TREES – Knowledge Base

PROPAGATION OF TREES

Different trees have different planting methods. Some plants are grown through seeds and some are grown by using any part of plant as buds or stem or roots. Two types of methods used to propagate trees:
1) Sexual method: Propagation through seeds
2) Asexual method: Propagation using parts of existing plant

1) Sexual method of tree propagation

This method is used to grow masses of trees in beds. In this method tree plants are grown by using seeds. Placing a mature seed in favorable conditions it starts germinating.

Keep in mind:
• Select good quality seeds.
• Select those seeds which can adapt to your area.
• Hybrid seeds have more uniformity, good production yield, and unique  cultural characteristics or might be specific disease resistant.
• Seed package must be checked carefully for germination percentage, any chemical treatment.

REQUIREMENTS

1) Light

Some seeds do not need light to germinate as peas, beans, calendula, centaurea, annual phlox, verbena, and vinca will germinate best in the dark but some verities need light supplement as begonia, browallia, impatiens, lettuce, and petunia. Covering the seeds with peat moss will permit low light application to the seeds. Artificial light supply by fluorescent fixtures suspended 6-12 inches above for 16 hrs can also be provided.

2) Oxygen

Proper oxygen reaching to seed during germination will increase respiration rate thus improving germination rate.

3) Temperature

The rate and percentage of germination depends upon the temperature requirements. Generally 65-75 degree F is best for the growth of most of the tree plants. Temperature can also be maintained using radiators and heating cables. Temperature is required to be maintained 24 hrs a day.

DORMANCY

Dormancy around any seed act as hard coat which restrict the seeds from germination during unfavorable conditions. Seed is covered by three parts outer seed coat, the endosperm and embryo. Seed dormancy is required be broken before germination.

Methods of breaking dormancy

1) Scarification

In this method seed dormancy is broken by scratching or softening the seed coat with water, required for the seeds to germinate.
• Acid scarification: It is another method in which concentrated sulfuric acid is used in glass container. Seeds are put into glass for 10 min. some seeds need to be soaked for several hrs depending upon hardness of seed coat.
• Mechanical method: This method involves rubbing of seeds with sandpaper or cracked with hammer.
• Hot water: Hot water is also used. Soaking the seeds at 170-212 degree F hot water for 12 to 24 hrs than planted.
• Moist scarification: In this method seeds are kept in warm, non sterile damp containers. It will take several months for the seeds to break their dormancy.

2) Stratification

This method is suitable for ripened seeds. Take clay pot or plastic bags put sand or vermiculite up to 1 inch than putting seeds on it covering up to ½ inches with sand. Keep the medium wet. Keep the bags in refrigerator for 10-12 weeks. After that placing the bags into warm and moist environment allowing the seedlings to germinate. When plants grown 3 inches shift them to pots.
Another method involves us of sphagnum or peat moses. Mixing the seeds with mixture in plastic bag. Keep the bag in refrigerator for 10-12 weeks. Roots and shoots will start growing during this period. Temperature should not be more than 35-45 degree F. while shifting to specified place.

2) ASEXUAL METHOD OF TREE PROPAGATION: Vegetative method

In this method new plants are grown by using existing parts of any tree plant. Clones of trees are generally grown by asexual method.

Various asexual methods used are:

1) Cutting

In this technique whole new tree is regenerated by cutting stem using sharp blade. After cutting the stem should be kept in mixture of part bleach. Remove all flower and foliage from the stem. Put the cutting into mixture of peat, coarse sand, vermiculite, soil and water well aerated to provide oxygen. Indirect light or keeping in dark should be preferred until new shoots appear.

Cutting Types

a) Stem Cutting: Take a stem with terminal bud, making a cut just below the bud. Dip the stem part in hormone than putting into growing mixture. One of the buds should be below the surface in soil. Maintain the moisture content.

b) Medial cutting: Here we do first cut just above the node and second cut 2-6 inches down to stem. Dip in hormone then fixing into soil mixture media.

c) Cane cutting: Cutting the cane like stems into sections. Each section must contain eyes and nodes. Putting the cutting horizontally half above and half below the surface level, eyes facing upward. Potting is done when new roots and shoots appear.

d) Single Eye: Cut the stem half inch above and half inches below the node. Keep the stem vertically or horizontally in medium.

e) Double Eye: Stem selected for this technique should have two leaves at opposite position. Select a nodal area where 12 inches above and 12 inches below a cut are provided. Bury the cutting into soil medium in such a way so that nodal area should touch the soil surface.

f) Heal cutting: Put a shield shaped cut half way around the bud area. Bury that shielded area horizontally into the soil medium.

