Browsing by Author "Briceno, E. X."
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- ItemIncrease in Cladosporium spp. populations and rot of wine grapes associated with leaf removal(ELSEVIER SCI LTD, 2011) Latorre, B. A.; Briceno, E. X.; Torres, R.Leaf removal reduces the epiphytic populations of several filamentous fungi found on grapevine (Vitis vinifera) Consequently this practice is used to prevent foliar diseases of grapevines and rots of grapes In this study the effects of leaf removal on Cladosporium rot (Cladosporium cladosporioides and Cladosporium herbarum) which often affects Cabernet Sauvignon in Chile were characterized The effects of leaf removal on epiphytic populations of Cladosporium spp on grape berry surfaces and on Cladosporium rot development were investigated Three leaf removal treatments were compared (i) severe leaf removal where leaves from two to three nodes above opposite and from all nodes below clusters were removed (ii) mild leaf removal where leaves opposite each cluster were removed and (iii) no leaf removal Regardless of the leaf removal treatment low population levels of Cladosporium spp were detected early in the ontogenic development of grape berries which increased as the berries matured reaching maximum populations on overripe berries Based on our results severe leaf removal favors the growth of Cladosporium spp on grape berries and increases the prevalence of Cladosporium rot at harvest This increase in Cladosporium spp was correlated with an increase in lenticel damage in Cabernet Sauvignon and Sauvignon blanc vines subjected to severe leaf removal Considering that Cladosporium rot significantly reduces yield and wine quality, farmers should avoid continuous exposure of grape clusters to sunlight in order to prevent severe outbreaks of Cladosporium rot (C) 2010 Elsevier Ltd All rights reserved
- ItemNeofusicoccum spp. Associated with Stem Canker and Dieback of Blueberry in Chile(AMER PHYTOPATHOLOGICAL SOC, 2009) Espinoza, J. G.; Briceno, E. X.; Chavez, E. R.; Urbez Torres, J. R.; Latorre, B. A.Blueberry (Vaccinium spp.) plantings have significantly increased in Chile during the last decade and, currently, over 10,700 ha are cultivated throughout the country. Among other diseases, stein canker and dieback has been frequently observed in commercial plantations with incidences between 15 and 45%. The aim of this study was to identify and characterize Neofusicoccum spp. causing stem canker and dieback of blueberry in Chile. Three species, N. arbuti, N. australe, and N. parvum, were identified based oil colony and conidia morphology, and nucleotide sequence analysis of the internal transcribed spacer (ITS) region (ITS 1-5.8S-ITS2). These Neofusicoccum spp. were found alone or coexisting with Pestalotiopsis spp., Truncatella spp., or Phomopsis spp. Koch's postulates showed all Neofusicoccum spp. isolated from infected plants to be pathogenic when inoculated on blueberry fruit and twigs using both mycelia and conidia suspension. All blueberry cultivars tested, including, Brigitta, Bluecrop, Brightwell, Duke, Elliott, Misty, and O'Neal, were susceptible to Neofusicoccum spp. infection. Pathogenicity tests showed N. parvum to be the most virulent species and Elliott to be the most susceptible cultivar. This report represents the first description of N. arbuti, N. australe, and N. parvum as canker-causing agents on blueberry in Chile.