Sequential inoculation of Phytophthora capsici, Radopholus similis and Meloidogyne incognita in causing slow decline of black pepper

capsid, and slow decline caused by P. capsid, Radopholus similis and Meloidogyne incognita are major diseases of black pepper (Piper nigram L.). The role of these pathogens in causing slow de-cline in black pepper has been clearly established (1,2,3,5,7,8). These pathogens act individually or in association in causing the disease, since all these organisms are soil borne and there is no spatial separation under natural conditions. Winoto (9) observed that black pepper plants infested with root knot nematodes were more susceptible to Phytophthora infections. However, Holliday and Mowat (4) could not fmd any relation between M javanica infestations and foot rot caused by P. palmivora in black pepper plantations in Malaysia. Since all these are potential pathogens, the follow-ing study was conducted to understand whether infestation of one of the pathogens predisposes the host to infection by others or any synergistic effect is involved in causing slow decline of black pep-per. The study was conducted in pot culture in-volving inoculation of all three pathogens individ-ually and in various combinations. Black pepper hybrid "Panniyur-l " was raised in earthen pots (12 " dia.) filled with fumigated potting mixture consisting of forest soil (three parts)