Techniques for planting and caring for rubber trees

ORIGIN

Rubber tree (Hevea brarileneis) belongs to the castor bean family, originating from South America. In 1877, rubber trees were first introduced into Vietnam. After more than a century of existence and development, rubber has affirmed its position as a long-term industrial crop with high economic value, with high economic value. The main product is latex. In addition to latex, wood and oil from rubber seeds also bring significant value… Besides, rubber planting also brings environmental benefits (greening bare land, preventing erosion…). Therefore, it is necessary to fertilize rubber trees from the beginning to achieve high and stable latex yields.

1. BOTANICAL CHARACTERISTICS

Rubber is a tree with roots 3 to 5 meters deep. If the soil is good, the roots can penetrate up to 10 meters deep. The height of the tree depends on the growth tip (top bud) and can be from 10-25m high. Rubber leaves are pinnate compound leaves. Rubber flowers are unisexual flowers, male flowers surround female flowers but cross-pollination occurs because male flowers bloom earlier than female flowers. The capsule consists of three chambers, each containing one seed.

When cutting across the tree trunk, you can clearly see three parts: wood, bark and layer. Rubber latex only appears in abundance in the shell, so the shell will be examined in more detail than other parts.

The shell consists of 4 layers.

– Moc Thiem layer: This layer under 1 year old is usually thin and insignificant, protecting the inner layers.
– Coarse sand layer: This layer has poor physiological activity. This is the thickest layer, with a sparse number of old latex cells that have lost the ability to produce latex.

– Cataract layer: This layer is quite thick, the density of pus cells is higher than the previous layer.

– Silk-sand skin layer: Quite thin in thickness, but here are mainly concentrated physiologically active latex cells (90% of latex tubes are found here)

– Stratum: Is where wood cells and phloem cells are produced, including a rubber latex tube system. Besides, the floor statue also operates cyclically.

To exploit latex effectively, you must scrape at the correct depth. If you scrape too much, you will produce little latex. If you scrape too late, you will yield a lot of latex, but the dry latex content is low, affecting the layer and back bark. When regenerated, there will be bulges and it will be impossible to continue exploiting that regenerated shell. Besides, it also causes purulent discharge, scraped mouth ulcers…

2. ECOLOGICAL REQUIREMENTS OF RUBBER

I.Climate and soil factors.

To grow rubber trees economically, all factors must be considered such as: Weather, climate, soil, mineral nutrition…

Temperature

Rubber trees grow well in humid tropical regions with an average temperature of 22⁰C-30⁰C (The appropriate temperature is 26-28< sup>0C). Low temperatures affect the latex extraction process and plant growth. Temperatures below 18⁰C affect the germination process of seeds and slow down the growth rate of plants. If below 10⁰C, seeds lose their ability to germinate. If it is below 5⁰C, the tree’s bark will crack, pus will flow a lot, the growth tip will dry out, and the tree will die.

If the pus is over 30⁰C, the pus quickly freezes or can freeze right on the scraping mouth and cause dry pus.

Rainfall and air humidity.

Rubber is usually grown in areas with rainfall from 1,500 – 2,500 mm/year. The appropriate number of rainy days in a year is 100 -150 days. Rubber trees need water but cannot tolerate waterlogging and wind. Rubber can withstand drought for 4-5 months, but latex output during these months will decrease.

Air humidity can be positively correlated with latex flow during exploitation. The most suitable air temperature is 75%.

Wind.

Rubber trees cannot withstand wind, strong winds often cause them to break. The appropriate wind level for rubber is 2–3 m/s.

Land

Rubber can be grown on 3 types of soil: Basalt red soil, Potzon gray soil on ancient alluvium and sand schist soil.

Rubber planting land must have a topsoil depth of over 1m because rubber roots do not penetrate the laterite layer, the water table and the parent rock layer.

II. MINERAL NUTRITION

Content of mineral elements in rubber latex.

