Evaluation of Metabolites of Myrothecium verrucaria as Biological Nematicide against Root-knot Nematode, Meloidogyne incognita in Vitro and in Vivo on Sugar Beet Plants

Nematicidal activity of heat-sterilizing filtrate culture of Myrothecium verrucaria was evaluated against Meloidogyne incognita in Vitro and the metabolites formulated as granules of M. verrucaria were prepared and tested on sugar beet plants infested with M. incognita comparison with DiTera™ and Rugby 10%G, under greenhouse conditions. Laboratory results showed that sterilized culture filtrate of the fungus M. verrucaria either by syringe or by autoclaving significantly reduced the percentages of egg hatching and increased the percentage of 2^nd stage juveniles (J₂) mortality of M. incognita. The most effective reductions of hatching were obtained at 50% concentration with the sterilized filtrate by autoclaving (94.23%), while the most effective reached 96.70% increasing in the percentage of mortality of J₂ after 3 days from treating by 50% concentration in case the sterilized filtrate by syringe. Results of  greenhouse experiment showed that, all treatments by the prepared fungal formulae of M. verrucaria or DiTerawith different rats significantly reduced the number of galls on sugar beet roots and final nematode population (J₂) in soil compared with control (nematode only). The higher rate (0.2 g /pot) was achieved the highest reduction in root-galling (86%) with DiTera treatment and the highest reduction in (J₂) with fungal formulae treatment (92.2%). Improvement in plant growth parameters were noticed by treatments. Analysis by GC-MS of the fungus metabolites was identified compounds to have antimicrobial and nematicidal activities. The prepared formulae from the Egyptian isolate of M. verrucaria can be used as safety bio-nematicide against M. incognita on sugar beet.