Maize growth in response to Azospirillum brasilense, Rhizobium tropici, molybdenum and nitrogen

Abstract

A B S T R A C TThe objective of this research was to evaluate the effect of Azospirillum brasilense, Rhizobium tropici, nitrogen (N) and molybdenum (Mo) fertilization on maize growth. The experiment was carried out in a greenhouse from October to November 2015, in a completely randomized design, in 2 x 2 x 2 x 5 factorial scheme, with 5 replicates, corresponding to the absence and presence of Azospirillum brasilense, Rhizobium tropici, N (30 kg ha -1 ) and five Mo doses (0, 7.5, 15.0, 22.5 and 30.0 g ha -1 ). The analyzed variables were: plant height, basal stem diameter, dry biomass of shoots, roots, total and N accumulated in the shoots. There was double or triple interaction between N fertilization, Azospirillum brasilense and Rhizobium tropici for the evaluated variables. However, isolated and/or combined effect of Mo was not observed. Seed inoculation with Azospirillum brasilense as well as their coinoculation with Rhizobium tropici in the absence of N fertilization was efficient to increase plant growth. Soil N fertilization at sowing was less efficient in promoting plant growth than when it was combined with seed inoculation with Rhizobium tropici.Crescimento do milho em resposta a Azospirillum brasilense, Rhizobium tropici, molibdênio e nitrogênio R E S U M O Objetivou-se nesta pesquisa avaliar o efeito de Azospirillum brasilense, Rhizobium tropici, nitrogênio e molibdênio no crescimento do milho. O experimento foi realizado em casa de vegetação no período de outubro a novembro de 2015, no delineamento inteiramente casualizado em esquema fatorial 2 x 2 x 2 x 5, com 5 repetições considerando a ausência e a presença de Azospirillum brasilense, Rhizobium tropici, nitrogênio (30 kg ha -1 ), além de cinco doses de molibdênio (0; 7,5; 15,0; 22,5 e 30,0 g ha -1 ). As variáveis avaliadas foram: altura, diâmetro basal do colmo, massas secas da parte aérea, raízes, total e nitrogênio acumulado na parte aérea. Verificou-se interação dupla ou tripla entre a adubação nitrogenada, Azospirillum brasilense e Rhizobium tropici para as variáveis avaliadas. Todavia, não foi observado efeito isolado e/ou combinado do molibdênio. Tanto a inoculação das sementes com Azospirillum brasiliense como a coinoculação deste com Rhizobium tropici na ausência de nitrogênio se mostraram eficientes para aumentar o crescimento das plantas. A adubação nitrogenada do solo na semeadura foi menos eficiente em promover o crescimento das plantas do que quando esta foi combinada com a inoculação das sementes com Rhizobium tropici.

Influence of Bacteria Isolated from Different Ecological Zone of Turkey on Maize Growth and Nutrient Uptake

“…The stem diameter value at Or1 was 22& higher than control treatment. Similar results repeatedly reported by the researchers (Lin et al, 2018;Picazevicz et al, 2017, Chattha et al, 2017and Gholami et al, 2012 where Molina et al (2017) measured 12% thicker stem at PGPR inoculated conditions.…”

Azospirillum spp. potential for maize growth and yield

“…Seed inoculation with A. brasilense as well as their co-inoculation with Rhizobium tropici in the absence of N fertilization was efficient to increase plant growth. Picazevicz et al, 2017. Inoculation by pelleting with a mixture of A. brasilense Az39 and Az30 and A. lipoferum Sp7…”

Rhizobacteria inoculation in maize associated with nitrogen and zinc fertilization at sowing

“…In maize crops, the use of Azospirillum brasilense and Bacillus subtilis has contributed to reducing the amount of industrial nitrogen fertilizer used as topdressing by 50 to 80% and heightened its effect when applied only at sowing (Lima et al, 2011;Dartora et al, 2016;Garcia et al, 2017;Mumbach et al, 2017;Picazevicz et al, 2017). These rhizobacteria can enhance zinc availability to crops by solubilizing this micronutrient, which is easily adsorbed by the soil, making it unavailable to plants before root development (Goteti et al, 2013;Mumtaz et al, 2017).…”