Download Hevea 1

1. TAXONOMY, ORIGIN, MORPHOLOGY AND CLIMATIC
REQUIREMENTS
Family : Euphorbiaceae
GENUS : HEVEA
1.1 Introduction
Rubber refers to a group of materials which are highly elastic. Rubbers are not
strong and flexible. These properties are added to rubber through various
treatments.
Synthetic rubber (SR) is a byproduct of petroleum industry.
Natural rubber (NR) is an agricultural commodity and it is a byproduct of
plant cell metabolism.
Most rubber producing plants are native to tropics.
Castella Species (sp):
native to Tropical America
Manihot sp:
native to Tropical America
Funtima elastica:
native to Africa
Parthenium argentatum: native to Central America
Hevea (sp):
native to Tropical America
At present almost all natural rubber is extracted from Hevea.
Hevea brasiliensis is the species that is cultivated for the extraction of rubber
contained in its latex.
Most of the basic concepts of NR industry were developed in 18th and 19th
centuries
These concepts fall into two main components viz.
a. Agricultural or Agronomic component and
b. Technology component.
Agricultural component includes identification of species, propagation,
exploitation and establishment of organized plantations.
1.2 Taxonomy
First botanical description of genus Hevea and of the type species Hevea
guianensis was by Fusee Aublet in 1775.
In 1779 L.C Richard proposed the generic name Siphonia as equivalent to
Aublet’s Hevea.
J. Mueller Argoviensis in 1865 grouped all the species, H. brasiliensis, H.
pauciflora H. spruceana, H. rigidifolia together under Hevea.
Schultes (1977) reviewed the history of infrageneric classification of Siphonia
and Hevea.
He recognized two sub genera under genus Hevea: i subgenus: Hevea and
ii subgenus: Microphyllae.
1
Up to Argoviensis, taxonomic treatments were by botanists in European
herbaria on materials, much of it collected by Richard Pruce during his
explorations of Amazon and Andes from 1849 to 1864.
Schultes in 1987 has also reviewed the species recognized in the genus by
previous workers.
Different numbers of species recognized by taxonomists before Schultes are
given below.
Taxonomist
M Argoviensis
Huber
Pax
Ducke
Seibert
Schultes
No. of Species
11
24
17
12
08
10
Year
1874
1906
1910
1935
1947
1987
Previously, rank of species was given to what later recognized as local
variants or varieties. Thus in the taxonomic treatment of Shultez only 10
species have been recognized. All are grouped under subgenus Hevea except
one.
Full taxonomic classification after Schultes (1977)
Family : Euphorbiaceae
Genus : Hevea
subgenus : Hevea
subgenus : Microphyllae
Species under two subgenera
subgenus: Hevea
H. guianensis
subgenus : Microphyllae
H. microphylla
H. brasiliensis
H. pauciflora
H. spruceana
H. rigidifolia
H. benthamiana
H. nitida
H. camporum
H. camargoana
2
1.3 Origin and distribution
Hevea species have originated in tropical America and are naturally found in
the Amazon basin and parts of the uplands adjacent to it.
Cultivated species, H. brasiliensis, occupies most of the South of the Amazon
river and as the natural stands of this species extends to the West of the river
it penetrates the North of the river (Fig. 1.1)
Fig. 1.1 Distribution of Hevea Sp. along the Amazon basin and its adjacent
highlands. (Source: Natural rubber: Biology, Cultivation and Technology Pub. by
Elsevier. )
3
1.4 Morphology
1.4.1. Growth form
Under conditions of optimum development H. brasiliensis is one of the tallest
in the genus and grows up to 40m in height.
1.4.2. Pattern of growth
H. brasiliens winters strongly. During wintering all the foliage is shed and the
trees are bare for a brief period.
Young shoots appear bearing young foliage distally and scale leaves
proximally scale leaves often bear flowers in their axils(Fig. 1.2).
1.4.3. Foliage
Trifoliate leaves, assume various positions as they develop. Color too changes
with maturity, from copper brown through apple green to dark or light green.
1.4.4. Flowers
Male and female flowers are borne separately in the same inflorescence (Fig
1.3). Main branches of the panicle end in female flowers (Fig. 1.3 & Fig. 1.4a &
1.4b). Male flowers have 10 anthers arranged on central column or axis
(Fig.1.4f). Female flowers have sessile stigma lobes situated on the ovary (Fig.
1.4g).
