Data/hora: 01/07/2024 12:05:41

Biblioteca(s): 	Epagri-Sede.	
Data corrente: 	20/07/2021	
Data da última atualização: 	20/07/2021	
Autoria: 	SILVA, M. R.; STRECK, N. A.; YANG, H.; OGOSHI, C.; COSTA, I. F. D.; ROSSATO, I. G.; PEREIRA, V. F.; MEUS, L. D.; ZANON, A. J.	
Título: 	Using hydro-thermal time for assessing rice blast risk in subtropical Brazil.	
Ano de publicação: 	2021	
Fonte/Imprenta: 	Agronomy Journal, Hoboken, Nova Jersey, EUA, v. 113, n. 2, p. 1-12, 2021.	
Idioma: 	Inglês	
Conteúdo: 	In South Brazil, interannual variability leads to contrasting blast epidemics across
years, varying from years when symptoms can barely be seen up to years with complete
yield losses. To avoid yield losses, rice (Oryza sativa L.) farmers apply more
than two fungicide applications per rice growing season, even if weather conditions
are not favorable for blast development. The objective in this study was to use accumulated
hourly hydro-thermal time (HTT) to assess interannual and regional weather
variability for rice blast risk, using large data collected from multiple locations and
years in southern Brazil. For each year × site × cultivar combination, HTT was calculated
using hourly data of mean air temperature, relative humidity, and wind speed
collected from weather stations. The HTT was correlated with blast onset to define a
threshold for blast onset. The seasonal HTT between years × sites ranged from 5.1 to
725.3 °C h&#8722;1 year&#8722;1. Blast risk started after accumulating HTT of 33.6, 66.8, and
75.6 °C h&#8722;1 from 1 June until rice emergence (EM) and after accumulating HTT of
12.5, 55.3, and 121.8 °C h&#8722;1 after EMfor susceptible, medium-resistant, and resistant
rice cultivars, respectively. Our results strongly suggest that it is possible to improve
fungicide management using the HTT approach over the calendar-based approach,
oncewewere able to discriminate the cultivar and year influence, the two most important
factors on rice blast epidemics in southern Brazil.	
Palavras-Chave: 	disease; management; Pyricularia oryzae.	
Categoria do assunto: 	F Plantas e Produtos de Origem Vegetal	
URL: 	http://intranetdoc.epagri.sc.gov.br/producao_tecnico_cientifica/DOC_49412.pdf	
Registro original: 	Epagri-Sede (Epagri-Sede)	
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