Rubber
Botanical Name- Hevea brasiliensis Muell-Arg.
Family - Euphorbiaceae

South Tamil Nadu :   RRII 430, RRII 105 and RRII 429
Kerala :                         RRII 422, RRII 430, RRII 429 and RRII 417
Other clones :             Tjir 1, PB 86, BD 5, BD 10, PR 17, GT 1, RRIM 600, PB 28/59, PB 217, PB 235, RRIM 703, RRII 5, PCK-1, 2 and PB 260

Soil –

• It requires deep and fertile soil with pH of 4.5 to 6.0.
• Requires tropical temperature of 20 – 30 C with the well distributed rainfall of 2000 – 5000 mm and an elevation of 300 – 800 m above MSL is ideal.

Climate –

• Tropical climate with annual rainfall of 2000 – 4500 mm is suited for cultivation.
• Minimum and maximum temperature should be ranged from 25 to 34°C with 80 % relative humidity is ideal for cultivation.

June – July

Propagated by green budding and brown budding

Bed size: 60-120 cm width and of convenient length.

• Seedling stumps – 23 x 23 cm, 30 x 30 cm and 34 x 20 cm
• Budded stumps – 30 x 30 cm
• Stump budding – 60 x 60 cm
• Bud wood nursery – 60 x 90 cm or 60 x 120 cm

• Basal – 2.5 t/ha of FYM and 350 kg/ha of Rock phosphate.
• 1.5 – 2 months after planting –10:10:4:1.5 N P K Mg mixture -2500 kg/ha.
• Urea @ 550 kg /ha -3 to 3.5 months

Pit size of 1 m3 are dug and filled up with top soil and compost.

Planting material                   Spacing (m)                                                        Population / ha
Budded plants
Hilly areas                                                                6.7 X 3.4                                                                      445
Plains                                                                        4.9 X 4.9                                                                    420
Seedlings
Hilly areas                                                                6.1 X 3.0                                                                      539
Plains                                                                        4.6 X 4.6                                                                     479
In situ sowing
Germinated seeds are sown in situ in the pits. Healthy ones are retained and the others removed.

• Manuring is done for immature rubber trees at pre-tapping stage.
• Apply 12 kg of compost or FYM and 120 g of rock phosphate in each pit before planting.

Apply 10:10:4:1.5 NPK and Mg as per schedule given below:
Months after planting                  Period of application                NPK and Mg mixture(10:10:4:1.5)
                                                                                                                      g/plant             kg/ha
3                                                                September/ October                         225                    100
9                                                                        April / May                                  445                     200
15                                                                 September/ October                      450                     200
21                                                                        April / May                                 450                     250
27                                                                 September/ October                       550                    250
33                                                                        April / May                                  550                    200
39                                                                September/ October                        450                    200
Apply 400 kg of mixture per ha in 2 doses, once in April/May and another in September/October from the 5th year till the tree is ready for tapping.

• For matured rubber trees under tapping, apply NPK 10:10:10 grade mixtures at the rate of 900 g/tree (300 kg/ha) every year in two split doses.
• Add 10 kg commercial Magnesium sulphate for every 100 kg of the above mixture, if there is magnesium deficiency.

• Growing of cover crops, incorporation of cover crops and weeding are important
  operations for soil conservation.
• Pueraria phaseoloides , Calopagonium muconoides,Centrosema pubescens and Desmodium evalifolium are common cover crops.

Banana, pineapple, tuber crops (Amorphophallus, dioscorea, colocasia and arrowroot), ginger, turmeric, vegetables (cowpea, cucumber, bhendi, amaranthus), cocoa, medicinal plants(Strobilanthus haenianus (Karimkurinji), Adhatoda vasica (Valiya Adalodakam) and Plumbago rosea (Chuvanna Koduveli) can be grown in the initial 4 to 5 years.

• Mulching or covering the plant basin with dry leaves, cover crop cuttings, grass cuttings, paddy straw etc is recommended.
• Protection of young rubber plants from strong sun:
• Using plaited coconut leaf tree guards and white washing brown portions of the main stem

• The rubber plants should be induced to produce branches at a height of 2.5 – 3 m to achieve high rate of growth with increased girth through leaf cap or leaf folding
  method.
• In young green tissues, the leaf folding or leaf cap method can be used.
• In the leaf folding method, the leaves of the top whorl are folded down at the point of contact of the petiole with the lamina using only the upper few leaves to enclose the apical bud.
• The leaves are then tied with a rubber band. After three to four weeks they are released. In plants where the terminal whorl of leaves is in the leaflet or bud break stage, the leaf cap method is recommended.
• Here, three mature leaflets are taken to form a cap to enclose the terminal bud and tied with a rubber band.
• The cap is then removed three to four weeks later.

