Combining residues of herb crops with soil heating for control of soilborne pathogens in a controlled laboratory system

• Published in: Crop protection Vol. 30; no. 3; pp. 368 - 374
• Main Authors: Klein, Eyal, Katan, Jaacov, Gamliel, Abraham
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.03.2011; [Amsterdam]: Elsevier Science
• Subjects: Biological control; Brassica; Crops; Essential oil; Herb residue; Pest management; Soil solarization; Essential oil; Herb residue; Pest management; Biological control; Soil solarization
• ISSN: 0261-2194; 1873-6904
• DOI: 10.1016/j.cropro.2010.12.005

Plant residues from herb crops were examined as organic amendments for the control of soilborne pathogens with and without soil heating for a short exposure of 2 weeks. Residues of herbaceous plants of oregano, sage, rosemary, tarragon, bay, wild rocket, spearmint and thyme were incubated for 14 days in a controlled laboratory system which emulates soil solarization. Green cabbage residues were included for comparison. The tested pathogens included Fusarium oxysporum f. sp. radicis-lycopersici, Macrophomina phaseolina, Rhizoctonia solani and Meloidogyne javanica. Heating soil amended with herb residues, particularly tarragon, spearmint and wild rocket, resulted in high mortality of the tested pathogens. Volatile compounds which were generated in heated soils amended with wild rocket or tarragon showed significant toxicity to M. phaseolina and R. solani. Only oregano, thyme, bay, wild rocket and tarragon amendments were effective in pathogen control without heating. Incorporation of leaf and stem residues of thyme, sage, tarragon, rosemary or wild rocket in soil and exposure to solarization under field conditions resulted in 95–100% mortality of the tested pathogen. This study demonstrates that the residues from herb crop production can serve as organic amendments for the control of soilborne pathogens, especially when combined with heating or solarization. ► Plant residues from herb crop production can serve as organic amendments combined with solarization for effective control of soilborne pathogens. ► Volatiles generated from wild rocket- or tarragon-amended and heated soils showed significant toxicity to some of the tested pathogens. ► Organic amendment type and environmental conditions should be examined with regard to the target pathogen and crop.