The aim of this work was to investigate how the nematode Bursaphelenchus cocophilus tends to distribute itself inside the coconut palm trees in advanced stages of the red ring disease. In the samples of the roots collected at the base of the stem of sick trees, the number of nematodes was considerably higher when compared to the number found in the roots situated between one and three meters away from the stem. It was observed that, as it stands back of the sick plant, the possibility to find nematodes in the root is remote, so that the chances of transmission of the disease, from one plant to another, by means of the roots are minimal. At the top part of the stem, where the tissue is softer, it is possible to find the nematode both in the discolored areas and in the adjacent tissues, apparently healthy. In the tissues of the petioles, nematodes were found in small amounts. Therefore, the practice of the scythe disinfections used in the harvesting and leaf pruning should be recommended with the purpose of decreasing the possibility of transmission of the disease. None of the obtained samples from tissues of the rachis and leaves were contaminated. The population of nematode is higher in the excrements of larval tunnels of the apical parts of the plant, which provide higher chances of being transported, from one plant to another, stuck on to the body of its main vector, the coconut palm weevil Rhynchophorus palmarum.
Cocus nucifera; Nematoda; distribution of the population
