Persistence of the red ring nematode in the roots and in the rhizosphere of recently eradicated coconut palms

Abstract

Red ring disease is one of the primary diseases that attacks the coconut palm (Cocos nucifera L.) in Brazil. This lethal disease is caused by a nematode (Bursaphelenchus cocophilus) and can spread via contaminated tools or by the South American palm weevil (Rhynchophorus palmarum). The goal of this research was to determine the persistence of nematodes within the roots and the rhizosphere of recently eradicated coconut palms, cultivated in the coastal region of the state of Alagoas. Soil and root samples from coconut palms with advanced symptoms of red ring disease were collected up to 6 months after the eradication of the plants. Sample processing was conducted at the Ecology and Insect Behavior Laboratory of the Federal University of Alagoas. Sample collection was ended when B. cocophilus were no longer found in the laboratory tests. B. cocophilus were able to survive in the coconut palm roots for at least 118 and 133 days after felling (DAF), in Coruripe and São Miguel dos Milagres, respectively. B. cocophilus could migrated from the roots to the soil, where they were found until 76 and 88 DAF, in Coruripe and São Miguel dos Milagres, respectively.