2) Leaf Cuttings

This technique is generally used for indoor plants, where roots are preferably generated from leaves instead of whole plant.
Type of leaf cutting:

a) Whole leaf with petiole: Removing the tree leaf with 1-2 inches of petiole. Putting the lower end of petiole into soil medium. New roots will start emerging from the end of petiole.

b) Whole leaf without petiole: Detach leaf form the tree plant without petiole. Plant leaf is buried into soil medium in vertical position. New plant will emerge from auxiliary bud, remove and plant it when new plant has grown with its roots.

c) Split vein: A leaf is detached from stock, put cuts on its veins on lower side. Keep the lower side on medium. Cover sides or margins of leaf with soil and rooting medium so as leaf should not curl up. New roots will start emerging from each cut done on lower surface of leaf.

d) Leaf sections: In this technique one cut is done vein on lower side of leaf as in Begonia. Keeping the lower side on medium where roots will emerge out. In case of snake plant cut the leaves into two sections, lower cut slanted and vertical cut straight to identify the top. Put the leaf tree into soil medium vertically. New roots will emerge at the base of cutting.

3) Root Cuttings

this technique is applied for those trees which are 3-4 years old.

a) Plants with large roots: This technique is generally used for outdoor plants. The plants having large roots are selected. Put a cut at top and a slanted cut 2-6 inches below the top cut. Keep the cut root in sawdust, peat moss or in sand at 40 degree F for 2 weeks. After specified period root is removed and planted vertically as top of the root at same level as surface of rooting medium

b) Plants with small roots: This technique is generally used for indoor plants. Taking 1-3 sections of root. Bury them into soil medium 12 inches below the surface of soil.

4) Layering

In layering technique new plant is grown by using parent plant as medium where stem grows to form a new plant. Layering is enhanced by wounding one side of stem. Rooting medium will provide aeration and constant moisture supply.

Type of layering techniques:

a) Simple layering: This technique is applied by selecting flexible, near earth surface stems. Bury the stems in soil by bending. keeping the tip in upward position. At the bend roots will start to emerge out.

Time of planting:
• Early spring: using dormant branches.
• Late summer: using mature branches.
Keep in mind:
• Monitoring periodically moisture content and root formation.

b) Tip layering: This technique involves fixing the tips of plants in holes of 4-5 inches. Initially tip will grow downward than will start rising upward like other plants. Egs. Purple and black raspberries, and trailing blackberries.

c) Compound layering: This technique involves alternatively fixing the flexible stems keeping one bud above and one bud below the earth surface. Each lower side wounded will grow into new plant. Plants like heart-leaf philodendron, pothos, wisteria, clematis, and grapes can be grown by this method.

d) Mound layering: This method is used for shrubs with heavy stems that grow close together. Here put a cut 1 inch above the soil surface in dormant season. Dirt is mounded around the base of the shrub. Where there are spring season new roots and shoots will start emerging at the base of young plant. Mount layering can be applied to grow apple rootstocks, spirea, quince, daphne, magnolia, and cotoneaster.

e) Air layering: Selecting that area on stem where bud is present. Cutting the bark ring 3-4 inches from bud. Using sphagnum moss removing water content by squeezing. Fix it on wound of stem. Keep it fixed using silver foil or plastic paper to keep it moist. Woody ornamentals plants such as azalea, camellia, magnolia, oleander, and holly can also be propagated by air layering.

5) Division

This method of vegetative propagation involves planting of trees through the crown. Any plant tree having more than one crown and separate stems than gently pull the plants apart. In case if crowns are attached through stem than cut from stem than dividing both parts and grow.

6) Grafting

In this technique, a piece of shoot having dormant buds used in medium to produce new plant with stems and branches. This technique involves cutting of one piece from one plant and grown on another plant as single tree.

