Doses and forms of Azospirillum brasilense inoculation on maize crop

Abstract

A B S T R A C TIn search of a more sustainable agriculture, the use of beneficial microorganisms has been highlighted, because they are low-cost and can reduce the use of fertilizers and increase grain yield. The present study aimed to evaluate the efficiency of A. brasilense inoculation and the best form and dose of inoculation in maize, measuring the impact on some physical characteristics and on its nutrition. The experiment was conducted in a greenhouse, in Ilha Solteira, SP, Brazil, in a completely randomized design, with four replicates and eight treatments: 1) control; 2) Seed 1x; 3) Seed 2x; 4) Soil 1x; 5) Soil 2x; 6) Leaf 1x; 7) Leaf 2x; 8) Seed 1x + Leaf 1x, respectively representing in each treatment the site and dose of application (1x, dose recommended by the manufacturer; 2x, twice the dose recommended by the manufacturer). No differences were found in any physical characteristics evaluated between treatments; however, for nutrient contents in the leaf tissue, there was effect on Zn content. It was concluded that, regardless of the presence of A. brasilense inoculation, forms or dose (in hybrid DKB 350), in general, there were no improvements in the characteristics evaluated. Doses e formas de inoculação com Azospirillum brasilense na cultura do milho R E S U M O Microrganismos benéficos vem sendo amplamente aplicados na agricultura, por possuírem baixo custo e possibilitarem a redução da utilização de adubos e incrementos na produtividade de grãos. Com o presente trabalho, objetivou-se determinar o efeito de doses e formas de aplicação do inoculante Azospirillum brasilense na nutrição de planta e na produção da cultura do milho. O experimento foi realizado em casa de vegetação, no município de Ilha Solteira, SP, em delineamento inteiramente ao acaso, com quatro repetições e oito tratamentos: 1) Testemunha; 2) Semente 1x; 3) Semente 2x; 4) Solo 1x; 5) Solo 2x; 6) Foliar 1x; 7) Foliar 2x; 8) Semente 1x + Foliar 1x, sendo, respectivamente dentro de cada tratamento, o local e a dose de aplicação (1x, dose recomendada pelo fabricante; 2x, dobro da dose recomendada pelo fabricante). Não foram verificadas diferenças para os tratamentos avaliados, nas características avaliadas, já para as concentrações de nutrientes no tecido foliar, houve efeito somente para o Zn. Concluiu-se que, independente da presença de inoculação, da forma ou da dose de A. brasilense avaliada, no híbrido DKB 350, de modo geral, não houve melhorias nas características avaliadas e na nutrição da cultura do milho.

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

“…Azospirillum brasilense increased leaf dry weight in the presence of this element and no significant effect was observed when only the microorganism or micronutrient were applied to the seeds (Table 1). Santini et al (2018) reported an increase in the zinc demand of maize plants stimulated by inoculation with Azospirillum brasilense, indicating that the micronutrient had a greater effect in the presence of these rhizobacteria. By contrast, Bacillus subtilis reduced stem dry weight but did not affect total dry weight when associated or not with zinc ( Table 2).…”

Effects of beneficial microorganisms on upland rice performance

“…Additionally, for instant carboxylation efficiency, EiC, the highest value was obtained with the BRM32114 + pool of T. asperellum mixture (0.08 (μmol m -2 s -1 ) (μmol mol -1 ) -1 ); however, there was no significant difference from that of the control treatment. The increase in enzymatic activity associated with photosynthesis, enhanced by biotic factors such as the introduction of beneficial microorganisms to the culture medium (Galmés et al, 2011;Nascente et al, 2017a,b;Santini et al, 2018;Buzo et al, 2019;Santos Júnior et al, 2019), can result in greater growth, which can increase productivity. Therefore, the mixed treatments of BRM32114 + pool of T. asperellum, 1301 + Ab-V5 and Ab-V5 + pool of T. asperellum stood out and provided the upland rice plants with higher values both in the photosynthetic rate and in the carboxylation efficiency.…”

“…Content of macronutrients in biomass of upland rice plants, cultivar BRS A501 CL, submitted to the inoculation of beneficial microorganisms, isolated or in mixture * -Significant difference from the control treatment by the Dunnett test at p ≤ 0.05; averages followed by the same letter do not differ by the LSD test (p ≤ 0.05); 1 to 26 -Number of treatments; The black bar refers to the control treatment. Treatments: isolated BRM32114 (1); isolate BRM32110 (2); pool of T. asperellum (3); isolate 1381 (4); Ab-V5 isolate (5); isolate 1301 (6) and mix BRM32114 + BRM32110 (7); mix BRM32114 + 1381 (8); mix BRM32114 + pool of T. asperellum (9); mix BRM32114 + 32110 + Ab-V5 (10); mix 32110 + Ab-V5 (11); mix 32110 + T. asperellum pool (12); mix 32110 + Ab-V5 + pool of T. asperellum (13); mix Ab-V5 + pool of T. asperellum (14); mix BRM32114 + pool of T. asperellum (15); mix 1381 + 1301 (16); mix 1381 + Ab-V5 (17); mix 1301 + Ab-V5 (18); mix 1381 + BRM32114 (19); mix 1301 + BRM32114 (20); mix 1381 + 32110 (21); mix 1301 + 32110 (22); mix 1381 + T. asperellum pool (23); mix 1301 + pool of T. asperellum (24); mix BRM32114 + BRM32110 + 1381+ pool of T. asperellum + 1301+ Ab-V5 (25) and control (without microorganism) 26water and nutrients, which can provide greater resistance to environmental stresses, such as increased temperature, reduced relative humidity, reduced porous soil space, and increased salt concentration (Chagas et al, 2016;Rosa et al, 2020;Pereira et al, 2020;Santini et al, 2018;Buzo et al, 2019;Santos Júnior et al, 2019).…”

Corn seed inoculation with Azospirillum brasilense in different nitrogen fertilization management

“…There was a significant difference between treatments for the thousand grain weight component with the application of nitrogen combined or not with A. brasilense (BF+CF, BF+BI+CF, BI+CF) compared to the others (BF+BI, BI, NFI, and CF) (Table 3). The thousand-grain weight is a valuable parameter since it is possible to obtain higher productivity increasing the accumulated reserves in the grains from the same number of the fertilized ovule (Santini et al, 2018). This was observed when we used nitrogen in at least two associated forms (BF+CF, BF+BI+CF, or BI+CF).…”