Aims: To evaluate the inhibitory effect of five structurally different imidazolium salts on the in vitro growth of plant pathogenic bacteria that belong to divergent taxonomic genera as well as their ability to reduce the severity of common bacterial blight of common bean caused by Xanthomonas axonopodis pv. phaseoli and bacterial speck of tomato caused by Pseudomonas syringae pv. tomato. Methods and Results: Growth inhibition of Xanthomonas, Pseudomonas, Erwinia, Pectobacterium and Dickeya strains by imidazolium salts was assessed in vitro by radial diffusion on agar medium and by ressazurin reduction in liquid medium. The reduction of common bacterial blight and bacterial speck symptoms and the area under de disease progress curves were determined by spraying two selected imidazolium salts on healthy plants 48 h prior to inoculation with virulent strains of the bacterial pathogens. All imidazolium salts inhibited the growth of all plant pathogenic bacteria when tested by radial diffusion on agar medium. The strength of inhibition differed among imidazolium salts when tested on the same bacterial strain and among bacterial strains when tested with the same imidazolium salt. In liquid medium, most imidazolium salts presented the same minimum inhibitory concentration (MIC) and minimum bactericidal concentration values (200 µmol l À1 ), the most notable exception of which was the MIC (at least 1000 µmol l À1 ) for the dicationic MImC 10 MImBr 2 . The imidazolium salts C 16 MImBr and C 16 MImCl caused significant reductions in the severity of common bacterial blight symptoms when compared with nontreated plants. Conclusion: Imidazolium salts inhibit the in vitro growth of plant pathogenic bacteria and reduce plant disease symptoms to levels comparable to an authorized commercial antibiotic product. Significance and Impact of the Study: New compounds exhibiting broadspectrum antibacterial activity with potential use in agriculture were identified.

-The N:K ratio influences the balance between vegetative and reproductive stages, because potassium plays important roles in the processes that regulate plant growth when the nitrogen availability is high. However, there is a lack of information on the N:K ratio suitable for cucumber cultivation in an NFT-hydroponic system. The objective of this study is to evaluate the different N:K ratios in fruiting nutrient solutions for cucumber production in a hydroponic system. Treatments consisted of two cucumber hybrids (Natsuno Kagayaki and Runner) and four nutrition solutions with different N:K ratios (w/w) (1:0.5, 1:1.0, 1:2.0, and 1:3.0) in the reproductive phase arranged as split plots in a randomized block design with four replications. On the 33 rd day after sowing (DAS), the SPAD index on the fourth expanded leaf from the plant apex, number of broaches, and harvests were evaluated. The aerial parts of the plants were collected on the 54 th DAS for evaluation of fresh mass, dry mass, and number of leaves per plant. The results showed that the highest concentration of K in the fruiting nutrient solution does not alter the length of the fruits but increases their diameter yield. The N:K ratios in the 1:2.0 and 1:3.0 (w/w) nutrient solutions provided greater yields in both evaluated hybrids. The hybrid Natsuno Kagayaki, however, showed the highest productivity, and it is recommended for hydroponic cultivation. No entanto, há carência de informações sobre relações N:K adequadas para o cultivo do pepino em sistema hidropônico-NFT. Objetivou-se com esse trabalho avaliar diferentes relações N:K da solução nutritiva de frutificação para produção de pepino em sistema hidropônico. Os tratamentos foram dois híbridos de pepino (Natsuno Kagayaki e Runner) e quatro soluções nutritivas com diferentes relações N:K (p/p) (1:0,5; 1:1,0; 1:2,0 e 1:3,0) na fase de reprodutiva, arranjados como parcelas subdivididas, no delineamento em blocos casualizados com quatro repetições. Aos 33 dias após a semeadura (DAS) avaliou-se o índice SPAD, na quarta folha expandida, a partir do ápice da planta, o número de brotações e teve inicio as colheitas. Coletou-se a parte aérea das plantas para avaliação de massa fresca, massa seca e número de folhas por planta aos 54 DAS. Os resultados demonstraram que a maior concentração de K na solução nutritiva de frutificação não altera o comprimento dos frutos, mas aumenta o diâmetro e a produtividade. As relações de N:K na solução nutritiva de 1:2,0 e 1:3,0 (p/p) proporcionaram maiores produtividades para os híbridos estudados. Entretanto, o híbrido Natsuno Kagayaki apresentou maior produtividade, sendo o mais recomendado para o cultivo hidropônico. Palavras-chave:Cucumis sativus. Híbridos. Índice SPAD. Potássio.

Here, we report the annotated draft genome sequence of Xanthomonas axonopodis pv. eucalyptorum pathotype strain LPF602 (synonym Xanthomonas axonopodis BSC45a), isolated from eucalypt leaves showing bacterial blight symptoms in Brazil. The availability of these genomic data will help improve the understanding of the evolution and molecular mechanisms involved in the pathogenesis of this microorganism.