RESUMO
RESUMO Avaliou-se a eficácia de fungicidas no controle da ferrugem do feijoeiro, em condições de campo. O experimento foi conduzido em Marília, SP, com plantas de feijão do grupo Carioca. Foram realizadas 3 pulverizações a cada 14 dias, utilizando-se 300 L de calda/ha, com os ingredientes ativos: trifloxystrobin + propiconazole (75 mL/ha), prothioconazole (100 mL ha-1); azoxystrobin (50 g ha-1) + nimbus 0,25% v/v e trifloxystrobin + tebuconazole (50 + 100, 60 + 120 e 75 + 150 mL ha-1). O controle proporcionado pelos ingredientes ativos foi avaliado nas folhas, sendo o índice de infecção calculado através de escala de notas dividida em nove níveis. Constatou-se q ue todos os fungicidas e doses utilizados foram eficientes no controle da ferrugem (Uromyces appendiculatus), proporcionando mais de 90% de eficiência. Na testemunha o índice de infecção chegou a 52% na terceira avaliação.
ABSTRACT The efficacy of fungicides for the controlof bean rust was evaluated, under field conditions. The experiment was conducted in Marília, SP (Brasil), using bean plants of the 'Carioca' group. Three sprayings were applied, each 14 days, with spray volume of 300 liters ha-1, with the following active ingredients: trifloxystrobin + propiconazole (75 mL ha-1), prothioconazole (100 mL ha-1), azoxystrobin (50 g ha-1) + nimbus 0,25% v/v and trifloxystrobin + tebuconazole (50 + 100, 60 + 120 and 75 + 150 mL ha-1). The disease control provided by active ingredients was evaluated on leaves, with its infection index calculated from a 9-degree disease index. All the fungicides and their doses used were efficient in controlling leaf bean rust (Uromyces appendiculatus), reaching more than 90% efficiency. In the control treatment the leaf infection index reached 52% at the third evaluation.
RESUMO
Xylella fastidiosa is a xylem-dwelling, insect-transmitted, gamma-proteobacterium that causes diseases in many plants, including grapevine, citrus, periwinkle, almond, oleander, and coffee. X. fastidiosa has an unusually broad host range, has an extensive geographical distribution throughout the American continent, and induces diverse disease phenotypes. Previous molecular analyses indicated three distinct groups of X. fastidiosa isolates that were expected to be genetically divergent. Here we report the genome sequence of X. fastidiosa (Temecula strain), isolated from a naturally infected grapevine with Pierce's disease (PD) in a wine-grape-growing region of California. Comparative analyses with a previously sequenced X. fastidiosa strain responsible for citrus variegated chlorosis (CVC) revealed that 98% of the PD X. fastidiosa Temecula genes are shared with the CVC X. fastidiosa strain 9a5c genes. Furthermore, the average amino acid identity of the open reading frames in the strains is 95.7%. Genomic differences are limited to phage-associated chromosomal rearrangements and deletions that also account for the strain-specific genes present in each genome. Genomic islands, one in each genome, were identified, and their presence in other X. fastidiosa strains was analyzed. We conclude that these two organisms have identical metabolic functions and are likely to use a common set of genes in plant colonization and pathogenesis, permitting convergence of functional genomic strategies.