Ronquillo-Narváez, Mayra P.

Profile Picture

Filters

20121
Reset filters

Settings

Citations

Publication Search Results

Now showing 1 - 1 of 1
  • Thumbnail Image
    Publication
    Etiología de la pudrición del cogollo de la palma aceitera (Elaeis guineensis Jacq.) en el Ecuador
    (2012) Ronquillo-Narváez, Mayra P.; Estévez-de Jensen, Consuelo; College of Agricultural Sciences; Verle Rodrigues, José Carlos; Goenaga, Ricardo J.; Department of Crops and Agro-Environmental Sciences; Cafaro, Matías J.
    Oil palm bud rot is an important disease affecting the oil palm industry in Ecuador. The disease causes yellowing and drying of young leaves, bud rot and yellowing of unopened leaves and even death of the palm when the rot reaches the meristematic tissues. During June 2011 a survey was conducted in seven oil palm plantations: Aiquisa, Kayalú, Palesema, Palpailón, Palmeras de los Andes, Alespalma and Tabuche, located in San Lorenzo and Quinindé, in the province of Esmeraldas-Ecuador. Diseased tissue was isolated from bud, leaves, meristem tip and roots in different culture media: acidified potato dextrose agar (APDA); corn meal agar amended with: piramicin, ampicillin, rifampicin, and entachloronitrobenzene (PARP); and nutrient agar (AN) for bacteria. Soil samples were collected for analyses of chemical properties. Roots were isolated for Phytophthora spp. and DAS-ELISA (Enzyme Linked Immunosorbent Assay) was carried out. Inmunoblot and DAS-ELISA serological tests were used to identify Erwinia. Pathogenicity tests were carried out in the Research Center for Oil Palm (CIPAL) in Ecuador to evaluate the fungi and bacterial isolates. Two varieties: CIRAD code 2505 and the unspecific hybrid O x G, considered susceptible and tolerant cultivars respectively, were used for the experiment. Thirteen isolates of Fusarium spp. (107 UFC) and four isolates of Erwinia spp. (105 CFU) used for inoculation. Fusarium species represented a 36.59% of the isolates, F. oxysporum and F. solani the most important. Phytophthora was not isolated in the PARP culture and was not detected by DAS-ELISA however, the serological strip detected positive in two samples for Phytophthora spp. The morphological, biochemical, serological and molecular tests indicated that the bacterial isolates 10, 11, 16, and 19 corresponded to the genus Erwinia. In the pathogenicity tests, F. oxysporum and F. solani caused necrotic lesions in the youngest leaves of CIRAD 2504 without causing death of the plant. F. oxysporum caused smaller necrotic lesions in younger leaves of the OxG hybrid in comparison with CIRAD 2504. The inoculation of the bacterial isolates en nursery oil palms did not showed any symptom. The analysis of soil chemical properties showed a positive, low correlation between disease severity and the content of phosphate (P), copper (Cu) and iron (Fe) in the soil, suggesting a low association. The correlation coefficients were: P (0.33), Cu (0.32) and Fe (0.39). Inoculation test with F. oxysporum and F. solani in two monthsold oil palm plants, resulted in necrotic lesions and descendant rotting of the youngest leaf.