Botryosphaeriales represent a diverse order of fungal pathogens of various woody plant species. In Serbia, these fungi are important pathogens of forest, ornamental, and fruit trees causing die-back, cankers, leaf blights, fruit, and root rot. The aim of this study was to evaluate the antifungal activity of Pinus sylvestris bark extracts and Trichoderma spp. against Botryosphaeria dothidea, Dothiorella sarmentorum, and Neofusicoccum parvum (Ascomycota, Botryosphaeriales) isolated from Picea abies, Thuja occidentalis, and Prunus laurocerasus trees planted in urban areas in Serbia. Bark extracts were prepared in water solution at two temperatures (80 and 120 °C). The extracts were tested using two concentrations (20% and 30%). Moreover, two Trichoderma isolates obtained from P. sylvestris bark were tested against Botryosphaeriales and their antagonistic potential was estimated in vitro using a confrontation test. Mycelial growth of B. dothidea and D. sarmentorum was significantly inhibited in the presence of bark extracts, while N. parvum showed no growth inhibition. Botryosphaeria dothidea growth was inhibited by 35 to 39% in the case of 20% extracts and by 39 to 44% in the case of 30% extracts. The growth inhibition of D. sarmentorum was between 48% and 56% in the case of 20% extracts and between 53% and 60% in the case of 30% extracts. The two Trichoderma isolates showed antifungal activity against the selected pathogens. An isolate BKG 4 showed the highest inhibition level, and it inhibited the growth of B. dothidea, D. sarmentorum, and N. parvum by 85%, 75%, and 62%, respectively. Preliminary results suggest that both P. sylvestris bark extracts and Trichoderma spp. could be used as biocontrol agents against B. dothidea, D. sarmentorum, and N. parvum, and this should be a further studied.
Potential of Trichoderma spp. and Pinus sylvestris Bark Extracts as Biocontrol Agents against Fungal Pathogens Residing in the Botryosphaeriales