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

International Society for Horticultural Science, A.D. Webster, C.M. Oliveira

Lugar: Belgica; Año: 2009 vol. 800 p. 907 - 912

0567-7572

The main pear-growing area in Argentina is situated in Rio Negro and Neuquén, Patagonia: 38°55? S.L. This area represents 79% of the country?s fruit growing surface. ?Williams?, ?Packham?s Triumph? and ?Beurré D?Anjou? cultivars comprise around 93% of the production. The continental, temperate and arid climate with an annual rainfall of 180 mm represents the main advantage for achieving high quality pears. This work reports the presence, epidemiology and incidence of fungal and bacterial diseases in pears, based on a literature survey and personal experience. Fungal diseases that were found are: powdery mildew caused by Podosphaera leuchotricha on ?Beurré D?Anjou? and red pear cultivars; pear scab caused by Venturia pirina, which occurs only in years when the weather conditions favor the disease development; and root rot caused by Phytophthora cactorum, found in those orchards that have injured plants and high humidity around the collar and root of the plant. The bacterial disease fire blight, caused by Erwinia amylovora, is not present. Bacterial blossom blast, caused by Pseudomonas syringae pv. syringae, is present on ?Packham?s Triumph? in springs with rainy weather. The most important postharvest pathogens include Penicillium expansum and Botrytis cinerea. Alternaria spp., Cladosporium spp. and Athelia epiphylla have been observed sporadically. Due to favorable agro-ecological conditions, and low incidence of diseases, integrated and organic fruit production programs could be developed, producing high quality pears with no fungicide residues.