Abstract: With the rapid development of protected cultivation in the vegetable industry, the occurrence of root-knot nematode has become increasingly severe. Biological control is an effective management strategy for managing this issue. This study focuseed on Clonostachys rosea NF-06, which was screened as biocontrol agent of root-knot nematode previously. Using encapsulation rate as an indicator, the study optimized the proportion of wall materials through single-factor and orthogonal experiments. Further evaluation was conducted focused on the shelf-life stability, stress tolerance, and their control efficiency against Meloidogyne incognita in pot. The results showed that under the conditions of 30% inoculum dosage of C. rosea fermentation broth, 0.5% seaweed oligosaccharide, 3% CaCl₂, and a cross-linking curing time of 24 hours, the addition of 2% sodium alginate, 3% starch, and 3% bentonite yielded the highest number of spore contents and encapsulation rate in the microcapsule formulation, reaching 6.3×10⁸ CFU/g and 95.5%, respectively. Additionally, the preparation of microcapsule significantly enhanced the shelf life, salt tolerance, acid and alkaline resistance, heat resistance, and UV irradiation resistance of C. rosea when compared to the fermentation broth. Furthermore, it improved the strain's efficacy in controlling tomato root-knot nematode and growth promoting on tomatoes. This study provides a scientific basis for the development and application of bio-nematicides.

Key words: Clonostachys rosea, microcapsule, Meloidogyne incognita, shelf life, stress tolerance