Evaluation of Bitertanol and Triadimefon for the Control of Gladiolus Rust Caused by Uromyces transversalis. J. F. Ferreira, Plant Pathologist, Vegetable and Ornamental Plant Research Institute, Private Bag X293, Pretoria 0001. W. G. Nevill, Plant Pathologist, College of Agriculture, Cedara, Private Bag X9059, Pietermaritzburg 3200. Plant Dis. 73:987-990. Accepted for publication 2 May 1989. Copyright 1989 The American Phytopathological Society. DOI: 10.1094/PD-73-0987.

Weekly applications of bitertanol or triadimefon gave significantly better control of gladiolus rust caused by Uromyces transversalis than did fenarimol and the control and performed better than oxycarboxin, penconazole, EDTA, CuEDTA, and DTPA. There was a direct relationship between the number of applications and the incidence of rust. Corm yield was adversely affected by rust, and weekly applications of bitertanol or triadimefon were necessary to ensure a reasonable yield. Marketable gladiolus inflorescences were harvested only from plots treated weekly with either of these two fungicides. Internode lengths on flower spikes were closely related to the intervals between applications of bitertanol or triadimefon.