Primary Screening of Microorganisms against Meloidogyne hapla (Chitwood, 1949) under the Conditions of Laboratory and Vegetative Tests on Tomato.

Highly adapted obligate endoparasites of the root system, root-knot nematodes (Meloidogyne spp.), cause great damage to agricultural crops. Our research is aimed at the assessment of nematicidal activity and effectiveness of antagonist fungal and bacterial strains against the most common type of root-knot nematode in the south of Russia. By means of molecular genetic identification, it was found that in the south of Russia, the species Meloidogyne hapla Chitwood, 1949 and Meloidogyne incognita (Kofoid and White, 1919) Chitwood, 1949 cause galls on the roots of open-ground and greenhouse tomato. Screening of microbial agents against second-stage juvenile (J2) M. hapla was carried out in the laboratory. At the end of the experiment, two liquid fungal cultures of Paecilomyces lilacinus BK-6 and Metarhizium anisopliae BK-2 were isolated, the nematicidal activity of which reached 100.0 and 70.2%, and exceeded the values of the biological standard (Nemotafagin-Mikopro) by 38.4% and 8.8%. The highest biological efficacy was noted in the liquid cultures of P. lilacinus BK-6, M. anisopliae BK-2, and Arthrobotrys conoides BK-8 when introduced into the soil before planting tomato. The number of formed galls on the roots was lower in comparison with the control by 81.0%, 75.5%, and 74.4%.