Suppressive effect of composts from residual biomass on Pythium ultimum

• Published in: Journal of plant diseases and protection (2006) 2018-10, Vol.125 (5), p.443-449
• Main Authors: Ebrahimi, Ehsan, Werren, Dagmar, von Fragstein und Niemsdorff, Peter
• Format: Article
• Language: English
• Subjects: Biomedical and Life Sciences; Life Sciences; ORIGINAL ARTICLE; Plant Pathology; Plant Physiology; Plant Sciences
• ISSN: 1861-3829; 1861-3837
• DOI: 10.1007/s41348-018-0163-7

Two experiments were established in the laboratory of the Department of Organic Farming and Cropping Systems and the greenhouse of the University of Kassel, Germany, in 2017. The experiments studied the suppressive effects of three composts: 1. household-waste compost (HC); 2. spent mushroom compost (SMC); and 3. vermicompost (VC) against Pythium ultimum on pea. For in vitro experiment, two different incubation periods for every compost extract (7 and 14 days) and tap water as control were established. All composts had a suppressive effect on the pathogen, and HC had the most limiting effect on the mycelium. HC suppressed the mycelium disk up to 34 mm, while SMC, VC and control showed 46, 64 and 106 mm mycelium inhibition, respectively. This experiment showed that a higher percentage of composts have significantly more liming effect on P. ultimum. Moreover, longer extraction time had significantly less suppressive effect on P. ultimum. The infection index for pots with 1% infection was not significantly different between VC (1.4) and HC (1.7); however, SMC (2.2) was significantly less suppressive. This work demonstrates that all composts are suppressive against P. ultimum, though SMC had significant difference toward the infection index by the control treatment in both infection levels.