• Trees attain tapeable stage in about 7 years.
• First tapping in seedling trees will commence when the trunk attains a girth of 55 cm at 50 cm height from the ground.
• In budded trees, the girth should be 50 cm at 125 cm height from the bud union.
• The depth of tapping should be 1 mm close to cambium, since greater number of latex vessels are concentrated near the cambium

• Ethrel is recommended to increase latex yield of trees tapped on panel D.
• It is applied at 5 % a.i. concentration with a brush below the tapping cut to a width of 5 cm after light scraping of the outer bark.
• The first application may be done after a drought period  preferably after a few pre-monsoon showers and subsequent applications may be done in September and November.
• However, continuous application of Ethrel is not recommended for periods of more than 3 years at a stretch.

Syndrome characterized by prolonged dripping of latex with the gradual decline in volume yield, Pre-coagulation of latex and partial or complete drying of tapping area (10-25 per cent).

Control : Reduce tapping intensity or give a tapping rest for 3 to 12 months.

Pests
1) Scale insect

Management-

• When severe infestation is noticed, spray malathion 50 EC@ 2 ml/lit.

2) Mealy bug

Management-

• Spray fish oil rosin – soap 25 g/lit.
• Release Australian lady bird beetle, Cryptolaemus montrouzieri @ 10/tree.
•  
• 3)Termite (White ant)-

• Management-
• Drench the soil at the base of affected plants with Chlorpyriphos 20 EC 2 ml/litre.

4) Cockchafer grub

Management-

• Drench soil at the base of plants in the affected area with the solution of Chlorpyriphos 20 EC @ 2 ml/litre
• .5) Mites

• Management-
• Spray Dicofol 18.5 EC @ 2.5 ml/lit.

Symptoms:

• It occurs during June – August, while general leaf fall occurs during December.
• On leaves dull grey, circular spots appear which enlarge and become irregular.
• The petiole exhibit sunken spot. Affected fruits rot. Leaves shed prematurely either green or after turning coppery red.
• The affected leaf form a thick carpet of rotting foliage which emits bad smell.

Management:

• Prophylactic sprays prior to onset of south west monsoon with Bordeaux mixture 1%. Addition of ZnSo4 @ 0.2% improves the efficacy.

2.Birds eye spot: Drechslera heveae (Helminthosporium heveae)

Symptoms:

• Circular spots with grey centre and with brown border occur in large number in nursery or on young plants in the field.

Management:

• Spray with 1% Bordeaux mixture

3.Corynespora leaf spot: Corynespora cossicola

Symptoms:

• Circular spots with brown or papery centre and with a dark brown ring appear on the young leaves.
• An yellow hallo develop around the ring. Short holes occur. Affected leaves dries up.

Management:

• Spray with 1% Bordeaux mixture

4.Pink disease: Corticium salminicolor

Symptoms:

• Prevalent  in wet areas. Young twigs and branches are mostly affected.
• The fungal growth encircles the stem, penetrates the bark and cortical tissues which eventually decay.
• The bark splits and peals off. If the infection in not recognized early the tree dies after the rainy season.

Management:

• Affected parts should be pasted with Bordeaux paste or painting tar.
• Copper fungicides should not be used in rubber because they will contaminate the latex.

5.Powdery mildew: Oidium heveae

Symptoms:

• White powdery fungal growth appears on young leaves and also on matured leaves.
• Infected leaves curl, crinkle, role inwards and fall off leaving the petiole attached to the tree giving a broom stick appearance.
• The infected flowers and tender fruits shed.

Management:

• Spary sulphur  3-5 times at 15 days interval.
• Carbendazim 0.1% or Tridemorph 1.5% dusting alternated with sulphur dust 70%
• Carbendazim +wettable sulphur and microsul (52% EC) is also effective.

6.Brown root diseases: Fomes noxius

Symptoms:

• The affected roots are encrusted with mass of soil and small stones held by net work of mycelium.
• The affected tap root becomes rotted and the entire tree is killed.

Management:

• Removal and destruction of the infected trees.
• Apply lime @ 2.5t/ha
• In the area of dead tree apply additional dose of lime @ 25 kg/ dead tree.
• Wash the partially affected root with Emisan or Aretan 0.1%.

Rubber yield steeply increases year by year, reaching a peak after 14 years of planting.
Annual yield
o 375 kg/ha from seedling tree
o 800 – 1000 kg/ha from budded plants.