A multi-criteria approach for the selection of efﬁcient
biocontrol agents against Botrytis cinerea on tomato
Received: 5 April 2017 / Accepted: 6 November 2017 / Published online: 10 November 2017
Ó International Organization for Biological Control (IOBC) 2017
Abstract In order to ﬁnd biocontrol agents that are
both efﬁcient against Botrytis cinerea Pers. and
adapted to tomato growing conditions in Algeria,
121 bacterial strains were collected from tomato plants
and nearby soils in two Bejaia greenhouses. A total of
37 strains were selected based on their ability to grow
on agar medium and on their different level of B.
cinerea mycelial growth inhibition in dual-culture
tests. These strains were identiﬁed at the species level
and those that corresponded to potential pathogens for
humans or mammals were discarded. Among the
remaining 25 candidates, three strains were selected
among the Pseudomonas genus for their signiﬁcant
protective efﬁcacy against B. cinerea on tomato, their
ability to grow at 15–25 °C and their inability to grow
at 37 °C. These three strains signiﬁcantly reduced the
development of necrotic lesion and the sporulation of
B. cinerea in a dose-dependent manner. This study
constitutes a ﬁrst step towards the biological control of
B. cinerea in tomato greenhouses in Algeria.
Keywords Gray mold Á Biocontrol Á Efﬁcacy Á
Pseudomonas spp. Á Solanum lycopersicum
Botrytis cinerea Pers. the causal agent of gray mold is
one of the most damaging fungal plant pathogen
worldwide (Dean et al. 2012) with signiﬁcant eco-
nomic impact for multiple cash crops including tomato
(Elad 2016). In Algeria, gray mold is considered as
one of the main tomato diseases (Aissat et al. 2008;
Adjebli et al. 2015). In the Bejaia region, most of the
tomato production occurs in unheated greenhouses.
Under these conditions, the fungus can infect and
cause damages to tomato leaves, stem and fruit (Aissat
et al. 2008). Leaf symptoms are frequent but result in
minor to mild damages to host health. In contrast, the
expansion of necrotic lesions on stems, due to routine
practices such as leaf pruning, may typically result in
plant death (Aissat et al. 2008). Infections of tomato
pruning wounds by B. cinerea result in stem cankers
and can cause substantial yield losses (O’Neill et al.
1997; Decognet et al. 2010). Hence, stem cankers must
be avoided to mitigate damages to host health and
reduce crop losses (Aissat et al. 2008).
Globally, chemical compounds constitute the main
control method to reduce gray mold incidence on
crops (Fillinger and Walker 2016). The use of
chemical pesticides, including those used against B.
Handling Editor: Fouad Daayf.
Y. Bouaoud Á A. Foughalia Á K. Aissat
cologie Microbienne, Faculte
de la Nature et de la Vie, Universite
Bejaia 06000, Algeria
Y. Bouaoud Á C. Troulet Á O. Berge Á M. Bardin (&)
Plant Pathology, INRA, 84140 Montfavet, France
BioControl (2018) 63:299–311