In February of 2004, at "Platô de Neópolis", Sergipe, Brazil, about 50 coconut plants were found bearing symptoms of a disease not yet recorded in Brazil. The trunk of diseased plants exhibited a reddish-brown or rust��colored liquid bleeding from scars. Inside the stem, the tissues under the lesions were rotting and turned brownish-yellow to black. Diseased palms had reduced growth and three to four months after the first symptoms were noticed the affected plants died. A fungus was isolated from diseased tissues and identified as Thielaviopsis paradoxa. Healthy plants were inoculated with the fungus and lesions developed demonstrating the pathogenicity of the isolate. Keywords: Ceratocystis paradoxa, Chalara, Cocos nucifera. The coconut tree (Cocos nucifera L.) is widely grown along the Northeastern coast of Brazil as well as in other areas of Brazil. There is a large and increasing demand for immature coconuts that are harvested and marketed for consumption of their liquid endosperm (coconut water). This is mostly supplied by dwarf variety plantations and average productivity has been limited in Brazil to around 3,400 fruits/hectare because of limited rainfall levels, pests and diseases (Cuenca, 1994). Warwick et al. (2004) noted the occurrence of what appeared to be a novel coconut disease for Brazil at Platô de Neópolis (State of Sergipe). About 50 coconut plants were observed to have symptoms of stem bleeding, a disease that was previously unrecorded in Brazil. RESUMOThe affected trunk areas exhibited dark discoloration and a reddish-brown or rust��colored liquid bleeding from different points (Figure 1). Diseased palms had reduced growth and a gradual but progressive necrosis of the lower pinnate leaf toward the midribs. Inside the stem, the tissues under the lesions were rotting and became brownish-yellow to black. Eventually the affected plants died. In every case, the plant showing symptoms was also being attacked by the weevil Rhynchophorus palmarum L. No attempt was made to treat the diseased plants, which died within 3-4 months of the observation of the early stem symptoms. Other biotic diseases that may be lethal to coconut palms in Brazil are: red ring, caused by the nematode Bursaphlelenchus cocophilus (Warwick & Bezerra, 1992); hartrot, caused by Phytomonas sp., a flagellate protozoa (Renard, 1989), and eye-rot caused by two species of Phytophthora (Quillec & Renard, 1984).In India, plants showing a similar disease were proven to be attacked by Thielaviopsis paradoxa (De Seynes) Höhn. (anamorphic Ceratocystidaceae). The studies in India showed that inoculation of healthy coconut plants with isolates obtained from diseased plants resulted in rusty brown discoloration of the bark within 2-8 weeks, followed by the oozing of a brownish liquid from stems. Re-isolation of T. paradoxa was made from such diseased tissues (Nambiar et al., 1986). Stem bleeding of coconut is known to occur in nearly all the countries which grow coconut (Ohler, 1964). The disease was first reported from Sri Lanka (Pe...

Stem bleeding disease (resinosis) of coconut palm is caused by Thielaviopsis paradoxa and is very important in the state of Sergipe, Brazil. Understanding the epidemiological behavior of the disease is essential for establishing more efficient control strategies. Thus, we characterized the temporal progression and spatial distribution of stem bleeding in a commercial orchard under conditions of natural infection in the area of Neopolis, Sergipe. Three plots with 729 plants each were selected and evaluated every two months for stem bleeding incidence. In the temporal analysis, the monomolecular model gave the best fit to data on disease incidence, as it accurately showed the temporal dynamics of the disease during the experiment period. The spatial pattern of stem bleeding varied over time, with initial infections presenting random pattern and then evolving to aggregate pattern during evaluations. This indicates that the disease may have originated from the pathogen survival structures, followed by auto infections caused by dissemination from plant to plant, either by humans, by contact between roots, or by the vector Rhynchophorus palmarum.

Peanut seeds were tested by the enzyme-linked immunosorbent assay (ELISA) for peanut stripe virus without aecting their viability. A portion of cotyledon (0.02-0.05 g) was removed from the end of the seed opposite the radicle and triturated in an antigen buffer. Virus was frequently detected in extracts of cotyledons and embryos but seldom in the testa. Portions of one infected seed in ten could be detected. Correlations among ELISA, infectivity assays, and growing out tests were obtained. The ELISA technique has the advantage of detecting individual infected seed allowing the elimination of the infected ones. Identified infected seed can be used for preservation of virus cultures.

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