MICROORGANISMS ASSOCIATED WITH CASHEW DIEBACK

Abstract

In Panama, the cashew (Anacardium occidentale L.) grows mainly in the lowlands of the Pacific Ocean slope. Data from the Statistics Institute (Government of Panama) indicate the existence of 963 253, distributed over 406 commercial hectares and backyards. The objective of this research was to identify the main microbial agents associated with the so-called "cashew dieback", with symptoms like: leaf spots of different shapes, colors, size, and sites of development on the leaf, presence or absence of a chlorotic halo around the leaf spots, leaf spots in the interveinal spaces or next to the veins, dark staining of the bark, darkening, death of the vascular bundles in a downward direction, drying of the twig in a downward direction, presence of areas with dark bark (blackened) and drying of the floral cluster. For this, samples of leaves, branches, flowers and stem segments with symptoms associated with the health problem were collected, followed by a phase of isolation and morphological characterization of the microorganisms and pathogenicity tests (Koch's postulates). According to the results, fungi Colletotrichum gloesporioides, Pestalotia heterocornis and Lasidioploidía theobromae, with a prevalence of 60%, 30% and 3%, respectively; affecting leaves, branches, flowers and fruits and molecularly identifying them through ITS genes (spacer DNA).