Avaliação da associação de rizobacterias na cultura do milho

Abstract

As rhizobacteria they are plant growth promoters. Inoculation of plant seeds cultivated with rhizobacteria can become an excellent alternative to reduce environmental risks caused by inadequate use of agricultural inputs and even increase crop productivity. The experiment was implemented in October / 2016 at the Federal University of the Southern Frontier (UFFS), Laranjeiras do Sul-PR, in a controlled environment, using as a substrate a RED Dystroferric LATOSOLO. The experimental design was completely randomized blocks (DIC), with 7 treatments with 6 replicates, totaling 42 experimental units. The treatments tested were: T1: Witness - no inoculation and addition of N, P and K sources; T2: Inoculation of Pseudomonas fluorescens with addition of N, P and K sources; T3: Inoculation of Pseudomonas fluorescens with N and K sources; T4: Inoculation of Azospirillum brasilense with N, P and K; T5: Inoculation of Azospirillum brasilense with P and K; T6: Inoculation of Pseudomonas flourescens and Azospirillum brasilense with sources of N, P and K; T7: Inoculation of Pseudomonas fluorescens and Azospirillum brasilense with only source of K. Twenty-one days after emergence (AED), 21 pots of the treatments were collected which represented the mean of each treatment and the following variables were determined: leaf dry mass (MSF), dry mass of stalk (MSC), total dry mass MS), leaf number (NFo), plant height (AP), leaf area (FA), leaf nitrogen content (NF), leaf phosphorus content (PF), leaf sulfur content (SF) foliar iron content (FeF), leaf manganese content (MnF) and chlorophyll content (CLOR). At 120 days after sowing (DAS) at the end of the crop cycle, the ears were harvested for the determination of the following variables: grain number (NG), grain weight (PG) and weight of one thousand grains (PMG), pH CaCl2, phosphorus efficiency (Ef-P), critical level of phosphorus (NiCri-P), sulfur in the soil (Ss), copper content (Cus), zinc content (Zns), iron content (Fes), manganese content (Mns), hydrogen + aluminum content (H + Al), aluminum content hydrogen content (H+), organic carbon (Corg). The data were submitted to analysis of variance (ANOVA) and the means were compared by the Scott-Knott test at the 5% level of significance. There was no statistically significant difference between the treatments of the following parameters: MSF, AP, NF, PF, SF, CuF, ZnF, FeF, MnF, H + Al, Al3+, H+, Corg, P-Rem, NiCri-P, Ss, Cus, Zns and Mns. The following variables showed significant differences for the treatments of the following parameters: MSC, MST, NFo, AF, CLOR, NG, PG, PMG, pH CalCl2, P-Meh 1, PR, and Ss. There was no interaction / synergism between Azospirrillum brasilense and Pseudomonas fluorescens for the different variables considered, regarding corn crop and soil chemical attributes.