Rubber diseases in Mindanao [Philippines]: white root rot and black stripe

Two important diseases of rubber, white root rot caused by Rigidoporus lignosus Imazeki and black stripe caused by Phytophthora palmivora Butler were recently studied in Mindanao rubber plantations. Field trials of fungicides against white root rot disease of rubber were conducted in two different hot spot areas in Cotabato province. Seven fungicides (mancozeb, maneb, copper hydroxide, hexaconazole, difenoconozole, chlorothalonil, and tridemorph) significantly reduced disease incidence applied as curative for six months at one-month interval. Fungal rhizomorph of R. lignosus failed to develop after treatment. On the other hand, black stripe, a tapping panel disease that occured in a one-hectare rubber plantation in Matalam, Cotabato was used as on-farm experimental site. Ten fungicides were tested for efficacy against the disease and four showed significant eradicative control for three months of bi-monthly application. Effective fungicides were metalaxyl, oxadixyl, benomyl, and mancozeb