Verticillium wilt, caused by Verticillium dahliae Kleb., is one of the most severe diseases of olive and other important crops worldwide. In the last decades the disease has occurred with increasing frequency and severity in most olive-growing areas. Its control has relied on chemical biocides but more eco-compatible and safer control mesures are necessary. Preventive methods (i.e. pathogen-free soil and planting material, suppressive substrates and biocontrol agents) have been implemented in the nurseries since they are considered key factors for an efficient disease control. Recently, alternative substrates for plant growth containing natural amendments and plant composted biomasses are being studied not only for agronomic properties, but also for their suppressiveness against soil-borne pathogens. To prevent V. dahliae infections our investigations were aimed at evaluating the suppressive activity of different composts and amendments, alone or enriched with biocontrol agents, against microsclerotia (MS) of the pathogen. The experimental products at 15% concentration (v/v) were mixed with a standard substrate and the mixtures were artificially contaminated with 50 MS/g. Trials were conducted under growth chamber and nursery conditions. In blind trial experiments, the pathogen was periodically monitored in the soil by either semi-selective medium and real-time nested Scorpion PCR. Results showed that some composts and amendments reduced significantly the density of V. dahliae MS in the rizosphere of young olive plants. Further studies are in progress to optimize the suppressive activity of these alternative substrates in order to protect olive plants from V. dahliae infection in the nursery.
Evaluation of composts and amendments for suppressive activity against Verticillium dahliae on nursery growing olive plants
LIMA, Giuseppe;DE CURTIS, Filippo;
2007-01-01
Abstract
Verticillium wilt, caused by Verticillium dahliae Kleb., is one of the most severe diseases of olive and other important crops worldwide. In the last decades the disease has occurred with increasing frequency and severity in most olive-growing areas. Its control has relied on chemical biocides but more eco-compatible and safer control mesures are necessary. Preventive methods (i.e. pathogen-free soil and planting material, suppressive substrates and biocontrol agents) have been implemented in the nurseries since they are considered key factors for an efficient disease control. Recently, alternative substrates for plant growth containing natural amendments and plant composted biomasses are being studied not only for agronomic properties, but also for their suppressiveness against soil-borne pathogens. To prevent V. dahliae infections our investigations were aimed at evaluating the suppressive activity of different composts and amendments, alone or enriched with biocontrol agents, against microsclerotia (MS) of the pathogen. The experimental products at 15% concentration (v/v) were mixed with a standard substrate and the mixtures were artificially contaminated with 50 MS/g. Trials were conducted under growth chamber and nursery conditions. In blind trial experiments, the pathogen was periodically monitored in the soil by either semi-selective medium and real-time nested Scorpion PCR. Results showed that some composts and amendments reduced significantly the density of V. dahliae MS in the rizosphere of young olive plants. Further studies are in progress to optimize the suppressive activity of these alternative substrates in order to protect olive plants from V. dahliae infection in the nursery.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.