Control of plant pathogens by using a compost tea

• Published in: Journal of plant pathology Vol. 89; no. 3; p. S52
• Main Authors: Pane, C, Valentini, F, Bonanomi, G, Cozzolino, L, Antignani, V, Puopolo, G, Zoina, A, Scala, F
• Format: Journal Article
• Language: English
• Published: 01.12.2007
• Subjects: Alternaria; Aspergillus wentii; Botrytis cinerea; Lepidium sativum; Lycopersicon esculentum; Pseudomonas syringae; Rhizoctonia; Rhizoctonia solani; Venturia
• ISSN: 1125-4653

Compost tea is increasingly being used to control plant diseases. Aerated compost teas are highly concentrated aqueous microbial suspensions obtained from the decomposition of composts in water for a defined period of time. Effective disease control with compost teas has been obtained for several air-borne pathogens such as Sphaerotheca spp., Venturia spp. and Alternaria spp. In this study, a compost tea was analysed for the abilility to suppress the following diseases: grey mould of bean and tomato caused by Botrytis cinerea, bacterial speck of tomato by Pseudomonas syringae pv tomato (Pst), and damping-off of Lepidium sativum by Rhizoctonia solani. This tea was produced by the aerobic water decomposition of a compost obtained from a mixture of municipal organic waste, green pruning residues, and tobacco and aromatic plant refuses (6:4:2, respectively). Compost tea contained 2,6 x 10 super(9) c.f.u. ml super(-1) of culturable bacteria (fluorescent Pseudomonads were absent) and 1,15 x 10 super(5) c.f.u. ml super(-1) culturable filamentous fungi (almost exclusively present as Aspergillus wentii). Tea was not phytotoxic in soil and foliar applications; inhibited B. cinerea conidial germination and suppressed leaf lesion development on bean and tomato and significantly reduced severity of bacterial speck on tomato plants. In contrast, soil drenching applications were unable to control Rhizoctonia dumping-off. From these results, it appears that the compost tea has a potential for useful applications in plant disease management.