Identification, characterization and biocontrol of Botrytis spp. causing faba bean chocolate spot using Trichoderma harzianum

Eighteen isolates of Botrytis spp., as well as 20 isolates of Trichoderma spp., were identified from faba bean and field pea fields in Adana and Mersin provinces. In addition, eight isolates of Botrytis strain, collected from faba bean leaves in Ethiopia, were included for molecular study. All fungal isolates were purified using a single spore method. Botrytis spp. collected in Adana was identified as B. cinerea while all isolates of Botrytis collected from Ethiopia were identified as B. fabae based on morphological features as well as phylogenetic analysis using two primers (ITS5/ITS4 and Bt2a/Bt2b). All fungal bioagents were identified as T. harzianum based on the internal transcribed spacer (ITS5/ITS4) and translation elongation factor (tef71/tef997) primers. The optimum temperature growth ranges for B. cinerea and T. harzianum isolates were 15-20 °C and 25-30 °C, respectively. From the pathogenicity test experiment, Bc7 and Bc8 were found to be the most virulent among screened B. cinerea isolates. All isolates of T. harzianum showed promising results in reducing faba bean chocolate spot epidemics both under in vitro and in vivo conditions. However, the efficacy was variable among the isolates tested.