PROTEIN

Nitrogen is essential during plant growth and development. Nitrogen increases stem circumference (stem), increases leaf density and dark green leaves. Nitrogen fertilization also regulates the nutrition of other elements such as phosphorus and potassium. Nitrogen directly participates in the synthesis of rubber latex… However, too much nitrogen fertilization will cause the wood to develop poorly, be brittle, and have poor resistance to pests and diseases. Nitrogen deficiency affects the growth of rubber trees, causing the foliage to grow narrow and the tree to be short.

KALI

Potassium has the ability to regulate metabolism, making an important contribution to the biochemical reactions of cells. Potassium affects the pus flow the most and increases the dry pus content.

If the plant lacks potassium, it will reduce stem circumference, height, number of leaves and cause the Magnesium content in the latex to increase, leading to the latex easily freezing on the scraper. Therefore, potassium can limit the disease of dry branches, increase sperm against storms, and partly overcome dry mouth.

LAN

Phosphorus is necessary for cell division and meristem development, stimulates root growth, and increases stem, leaf and fruit formation. Plants lacking phosphorus have poorly developed growth tips, red or brick red leaves, small leaves, and underdeveloped stem rims. Phosphorus is most needed during the seedling stage.

TRACE ELEMENTS

Micronutrients are elements that rubber trees need in small amounts but are indispensable because they are one of the determining factors in rubber latex productivity and quality. If micronutrients are lacking, it will affect the growth and development of rubber trees. You can use synthetic micronutrients HUMIX to fertilize rubber trees twice a year, at the beginning and end of the rainy season, to stabilize the latex level and amount of latex.

III. GROWTH STAGES OF RUBBER TREES

Rubber trees can bloom for the first time after a period of about 3-5 years depending on the variety, type of seedling and external conditions. Each year, the tree flowers 1-2 times. However, to divide the growth stages of rubber trees, people do not rely on the physiological characteristics of the tree but on the periods during which the tree produces different latex yields to divide them into growth stages.

Seedling stage in the nursery.

It is the time from sowing seeds until the tree leaves the nursery. This time can last from 6-24 months depending on the type of stump.

At this stage, the tree mainly grows in height while the trunk circumference increases slowly. On average, each month a tree can add 1 layer of new leaves.

In conditions of temperature below 18⁰C, drought or disease, the growth rate of plant height, number of leaves, and stem diameter slows down. This is a disadvantage of areas with cold winters that produce seedlings.

Seedlings need to be carefully cared for with nutrition and water to quickly achieve grafted tree standards.

Seedlings need to be watered regularly and combined with spraying HUMIX CD Rubber Foliar Fertilizer when the tree has a stable layer of leaves and stop spraying 1 month before transplanting.

Basic construction phase (KTCB)

This is a long period of time (5-7 years) in which farmers only invest and do not earn profits, so finding ways to shorten this period is an important direction in current rubber production.</p >

For rubber trees that are 1-3 years old, farmers need to have a plan to intercrop short-term crops to contribute to increased income while also helping to preserve the land. Depending on the land and capital source, choose the appropriate intercropping crop.

In addition, to shorten this period, it is necessary to take care from the beginning, especially fertilizing and weeding. If there is a lack of nutrition during this period, the growth stage will be poor and the amount of pus will be low. Furthermore, compensating for plant nutritional deficiencies when the plant enters the business stage is often not very effective and is much more expensive.

Rubber trees can balance their watering during this period unlike other long-term industrial crops (pepper, coffee…).

During this period, apply Bio-Organic Fertilizer HUMIX Specialized for Rubber Use.

The latex exploitation stage (or business stage)

This is the longest period from the tree starting to exploit latex until the tree is liquidated. Based on the ability to produce latex, people divide it into 3 periods: the period of young rubber exploitation, the period of middle-aged rubber exploitation and the period of old rubber exploitation.

The period of young rubber exploitation.

