Rubber (Hevea brasiliensis Muell-Arg.) ; 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

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

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 tappable 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

S/2 d/2                              (Half spiral, alternate day for 6 months and rested for 3 months)                   100% Intensity
S /2 d/2 6m /9                 (Half spiral, alternate day for 6 months and rested for 3 months)                     67% Intensity
S /2d/3                              (Half spiral, third day)                                                                                                 67% Intensity
S/2 d/3 1m/2                     (Half spiral, daily for one month and rested for next month)                           100% Intensity
S /1 d/4                              Full spiral,fourth day                                                                                                 100% Intensity
V /2 d/2 12m/16                Half circumstances and cut alternate day for 12 months and rested                75% Intensity  

for the next 4 months          

Fixing a polythene rain guard to the trunk of the tree above the tapping panel during the raining season is recommended in areas where the annual yield is 700 kg/ha or more.
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
Scale insect
When severe infestation is noticed, spray malathion 50 EC@ 2 ml/lit.
Mealy bug
 Spray fish oil rosin – soap 25 g/lit.
 Release Australian lady bird beetle, Cryptolaemus montrouzieri @ 10/tree.
Termite (White ant)
Drench the soil at the base of affected plants with chlorpyriphos 20 EC @ 2 ml/litre.
Cockchafer grub
Drench soil at the base of plants in the affected area with the solution of Chlorpyriphos 20 EC @ 2 ml/litre.
Mites
Spray Dicofol 18.5 EC @ 2.5 ml/lit.

Abnormal leaf fall and Secondary leaf fall
 Prophylactic spraying of the foliage prior to the onset of South-West monsoon with 1% bordeaux mixture at 4000 – 5000 l/ha using high volume sprayer
 Oil based copper oxychloride using low volume sprayer or through aerial application. Two rounds of spray using about 17 to 22 l of fungicide oil mixture per ha per round (1:6 proportion) at 10 to 15 days interval or a single round of spray with about 30 – 37 l of fungicide oil mixture per ha (1:5 proportion)


Powdery mildew
 Dusting during the defoliation period commencing from the bud break in about 10% of the trees, giving 3 to 5 rounds at weekly to fortnightly intervals before 10 a.m. using 11 to 14 kg of 325 mesh fine sulphur dust/round/ ha
 Sulphur dust can be mixed with talc in the proportion of 7:3
 Wettable sulphur (1 kg in 4000 l of water) is also effective in nurseries and for young plants as a spray
Bird’s eye spot
 Repeated sprayings with 1% bordeaux mixture or mancozeb or copper oxychloride @ 0.2 %
Leaf spot
 Spray 1% bordeaux mixture or mancozeb @ 0.2% or carbendazim @ 0.1% at fortnightly intervals
Pink disease
 Frequent tree to tree inspection during July – September period for detecting the infected trees and application of Bordeaux paste in the early stages upto 30 cm above and below the affected region
 In advanced cases apply Bordeaux paste and when it dries up scrape off the superficial mycelium and damaged bark and apply Bordeaux paste once again
 Prune off and burn the dried-up branches after disinfecting by Bordeaux mixture spraying
Patch or bark canker
 The affected region may be scraped to remove all the rotting bark and the coagulated rubber and the wound washed well with mancozeb @ 0.75 %
 When the fungicide dries up apply wound dressing compound
Dry rot, stump rot, collar rot or charcoal rot
 Clean up affected areas by washing with carbendazim @ 0.1%
 Scrape out the fructifications. Affected bark and wood show black lines. Wash the wound again with fungicide solution.When it dries up apply a wound dressing compound
 Avoid accumulation of rubber at the base of the trees
Brown root
 Open up the root system
 Completely killed and dried roots may be traced and pruned
 Partially affected and healthy roots washed with carbendazim @ 0.1%
 Drench the base with carbendazim @ 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.

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