The causative organism of maize rust is?

The causative organism of maize rust is a fungus. Maize rust is a fungal disease that affects maize plants and is caused by the fungus Puccinia polysora. The fungus infects the leaves of the maize plant, causing yellow to brownish-orange rust-like pustules or spots on the leaves. Maize rust can have a significant impact on crop yield and quality, and it is important for farmers to take steps to prevent and control the disease. This can include the use of disease-resistant maize varieties, crop rotation, proper sanitation practices, and timely application of fungicides when necessary. So, the correct answer is fungus.