The pathogen of rice blast or 'rotten neck' is

The pathogen of rice blast or 'rotten neck' is Pyricularia oryzae.
Rice blast disease, which is caused by the fungus Pyricularia oryzae, inflicts serious damage to rice leaves (leaf blast) and panicles (panicle blast). Panicle blast is directly linked to rice production and quality.
The fungus reproductive structures, spores, can spread from these two sources to rice plants during the next growing season and initiate new infections.