Type of grafting techniques:

a) Cleft grafting: In the cleft grafting select a stock of plant, up to one inch in diameter. Using cleft grafting tool split the stock into two parts not to separate them. On other hand cut the scion into wedge shape. Cutting narrow on one side compatible with the size of split on stock. Inserting the narrow part of scion into the split part of stock. Fixing the join between two tree plants properly using paraffin. After six to eight weeks scion will start growing. Do not peels of the tape, Let it peel off naturally.

Time of grafting: February and March

b) Bark grafting: In this technique Root stem or branches with diameter 1- 2 inch are used. Cut the top of branch with diameter 2 inches. From one side of this stock put a cut from outer bark in downward direction up to 3-4 inches depth. On other side scion is cut halfway up to 4 inch. Inserting the scion into the insertion done through bark on stock. Fix it by using plastic bag or Aluminum foil.
Keep in mind:
• Maintain the moisture level.

Time of grafting: Late spring when barks become soft.

c) Toung or whip grafting: In this technique a cut is provided on scion in oval shaped form about 1 inch. Same cut id done on the root stock as like the shape of toung. Fix the scion piece on stock so that surfaces of both parts match each other. After finishing the grafting tying the graft with rubber band, tape or tree wound dressing.

Keep in mind:
• Keeping the grafts moist and at 40-45 degree F temperature.

Time of grafting: February and early March.

7) Budding

Bud grafting involves union of one bud with small piece of bark from scion with root stock. Faster technique for growing trees. Budding is done in growing season June and September.

Types of Budding:

a) Patch budding: This technique is used when plants are actively growing. Making a rectangular cut on the bark area of root stock. Putting a bud or bark piece of same size on rectangular part of root stock. Affix the patch by using plastic bag.

b) Chip budding: This method is used when bark is not slipping. It involves removal of chip bark inward with knife up to 45 degree angle with a small piece of wood attached from a portion between nodes of a young stem of the root stock. The bottom cut is then connected by second inward cut at 45 degree angle. Fit the bud chip with stock and wrap the union.

c) T budding: In it T shaped cut is done on bark means one horizontal cut another cut is done moving through the center of horizontal cut downward. Loosen the bark by twisting the knife into intersection. Taking a piece of shield shaped piece scion with bud on it, bark and thin section wood. Push the shield under the loosened stock bark wrap the union leaving the bud exposed.

GROWING TREES AND REQUIREMENTS

1) Soil requirement:

Soil is the basic element required to be well nourished with suitable chemicals for the cultivation of trees. Soil rich in mineral particles provide nutrients and aerated space required for the plant to grow. 16 elements are required for any tree plant to grow well. Carbon, oxygen, hydrogen is provided by air and others are provided trough soil so the soil must be rich enough to provide all elements required for the plant growth.

Three type of soils

1) Clay: Very fine particles.

Advantage: Very fertile.
Disadvantage:
• Lack good drainage properties.
• Don’t work in wet conditions.
• They remove air when compacted.
• During drought they become very hard even get cracked.

2) Sanda and garvels: These soils have large particle size. They are called hungry soil as they need much quantity of manures, humus and fertilizers.

Advantage: Easy to work.
Disadvantage:
• Low water holding capacity.
• Dry quickly.

3) Peats and heaths: These are very acidic in nature and very less drainage capabilities. Heath consists of large mixture of sand and has less fertility whereas peat has low mineral content and its water holding capacity is also low.
Mixture of clay and sand is best for tree growth. Soil alkalinity required to be maintained properly if soil is less alkaline than adding calcium salt in a form of lime where as acidity can be increased by adding hydrogen. Consistency of soil is required to be maintained properly as roots have to grow through soil.

Keep in mind:
• Check consistency of soil.
• Check alkalinity of soil before growing.

2) Fertilizer

Different trees have different fertilizer requirement. Organic manure or garden compost is the best drug to be applied to soil to fulfill all deficiencies of minerals. Mulches are also used during spring season to control weed growth. Surface layer of organic matter helps to maintain moisture level.

3) Water

Water is itself alive to give life. It is rich in minerals can also be added with other minerals to provide efficient nutrients required for plant growth. Watering the trees weekly deep into roots will encourage the plant growth.

