Purpureocillium lilacinum and Metarhizium anisopliae isolates for biocontrol against lesion and root-knot nematodes infecting sugarcane in greenhouse conditions

Sugarcane is a major crop in Brazil, and its extended growth cycle favors the buildup of phytonematodes such as Pratylenchus zeae and Meloidogyne javanica. This study aimed to evaluate the individual effects of different isolates of Metarhizium anisopliae and Purpureocillium lilacinum from the fungal collection maintained by the Biological Control Laboratory, Biological Institute, on nematode suppression and sugarcane agronomic performance. Two greenhouse experiments were conducted: Experiment I used naturally infested soil collected from commercial sugarcane fields, while Experiment II used sterilized substrate inoculated with P. zeae. In Experiment I, seven treatments were evaluated, including four P. lilacinum (IBCB Pl 01; 02; 06 and 07) and two M. anisopliae isolates (IBCB Ma03 and 04). At 131 days after transplanting, isolates Pl06 and Ma04 significantly reduced P. zeae populations by 59% and 66%, respectively, and also promoted greater plant growth. For M. javanica, isolates Pl02 and Pl06 achieved the highest suppression, with reductions of 87% and 68%. In Experiment II, Ma04 again stood out, reducing P. zeae by 74% and presenting the lowest reproduction factor (Rf = 2.5). Pl06 also showed high effectiveness, with 64% suppression and Rf = 3.5. Both isolates consistently improved plant height and shoot dry mass. These findings confirm the potential of Ma04 and Pl06 isolates as effective biological control agents against nematodes in sugarcane, and demonstrate the importance of isolate selection for integrated nematode management in long cycle crops.