Zagazig J. Agric. Res., Vol. 40 No. (3) 2013 EFFECT OF CULTURE FILTERATES OF THREE Trichoderma SPECIES, Fusarium solani AND Rhizoctonia solani ON EGG HATCHING AND JUVENILE MORTALITY OF Meloidogyne incognita IN VITRO Philemon K. Misiha 1 *, A. Z. Aly 1 , M.E. Mahrous 2 and M.R.A. Tohamy 1 1. Agric. Bot. and Plant Pathol. Dept., Fac. Agric., Zagazig Univ., Egypt 2. Plant Protection Dept., Fac. Agric., Zagazig Univ., Egypt ABSTRACT Culture filtrates of three Trichoderma spp. (T. album, T. harzianum and T. viride), Fusarium solani (Mart.) Sacc., and Rhizoctonia solani Kühn have been found to cause adverse effects on egg hatching and juvenile mortality of the root-knot nematode, Meloidogyne incognita (Kofoid and White) Chitwood in vitro. The nematicidal activity was directly proportional to concentration of culture filtrates. T. viride gave the highest effect followed descendingly by T. harzianum and T. album. Moreover, the inhibitory effect of tested Trichoderma spp., culture filtrates on egg hatching was more pronounced when they were grown on gliotoxin fermentation medium (GFM) as compared to the parallel values when they were grown on potato dextrose broth (PDB) medium. Culture filtrates of F.solani and R.solani significantly reduced number of hatched juveniles and increased juvenile mortality of M.incognita. The inhibition of nematode hatching was significantly affected by fungal species, presence of fungal spores and mycelia in the filtrate and concentration used. Whereas the fungal species and concentration resulted significant effect on numbers of juveniles that exhibited no movement and counted as dead, while no observable differences were detected in filtrates contained spores and mycelia as compared to those free from spores and mycelia. Generally, F.solani resulted significant higher effects in abrupt egg hatching and increased juvenile mortality as compared to the respective values for R.solani. Key words: Trichoderma spp., Fusarium solani, Rhizoctonia solani, Meloidogyne incognita, egg- hatching, juvenile mortality. INTRODUCTION Root-knot nematodes Meloidogyne spp. constitute a major group of plant pathogenic nematodes affecting crop production. Their world wide distribution, extensive host range and involvement with fungi and bacteria rank them among the top five major plant pathogens affecting the world`s food supply (Sasser, 1979). In Egypt, nematological studies revealed that root-knot nematodes cause severe damage to the majority of economic crops especially in localities with sandy soils (Ibrahim, 1985). For several decades, nematicides have been used to control these pests with remarkable results. However, concerns about public health and environmental safety have led to restrictions on chemical nematicide applications for nematode control. Therefore, development of alternative new environmentally methods such as biological control to enhance current management systems are very necessary (Meyer, 2003). Many organisms including fungi, bacteria, soil invertebrates and predatory nematodes have been reported as biocontrol agents against plant parasitic nematodes (Stirling, 1991). Since fungi and nematodes occur concomitantly in the rhizosphere, the toxic metabolites naturally produced by these fungi might be responsible for keeping low levels of nematode populations. Zagazig Journal of Agricultural Research www.zu.edu.eg/agr/journals * Corresponding author: Tel. : +201224983832 E-mail address: bason_philemon@yahoo.com