Low Incidence of Fungal and Bacterial Diseases in the Pear Production of North Patagonia, Argentina.

DOBRA,A.C.; SOSA,M.C.; DUSSI,M.C.

ACTA HORTICULTURAE

Editores: Webster-Oliveira ISHS (International Soc. for Horticultural Science)

Lugar: Peniche, Portugal; Año: 2008 p. 907 - 912

0567-7572

Abstract The main pear-growing area in Argentina is situated in Río Negro and Neuquén, Patagonia: 38º 55´ S.L. This area represents 79% of the country grown surface. ‛Williams’, ‛Packham’s Triumph’ and ‛Beurré D´Anjou’ cultivars comprise around 93% of the production. The continental, temperate and arid climate with and annual rainfall of 180 mm represents the main advantage for the pear’s quality. This work reports the presence, epidemiology and incidence of fungal and bacterial diseases in pears based on literature survey and personal experience. Fungal diseases that were found are: Powdery Mildew caused by Podosphaera leucotricha (Ell. & Ev.) Salmon on ‛Beurré D´Anjou’ and red pears cultivars. Pear scab caused by Venturia pyrina Aderh. is not a serious problem, occurs only in years when the weather conditions favor the disease development and no more than two applications of fungicides during the growing season is needed to control it. Collar Rot caused by Phytophthora cactorum (Lebert & Cohn) Schroët is found on those orchards that present injured plants and high humidity around the collar and root of the plant. Bacterial diseases, like Fire Bligth caused by Erwinia amylovora (Burrill) Wilson are not present. Bacterial Blossom Blast of pear caused by Pseudomonas syringae pv. syringae Van Hall is present on ‛Packham´s Triumph’ on rainy weather springs. The most important diseases in post harvest include Penicillium expansum Link and Botrytis cinerea. Pers.. Alternaria spp., Cladosporium spp. and Athelia epiphylla Pers. have been observed sporadically. The low incidence of fungal and bacterial diseases allows apply fruit integrated and organic production programs and produce high quality pears with low fungicides residues.