This period lasts from 10 to 12 years, the tree develops strongly in the number of branches, trunk circumference, bark thickness and latex output continues to increase.

The bark at this stage is thin, soft and growing rapidly, so tapping requires high skill, avoiding scraping off the wood.

Rubber gardens during this period were often dark and damp, creating a very favorable environment for many diseases to develop into epidemics, especially powdery mildew and defoliation disease in the rainy season…

During this period, it is necessary to provide adequate nutrition to increase pus production. Use HUMIX HCSH fertilizer Specialized for Rubber.

b. The middle age of rubber exploitation.

When productivity no longer increases much and maintains that productivity level, rubber enters the middle age of exploitation. Depending on the care regime, previous exploitation, current exploitation and variety, this period can be long or short. If the garden in previous periods is not well cared for, when entering this period, it will only maintain high productivity for a short time and then productivity will decrease. Besides, excessive exploitation of the previous period and violation also caused great obstacles.

Old rubber exploitation period.

When the latex yield drops sharply and there is no way to recover, then the tree has entered the period of old rubber exploitation. At this time, the garden is very susceptible to defoliation disease in the rainy season.

• NEW PLANTATION AND CARE OF RUBBER.
• SAME.

In the early stages of rubber growing, plants are often planted. People choose good seeds from parent trees to breed and expand the area. However, gardens grown from seeds are often uneven and highly variable. Therefore, today people use asexual propagation by grafting. There are many types such as: GT1, RRIM 600, PB235, VM515, Pb260, RRIC121

• PLANTING NEW RUBBER TREES
• Choose planting land.

Soil with a layer thickness of 1m or more, without an intervening layer of parent rock or laterite, the underground water level at its highest point is at least 1m above the ground and the water level does not exceed 1 month.

Density

Red soil: 7×3 m corresponding to 476 trees/ha

Grey soil: 6×6 m corresponds to 555 trees/ha

Dug hole: 70cm long, 50cm wide, 60cm deep

Time:

New planting at the beginning of the rainy season when the soil has enough moisture. The planting schedule for the Southeast and Central Highlands regions is as follows:

Growing bare Stump: June 1 – July 15 of the solar calendar.

Growing Stump potting: May 15 – August 30 of the calendar.

Intercropping in rubber gardens

During the period when the rubber trees are still small and have not yet dispersed, farmers intercrop between two rows of rubber trees, vegetables, sesame or legumes. The intercropped plants must be kept far away from the rubber rows. about 1m.

FERTILIZER

Using HUMIX fertilizers used to fertilize rubber trees include:

HUMIX SCR Rubber Synthetic Organic Fertilizer

HUMIX Treated Chicken Manure.

HCSH HUMIX CD Rubber Fertilizer

HUMIX CD Rubber Foliar Spray.

Nursery

Prepare potting soil: The amount of soil and manure prepared for a potting bag is 20 – 30g of Treated Chicken Manure mixed with 2,000 – 2,200g of powdered soil. When the plant has a stable layer of leaves, use HUMIX CD Rubber Foliar Spray mixed at a ratio of 1/200 (1 liter of fertilizer mixed with 200 liters of water). Spray periodically every 10 days and stop spraying 1 month before transplanting.

New planting.

Use Synthetic Organic Fertilizer HUMIX SCR Rubber as a primer at 1-2 kg/hole and mix the fertilizer thoroughly into the hole before planting Stump.

Basic construction phase.

Use HUMIX Biological Organic Fertilizer Specialized for Rubber Use. Fertilize twice a year at the beginning and end of the rainy season.

In years 1-2, fertilize 1.2 tons/ha/year.

In years 3-5, fertilize 1.2-2 tons/ha/year.

From after planting to 1 year of age, supplement nutrients for plants with HUMIX Foliar Spray Specialized Rubber Fertilizer mixed at a ratio of 1/100 to water the roots or spray at a ratio of 1/200 (40ml/8 liters). on leaves, periodically every 7 -10 days.