Fig 1.2. Branch of H. brasiliensis with flowers to show relative position of
inflorescence and leaves. (Source: Outlines of perennial crop breeding in the
tropics Pub. By Veenman & Zonen, Wageningen)
4
Fig 1.3. Inflorescence of H. brasiliensis female (A) and male (B) flowers. ( (Source:
Outlines of perennial crop breeding in the tropics Pub. By Veenman & Zonen,
Wageningen).
5
Fig.1.4. Details of inflorescence and flowers.
a & b. Branchlet of an inflorescence with terminal female flowers and
laterally inserted male flowers
c. Male flowers; d & e. Female flowers: d. before opening, e. after opening
(anthesis), f. A partially dissected male flower to show two tiers of stamens
arranged on the central column and g. Dissected female flower showing
sessile stigma lobes. (Source: Outlines of perennial crop breeding in the tropics
Pub. By Veenman & Zonen, Wageningen.)
1.4.5. Fruit
Fruit is commonly a Tri-locular capsule containing 3 seeds (Fig. 1.5). Rarely
four locular fruits are also found.
Fruit dehisces explosively due to twisting, (on drying), of woody valves (Fig.
1.6).
6
Fig. 1.5. Rubber fruit showing 3 locules.
Fig.1.6. Showing woody endocarp
after
matured fruit
dehisced.
1.4.6. Seeds
Seeds of H. brasiliensis are rounded (Fig.1.7)
Surface is shiny and mottled. Average fresh weight of a is about 5g. Seeds
lose their viability rather rapidly.
Fig 1.7. Seeds of H. bresiliensis
7
2. HEVEA CLONES AND FACTORS INFLUENCING THEIR
SELECTION FOR PLANTING
2.1 Clone
Clone can be defined as a vegetatively propagated colony or progeny of a
single mother plant.
Thus individuals of the progeny or colony have the same genetic make up as
their mother.
But in vegetatively propagated rubber plants only scion is vegetatively
propagated.
Rootstock comes from open pollinated seeds.
2.2. Important characters in a rubber clone
Yield is the primary character of economic importance.
Two most important secondary characters, in a rubber clone are
a) Vigour
b) Tolerance to major foliar diseases
2.3. Breeding objective:
The main objective in the Hevea breeding program had been to breed high
yielding clones, which are vigorous and tolerant to major leaf diseases.
2.4. Economic importance of yield, vigor and tolerance to major
foliar diseases
2.4.1. Yield
High yielding clones increase the productivity through increased yield per
tree per tapping.
Since there is no additional cost involved, use of genetically improved high
yielding clones is the cheapest way to increase the productivity.
Use of high yielding clones (HYC) is particularly important in perennial
crops such as rubber. In perennial crops, unlike in annual where replanting
cycle is short, once a plantation is established it is going to be in the field for a
long period and therefore if a wrong clone is selected one has to bear the
consequences for a long time. In rubber recommended replanting cycle is
about 30 years, including the immature period.
2.4.2. Vigour
Vigour determines the tappability of a rubber tree irrespective of its age.
Vigorous clones reach tappability early and such clones give quick returns on
investment.
Vigour also contributes to high yield through
a) Longer tapping cuts
b) Increased drainage area and
c) Increased in the number of latex vessels rings.
Vigorous clones give higher volume of timber at uprooting for replanting.
8
Timber is an important byproduct which gives an additional income.
2.4.3. Tolerance to major foliar diseases:
Diseases influence the income in two ways
a) Direct loss of yield and
b) Increase in COP due to additional inputs such as
agrochemicals and labor to control the diseases.
2.5. Other important secondary characters:
a) Color of latex.
b) Tolerance to wind damage.
c) Tolerance to brown blast.
Breeders cannot breed HYC possessing all the secondary characters. A
suitable clone for a particular area can be selected by considering several
factors.
2.6. Factors that control the choice of clones for commercial
planting:
i.
ii.
iii.
iv.
v.
vi.
Rainfall.
Elevation.
Diseases prevalent in the area.
Tolerance / susceptibility to diseases.
Availability of budwood / planting material.
Clonal composition on the estate.
2.7 Clone recommendation
2.7.1. Clone recommendation for the plantation sector
Group I: Each clone to be planted up to 10% of the extent
RRIC 100*, RRIC 102, RRIC 121, RRIC 1301, RRISL 203
PB 2601
RRIC 100 has been temporarily removed from group I as a very large extent
of rubber land in Sri Lanka has been planted with this clone. But it can be
used in replanting of old RRIC 100 clearings in order to maintain the extent.
