ISHS Acta Horticulturae 469: International Symposium on Composting & Use of Composted Material in Horticulture
RECYCLED ORGANIC MATERIALS (ROM) IN THE CONTROL OF PLANT DISEASE |
| Authors: | D. Pitt, Emma L. Tilston, Andrew C. Groenhof |
| Keywords: | soil-borne pathogens, plant pathogens, disease suppression, plant diseases, phytosanitation, composts |
| Abstract:
The phytosanitary potential of recycled organic material (ROM) in control of soil-borne pathogens was examined in pot trials under controlled conditions. Disease suppressiveness of ROM composts was compared with equivalent autoclaved versions of each compost and with a commercial John Innes potting compost. Disease levels of take-all (Gaeumannomyces graminis) were significantly reduced by up to 80%, as were those of root-rot of peas, Phoma medicaginis (66%) and red-core of strawberries, Phytophthora fragariae (70%); whilst symptoms of clubroot of brassicas (Plasmodiophora brassicae) were greatly reduced, or negligible in some cases. No single compost was highly suppressive to all diseases tested, but most of those examined were variously effective to some degree. With few exceptions the ROM composts supported excellent seed germination and good plant growth performances. It is postulated that the disease suppressive properties of ROM composts are due to a combination of direct parasitism, competition for resources and the production of anti-fungal compounds. In addition to the putative microbial effects, the lowered incidence of clubroot associated with some inoculated autoclaved composts suggests the presence of thermostable components, possibly of microbial origin, or the generation of antifungal substances during autoclaving. The disease suppressive properties of ROM composts in relation to dose-response, field applications and their commercial potential are considered. | |
Download Adobe Acrobat Reader (free software to read PDF files) | |
