Produção de um inoculante biológico para a cultura do algodão
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Data
2022-08-03
Autores
Júnior, Daniel Mandetta de Souza
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Universidade Estadual Paulista (Unesp)
Resumo
O objetivo do presente trabalho consiste no isolamento de bactérias com potencial para produção de inoculante para a cultura do algodão, para tanto, foi realizado o isolamento de microrganismos provenientes dos órgãos vegetais (raiz, caule e folha) do algodoeiro. O isolamento resultou na obtenção de 356 isolados. Estes isolados foram testados em laboratório para avaliação de atividades-chave para a promoção do crescimento vegetal tais quais, solubilização de fosfato inorgânico, fixação biológica de nitrogênio e produção de ácido indolacético (AIA). Ao final dos testes um total de 6 isolados foram selecionados com base nos seus resultados positivos em laboratório. Após isso foram montados dois experimentos em casas de vegetação. Os experimentos contaram com 6 tratamentos inoculados (isolados: 17, 21, 71, 84, 140 e 312) e um controle, sem inoculação. No primeiro experimento avaliou-se a massa seca de parte aérea e de raiz, e teor de N e P da parte aérea. O isolado 312 foi superior ao isolado 17 em relação a massa seca da parte de área, nenhum tratamento inoculado diferiu do controle. No entanto, o isolado 312 apresentou valores maiores que o controle. O segundo experimento foi montado utilizando os mesmos isolados em duas condições distintas de adubação, com 50 e 100% da adubação recomendada. Não foi observada diferença significativa entre as variáveis (massa seca de parte aérea e massa seca da raiz) e isso se deve possivelmente a má qualidade da semente empregada. Apesar dos resultados promissores in vitro os isolados não foram superiores ao tratamento controle em condições de casa de vegetação. É sugerido que se realize a identificação do isolado 312, e que este seja testado em campo, em diferentes concentrações, bem como, em solos mais pobres em N e P, para averiguar sua real capacidade na promoção de crescimento vegetal.
The objective of the present study is the isolation of bacteria with potential for the production of inoculants for the cotton crop. For this, microorganisms were isolated from the plant organs (root, stem and leaf) of the cotton plant. The isolation resulted in 356 isolates. These isolates were tested in the laboratory to evaluate key activities for plant growth promotion, such as inorganic phosphate solubilization, biological nitrogen fixation and indoleacetic acid (IAA) production. At the end of the tests a total of 6 isolates were selected based on their positive results in the laboratory. After that, two experiments were set up in greenhouses. The experiments had 6 inoculated treatments (isolates 17, 21, 71, 84, 140, and 312) and one control, without inoculation. In the first experiment, the dry mass of aerial part and root, and N and P content of the aerial part were evaluated. The isolate 312 was superior to isolate 17 with respect to area dry mass, and no inoculated treatment differed from the control. The isolate 312, however, showed higher values than the control. The second experiment was set up using the same isolates in two different fertilization conditions, with 50 and 100% of the recommended fertilization. No significant difference was observed between the variables (aboveground dry mass and root dry mass) and this is possibly due to the poor quality of the seed used. Despite the promoting in vitro results, the isolates were not superior to the control treatment under greenhouse conditions. It is suggested that isolate 312 be identified and tested in the field at different concentrations, as well as in soils poorer in N and P, to verify its real capacity to promote plant growth.
The objective of the present study is the isolation of bacteria with potential for the production of inoculants for the cotton crop. For this, microorganisms were isolated from the plant organs (root, stem and leaf) of the cotton plant. The isolation resulted in 356 isolates. These isolates were tested in the laboratory to evaluate key activities for plant growth promotion, such as inorganic phosphate solubilization, biological nitrogen fixation and indoleacetic acid (IAA) production. At the end of the tests a total of 6 isolates were selected based on their positive results in the laboratory. After that, two experiments were set up in greenhouses. The experiments had 6 inoculated treatments (isolates 17, 21, 71, 84, 140, and 312) and one control, without inoculation. In the first experiment, the dry mass of aerial part and root, and N and P content of the aerial part were evaluated. The isolate 312 was superior to isolate 17 with respect to area dry mass, and no inoculated treatment differed from the control. The isolate 312, however, showed higher values than the control. The second experiment was set up using the same isolates in two different fertilization conditions, with 50 and 100% of the recommended fertilization. No significant difference was observed between the variables (aboveground dry mass and root dry mass) and this is possibly due to the poor quality of the seed used. Despite the promoting in vitro results, the isolates were not superior to the control treatment under greenhouse conditions. It is suggested that isolate 312 be identified and tested in the field at different concentrations, as well as in soils poorer in N and P, to verify its real capacity to promote plant growth.
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Palavras-chave
Microbiologia agricola, nitrogenio fixação, cotonicultura, inoculação, Agricultural microbiology, nitrogen fixation, cotton farming, inoculation