पेड़ का चयन, वंश-वृद्धि, रोपण योजनाएं और कैनोपी प्रबंधन
Tree is a perennial plants with an elongate stem or trunk, supporting branches and leaves in most species. Trees provide additional necessities such as shelter, medicine, tools, etc. They create a peaceful, aesthetically pleasing environment. They balance between oxygen and carbon dioxide which is essential for the life of fauna.
Trees serve as natural air conditioner specially in hot and dry climate by increasing humidity around them through transpiration, lower down temperature and thus change microclimate of surroundings. Trees regulate the rainfall and check the spread of desert. They are also the guardian of soil and check soil erosion by binding the soil particles with their roots.
They improve fertility of soil by adding organic manure in the form of leaves every year. They are used in landscape plan for aesthetic and functional purpose. Trees are used in garden as specimen, avenue plantation, wind breaks, and screening. A judicious planting of trees enhance the beauty of surrounding.
Selection of trees
This depends upon many factors which should be kept in mind when selection is being done.
1. Purpose of Growing
Specimen tree: Such trees are planted singly for their attractive shape, beautiful foliage, flower or for drooping braches reflect humbleness, for example: Araucaria cookie, Callistemon lanceolatus, Salix babylonica, Cassia fistula, Magnolia grandiflora, Plume-ria alba, P. acutifolia, Cassia nodosa, Ficus elastic Decora or Black Prince,etc.
Shady trees: Such trees have mostly round canopy or umbrella crown. Leaves are large and dense so that no or very little sun is allowed underneath them. Common trees are Azadirachtaindica, Kineliapinnata, Alstoniascholaris, Ficusreligiosa, F. benghalensis, F. infectoria, F. benjamina, Mimusposelengi, Pterospermumnacerifolium, Morus sp. Eugenia jambolina, Mangiferaindica, Pongamiapinnata, Swieteniamahagoni, etc.
Flowering trees: These trees produce colourful flowers and are planted for their beautiful flowers e.g., Bauhinia variegate, B. blakeana, Callistemon lanceolatus, Cassia fistula, Cassia siamea, Delonixregia, Erythrina variegate, var. Orientalis, Jacaranda acutifolia, Plumeria alba, Plumeriaacutifolia, Butea monosperma, Chorisiaspeciosa, Heterophragmaadenophyllum, Spathodeacampanulata, Thespesiapopulnea, Lagerstroemia speciosa,etc.
Trees for avenue or road side: Trees planted along side avenues or roads are generally for shade or for flowers. Commonly planted trees are Cassia fistula, Greville arobusta, Jacaranda acutifolia, Heterophragma adinophyllum, Ficusin fectoria, Milletia ovalfolia, Kigeliapinnata, Pterospero mumacerifolium,
Screening purpose: When tall upright trees are planted very close to give an ultimate look of curtainor screen. Such trees are planted to hide some objective or sides. For example, Grevillearobusta, Eucalyptus sp., Poplar sp., Polyalthialongifolia, P. pendula, etc.
For fragrant flowers: There are several trees that are planted for beautiful fragrant flowers. For this purpose trees like KanakChampa, Pagoda tree, Bara Champa, SwarnChampa, Molsari, Akasneem, etc.
For Checking air pollution: Industries are the major source of pollution and hence in such areas deciduous trees or trees having thick shining leaves will be more successful e. g. Morus, Poplar hybrid, Plumeriaacutifolia, Ficusinfectoria, etc.
2. Climate Factors
Selection of trees will depend upon prevailing climate condition of the locality and trees of other climate conditions may or may not do well later on decline. This depends upon adaptability of individual types.
Trees of tropical climate like Delonixregia, Neonaucleapurpurea decline later on in subtropical climate. Similarly, trees of temperate climate do not grow well in tropical regions.
3. Soil Factors
In general trees are adaptable to varying soil conditions but specific trees excel in particular conditions. In alkaline and saline soils , the trees which can be grown successfully are: Casurinaequistiefolia, Cassia fistula, Parkinsonia aculeate, etc.
4. Availability and Cost Factors
The selection of trees for general planting should be done which are easily available at low price; however, specimen trees may be exception to this. For example, plants of Araucaria or Ficus elastic var. Decoraor Black Prince are sold at exorbitant prices but still these are in demand due to their beauty and rarity.
Planting Scheme for Road side
There are different types of roads of depending upon width and vehicular traffic. Thus, the selection of trees differs from road to road. For wider roads- tall trees, for medium roads-medium of trees and for narrow roads-dwarf trees are selected.
For national highways tall shady trees like Azadirachtaindica, Ficusinfectoria, Terminalia arjuna, Pterospermumacerifolium, Kigeliapinnata, Millingtoniahortensis, Polyalthialongifolia, should be selected.
