Title:	Temporal progress of southern rust in maize under different environmental conditions.
Authors:	GODOY, C. V. AMORIM, L. BERGAMIN FILHO, A. SILVA, H. P. SILVA, W. J. BERGER, R. D.
Affiliation:	CLAUDIA VIEIRA GODOY, CNPSO; LILIAN AMORIM, UNIVERSIDADE DE SÃO PAULO; ARMANDO BERGAMIN FILHO, UNIVERSIDADE DE SÃO PAULO; HERBERT P. SILVA, ZENECA SEMENTES LTDA; WILLIAN J. SILVA, HÍBRIDOS ESPECIAIS COLORADO; RICHARD D. BERGER, UNIVERSITY OF FLORIDA.
Date Issued:	2003
Citation:	Fitopatologia Brasileira, v. 28, n. 3, p. 273-278, maio/jun. 2003.
Description:	The progress of the severity of southern rust in maize (Zea mays) caused by Puccinia polysora was quantified in staggered plantings in different geographical areas in Brazil, from October to May, over two years (1995-1996 and 1996-1997). The logistic model, fitted to the data, better described the disease progress curves than the Gompertz model. Four components of the disease progress curves (maximum disease severity; area under the disease progress curve, AUDPC; area under the disease progress curve around the inflection point, AUDPCi; and epidemic rate) were used to compare the epidemics in different areas and at different times of planting. The AUDPC, AUDPCi, and the epidemic rate were analyzed in relation to the weather (temperature, relative humidity, hours of relative humidity >90%, and rainfall) and recorded during the trials. Disease severity reached levels greater than 30% in Piracicaba and Guaíra in the plantings between December and January. Lower values of AUDPC occurred in later plantings at both locations. The epidemic rate was positively correlated (P < 0.05) with the mean daily temperatures and negatively correlated with hours of relative humidity >90%. The AUDPC was not correlated with any weather variable. The AUDPCi was negatively related to both variables connected to humidity, but not to rain. Long periods (mostly >13 h day-1) of relative humidity >90% (that corresponded to leaf wetness) occurred in Castro. Severity of southern rust in maize has always been low in Castro, thus the negative correlations between disease and the two humidity variables.
Thesagro:	Milho
NAL Thesaurus:	Puccinia polysora Corn
DOI:	10.1590/S0100-41582003000300008
Type of Material:	Artigo de periódico
Access:	openAccess
Appears in Collections:	Artigo em periódico indexado (CNPSO)