Answer:Puccinia striiformis f.
Stripe (yellow) rust, caused by Puccinia striiformis f. sp. tritici (Pst), is a serious disease of wheat occurring in most wheat areas with cool and moist weather conditions during the growing season. The basidiomycete fungus is an obligate biotrophic parasite that is difficult to culture on artificial media.
Explanation:Does rust turn black?
Image result
Rust from Iron (III) oxides with limited oxygen and low moisture results in black rust. Black rust can be visually identified as a thin, black film which is the result of oxidation in a low oxygen environment.
There are several fungicides that can be used to protect plants from infection. Mancozeb as a protectant and myclobutanil as an eradicant are generally effective against all rusts while triadimefon is effective against only specific rusts.