Puccinia canaliculata (Schw.) Lagerh. from Salisbury, MD, identified in greenhouse tests as specific to yellow nutsedge, was field evaluated for biological control of yellow nutsedge over a 2-yr period. Treatments included all combinations of P. canaliculata and 0.3 or 0.6 kg ai/ha benzaton. Disease development was reduced 50% by treatment with bentazon, compared with P. canaliculata alone. P. canaliculata reduced tuber recovery by 44%. Phytotoxicity was significantly higher from the rust treatments than controls. Treatment with P. canaliculata did not affect the number of shoots/m2.
