title: Influence of the stabilisation of organic materials on their biopesticide effect in soils.
abstract: Some organic materials have shown a suppressive effect on several diseases induced by soilborne plant pathogens. We have carried out a laboratory experiment (microcosm) to ascertain the influence of the stabilisation process of sewage sludge on it biopesticide effect when Pythium ultimum or Phytophthora sp. were introduced to soil as pathogens for pea or pepper. When P. ultimum was introduced there was a 63.8% reduction in the weight of the stems grown in the control, 47.6% in the presence of sewage sludge, but only 24.7% with compost. The same biopesticide effect was evident from the weight of the roots. The biopesticide effect was also strong when compost was used as organic amendment in the presence of Phytophthora, as could be seen from stem and shoot weight and length. The data showed that the degree of stabilisation of the organic material (compost) had a positive influence on it biopesticide effect. The changes undergone by a soil after the addition of organic materials helped to explain the biopesticide effect of the amendment. The organic treatments reduced P. ultimum and Phytophthora sp. populations.
authors.affiliation: Centro de Edafología y Biología, Aplicada del Segura (CEBAS-CSIC), Campus Universitario de Espinardo, Conservation and Organic Waste Mgmt, Department of Soil and Water, P.O. Box 4195, 30080 Murcia, Spain. cgarizq@cebas.csic.es
authors.forename: C
authors.initials: C
authors.lastname: Garcia
authors.forename: J A
authors.initials: JA
authors.lastname: Pascual
authors.forename: E
authors.initials: E
authors.lastname: Mena
authors.forename: T
authors.initials: T
authors.lastname: Hernández
mesh_terms: D000704:Analysis of Variance; D001419:Bacteria / Q000254:growth & development; D015169:Colony Count, Microbial; D005658:Fungi / Q000254:growth & development; D009868:Oomycetes / Q000187:drug effects*; D018532:Pisum sativum / Q000254:growth & development* / Q000382:microbiology; D010575:Pesticides / Q000633:toxicity*; D031701:Piper / Q000254:growth & development* / Q000382:microbiology; D018517:Plant Roots / Q000254:growth & development; D012722:Sewage; D012987:Soil
chemical_list: D010575:Pesticides; D012722:Sewage; D012987:Soil