4) Climatic requirements

Growth and development of any tree plant is influenced by various factors like light, temperature, relative humidity, air and rainfall.

PREPARATION OF GROUND

Trees are perennial in nature. Once trees are grown will stay long up to many years may be go through many generation. Trees are generally tall in height and their roots go deep into soil. Keeping in mind the height, size, shape and type of plant ground should be prepared to support growth of trees. At selected place dig the pit up to 60 x 60 x 60cm in size. Mixture of soil with 8-10 kg farm yard manure and 5% chlorpriphos (5 ml/ liter) in water should be mixed with soil. Application of manure will provide nutrients and elements required for proper growth of tree plant where as 5% chlorpriphos will protect the tree plant from attack of termites. Putting the plant at center and refill the pits followed by immediate application of water.

Distance Requirement: Plants should be kept apart at such distance so that shape and size of tree should not affect each other’s growth. Ideal distance between tall and spreading trees should be 35-40 feet. Distance requirement for medium size & Dwarf trees are to be 25-30 feet & 15-20 feet respectively.

Time of plantation: Time of planting is main consideration. Every plant has particular seasonal requirements to grow which should be full filled. Trees vary according to their variety and climatic conditions so before planting any tree plant one must improve his knowledge.

Two seasons of planting the trees:
1) Monsoon (June –August): Evergreen plant trees like citrus and mango can be grown.
2) Spring (Feb to March): Trees grown in spring season grow very rapidly due to high moisture content and low desiccation of plants.
3) Dormant Season: (January and February): Deciduous trees can be grown in dormant season with proper care and tolerance power not to suffer from incoming hot weather.

Guidelines for planting trees:
• Plant one sapling per pit.
• Plant with the ball of earth intact.
• Plant sapling during monsoon.
• Give spacing based on canopy spread.
• Protect sapling against scrolling sun with organic covers as wheat straw or banana leaves.
• Protect from animals grazing using guards.
• Pruning required to frame the tree.
• Feed the trees regularly with organic manure.

MAINTENANCE OF TREES

Trees grown on roadside, in public garden or in house yard required to be well maintained by stacking, pruning and weeding.

• Stacking: Stacking means removing woody pieces from the tree branches. It is a essential process required to be done for normal growth of tree. Stacking help to keep the tree straight otherwise tree can bend on later on stages plant growth. Iron bars and straight bamboos can be used to support the stacking. A distance of 5 cm should be kept between plant and support, to avoid any kind of damage to tree plant. Stacking is necessary for trees with trunk diameter more than an inch and height exceeding 4 feet.

• Weeding: weeds are the unwanted plants grown near to main plant. They can consume nutrients required for the plant growth thus they should be removed as soon as possible. Different verities of weedicides are available in market as per requirement of plant type, to overcome the weed growth. Mulch layer when applied at base of tree plant also act to prohibit the growth of weeds.

• Irrigation: Irrigation involves application of water required to be maintained for few years after the growth of plants. A sturdy base allows the roots to receive sufficient water. Trees have long roots which penetrate deeply into soil. Deeper roots can gain water from dept of earth so after proper growth of plants watering is done rarely. Spring season can full fill all requirement of trees for Water so rare need to apply water.

• Training: when any tree plant is growing well, sometimes their branches got hang over the roads and buildings. As damaged and dead branches got hanged. Training process involves cutting of all such parts of trees to make them good looking and shaped. The plant parts become naked after cutting can be attacked by pathogens so mixture of Bordeaux should be pasted at cuts.

Keep in mind:
• Time: Feb-March (evergreen trees).
• Jan-Feb (winter deciduous trees).
• Remove dead wood and head back at 3 – 3.5m.

SCHEMES USED FOR PLANTING TREES

1) Roadside scheme
2) Landscape scheme

PLANTING SCHEME FOR ROADSIDE

Plants on road side are grown not only for astonishing and bold look but also serve to save ecosystem of that particular areas. Road side planting scheme varies with width of road and vehicle traffic going through. Plants must be selected as requirement of ecology and type of area as:
For wider roads- Tall trees
For narrow roads- Dwarf tree species
For medium roads – Medium sized trees

Benefits of various roadside trees

• Noise pollution control: Trees are planted along the national highways generally having 20-30 meters wide belt, Shady in nature. These types of trees have great capability to control noise pollution caused by traffic on national highways such as Ficus Infectoria, Azadirachthaindica, Terminalia arjuna, Kigeliapinnata, Millingtoniahortensis, Polyalthia longfolia, Eucalyptus, Mangiferaindica, Sygiziumcumini, Delbergia sissoo etc. are some common examples.

