Epidemics of Soybean Rust (Phakopsora pachyrhizi) in Brazil and Paraguay from 2001 to 2003

Abstract

In 5 March 2001, a severe rust outbreak was recorded at Pitapó, Paraguay, and the causal organism was determined to be Phakopsora pachyrhizi using polymerase chain reaction (PCR) and DNA sequence analysis. In May, rust surveys showed spread throughout most of Paraguay and into western and northern Parana, Brazil. In the 2001-02 season, rust was widespread in Paraguay, but losses were reduced due to severe drought; however, in Brazil it spread to more than 60% of the soybean acreage, causing field losses estimated at 0.1 million metric tons (MMT). In 2003, the disease was observed in more than 90% of the fields in Brazil, and the projected losses in Mato Grosso and Bahia alone are 2.2 MMT (US$487.3 million). Approximately 80% of the soybean acreage in Brazil was sprayed twice with fungicides at the cost of US$544 million. Differences in efficacy have been observed among the commercial strobilurin and triazol fungicides.

Tolerância de genótipos de soja à ferrugem-asiática

“…), relatada pela primeira vez no Brasil em 2001. Desde a safra agrícola de 2003/2004, essa doença tem sido constatada em todas as regiões produtoras de soja no país, exceto em Roraima, causando perdas da ordem de 10% a 90% (YORINORI et al, 2005).…”

Aplicação de fungicidas na soja baseada na detecção de uredósporos de Phakopsora pachyrhizi

“…(Conab, 2011). Apesar de a produtividade de soja no Paraná estar acima da média nacional (3360 kg ha -1 ), a ferrugem asiática, causada por Phakopsora pachyrhizi Sydow, causa perdas elevadas de produção, podendo variar de 10 a 90% Yorinori et al, 2005).…”

Molecular mapping of soybean rust resistance in soybean accession PI 561356 and SNP haplotype analysis of the Rpp1 region in diverse germplasm

“…SBR was Wrst identiWed in Japan in 1902 (Hennings 1903), Hawaii in 1994 (Killgore and Heu 1994), and Brazil in 2001 (Yorinori et al 2005). After SBR was Wrst discovered in the continental USA in plots at the Louisiana State University research station in 2004 (Schneider et al 2005), the disease spread to 20 US states, to Ontario in Canada, and to 9 states in Mexico (Isard et al 2005;Hershman et al 2011).…”

“…Soybean yield losses up to 80 % in experimental trials have been reported in Asia (Hartman et al 1991) and 63 % have been reported in Brazil during 2003, 60 % in Paraguay during 2001 (Yorinori et al 2005), up to 100 % in South Africa (Caldwell and McLaren 2004), and up to 55 % in the USA (Mueller et al 2009). Because commercial soybean cultivars resistant to SBR are not available in the USA, fungicide applications are the only method currently available to control the disease.…”

“…(Hyuuga) (Monteros et al 2007) were mapped on chromosome 6 (LG C2), Rpp4 (Silva et al 2008) and Rpp6 (Li et al 2012) were mapped to diVerent regions than Rpp1 on chromosome 18 (LG G), and Rpp5 (Garcia et al 2008) was mapped on chromosome 3 (LG N). Due to the high virulence variability of P. pachyrhizi isolates, Rpp1, Rpp1-b, and Rpp3 already have been defeated in the Weld in Brazil (Ribeiro et al 2007;Yorinori et al 2005). This shows that SBR resistance genes are not durable and it is important to discover additional resistance genes in soybean.…”