Efficiency of inoculant with Azospirillum brasilense on the growth and yield of second-harvest maize1

Abstract

The misuse of fertilizers has become a growing concern in terms of agricultural and environmental sustainability. One alternative to reduce the impact of chemical fertilizers is the use of inoculants containing nitrogen-fixing and plant growth promoting bacteria. This study aimed at evaluating the effects of an inoculant with Azospirillum brasilense on the growth and yield of secondharvest maize. The experimental design was randomized blocks with three replications, in a 3 × 5 factorial scheme. The treatments consisted of three inoculation methods (control without inoculation, seed inoculation and leaf-sprayed inoculation at the V4 stage) and five cover N-fertilization doses (0 %, 25 %, 50 %, 75 % and 100 %, with the 100 % dose corresponding to 50 kg ha-1 of N as urea). Inoculated plants showed a greater growth for height (9.5 % and 16 %), stem dry biomass (49 % and 6.75 %) and root dry biomass (123 % and 97 %), respectively for seed inoculation and spraying, as well as increases in ear size (8 %), chlorophyll content (4 %), 1,000-grain weight (12 %) and grain yield (29 %), when compared to non-inoculated plants. The effects of N doses were only significant for 1,000-grain weight and grain yield (kg ha-1), with seed inoculation providing a higher yield for second-harvest maize.

Effects of Azospirillum brasilense on growth and yield compounds of maize grown at nitrogen limiting conditions

“…Except when using the commercial dose of the inoculant (T4), once more all the treatments in which the inoculant was combined with N fertilizer had higher or equal CC values than the treatment in which the full recommendation of N fertilizer was employed (T2). Such as in the present work, Quadros et al (2014), Costa et al (2015) and Araújo et al (2015) also reported increasing in CC after seed or foliar inoculation in maize.…”

“…In this regard, while in Biari et al (2008), Braccini et al (2012), Costa et al (2015) and Morais et al (2016) found an increase in seed weigh of maize after plant inoculation combined to N fertilizer rates, on the other hand, in Novakowiski et al (2011) there was no significant interaction between N levels and inoculation for TSW. However, while the later authors used the bacteria strain Sp245, Hungria et al (2010) pointed out that only the strains AbV4, AbV5, AbV6 and AbV7 are the most effective for maize.…”

ISOLATION AND CHARACTERIZATION OF PLANT GROWTH PROMOTING BACTERIA ISOLATED FROM GARLIC (allium sativum).

“…Ramos et al (2010) mentioned that the interaction of A. lipoferum BR 11084 strain on corn showed a significant development as far as nitrogen fertilization. Costa (2015) also observed the positive effect of A. brasiliense Ab-V5 and Ab-V6 strains and nitrogen fertilization association at vegetative growth stage of maize and at dry mass of stalk and leaves. De Oliveira et al (2015) reported that Pseudomonas supported corn plants in their growth and increased the length and diameter of ears.…”

<b>Forage yield of Coastcross-1 pastures inoculated with <i>Azospirillum brasilense

“…However, the high cost of nitrogen fertilizers and the growing concern about the development of a more sustainable and less polluting agriculture, lead to the search for alternatives to reduce the environmental impact of chemical fertilizers (Costa, Quirino, Naves, Santos, & Rocha, 2015), without causing losses in productivity.…”

“…And, on a larger scale, for the production of phytohormones, responsible for the increase of the surface area of the roots of grasses and, consequently, larger area explored in the soil with increase in the absorption of minerals, including the N, and water, resulting in a more productive and resistant plant (Moreira, Silva, Nóbrega, & Carvalho, 2010;Hungria, Campo, Souza & Pedrosa, 2010;Costa et al, 2015).…”