ISHS Acta Horticulturae 387: III International Protea Research Symposium
FIELD STUDIES ON THE EFFECTIVENESS OF PHOSPHONATE SUPPRESSION OF PHYTOPHTHORA ROOT ROT IN PROTEAS |
| Authors: | L.V. Turnbull, L.R. Crees |
| Abstract:
Phosphonate suppression of root rot in proteas, caused by Phytophthora cinnamomi, was tested in field trials over a two-year period. Effectiveness of chemical control varied, dependent upon plant species, site topography, soil moisture content and soil temperature. Phosphonate, applied as a foliar spray at 1.2 g a.i.l-1 at 6 weekly intervals, resulted in 100% plant survival (cƒ 19% in unsprayed control plants) in Leucadendron ‘Sylvan Red’ and 75% survival in Leucospermum ‘Firewheel’ (cƒ 44% in unsprayed plants). Under site conditions conducive to high disease pressure, increased spraying intensity (3 weekly, 2.4 g a.i.l-1) did not prevent infection (81% of plants) and death (50%) of Leucospermum ‘Firewheel’ by P. cinnamomi. | |
Download Adobe Acrobat Reader (free software to read PDF files) | |
