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

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

Portugal

Simposio; 10th International Pear Symposium; 2007

ISHS

The main pear-growing area in Argentina is situated in Rio Negro and Neuquén, Patagonia: 38º 55´ S.L. This area represents 79% of the country’s fruit growing surface. ‘William’s’, ‘Packam’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 per annum 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 (Ell. y Es.) on Beurré D`Anjou and red pear cultivars. Pear scab caused by Venturia pirina (Aderh.) is not a serious problem; it occurs only in years when the weather conditions favor the disease development and no more than two applications of fungicides during the growing season are needed to control it. Root Rot caused by Phytophthora cactorum (Lebert & Cohn) is found in those orchards that have injured plants and high humidity around the collar and root of the plant. Bacterial diseases, like Fire Blight caused by Erwinia amylovora (Burrill) Winslow is not present. Bacterial Blossom Blast caused by Pseudomonas syringae pv. syringae (van Hall) is present on ‘Packam’s Triumph’ when we experience springs with rainy weather. The most important diseases post harvest include Penicillium expansum (Link) and Botrytis cinerea (Pers.). Alternaria spp. Cladosporium spp. and Athelia epiphylla (Pers.) 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 fungicides residues.