• Inner roads of colonies and cities are planted with the colorful trees(7 to 15m belts) such as Acacia longifolia, Acacia dealbata, Acacia pyracantha, Bauhinia variegata, Bauhinia blakeana, Barringtonia racemose, bauhinia speciose, Buteamonosperma, Callistemon lanceolatus, Cassia fistula, Cassia nodosa, Cassia siamea, Delonix regia etc.

• Groom providers: Many flowering trees are planted on the inner roads of colonies and cities covering 7-15m belt. These are specially selected plants that provide surprising, awesome looks and fragrances to colonial areas. Egs: Acacia longifolia, Acacia dealbata, Acacia pyracantha, Bauhinia variegata, Bauhinia blakeana, Barringtonia racemose, bauhinia speciose, Buteamonosperma, Callistemon lanceolatus, Cassia fistula, Cassia nodosa, Cassia siamea, Delonix regia etc.

• Filtration of air: Some special verities of trees are capable of inactivating pollutants through their chemical and biochemical processes. For controlling pollution Trees with thick canopy, having broad hairy leaves and shiny waxy coating are selected. These trees effectively absorb the dust particles and pollution chemicals and hence they work as natural air purifiers.

• Cooling effect on weather: Giant trees grown on road sides provide shade along with protection from dangerous waves from sunlight. Shade of trees provides coolness to hotter environment. Common example of such trees are Ficus Infectoria, Mimusopselengi, Alstoniascholaris, Cedrellatoona, Swieteniamahagoni, Swietenia macrophylla, Azadirachthaindica, Ficus religiosa, Mangiferaindica and Polyalthia longifolia.

• Shady trees planted on both sides of the road do not only provide shade but also provide coolness during hot weather. Common example of such trees are Ficus Infectoria, Mimusopselengi, Alstoniascholaris, Cedrellatoona, Swieteniamahagoni, Swietenia macrophylla, Azadirachthaindica, Ficus religiosa, Mangiferaindica and Polyalthia longifolia.

LANDSCAPE SCHEME

The plants under landscape scheme are planted to beautify our surrounding. They serve architectural, functional and engineering purposes

Functional uses of plants

• They act as barrier for any particular location visually as well as physically.
• They have capabilities to provide protection from solar radiation, wind pressures and humidity along with provide control to noise pollution.
• Their plantation can control soil erosion.
• They refresh the air by controlling pollution level.
• Provide comfort zone to human civilization.
• Wild life habitat.

Architectural uses of plants

• Provide screening effect to protect from direct sunlight.
• Providing bold back ground.
• To create ceiling, walls and floor of outdoor room.
• To provide shelter in pavilion, gazevo, glorietas, etc.

Engineering uses of plants

• Direction of trees acts as guide for the traffic.
• Shady and eye appealing looks provide comfort to drivers and rider from sun glares.

Factors required to be considered while selecting trees for landscape purpose:

• Habitat
• Form
• Height Spread
• Trunk height
• Texture- Fine, medium and coarse
• Growth rate- slow, medium and fast
• Leaf retention period- Deciduous, Semi-deciduous and Evergreen
• Foliage color- Emerging, mature and fall color
• Flowering season and peak flowering duration
• Flower- Color, shape, size, fragrance
• Inflorescence- Size, type and number of flowers in it
• Fruits- Color, shape, size, season and duration
• Susceptibility or resistance to natural hazards, drought, wind, flood,
• Insect pests and diseases that can provide damage to the trees
• Ease of transplanting Other peculiar characteristics