Business stage

Use HUMIX Biological Organic Fertilizer Specialized for Rubber Use twice a year.

The first fertilizer application in April-May is 1.5-2 tons/ha.

The second time of fertilization in October is 1.5 -2 tons/ha.

Every year, add HUMIX Treated Chicken Manure at a rate of 2 tons/ha to both provide nutrients for the plants and keep the soil moist.

How to fertilize: From the first to the fourth year, dig trenches according to the projection of the tree canopy, spread fertilizer evenly then cover with soil.

From the fifth year onwards, apply fertilizer in a wide band between two rows of rubber trees that have been cleared of weeds and then covered with dry leaves.

• PEST PREVENTION
• PESTS

For rubber trees, the problem of pests is not a concern, but that doesn’t mean we don’t care. There are some common pests in rubber gardens as follows.

The sentence damages the leaves.

The fish bite the old leaves, leaving the leaf veins, while the larvae eat the young roots of the plant. He has a great influence on the synthesis process. If the hook bites and destroys too much, it will cause the tree to become malnourished, stunted, and affect its ability to produce latex.

Mechanical method: Use a racket to catch.

Chemical measures: Spray pesticides through leaves and soil using Bian 40 ND, Sumiudin 0.05-0.1%

Types of leaf-eating pests: On top buds, use Rasudin 40 ND, Bian 40ND spray at the stage of young leaf formation that is not yet stable.

Termites.

Termites eat tree roots, causing tree death. And sometimes even gnaw the fresh shell.

Cultivation measures: Moisturizing root cabinet must be far away from the root.

Do not fill the planting hole with fresh grass waste.

Chemical method: Bam 5H 15-20 kg/ha.

Lantrek 40 EC concentration 0.15-0.2% is used to water the roots.

Red spider and yellow spider.

Causes damage during young buds, sucks mainly at the seedling stage, basic garden construction. They suck on the underside of leaves, causing the leaves to deform, shrink and create ripples.

Medication: Comite 73 EC, Admire 050 EC, Ortus 5SC

• DISEASE.
• Powty Mildew (Oidium Heavea Fungus).

The disease often appears when new leaves grow or on young leaves that are nearly mature. Appears in January – April depending on the region. If there is a lack of nitrogen, fog and the plant is exposed to cold, the disease will cause more harm.

Symptoms:

Infected leaves often grow drooping, lose all their usual shine, and curled leaf blades at the lower edge often show white powdery patches. It often appears from the top of the leaf and down to the edge of the leaf. If the disease is severe, the leaves will fall en masse, causing defoliation for the second time in a year, and can cause dry branches.

Measures:

– Choose disease-resistant varieties

– Increasing nitrogen and potassium fertilizers helps concentrate leaf production and avoid leaf production during peak disease months.

– Treat the disease with powdered sulfur sprayed on both sides of the leaves 5-6 times, 1 week apart

– Spray Sumieight 0.2%

Colletortrichum Gloesporioides black leaf tip disease

Like powdery mildew, this disease often causes damage to young leaves and buds, mainly on young rubber trees, and the disease often appears in the rainy season. Severe disease can cause the tree to die from top to bottom.

Symptoms:

Disease spots often appear on leaf tips that are round and less than 2 mm in diameter, the inside of the spot is yellow and the cover is brown.

Measures:

– Disease prevention is key, you must create conditions for the garden to be well-ventilated.

– Do not plant varieties that are susceptible to the disease.

– Spray room with Zineb(0.3-0.5%), copper chlorine oxide(0.5-1%)…

Wet season leaf drop disease (Phytophthora Botryosa and P. Palmivora).

The disease often appears in the rainy season, especially in areas with heavy rain and causes serious damage in mining gardens.

Symptoms:

The leaves have dark brown spots, with white spots in the middle, young shoots have black spots, dry and die, young fruits also have black spots, dry and fall off. On the fallen leaf stalks there are white dry pus lumps. The disease also spreads to the scraping mouth, causing a very dangerous ulcer with scraping mouth stripes.

