Rubber tree or Hevea Brasiliensis is the main sources of supply for the most of world’s natural rubber.This plant was originated from the regions of rainforests in Amazonia, Brazil. Due to this plant ability to produce latex that can be used as a natural rubber in industrial sectors, the plantation of rubber has been increased in almost various parts all over the world, such as in the tropics of Africa, South and Central America and Southeast Asia. According to Gleason (2005), Asian countries such as Thailand, India, Indonesia, and China are stated as a world biggest producer of rubber. Malaysia also listed as others biggest producer of rubber alongside the country such as Vietnam, Brazil, Philipines, Cambodia, and Liberia. Rubber tree had been introduced to Malaysia since the 19th century by the British colonist.
As a nation that has tropical climate suitability and plenty area of soil availability, it had made the rubber plantation in Malaysia rapidly increasing throughout many years. Malaysia’s once had ranked as the largest contributors to the world rubber supply, however, in 1990, Malaysia lose it ranks as worlds biggest rubber producer because of the development in others agricultural sectors (Mustafa, Latif and Egwuma, 2016).The replacement of rubber plantation area with oil palm plantation had caused the total production of natural rubber decreased.
In 2015, the annual growth rate of Malaysia’s total production of natural rubber had recorded at -5.1 percent with 722,122 tonnes total production compared than in years 2010 with a total of 939,241 tonnes. (Department of Statistics, 2016). Despite the declining of total productions, Malaysia’s still listed as the 3rd largest supply of the worlds rubber production. New land development that been planned by the Government had caused the downward trends of rubber plantation area in Malaysia.
Oil palm industry had been successfully replacing the role of natural rubber as the main commodity (Malaysian Rubber Research and Development Board, 1983). In 1990 to 200, the total of rubber plantation among estate and smallholders has been declining (Tab. 1). According to Ratnasingam, Iora?, and Wenming (2011), the total of rubber plantation in 2009 was 32.24% smaller compared to the total rubber plantation in the year 1990. Nevertheless, the change of role did not alter the importance of natural rubber in contributing to Malaysia’s Gross Domestic Product. In 2015, agriculture sector had contributed 8.9% to the Gross Domestic Product, the oil palm industry was the biggest contributor to agriculture sector with 46.
9 %, followed by other agriculture, 17.7 %, livestock industry, 10.7 %, fishing industry, 10.7 %, rubber industry, 7.
2 %, and forestry & logging industry, with 6.9 %. Large scales of the plantation had to face many challenges in order to produce good quality yield. According to Jayasinghe (1999), the cultivation of rubber tree as the new agricultural crops had caused the increasing number of diseases in rubber tree. Outbreaks of diseases in rubber tree plantation can affect the yield production if the control activities are not taken immediately. There is plethora type of diseases of rubber tree that can be divided into four major categories: which is leaf; stem and branch, panel and root diseases (Wastie, 1975).
Leaf diseases are the most common disease that attacks rubber plant in the field and also in the nursery stage. Commonest leaf disease that had reported was Powdery Mildew, abnormal leaf fall, Colletotrichum and Corynespora leaf disease.