BENEFITS OF USING GARDEN TREES

• Improve air Quality: Tree are capable of absorbing carbon dioxide from the environment and in return emit oxygen thus refreshing the air and reducing polluted particles from air. Planting trees in your yard improves the quality of air which directly affects our health system.
• Reduces rain off: Planting of small trees in your yard can prevent soil erosion during rainy season and also protect your garden flood conditions during bad weather cycle.
• Protection from sunrays: Trees protect us from Extreme UV rays from sunlight. Small Trees planted in garden can act as source of shade to grow vegetables.
• Protection of fruit trees: Putting big trees can stop the damage to fruits trees by acting as bar for wind passage.
• Attracts pollinators: Planting those trees that can attract bees to pollinate. Bee keeper can have benefit by planting bee attracting plants.
• Protection of house: Trees planted in proper site can hide damaged area of any house as damaged wall and fencing. Trees are the privacy protectors. Trees grown in yard keep your privacy as no one from outside can see inside,
• Beautiful look: Trees provide beautiful look to you house yard throughout the year. Plants should be planted as per their climatic condition thus whole year your garden will bloom.

Investment on growing trees can compensate the damage done by ultraviolet rays-

Earth stratosphere is surrounded by gases. At a distance of 65 km from earth, there is presence of a layer called ozone layer. The purpose of ozone layer is to absorb medium frequency rays from sun near about 97-99% which can create huge damage to living organisms if reaches earth. Ozone layer can reduce the level of ultraviolet waves up to 50%. Ultraviolet rays are highly dangerous as can cause skin cancer, sunburn, permanent blindness; cataract can harm plants and animals. Ozone layer prevents ultraviolet rays reaching to earth.
Naturally formed ozone layer is now getting damaged by man made chemicals. Ozone layer is depleting day by day, holes are formed inside the layer because of various chemicals of factories, especially manufactured halo-carbon refrigerants, solvents, propellants, and foam- blowing agents said to be ozone-depleting substances.

Depletion of ozone layer increases the level of Ultraviolet rays on earth atmosphere resulting into various kinds of consequences as mentioned below:

Effects on humans:
Environments of Australia, New Zealand, Argentina and South Africa are greatly affected areas. Ozone holes are more prominent in all these areas. Ozone depletion impact human health positively by production of vitamin D and negatively for being a reason of sunburn, skin cancer and cataracts. Troposphere ozone formation on earth creates risk to health of humans.

Effects on animals: A study in 2011 in at zoology in London has found damage to whales by sunburns. Studies has shown there sharp depletion of ozone layer in gulf of California which lead the Ultraviolet rays to reach earth atmosphere and damage the DNA of whales and blamed to cause skin damage. Negative effects of UV waves can also be visualized on other animal too like Dogs, cats and sheep.

Effects on crops:
Crops are dangerously affected by UV waves. As cyanobacteria required for the retention of nitrogen in rice are effected by levels of UV waves which further damage the plant growth.

Effects on plants:
Increased levels of UV waves on earth atmosphere damage DNA of plants. It has shown to reduce the quantum yields of photo system of plants. Some plants have flavonoids that can absorb UV waves too.

Role of trees in protecting ozone layer

• Environmental problems can be solved by investing in nature and restoring the nature which will produce other benefits too. Ground level formed ozone layer is different from atmospheric ozone. Ground level ozone involves nitrous oxide and other pollutants. Trees grown have capability to absorb both nitrous oxide and pollutant chemicals.

• Plants grown on earth reduce the Carbon dioxide level to a large extent reduces the green house effect also improves air quality by releasing oxygen to the air.

• Trees found in Swaziland and Australia has great capability to reduce dust content and that could also contribute to protect normal ozone layer.

• Creating large dams which improve water vapor level of country by evaporation and condensation resulting into heavier precipitation. Plants grown near all such area will allow the water vapors to move upwards with winds. This upward flow of vapors will greatly influence the oxygen level.

• Flavonoids, xanthophylls and phenolic acids are most important plant pigments and chemicals that are widely distributed in plants. These compounds have antioxidant properties. These plants are rich enough to provide protection from UV waves from sun. Aromatic chemical compounds called Sinapate ester can provide UV protection in bulk. Eg. krameria triandra can absorb 25-30 % where as sesame oil can absorb 30 % of UV rays.

• Reactive oxygen trees are able to tolerate UV radiation stress. Cultivating coconut, peanut, olive and cottonseed oils can provide 20 % of UV protection.