Biological control of Fusarium wilt of Ustica landrace lentil

Abstract

Abstract Biological control by means of microorganisms represents an important aspect of sustainable agriculture and food production for organic crops. In this randomized block experimental study, conducted on the island of Ustica, Sicily (Southern Italy), three commercial products containing antagonist micro-organisms, i.e. Cilus Plus (Bacillus velezensis), Micostat F (Glomus spp., Trichoderma spp, Streptomyces spp. Bacillus subtilis, and Pichia pastoris) and Mycostop (Streptomyces griseoviridis), were evaluated for the control of Fusarium wilt of lentil, over a 2-year period (2013-2015) in two separate fields. In the first year, at early bloom lentil stage, Mycostop in field A and Cilus Plus in field B significantly reduced F. oxysporum inoculum density by 44.0% and 37.5%, respectively. In the second year, at the same growth stage, Mycostop was most effective in reducing inoculum density of F. oxysporum (58.4% and 51.4% in field A and B, respectively). In the first year, at full bloom lentil stage, Micostat F significantly outperformed all other treatments in terms of incidence of disease, with an average reduction of 41.7% and 28.3% in field A and B, respectively. In the second year, Mycostop was most effective with a mean reduction of 44.4% and 50.0% in field A and B, respectively. As far as lentil grain yield is concerned, in the first year it was significantly increased following Micostat F treatments in field A, with an average rate of 37.5%, whereas Mycostop and Cilus Plus treatments, in field B, both produced average increases of only 13.0%. Lentil grain yield was also significantly greater in the second year after treatment with Micostop and Micostat F in field A, both with an average increase of 58.7%, and after Cilus Plus, in field B (mean 66.7%). These results support the effectiveness of all three commercial formulations to control Fusarium wilt of lentil, albeit with varying susceptibility of the pathogen to individual antagonists. In particular, F. oxysporum showed greater susceptibility to Mycostop and Micostat F in reducing both inoculum density and incidence of disease, while Cilus Plus was less efficient in reducing the same parameters. In conclusion, our data suggest that these commercial formulations may improve Fusarium wilt management as well as increase lentil yields.