Invasive Species Compendium

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Abstract

First report of Colletotrichum nymphaeae causing anthracnose on Carya illinoinensis in Brazil.

Abstract

Since 2014, anthracnose symptoms have been observed in pecan (Carya illinoinensis) orchards in the municipality of Santa Maria, Rio Grande do Sul, Brazil. The infected fruits were dark, depressed and covered with irregular-shaped lesions. These produced abundant acervuli filled with light orange conidia. The lesions expanded over time, resulting in abscission of the fruit. The disease occurred from January to March and intensified in years with rainy summers, with 20 to 60% fruit drop reported by the growers. On leaves, symptoms consisted of circular lesions up to 5 mm with clearly delineated and cracked centers, dark brown margins and a surrounding yellowish halo. Fungal isolates collected in February 2019 from diseased fruits and leaves of pecan seed trees were identified as Colletotrichum nymphaeae based on morphological and molecular characteristics. Pathogenicity of isolates was also confirmed. This is thought to be the first report of Colletotrichum nymphaeae causing anthracnose in Carya illinoinensis in Brazil.