Group II: Each clone to be planted up to 3% of the extent
RRISL 201, RRISL 205, RRISL 206, RRISL 210 RRISL 211, RRISL 215
RRISL 216, RRISL 217, RRISL 219, RRISL 2001, RRISL 2003, BPM 24, PB
217, PB28/59, PB 2351
9
Group III: To be planted as Estate/RRI collaborative clone trials.
Each clone to be planted up to 2 hectares.
RRISL 221 RRISL 2000 RRISL 2005
RRISL 222 RRISL 223 PB 255
RRISL 208 RRISL 225 PR 255
RRISL 219 RRISL 226 PR 305
RRISL 220 RRII 105
GPS 1
PR 255
RRISL 2006 PR 305
RRISL 2002 RRIM 712
RRISL 2004
PB 255
1 These
clones should be tapped at 67% intensity until intensification before
uprooting.
2.7.2.Clone recommendation for smallholders and private estate
Group (a)
RRIC 100, This is recommended for non traditional area.
Group (b)
RRIC 102, RRIC 121, RRISL 203
Group (c)
RRISL 2001 Thos recommended for holdings more than 5 ha in extent and
the area planted should not exceed 10% of the total extent
2.7.3 Clone recommendation for planting at high elevations (above
300m up to 900m)
Group (a)
RRIC 100 and RRIC 130
Group (b)
RRIC 102, RRIC 133 and RRISL 206
Each clone in group B should not exceed 5ha in a plantation
10
Notes:
RRISL 221 should not be planted in human pockets.
RRIC 130 is prone to wind damage and should not be planted in areas prone to
strong wind.
Clones RRIC 130, RRISL 217, PB 217. PB 235, PB 28/59 and PB 260 should be
tapped at 67% intensity i.e. 1/2Sd2 until intensification..
In the intermediate zone planting may be extended to areas beyond 900 m
elevation on trial basis wit the collaboration of RRISL.
11
3. ROOTSTOCK AND BUDWOOD NURSERIES
3.1. Introduction
In Sri Lanka budgrafted planting material is used in the establishment of
commercial rubber plantations.
To produce budgrafted rubber plants rootstocks and budwood are essential.
To produce rootstocks and budwood, it is necessary to establish and maintain
rootstock nurseries and budwood nurseries respectively.
3.2. Production of rootstock
To produce rootsock it is necessary to establish
i.
Germination beds (to germinate seeds) and
ii.
Rootstock nurseries (to raise germinated seeds up to bud grafting).
3.2.1 Germination beds
Beds should be one meter in width. Length can vary depending on the
availability of suitable land and on the space requirement. One square meter
(1m x 1m) area can accommodate about 1000 seeds. Beds should be covered
with a layer of fresh river sand up to a thickness of 4 to 5 cm.
Main seed fall season in wet areas is August and September and in dry areas
seeds fall in February and March. Fresh and heavier seeds should be selected
as they germinate early and produce vigorous plants.
Press the seed down until topside of the seed nearly in level with the surface
of sand (Fig. 3.1a).
a
b
Fig. 3.1. Seeds sown in germination bed (a) and correct stage to transplant in the stock
seedling nursery (b). (Source: Handbook of rubber Vol. I Pub. by RRSL)
12
Water daily, provide shade and protect with a wire mesh to protect it from
animals.
Seeds start germinating after about 2 weeks and should be transplanted in the
rootstock seedling nursery with first sign of germination (Fig.3.1b).
Remove germinated seeds. Put the non-germinated seeds back in the nursery.
Collect germinated seeds every other day on 4 occasions and after that
discard non-germinators. It has been observed that only about 50% of sown
seeds germinate during this period (15 days).
Germinated seeds can be used to start ground rootsock seedling nurseries or
poly bag rootstock seedling nurseries.
3.2.2. GROUND ROOTSTOCK SEEDLING NURSERIES
Ground rootstock seedlings are used for brown budding and green budding
Nursery site
Site must be well drained, flat or undulating. Soil conservation is necessary if
undulating.
Site should be close to a continuous and readily available source of water.
Land preparation
Loosen the soil to a depth of 90cm. Remove all stones, pebbles and old
stumps.
Beds should be separated by paths and drains.
