The search for non-chemical methods to control soil-borne pathogens has recently intensified ahead of the forthcoming phase-out of methyl bromide in 2005. We tested pre-planting treatments carried out with a self-propelled soil-steaming machine designed for the release of steam after incorporation in soil of a substance that causes an exothermic reaction. Two trials were conducted during 2005 in glasshouse conditions in Florence by assessing the effectiveness of steam treatments with calcium oxide against Rhizoctonia solani on radish (Raphanus sativus L.) and rocket (Eruca sativa Miller). The thermal values achieved in soil with steam treatment changed when energy-releasing exothermic reaction chemicals were spread onto soil prior to treatment, thereby generating a temperature peak. Plots were prepared in sandy soils, and random layouts were used, performing two consecutive trials during the summer. Mycelial disks from 7-day-old cultures of isolate of Rhizoctonia solani were mixed with soils and used for artificial soil inoculation. The equipment used was able to spread and incorporate CaO (1000 kg ha-1) into the soil, then inject steam. Radish and rocket were sown two days after treatments. The combination of steam and CaO reduced the incidence of diseases caused by Rhizoctonia solani better than using only steam. Combing steam with CaO we obtained a disease reduction of 92.2 % on rocket and 90.5 % on radish, while the disease reduction obtained using only steam were of 82.0 % on rocket and 80.2 % on radish. Our conclusion is, therefore, that a combination of steam and exothermic reaction can be included in integrated pest management programs.
Steam and exothermic reactions for the control of Rhizoctonia solani on radish and rocket by the use of a self-propelled soil steaming machine
TRIOLO, ENRICO
2006-01-01
Abstract
The search for non-chemical methods to control soil-borne pathogens has recently intensified ahead of the forthcoming phase-out of methyl bromide in 2005. We tested pre-planting treatments carried out with a self-propelled soil-steaming machine designed for the release of steam after incorporation in soil of a substance that causes an exothermic reaction. Two trials were conducted during 2005 in glasshouse conditions in Florence by assessing the effectiveness of steam treatments with calcium oxide against Rhizoctonia solani on radish (Raphanus sativus L.) and rocket (Eruca sativa Miller). The thermal values achieved in soil with steam treatment changed when energy-releasing exothermic reaction chemicals were spread onto soil prior to treatment, thereby generating a temperature peak. Plots were prepared in sandy soils, and random layouts were used, performing two consecutive trials during the summer. Mycelial disks from 7-day-old cultures of isolate of Rhizoctonia solani were mixed with soils and used for artificial soil inoculation. The equipment used was able to spread and incorporate CaO (1000 kg ha-1) into the soil, then inject steam. Radish and rocket were sown two days after treatments. The combination of steam and CaO reduced the incidence of diseases caused by Rhizoctonia solani better than using only steam. Combing steam with CaO we obtained a disease reduction of 92.2 % on rocket and 90.5 % on radish, while the disease reduction obtained using only steam were of 82.0 % on rocket and 80.2 % on radish. Our conclusion is, therefore, that a combination of steam and exothermic reaction can be included in integrated pest management programs.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
