Purpureocillium lilacinum strain AUMC 10620 as a biocontrol agent against the citrus nematode Tylenchulus semipenetrans under laboratory and field conditions

• Published in: European journal of plant pathology 2023-09, Vol.167 (1), p.59-76
• Main Authors: El-Marzoky, Amr M., Elnahal, Ahmed S. M., Jghef, Muthana M., Abourehab, Mohammed A. S., El-Tarabily, Khaled A., Ali, Mohamed A. M. S.
• Format: Article
• Language: English
• Subjects: Abamectin; Agricultural practices; Agriculture; Biological control; Biomedical and Life Sciences; Citrus trees; Ecology; Eggs; Exposure; Fruit trees; Fruits; Fungi; Fungicides; Hatching; Insecticides; Integrated pest management; Larvae; Life Sciences; Nematodes; Pest control; Plant Pathology; Plant Sciences; Purpureocillium lilacinum; Spores; Tylenchulus semipenetrans
• ISSN: 0929-1873; 1573-8469
• DOI: 10.1007/s10658-023-02684-1

Three concentrations (1.25, 2.5, and 5 × 10 7 spores ml −1 ) (of the biocontrol fungus Purpureocillium lilacinum (strain AUMC 10620) were tested on citrus nematode Tylenchulus semipenetrans under in vitro and field conditions. Larvae and eggs were exposed to the fungal spores in vitro for 24, 48, and 72 h, and the findings were recorded at each time point. These results were compared with the application of the nematicide abamectin. Strain AUMC 10620 effectively reduced larval activity and egg hatching of T. semipenetrans under laboratory conditions. The highest concentration (5× 10 7 spores ml −1 ) of P. lilacinum , resulted in 89.01% immobility in the larvae, compared to abamectin, which resulted in 65.93% immobility after 48 h of exposure. These percentages of immobility were increased after 72 h of exposure (100 and 85.09%) when P. lilacinum at a concentration of 5 × 10 7 spores ml −1 and abamectin were used, respectively. On the other hand, the two other P. lilacinum concentrations (1.25, and 2.5 × 10 7 spores ml −1 ) affected the T. semipenetrans larvae to a lesser extent. The highest fungal concentration 5× 10 7 spores ml −1 inhibited the hatching of T. semipenetrans eggs in vitro with 71.34, 80, and 86.67% after 24, 48 and 72 h of treatment compared to the abamectin treatment which showed 76.67, 78, and 87% after the abovementioned periods, respectively. In addition, the application of P. lilacinum (5 × 10 7 spores ml −1 ) or abamectin under field conditions significantly ( P   0.05) differences between the two treatments. Three weeks after the field application, the percentage of nematode reduction was significantly ( P