Data/hora: 16/06/2024 08:52:42

Provedor de dados: 	102	
País: 	Brazil	
Título: 	Epidemiology of apple leaf spot	
Autores: 	CRUSIUS,LUCIANO U.; FORCELINI,CARLOS A.; SANHUEZA,ROSA M.V.; FERNANDES,JOSÉ M.C.	
Data: 	2002-02-01	
Ano: 	2002	
Palavras-chave: 	Colletotrichum; Disease forecast; Disease management.	
Resumo: 	Apple leaf spot (ALS) caused by Colletotrichum spp. is a major disease of apple (Malus domestica) in Southern Brazil. The epidemiology of this disease was studied in experiments carried out in the counties of Passo Fundo and Vacaria, State of Rio Grande do Sul, from February 1998 to October 2000. The disease was found in all the six apple orchards sampled in the growing seasons of 1997/98 and 1998/99. The fungus isolates associated with ALS fit the characteristics of C. gloeosporioides (75%), C. acutatum (8%), and Colletotrichum sp. (17%). The pathogen overwintered in dormant buds and twigs but not in dropped leaves or fruit mummies. Two sprays of copper oxychloride (at 0.3%) reduced the fungus initial inoculum by 65-84.6% in buds and 85.6-93.7% in twigs, but had no effect on the early season progress of the disease. Disease severity increased proportionally to elevation of temperature from 14 to 26-28 °C. At 34 °C, however, infection was completely inhibited. The duration of leaf wetness required for infection ranged from two hours at 30 °C to 32 h at 16 °C. The relationship of temperature (T) and leaf wetness (W) to disease severity (Y) was represented by the model equation Y = 0.00145[((T-13)1.78)((34.01-T )1.09)] * 25/[1+14 exp(-0.137W)], R² = 0.73 and P &lt; 0.0001. Currently, this information is being used to manage the disease and to validate a forecast system for ALS.	
Tipo: 	Info:eu-repo/semantics/article	
Idioma: 	Inglês	
Identificador: 	http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-41582002000100010	
Editor: 	Sociedade Brasileira de Fitopatologia	
Relação: 	10.1590/S0100-41582002000100010	
Formato: 	text/html	
Fonte: 	Fitopatologia Brasileira  v.27 n.1 2002	
Fonte: 	info:eu-repo/semantics/openAccess