For economic reason, earlier most of national highways were planted with Dalbergiasisoo, Mango seedling, Jamun, etc. but now fast growing tree i.e. Eucalyptus has been planted. For inner roads of cities/ colonies and roads of big campus, mostly colour ful trees are preferred. Therefore, planting alongside such roads can be done according to following schemes keeping various advantages in view.
I. One kind of flowering trees on trees on both sides
In this scheme only one kind of flowering tree is planted on both the sides of roads. So when trees come in bloom there is riot of colour and roads look elegant for particular period. Different trees in different colours are available for this purpose. However, for the rest of blooming time roads will look dull.
Trees that can be selected are: Cassia fistula, Delonixregia, Cassia nodosa, Cassia javanica, Lagerstroemiavspeciosa, Grevillearobusta, Thespesiapopulnea, Bauhinia variegate,
II. Two kinds of flowering trees blooming at one time on both sides of road
In this scheme, two kinds of trees blooming at the same time are planted alternatively on both sides of the roads. The overall effect of two colours is very much pleasing and there is variation in flower colour, shape of trees, leaf size, etc. which avoids monotonous effect. Different trees selected are: Grevillearobusta (yellow)- Jacaranda acutifolia (blue)- Grevillearobusta , Cassia fistula (yellow)- Delonixregia(red)- Cassiafistula, Cassia fistula (yellow)-Cassia nodosa(pink)- Cassiafistula
III. Two kinds of flowering blooming at different time on both sides of roads
According to this scheme two different flowering trees blooming at different time are planted alternately on both sides of the roads. Since the flowering time is different, so one tree will be blooming in one part of the year and the other in another part of the year, hence, road sides will be colourful for longer period. There will not be monotonous effect. Different trees which can be selected are:
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Bauhinia triandra (purple colour in November)-Spathodea companulata (red colour in end of April)- Bauhinia triandra
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Cassia fistula (yellow in May- June)- Jacaranda acutifolia(blue in March April)- Cassiafistula
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Grevillearobusta (yellow in April)-Bauhiniatriandra-Mauve in March- Grevillearobusta
IV. Shady trees only on both sides of roads:
Shade during summer is required. Therefore, only shady trees are planted on both sides of road which provide coolness during hot part of the day. Suitable trees are planted: Ficusinfectoria, Mimusposelengi, Alstoniascholaris, Cedrellatoona, Swieteniamahagoni, Swieteniamacrophylla, Pterospermumacerifolium, Azadirachtaindica, Ficusreligiosa, Polyalthialongifolia,
Planting of Trees
Preparation of ground:
Trees are perennial and will live for several years. Since the preparation of ground is done just once so it is worthwhile to follow proper method ofplanting.
According to the landscape plan, pits should be dug of 60 x 60 x 60 cm size. Soil should be well mixed with 10-15 kg well rotten FYM and Chlorpyrifos@ 5 ml/l of water to check the attack of termites. Refilling of pit should be done which is followed by immediate watering to settle down the soil. After settling down the soil, planting of trees is done in the centre of pit.
Planting time:
For mass plantation best planting time is rainy season. After 2-3 good showers planting should be done so that water does not become a limiting factor. Plants establish easily and grow luxuriantly. Planting can also be done in February-March depending upon the availability of water.
Maintenance and Care of Trees
After planting the trees, constant care is necessary to get the desired effect. Different necessary operations are:
Staking:
Staking is necessary to keep the trunk of trees straight otherwise trunk would bend and plants make abnormal growth. Stake should be such that it suits the size of the tree and should be strong enough to provide the support. For this mostly, straight bamboos or iron bars can be used. It should be placed about 5 cm away from the main trunk so that it does not harm root system.
Fencing and tree guards:
Young trees protection against grazing by animals, human carelessness and adverse weather condition until they are fully established. The type of fencing depends upon factors like cost involved and availability of material.
Most common and cheap fencing is obtained by putting thorny bushes around the tree. Other materials like bricks, perforated bitumen drum and wire netting are also used. These all materials make the poor aesthetic effect and hence, cemented architectural structures or fabricated iron tree guards though little costly can be used.
Weeding:
Weeding is important to prevent the shadowing and suffocation of young trees by vigorous growing weeds until these trees outgrow surrounding vegetation. Two to three weeding are sufficient in a year.
Irrigation:
Irrigation in first few years must be done regularly and according to requirement. Watering during hot and dry period is necessary.
Gap filling:
Replacement of dead trees is also very important and replanting should be done at the earliest with the tree of same age so that it does not disturb the uniformity of the trees.
Training of young trees:
All Dead wood, misshapen or dangerous branches hanging over roads, building, etc. should be cut. Damaged or decayed branches should be cutaway. All cuts more than 5 cm should be painted with Bordeaux mixture against the attack of pathogens.
Authors
Dev Kishan Jat and Dr. Daya Shankar Meena
PDDU AG. College Deoli (Sirohi) Tonk
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