Planting distance
Germinated seeds from the germination bed are transplanted in the rootstock
nursery. Shade should be provided to young seedlings using Bracken fern.
Two planting distances are recommended:
i.
Seedlings planted in pairs of rows on 23cm triangular spacing. Spacing
between centers of two adjacent pairs of rows is 60cm. (Fig. 3.2a) and
ii.
If nursery space is not a problem single rows with spacing of 15cm
within rows and 60cm between two adjacent rows can be adopted. (Fig.
3.2b)
Advantage: A vigorous growth due to more space; less foliar diseases.
13
Fig. 3.2. Double row (a) and single row (b) spacing in ground rootstock seedling.
(Source: Handbook of rubber Vol. I Pub. By RRISL).
Manuring
Mixture depends on the soil group to which soil series belong. For this
purpose rubber soils has been classified under seven series.
Before planting
3:1 mixture of imported rock phosphate (IRP) and dolomite is used for group
I and group III soils at the rate of 500kg/ha. Fertilizers should be well forked
into a depth of 15-20cm.
For group II soils (Matale Series): Only IRP at the rate of 350kg/ha. Is
recommended’
After planting
Soil series
Mixture
Soil Group
Sul. of Amm.
Urea based
based mixture
Parambe
GP I
R/SA 9 : 12 : 4 : 2
R/U 15 : 15 : 7
Matale
GP II
R/SA 9 : 11 : 11
R/U 12 : 14 : 14
Homagama
Boralu
Deniyaya
Agalawatta
Ratnapura
GP III
R/SA 8 : 9 : 9 : 4
R/U 12 : 14 : 14
Dosage:
Urea based mixture -
25g/plant + 5g Kieserite/plant
14
Ammonia based mixture - 30g/plant
In Matale series 30g/plant
Frequency:
Every 3 months starting from one month after planting in the nursery bed up
to about 2 months before grafting.
Thinning or culling of weak plants:
Remove weak, diseased and stunted plants during 1st four months after
planting.
Culling percentage is about 40%
Life span:
For brown budding 2 years
For green budding 2 rounds of budding
Stock seedlings that do not reach buddable girth within one year will not
produce a good quality budded stump.
LATEST RECOMMANDATION OF RRISL IS TO HAVE ONLY
POLYBAG ROOTSTOCK NURSERIES AND BUDGRAFT ROOTSTOCKS
RAISED IN POLYBAGS USING YOUNG BUDDING TECHNIQUE.
3.2.3. POLYBAG ROOTSTOCK SEEDLING NURSERIES
Stock seedlings are raised in polythene bags. They are used as rootstocks for
young budding.
3.2.3a.Specification of Polythene
Black, gusseted tubing of gauge 500 or 300
3.2.3b.Dimension of bags ( Lay flat Dimensions)
Width :15 cm or 17 cm
Length :37 cm or 45 cm
Perforate bags before filling
Bags should be filled with top soil preferably having loamy texture. Sieve the
soil and then mix thoroughly rock phosphate at the rate of 50g per bag, before
filling.
3.2.3c. Polybag Nursery
Site : Close to a source of readily available water throughout the year.
Arrangement and spacing of polybags :
15
Filled bags are arranged in 15cm deep trenches either as single rows or double
rows. Distance between 2 adjacent double rows is 60cm (Fig.3.3a). Distance
between 2 adjacent single rows should be 45 cm (Fig.3.3b).
Seeds : Selection and germination of seeds are same as for ground rootstock
nurseries
Fig. 3.3. Double (a) and (b) single row arrangement of polybags in ground
rootstock nurseries. (Source: Handbook of rubber Vol. I Pub. By RRISL).
LATEST RECOMMENDATION OF RRISL IS TO ADOPT SINGLE ROW
ARREANGEMENT (FIG 3.3B) WHEN ESTABLISHING POLYBAG
ROOTSIOCK NURSERIES
Planting in polybags: As soon as seeds germinate in the germination bed, plant
one germinated seed per bag.
After 7 days remove weak or diseased seedlings and replace with fresh
germinated seeds.
Watering :
Watering should be done daily.
