Initial performance of maize in response to humic acids and plant growth-promoting bacteria

Abstract

O tratamento de sementes com inoculantes a base de bactérias promotoras de crescimento de vegetal (BPCV) ou a aplicação de ácidos húmicos (AH) podem aumentar a produtividade de plantas de interesse agrícola. A hipótese deste trabalho propõe que é possível combinar o efeito de promoção do crescimento vegetal característico dos AH com a inoculação de estirpes selecionadas de BPCV no tratamento de sementes de milho com vias a obtenção de respostas superiores à aplicação isolada de ambos no desenvolvimento inicial do milho. Para atender esse propósito foi feita a aplicação isolada de AH ou a inoculação de BPCV das espirpes Burkholderia gladioli e Rhizobium cellulosilyticum, e o uso conjunto de BPCV e AH através do tratamento de sementes de milho. Ao final do experimento (45 dias após a germinação), as plantas foram avaliadas biometricamente, nutricionalmente e foi realizada a contagem de bactérias nas plantas pela técnica do Número Mais Provável. Os resultados demonstraram ser possível combinar os efeitos dos AH com a inoculação de estirpes selecionadas de BPCV com vias a obtenção de respostas superiores à aplicação isolada de ambos. Assim o uso de bioestimulantes à base de AH, em combinação com BPCV é positivo e complementar comparativamente aos insumos geralmente usados no tratamento de sementes de milho.Palavras-chave: substâncias húmicas; bactérias diazotróficas; matéria orgânica do solo. ABSTRACT RESUMOInitial performance of maize in response to humic acids and plant growth-promoting bacteria 1 Seed treatment with inoculants based on plant growth-promoting bacteria (PGPB) or the application of humic acids (HA) may increase the productivity of plants of agricultural interest. The hypothesis of this work is that it is possible to combine the effect of plant growth promoting characteristic of HA with the inoculation of PGPB selected strains in the treatment of maize seeds. Thus, providing superior responses than in single applications of both in the initial maize development. To meet this purpose, we conducted isolated application of HA or PGPB inoculation of Burkholderia gladioli and Rhizobium cellulosilyticum, and the combined application of PGPB and HA for treatment of maize seeds. At the end of the experiment (45 days after germination), the plants were evaluated biometrically, nutritionally and a bacteria count was performed in plants using the Most Probable Number technique. The results showed that it is possible to combine the effects of HA with the inoculation of selected strains of PGPB, obtaining superior responses to the isolated application of both. Thus, the use of HA-based bio-stimulants in combination with PGPB is positive and complementary compared to inputs generally used in the treatment of maize seeds.

Effects of Water Stress and Modern Biostimulants on Growth and Quality Characteristics of Mint

“…The application of Ascophyllum nodosum extracts as plant biostimulants has been reported in several studies [19,22]. Humic acid may increase the leaf area, stem diameter, plant dry weight in different plants [23,24] and may ameliorate stress conditions in tomatoes [25]. Potassium, phosphorus, and microelements play critical roles in the growth and morphology of most plants [26,27].…”

Compost and humic acid amendments are a practicable solution to rehabilitate weak arid soil for higher winter field pea production

“…Humic acids have been shown to have a potent synergistic effect with soil microbes, particularly for Bacillus spp. and Pseudomonas bacteria that increases plant growth, chlorophyll content, and nutrient absorption 30 , 31 . The synergistic impact in our investigation when humic acid was paired with compost, notably in enhancing P uptake.…”