Many diseases and pests of C. verum also attack Cinnamomum burmannii (). The most serious disease is the stripe canker (cancer) caused by Phytophthora cinnamomi that often leads to widespread damage to plants (Djafaruddin and Hanafiah, 1975). Other diseases include pink disease (Corticium salmonicolor syn. C. javanicum), white rot (Fomes lignosus), rust (Accidium cinnamomi) and anthracnose (Glomerella cingulata). A list of diseases occurring in Indonesia is given below.
As a tropical country Indonesia’s climate is conducive to the development of many pathogens. Usually, cinnamon grows in the wet climate with a relative humidity of 80–95%, which predisposes the plant to many pathogens. However, data on yield loss caused by pathogens in Indonesia is still very limited.
Diseases commonly found on cinnamon plants in Indonesia are summarised below.
Red rust (Cephaleuros sp.)
Symptoms: Greyish orange or brownish orange spots on the upper leaf surface. On top of the spots can be seen the spores or conidia. On the lower leaf surface the spots appear brown.
Black rust (Puccinia cinnamomi)
Symptoms: Wet greyish brown irregular spots on the lower leaf surface. The spores of the fungi are clearly seen.
Grey leaf spots (Pestalotia cinnamomi)
Symptoms: Grey necrotic spots on the leaves. The spots enlarge between the leaf ribs. Sometimes the fungus also infects the twigs near the petiole.
Anthracnose (Colletotrichum sp.)
Symptoms: Blackish brown leaf spots, especially on the young leaves. In the more severe infection the old leaves and twigs are also attacked. Young leaves role up and become black. It can cause dieback and plant death.
Swollen and rotten leaf disease (Aecidium cinnamomi)
Symptoms: Lower leaf surface is swollen like blister blight, and becomes greyish to brownish grey. Tissues rot and show white to black spots. The leaves become concave and convex. The blister blight form is irregular; sometimes in one leaf there are lot of blisters and sometimes only one or two.
Pink disease (Cortitium salmonicolor)
Symptoms: The parts of the plant attacked are twigs, branches and stem. The affected twigs and branches appear pink due to mycelial growth on the upper and lower part of the branch. The mycelium layer penetrates the bark and wood. Small branches die off due to the fungus infection. On the big branches that are infected the leaves get yellow and gradually die when the upper branches are infected, and further infection quickly spreads to the lower branches.
Split canker disease (Endothia sp.)
Symptoms: The disease especially attacks young plants. Split and striped cankers are seen. The swollen part looks like grafting. The grafting like part is the dead bark.
For striped canker disease, part of the infected stem is removed with a knife and then painted with fungicides. The heavily infected plants are cut down and destroyed.
Symptoms: Infects plant stems especially the young ones (about five-years old). The leaves become yellow, and sometimes the plant dies. The bark becomes dry, thick, and forms a hollow space, rough and brittle. The size of the canker is approximately 5–8 cm. On older plants (five- to ten-years old), the symptom is intermittent stripes. Brown ooze flows out from the stripes. The length of the stripes is more or less 2 m, and depends on the age of the plants.
Gall caused by the bite of Eriophyes doctersi
Symptoms: On the upper surface of young leaves; gall look convex and black. The leaves are still smooth. The lower surface is more concave with more black spots and sometimes becomes hairy.
Generally, farmers do not apply any fungicides to control the disease. Some sanitation and eradication of the infected plants is recommended to contain the disease.
Insect pests affecting the Indonesian cassia include caterpillars of cinnamon butterfly (Chilasa clytia), leaf miners (Aerocercops spp.), caterpillars of leaf webber (Sorolopha archimedias) and mole crickets (Gryllotalpa spp.), all of which are damaging to young seedlings. Insecticide application is not practiced.