3.2.3d. Manuring
Soluble fertilizers are used therefore they are expensive. When supplied in
soluble form nutrients are absorbed quickly by plants and hence will respond
quickly and show fast growth. This is important in young budding as stock
seedlings should be in buddable stage in 3 to 4 months. Fertilizer
recommendations for polybag stock nurseries are based on soil groups
(Tables 3.1a & 3.1b)
16
Table 3.1a. Soil types, soil groups and recommended fertilizer mixtures:
District
Soil type
Group Mixture
Kegalle & Kurunegala
Parambe
I
R/YB 13: 17:6:3
Matale
Matale
II
R/YB 13: 16 : 16
Ratnapura,Awissawella,
Badulla & Moneragala
All other
Soil Types
III
R/YB 9: 12 : 11:4
Table 3.1b. Composition by weight:
Mixture
R/YB 13:17:6:3
R/YB 13:16:16
R/YB 9:12:11:4
Sul: of
Amm.
31
32
23
Diamm
Phosphate
38
35
25
Sul : of
Potash
13
33
23
Epson
Salt
18
39
Total
100
100
100
Formulation 1 (used in polybag rootstock seedlings before bud grafting)
Preparation of liquid formulations:
112g of the appropriate mixture dissolved in 4.5 liters of water.
Rate of application: 50 ml of the formulation I per bag.
Time and period of application : commencing at 2 weeks after planting in
polybags up to 2 weeks before bud grafting.
Frequency of application: once in two weeks.
3.2.3e.Disease control
Since polybag plants are kept close to each other routine disease control
measures are necessary to produce healthy rootstock seedlings.
Spray weekly one from each of the following groups alternatively.
Group A
Copper Sandoz or Harcross Copper oxychloride 3 g to 4 g in one liter of
water.
Group B
Diathane or Captan or Antracol 3 g to 4 g in one liter of water.
If Oidium is present spray Thiovit 3g in one liter of water during January March period at weekly intervals.
17
3.3. Production of budwood
Budwood or bud sticks from which buds are removed for grafting are
obtained from nurseries established for this purpose.
Brown budwood nurseries
Brown budwood to obtain buds from stems of 12 to 18 months of growth.
These buds are used in brown budding
Green budwood nurseries
To obtain buds for green budding, young branches of 9 to 10 or 6 to 8 weeks,
depending on the age, are required.
Location:
Flat or undulating land
Well drained soil
If sloping, beds prepared on contours
3.3.1. Spacing:
i.
Spacing For brown budwood nurseries
Convenient width for brown budwood nursery beds is 4.25m. This
allows 4 rows of plants. Distance between rows is 90cm and plants
within the rows are spaced at 120cm and triangular planting adopted.
60cm margin is allowed on either side. If necessary 30cm drain should be
provided. (Fig. 3.4).
Fig. 3.4. Layout of a brown budwood nursery bed. (Source: Handbook of rubber Vol.
I pub. By RRISL).
ii.
Spacing for green budwood nurseries
18
More spacing is given since plants are maintained as bushes.
A conenient width of green budwood nursery bed would be to have 4
rows of plants spaced 120cm apart and a margin of 60cm on either side
with drain of 30cm wide where necessary. On sloping land drain should
be prepared on the contour. Spacing the plants at 1m x 2m will give
more space for the new shoots to grow after pruning. With this spacing 1
hectare of nursery can accomadate about 5,000 plants, depending on the
terrain
2.3.2. Establishment of budwood nurseries
Planting materials to establish green and brown budwood nurseries:
Bare root budded stumps or polybag plants can be used.
Obtain authentic materials from RRISL.
Planting hole: 60cm x 65cm and 75cm deep.
Season:
May/June or October/November.
Care: Regular removal of stock shoots.
3.3.3. Manuring.
Depends on the age. Same recommendation as for young immature rubber in
commercial clearings.
2.3.4. Harvesting of budwood
3.3.4.i. Harvesting brown budwood
Prior to harvesting paint a colour band 15cm above the bud union. No shoot
is allowed below this band.
First harvest could be made 12-18 months after field establishment.
Fig. 3.5. First harvest of budwood from a new brown budwood nursery.
(Source: (Source: Handbook of rubber Vol. I pub. By RRISL).
19
Cut is made 30cm, at an angle of 450, above the bud union (Fig. 3.5) i.e. 15 cm
above the colour band.
Two buds are allowed to develop from the region above the colour band for
the next crop of budwood.
When these branches are 12 to 18 months old 2nd harvest could be made. (Fig.
3.6a)
Fig. 3.6. Recommended method for collecting brown budwood from brown
budwood nursery. (Source: Handbook of rubber Vol. I pub. By RRISL).
