Leaf diseases of Hevea brasiliensis Müll. Arg. in major rubber growing areas of Cotabato, Philippines

Rubber (Hevea brasiliensis) is a priority tree crop that produces natural rubber (NR), making it an important plantation commodity in the Philippines. However, NR production is confronted with major constraints, including rubber diseases resulting in low latex yield. Twenty-five rubber farms located in five major rubber-producing municipalities (Kidapawan, Antipas, Makilala, Matalam and President Roxas) of Cotabato, Philippines, were surveyed for prevalence of major rubber leaf diseases. Information on farm practices and environmental variables was collected. The majority of rubber farmers were smallholders with hectarage planted ranging between 1 and 15 hectares. The most planted clones are RRIM 600 and PB 260, which are high-yielding yet susceptible to many foliar pathogens. Six leaf diseases, viz. Oidium powdery mildew, Colletotrichum leaf disease, Corynespora leaf fall/spot, Phytophthora leaf blight, bird’s eye spot and algal spot, were documented in this study. Powdery mildew was the most prevalent in Cotabato with the highest percentage and severity of infections in all plantations, followed by Colletotrichum leaf disease. Information on disease prevalence in surveyed areas is important for disease management actions.