| Nombre científico |
Tipo de plaga |
| Ullucus virus C |
Virus |
| Unaspis yanonensis (Kuwana) |
Insectos |
| Uredo gladioli-buettneri Bubák |
Hongo |
| Urochloa panicoides P. Beauv. |
Maleza |
| Urocystis agropyri (Preuss) A.A. Fischer Waldheim |
Hongo |
| Urocystis colchici (Schltdl.) Rabenh |
Hongo |
| Urocystis gladioli (Req.) W.G. Sm. |
Hongo |
| Urocystis sorosporioides Körn. ex Fuckel |
Hongo |
| Uromyces ciceris-arietini Jacz in Boyer & Jacz |
Hongo |
| Uromyces decoratus Syd. & P. Syd. |
Hongo |
| Uromyces musae Henn. |
Hongo |
| Uromyces nyikensis Syd. & P. Syd. |
Hongo |
| Ustilago kenjiana S. Ito. |
Hongo |
| Ustilago mulfordiana Ellis & Everh |
Hongo |
| Ustilago shiraiana Henn. |
Hongo |
| Ustilago violacea (Pers.) Roussel |
Hongo |
| Ustulina zonata (Lév.) Sacc. |
Hongo |