Four buds, two from each branch, are allowed to develop for the 3rd crop.
(Fig. 3b).
This process can be continued till the nursery is uprooted. By about 6 to 10
years there will be about 7 to 8 branches (Fig.3.6c) per plant in budwood
nurseries, 15 to 20 buds per meter of budwood can be obtained.
3.3.4.ii. Harvesting of green budwood
a. From an old brown budwood nurseruy
In an old brown budwood nursery branches are pollarded, just above a whorl
of leaves, at a point where bark has turned brown. Shoots that develop from
the axils of the leaves can be harvested as green budwood when they Are
about 8 to 10 weeks old. Once the shoots are harvested another round of
green budwood can be harvested by pollarding the branches above next
whorl of leave, below (Fig. 3.7a, b and c)
20
Fig.3.7. Successive pruning above leaf whorls to induce axillary buds to
green shoots to be used as green budwood. (Source: Handbook of rubber
Vol. I
pub. By RRISL).
b. From green budwood nursery(For Young and Green budding).
Prior to harvesting budwood, colour band should be painted on every plant
15cm above the bud union. No shoot should be allowed to appear below this
colour band (REFER TO THE COLOUR CODE FOR CLONE IDENTIFICATION ).
When the plants are about 8 months they grow up to about 5 – 6 leaf whorl stage..
When these shoots are pruned just above a whorl of leaves (Fig. 3.7) lateral shoots
will grow from axillary buds and these shoots can be harvested, in 8 to 10 weeks, as
bud sticks for bud grafting. At the end of the bud grafting season all the plants are cut
back at 30 cm and 2 stems per plant are allowed to develop which may be subjected to
pruning and harvesting in the following year. Usually more than two shoots appear
and extra shoots can be allowed to grow and these extra shoots can be harvested
leaving two shoots (3.7d) if two rounds of bud grafting per year is carried out (See the
time schedule (3.1) for budded plant production). If only one round of bud grafting is
carried out extra shoots should be removed as they appear allowing only two shoots
(3.7e)
Stagger the pruning to ensure a continuous supply of green budwood
throughout the grafting season.
Two to three scale buds per stick are available for bud grafting. About 50% of
the axillary buds can also be used if leaves are pruned at the base, leaving the
21
petiole intact, 3 to 4 weeks before grafting. By this time petioles will dry up
and fall off so that axillary buds could be used in green budding.
Harvesting of budwood, green or brown, should be done early in the
morning.
Fig. 3.7e
Fig.3.7d
3.3.4.iii. Harvesting of budwood for young budding
Very similar to that of harvesting green budwood, but age of the budwood is
only 6 to 8 weeks.
Labeling, packing and storage of budwood
Write the clone name or number on cut ends (for brown budwood) by using a
copying pencil or else another suitable labeling method should be adopted.
In the case of brown budwood cut ends should be sealed by immersing in
molten paraffin wax and stored in moistened sawdust if transported over a
long distance. For transporting over a short distance, brown budwood is
wrapped in banana sheath.
Green budwood is transported in sealed polyhene sleeves and unlike in
brown budwood cut ends of green budwood are not sealed with molten
paraffin wax. Clone identification labels are attached to or inserted in
polythene sleeves
Precautions to be adopted in a budwood multiplication nursery





Only the authentic material obtained from the Rubber Research
Institute should be used in the establishment of budwood nurseries.
More than one clone should never be planted in one block or bed.
Surround each block or bed, planted with a particular clone, by two
strands of galvanized wire.
A separate access should be provided for each clonal block or bed.
The correct nomenclature of the clone should be displayed using
permanent lettering in each block or bed.
22



Over budding of existing clones with new clones should never be
practiced.
A plan of each nursery, with planting points of each clone correctly
numbered, should be maintained.
If possible, the cutting of budwood from various points should be
recorded along with the date and number. The name of consignee of
the budwood should also be recorded for future reference.
Schedule 3.1. Time schedule for budded plant production.
3. 4. Types of buds
Three types of buds can be recognized (Fig. 3.8) on a rubber branch. Leaf scar
buds
and scale leaf buds are used for brown budding. For green budding and
young budding, scale leaf buds are used and also 50% of axillary buds can be
used, if they are pretreated as described earlier.
23
Fig.3.8. Different types of buds in a budwood stick. (Source: Handbook of rubber Vol.
I pub. By RRISL).
24