Data/hora: 11/06/2024 00:48:52

Provedor de dados: | 102
País: | Brazil
Título: | Susceptibility of fruits of the 'Valência' and 'Natal' sweet orange varieties to Guignardia citricarpa and the influence of the coexistence of healthy and symptomatic fruits
Autores: | Baldassari,Ricardo Braga; Reis,Renato Ferrari; Goes,Antonio de.
Data: | 2006-08-01
Ano: | 2006
Palavras-chave: | Citrus sinensis; Phyllosticta citricarpa; Conidia; Ascospores.
Resumo: | The importance of the presence of symptomatic fruits with citrus black symptoms (CBS) on the disease severity level in subsequent crop production was assessed in an orchard planted with Valência and Natal sweet orange varieties. Additionally, the period of susceptibility of the fruits of these varieties was evaluated. Fruits were covered with paper bags at the stage of 75% fallen petals and were then exposed to natural infection at weekly intervals, from October 2000 to April 2001. This process was carried out in plants where the fruits from the previous harvest had been picked as well as in plants where fruits remained until natural drop. The evaluation of disease severity used a scale that varied from 0 (absence of symptoms) to 6 (severe symptoms). It was observed that, for the Valência and Natal varieties, conidia of Phyllosticta citricarpa that had formed on the lesions of fruits from the previous harvest did not significantly increase the severity of disease on the fruits of the subsequent harvest period. In this study, the protection of the fruits until 10 weeks after petal drop did not affect the number of lesions, indicating that ascospore discharges after that date were, probably, responsible for disease severity. Fruits exposed between the 20th and 24th week after 75% of the petals had fallen were symptomatic, indicating that, at this stage, the fruits were still susceptible to the pathogen.
Tipo: | Info:eu-repo/semantics/article
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-41582006000400002
Editor: | Sociedade Brasileira de Fitopatologia
Relação: | 10.1590/S0100-41582006000400002
Formato: | text/html
Fonte: | Fitopatologia Brasileira  v.31 n.4 2006
Fonte: | info:eu-repo/semantics/openAccess