect the connection from drying out;

monitor for overgrowth;

remove shoots below the graft;

regulate the load;

tie up strong young shoots;

avoid over-tightening with strapping material;

form a stable connection with the crown.

19. Basic principle of use

The rootstock and scion should not be selected separately from each other.

The correct sequence is:

determine the function of the natural zone;

conduct soil and water analysis;

determine the required durability of the wood;

select a suitable rootstock;

select a compatible scion;

check the origin of the material;

to get vaccinated;

observe the fusion;

include a tree in a plant guild;

keep a separate passport;

conduct an extended assessment after 16 years;

preserve successors and reserve material.

20. Final formula

The rootstock provides a connection to the site. The scion preserves the variety and fruiting function. The soil determines the choice of rootstock. Climate checks compatibility. The ecosystem determines the location of the tree. The passport preserves its origin. His successors continue his line.

In the DREVO system, grafting becomes a tool for connecting three levels:

soil sustainability → tree durability → preservation of plant heritage.