Application rates of Azospirillum brasilense in cucumber seeds

Diego Muniz da Silva Santos, Fábio Steiner, Alan Mario Zuffo, Augusto Matias de Oliveira and Jorge González Aguilera

Abstract: The use of high-quality seedlings is a key factor for the success of the vegetable production system, and the use of plant growth-promoting bacteria (PGPB) can be decisive for the production of quality cucumber seedlings. Seeds from two cucumber cultivars (Aodai Melhorado and Marketmore76) were used to investigate the effectiveness of applying inoculant rates containing Azospirillum brasilense to improve germination rate and initial seedling growth. Seeds previously inoculated with inoculant containing the strains AbV5 and AbV6 of A. brasilense [0 (control), 4, 8, and 16 mL kg–1 of seed] were placed to germinate in a germination chamber at 25°C for 8 days. The experimental design used was completely randomized in a 2 × 4 factorial scheme, with four replications of 50 seeds. The results reported that the inoculant application containing the strains AbV5 and AbV6 of A. brasilense reduced germination percentage and germination rate index, whereas the inoculation of A. brasilense resulted in an increase in the mean germination time, especially for the Marketmore76 cultivar. The inoculation of seeds with A. brasilense has little effect on the shoot and root growth of cucumber seedlings. The negative and positive effects of the application of A. brasilense on the growth of cucumber seedlings are dependent on the genotype used. These results indicate that further studies should be conducted to investigate other application methods and use of other strains of A. brasilense to prove the beneficial effects of using these PGPB in improving the quality of cucumber seedlings.

Keywords: Cucumis sativus L.; plant growth-promoting bacteria; seed inoculation

Date published: 2022-10-21