Measures:

– It is necessary to open ditches to prevent waterlogging and ventilate the garden.

– When the tree is more than 50% seriously ill, you must stop scraping until new leaves grow in the shape of bird’s feet, then start scraping again.

– This stage is difficult to prevent and treat because the rubber tree is too tall at this time.

Pink fungus disease (Corticium Salmonicolor fungus).

This disease often causes serious damage during the exploitation stage of young rubber, and is most damaging at the age of 3-8 years. This disease often appears in the rainy season and can cause branches to die and, if severe, the tops must be cut off. The disease easily spreads into epidemics by wind, rain and insects.

Symptoms:

The disease often appears at the branch branch, first there are pus drops and white fungus like spider webs, then the disease slowly turns dark pink and spreads. In severe disease, pus flows into long streaks and turns black. Finally, the leaves wilt and turn yellow, and wild shoots grow right below the lesions.

Prevention:

– Clean the fields, destroy dry branches caused by diseases.

– Aerate the garden during the wet rainy season.

– Use varieties that are resistant to pink fungus.

– Using chemical drugs: Validacin 5L(specific drug)1.2 %, Validacin 3L 2%, Bordeaux solution 1% (spray) and 5% (scan).

Scraper ulcer disease (Phytophora palmivora fungus)

The disease that causes damage to the scraping surface in the rainy season 6-11 has many different names such as black stripes and scraping mouth rot. The disease is rot, dry scraping mouth regenerates and reduces pus production.

Symptoms

The regenerated shell near the scraping line has parallel black lines. Then it gradually grows, forming black indentations wider than a toothpick and about a few centimeters long. Fungal diseases attack the shell, damaging the pus system, causing foul-smelling pus leaks, sores in the mouth, and cracking of the shell.

Prevention

– Do not shave when the shaving bark is still wet, do not shave because fungi can easily penetrate and cause disease.

– Create a well-ventilated garden.

– Use Ridomil mixed with lime water at a concentration of 2-3% and apply a 2-3 cm wide bandage on the shaved mouth after collecting pus in the rain.

Dry latex disease

Also known by many names: dry mouth scraping, brown bark. The disease often appears during the mining period. Currently, the cause has not been clearly determined, it is still considered a physiological disease.

Symptoms

The latex freezes right on the scraper’s mouth before falling into the bowl, the bark underneath gradually peels off with many longitudinal cracks, eventually large, hard humps emerge and gradually reach the base of the tree and finally the tree has to be abandoned.

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Prevention

– Shave properly.

– Fertilize fully, especially for latex-stimulating gardens.

– When the garden has more than 10% diseased plants, stop scraping.

OPERATION OF RUBBER LATE.

When 70% or more of the trees meet the standard of trunk rim (> 50cm) and the height measured from the ground reaches 1m, exploitation will begin. In the second year of scraping, shave the trees that meet the next standard and in the third year of scraping, shave all the remaining trees in the garden.

Shaving season: Open for shaving in March-April and October-November of the year. Stop scraping when the rubber tree begins to lose its leaves in January-February. When the leaves begin to sprout in a bird’s foot shape, scrape again.

Shaving technique: How to open the mouth from east to west, that is, from front to back and open in one direction in the plot.

How to open: The first 3 lines of shaving are for standard shaving, the second line is for scraping, the 3rd line is for complete shaving.

Downward shaving: From the first year to the 11th year and the shaving slope is 30-35⁰

Scraping backwards: From the 12th year onwards, rubber trees begin to scrape backwards with a shaving speed of 35⁰

Shaving time: Shave early in the morning when you can clearly see the shaving mouth. Shave as early as possible. During the rainy season, you must let the water drain from the shaving surface before shaving. Remove the pus at 10-11 am to avoid removing it too late as it will cause the pus to freeze.