Comparison of asian soybean rust chemical control on a susceptible and a resistant cultivar in Brazil.

The development of resistant cultivars to the Asian soybean rust (ASR), caused by Phakopsora pachyrhizi, brought an additional tool to the disease management in Brazil. ASR develops slower in resistant cultivars than in susceptible ones, allowing a reduction of the number of fungicide sprays, but chemical control is still necessary. A field trial was conducted in Ponta Grossa, Parana State, in order to compare the effects of ASR chemical control with four fungicide formulations, in both resistant (BRSGO 7560) and susceptible (CD 249 RR) soybean cultivars. The fungicides were applied twice, beginning at soybean growth stage R3?R4, when first uredinia were observed, and at soybean stage R5.3?R5.4. The fungicides used were premix formulations of pyraclostrobin + epoxiconazole + fluxapyroxad (40+64.8+40 g a.i./ha), azoxystrobin + cyproconazole (60+24 g a.i./ha), pyraclostrobin + epoxiconazole (79.8+30 g a.i./ha), and epoxiconazole (125 g a.i./ha). The ASR severity at soybean growth stage R7 on nonsprayed plots reached 75.4% on the resistant cultivar and 98.6% on the susceptible cultivar. Lower ASR severity index were observed in the resistant cultivar, with the treatments pyraclostrobin + epoxiconazole (9.8%), pyraclostrobin + epoxiconazole + fluxapyroxad (10.5%), and azoxystrobin + cyproconazole (10.9%), with an average of disease control ranging from 90.8 to 91.3%. The treatments with pyraclostrobin + epoxiconazole and pyraclostrobin + epoxiconazole + fluxapyroxad provided the lower yield reductions on both soybean cultivars. The yield and grain weight reductions in the nonsprayed treatment were 32 and 28%, respectively, on the resistant cultivar and 44 and 32%, respectively, on the susceptible cultivar

Fungicides performance on the control of asian soybean rust (Phakopsora pachyrhizi) in Goias State, Brazil.

The use of fungicides remains the most important tool to Asian soybean rust (ASR) control in Brazil. The reduction of the Phakopsora pachyrhizi sensibility to triazols changed the strategy to the exclusive use of fungicides to strobilurines with triazols premix formulations. Two field trials of the Brazilian network for ASR chemical control were conducted in Goiania and Senador Canedo at Goias State in order to compare the efficacy of 17 fungicides on ASR control. The treatments were composed by two triazols, one strobilurine, one carboxanilide, and 13 premix formulations of strobilurine + triazol. The fungicides were applied twice, beginning at soybean growth stage R1 in absence of ASR symptoms (preventatively), and 21 days after first spray. The soybean cultivars were BRS 8160 RR in Goiania and BRS Valiosa RR in Senador Canedo. The area under disease progress curve (AUDPC) was calculated for each treatment based on four ASR severity evaluations from R1 to R7 soybean growth stages. The lower AUDPC and higher soybean yield were observed for almost all fungicides in premix formulations of strobilurine with triazols. The carboxanilide oxycarboxin and the triazols tebuconazole and cyproconazole were not so efficient on ASR control. The lowest reductions of soybean cycle due to ASR were observed with picoxystrobin + tebuconazole, which were 12 days later in relation to the untreated plots in Goiania and 10 days later in Senador Canedo

Avaliação de resistência de planta adulta nas cultivares de arroz irrigado à Magnaporthe grisea.

O objetivo desta investigação foi identificar cultivares de arroz irrigado com resistência diferenciada na fase adulta

Molecular testing for the clinical diagnosis of fibrolamellar carcinoma.

Fibrolamellar carcinoma has a distinctive morphology and immunophenotype, including cytokeratin 7 and CD68 co-expression. Despite the distinct findings, accurate diagnosis of fibrolamellar carcinoma continues to be a challenge. Recently, fibrolamellar carcinomas were found to harbor a characteristic somatic gene fusion, DNAJB1-PRKACA. A break-apart fluorescence in situ hybridization (FISH) assay was designed to detect this fusion event and to examine its diagnostic performance in a large, multicenter, multinational study. Cases initially classified as fibrolamellar carcinoma based on histological features were reviewed from 124 patients. Upon central review, 104 of the 124 cases were classified histologically as typical of fibrolamellar carcinoma, 12 cases as 'possible fibrolamellar carcinoma' and 8 cases as 'unlikely to be fibrolamellar carcinoma'. PRKACA FISH was positive for rearrangement in 102 of 103 (99%) typical fibrolamellar carcinomas, 9 of 12 'possible fibrolamellar carcinomas' and 0 of 8 cases 'unlikely to be fibrolamellar carcinomas'. Within the morphologically typical group of fibrolamellar carcinomas, two tumors with unusual FISH patterns were also identified. Both cases had the fusion gene DNAJB1-PRKACA, but one also had amplification of the fusion gene and one had heterozygous deletion of the normal PRKACA locus. In addition, 88 conventional hepatocellular carcinomas were evaluated with PRKACA FISH and all were negative. These findings demonstrate that FISH for the PRKACA rearrangement is a clinically useful tool to confirm the diagnosis of fibrolamellar carcinoma, with high sensitivity and specificity. A diagnosis of fibrolamellar carcinoma is more accurate when based on morphology plus confirmatory testing than when based on morphology alone

