Currently, rubber is one of the crops for high economic value. The major source of income from rubber trees, has stimulated farmers to increase fertilizer investment. In addition, measures to exploit high latex production are also ongoing, which has facilitated some diseases. One of the most dangerous pests in the rainy season is the rubella ulcer. Diseases have reduced the production of latex and severely affected the regeneration of the new plant.
The disease enters the shaved mouth and the regenerating shells are adjacent to the shaved mouth. Stripes are slightly pale brown in the shade and run parallel to the trunk. Then, the disease spreads along the vein of the regenerating cortex, forming the dark brown strips vertically, which then binds together into large plaques. When it is heavy, from the regenerated shell, the latex is yellowed and smells bad, revealing the wood. Part or all of the regenerating surface of the shaved face turns dark brown and ulcer.
* Hazard and condition conditions:
Disease caused by fungus Phytophthora palmivora. It usually occurs in rainy season, especially in rainy season. The disease is spread by the spores of the fungus through rain water, wind, through the razor blade … The disease is appropriate in the conditions of dense rubber plantations, high humidity and cool. Diseases are also common in over-fertilized nitrogenous fertilizers, but lack of preventive measures such as topical application, anti-wetting vaseline wet season. Excessive shaving, scraping into wood, shaving when the plant is wet, shaving close to the soil during the rainy season … is also one of the favorable conditions for invasive disease.
* Some preventive measures have been applied and highly effective:
– First, select some low-disease varieties to plant such as: PB260; PB235; LH 90/952 …
– Garden cleaning, except weeds, to create ventilation in the garden. Do not create rubber canopy too low.
– Prevent rain water from other gardens from entering the rubber garden.
– Fertilizer to avoid excess nitrogen, as it will make dense gardens, easy to infection. Where possible, use foliar fertilizers such as Multi-K or Polyfeed 15-15-30 to enhance the plant’s resistance to pests.
– Do not shave when the plants are wet, do not scrape, do not shave too low (too close to the ground) because it makes it easy to land on the shaved raindrops.
– Periodically clean shaving face, shave and apply Dimethomorph + Mancozeb (Acrobat MZ 90/600 WP): Mix 30g / 1l water, Metalaxyl + Mancozeb (Ridomil MZ – 72, Mexyl MZ – 72) % (20g in 1 liter of water), brush on the shaved mouth after picking up the pus and adding layers of vaseline to prevent wet. Currently, in the rainy season, the drug should be used to prevent disease 1-2 times / month. In rainy months, people used to prevent diseases up to 3 times / month. Special attention should be paid if the orchard has been planted with highly susceptible clones such as RRIM 600, PB 310, PB 255, PR 255 …
– Regularly check the garden to detect diseased plants and handle the medication in time. Plants are diseased, marked and shaved, and then scanned twice a week until the disease is re-shed, to avoid spreading to other plants through razors. Note before applying the treatment, shaving face and shaving should be cleaned, the damaged part removed and the sharp knife sharpened the infected shell has changed color.