Geographical distribution of Peronosclerospora spp., the causal organism of maize downy mildew, in Indonesia

Downy mildew is a major disease in maize caused by a number of species of the genus Peronosclerospora and Sclerospora. This study aimed to determine the geographical distribution of dominant species of downy mildew that infects maize in corn production areas in Indonesia. The research was conducted applying survey by visiting the centers of maize production in Indonesia. Samples of leaves affected by disease were taken to the laboratory of plant diseases of Indonesia Cereals Research Institute (ICERI) to observe its morphology under microscope evaluation. The results show that Peronosclerospora spp. has spread in almost all of the island or a large area in Indonesia. In one area it can be found in more than one species, whereas one species was found in some endemic areas of downy mildew. The P. philippinensis only found in Sulawesi Island, while P. maydis and P. sorghi found in all islands.