Eficiência de fungicidas para controle de giberela do trigo: resultados dos Ensaios Cooperativos - Safra 2019

O trigo (Triticum aestivum L.) é uma cultura de grande importância mundial e com crescente demanda no mercado brasileiro, principalmente por derivados desse cereal. No entanto, a produção brasileira não atende à demanda de consumo interna. Entre os fatores limitantes da cultura destaca-se as doenças causadas por fungos, que podem comprometer o desenvolvimento das plantas e gerar perda de rendimento quando relacionadas a condições climá­ticas favoráveis à ocorrência e severidade de patógenos (Lau et al., 2011). A giberela causada pelo fungo Gibberella zeae, (Schw) Petch. (anamorfo Fusarium graminearum Schwabe) é uma das doenças fúngicas mais destrutivas da cultura do trigo e de ocorrência generalizada em todas as regiões tritícolas, devido ao difícil controle e por ser altamente influenciada pelo ambiente. (...)O uso de cultivares resistentes é a medida preferencial de controle de doenças. Entretanto, atualmente não existem cultivares de trigo indicadas para plantio, que sejam resistentes o suficiente a ponto de não necessitar de ao menos uma aplicação de fungicidas .(...)A Rede de Ensaios Cooperativos reúne diversas instituições de pesquisa e empresas produtoras de fungicidas, visando avaliar anualmente a eficiên­cia de produtos (registrados ou em fase de registro) no controle da giberela a campo, sob infecção natural, nas principais regiões produtoras de trigo (Santana et al., 2012, 2014, 2016a, 2016b, 2016c, 2019). Este documento relata os resultados obtidos com os ensaios cooperativos para controle de giberela do trigo com uso de fungicidas, na safra de 2019. Palavras-chaves: trigo, Triticum aestivum L., giberela, controle químico, Rede de Ensaios Cooperativosbitstream/item/221447/1/CircTec-62-online.pd

Eficiência de fungicidas para controle de brusone de trigo: resultados dos ensaios cooperativos, safra 2019.

A brusone do trigo, causada pelo fungo Pyricularia oryzae Cavara [teleomor-fo: Magnaporthe oryzae (T.T. Hebert) M.E. Barr], tem sido considerada uma doença importante desde o final dos anos 80, causando altas perdas de pro-dutividade em culturas no centro-sul brasileiro. O fungo pode infectar todos os órgãos aéreos da planta, incluindo folhas, colmos e espigas, mas a forma mais destrutiva da doença ocorre quando infecções precoces incidem nas espigas, podendo afetar parcial ou totalmente a ráquis. As espigas infecta-das apresentam branqueamento e produzem grãos ?chochos?, deformados, pequenos e com baixo peso específico, ocasionando redução do rendimento final e da qualidade de grãos, levando a perdas significativas nas lavouras. O patógeno tornou-se amplamente distribuído na maioria das regiões tritícolas brasileiras, principalmente devido à falta de cultivares com alto grau de re-sistência genética e à ausência de fungicidas eficientes (Prestes et al., 2007; Maciel et al., 2014; Torres et al., 2015).bitstream/item/221153/1/CircTec-Online-55-2021.pd

Eficiência de fungicidas para controle de giberela do trigo: resultados dos Ensaios Cooperativos - Safra 2018.

A giberela causada pelo fungo Gibberella zeae (Schw) Petch. (anamorfo Fusarium graminearum Schwabe), é uma das doenças fúngicas mais destrutivas da cultura do trigo e de ocorrência generalizada no mundo. A giberela é considerada uma doença de difícil controle e altamente influenciada pelo ambiente. A infecção por giberela causa danos significativos na produção de trigo em regiões de clima úmido e quente, principalmente no estádio de floração, favoráveis ao desenvolvimento da doença (Casa et al., 2007; Reunião..., 2018). Além disso, a contaminação por micotoxinas implica na desvalorização e na rejeição dos grãos no mercado moageiro (Fernandes e Tibola, 2011).bitstream/item/215108/1/CirTec52-Flavio.pd

Eficiência de fungicidas para o controle da mancha-alvo, Corynespora cassiicola, na safra 2012/13: resultados sumarizados dos ensaios cooperativos.

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