author(s)
Arunakumar GS, Revanna S, Vineet Kumar, Vinod Kumar Yadav and Sivaprasad V

abstract
The present investigation was carried out in view of destructive nature of root knot nematode (Meloidogyne incognita) incidence in mulberry and to identify the associated root rot causing fungal pathogens. A roving survey was carried out in five traditional mulberry growing districts of southern Karnataka in two consecutive years (2016 & 2017). The results indicated that incidence of root knot nematode was found in all the five districts of southern Karnataka. The highest RKN incidence was noticed in Ramanagara district (50%) whereas; the lowest was recorded in Mysore district (20%). Remaining three districts viz., Mandya, Chamarajnagar and Hassan showed 30, 40 and 35.5 percent incidence, respectively. The scanning electron microscopy (SEM) examinations indicated the penetration of infective second stage juveniles (J2) results in degeneration of epidermis and showed the presence of nematode egg mass and juveniles in outer periphery of root epidermis. On the basis of isolation and morphological studies, four different fungal pathogens were associated with root knot nematode and identified as Fusarium solani (Mart.) Sacc., F. oxysporum Schlecht., Macrophomina phaseolina and Pythium spp. In addition to that bio-control agents Trichoderma harzianum Rifai. and T. viride Pers and other saprophytic fungal organisms were found in the root zone of mulberry.