INFLUENCE OF THE DATE OF APPLICATION OF INOCULANTS VIA SEEDS ON BIOLOGICAL NITROGEN FIXATION AND SOYBEAN PRODUCTIVITY (Atena Editora)

Abstract

The objective was to evaluate biological nitrogen fixation parameters and grain yield in soybeans submitted to different treatments involving early sowing dates in association with pesticides, inoculants and protector. The experiment was installed in the 2018/19 harvest at the Centro Regional Center Norte, Pindorama –SP. The treatments were: T1= control; T2 = 200 kg ha-1 of N (urea) in installments; T3 = standard inoculation with Biomax ® Premium L Soja (A) on the day of sowing; T4 = Biomax ® 10 (B) + Max Protection (C) on the day of sowing; T5 and T6 = T4 applied respectively, at 7 and 14 days before sowing. The doses of biological inputs applied via seeds corresponded to 100 mL/ 50 kg seeds for A and B and 50 mL/ 50 kg seeds for C, respectively. all seeds received the technological package from Bayer with the commercial products Derosal Plus at a dose of 2 mL/kg of seed and Cropstar (5 mL/kg). The experimental plot consisted of 4 lines of 15 m, with spacing between lines of 0.5 m. The experimental design was DBC with six treatments and 4 replications. After collecting plants in R3, the total number of nodules (NNODT) and dry mass of total nodules (MSNODT), total nitrogen accumulated in the shoot (NPA) were measured; shoot dry mass (MSPA) and root dry mass (MSR). At the time of maturation (R8) the grain yield (PG) and later the total nitrogen accumulated in the grains (NG) were evaluated. It was found that T4 (Biomax ® + Max Protection) applied on the day of sowing promoted increases in NNODT, MSNODT, NPA, MSPA and MSR with respectively 32.67 nodules/plant, 410 mg/plant, 34.45 g.kg-1, 31.17 and 5.44 g/plant. As for PG, treatment T4 with 3037.50 kg/ha was similar to treatments T5 and T6, whose pre-inoculation time was longer. It is concluded that the longer the storage time of seeds with pesticides, inoculants and protectors, most of the variables related to biological nitrogen fixation are reduced. The application of inoculant + protector associated with Bayer's technological package is recommended as long as it does not exceed 14 days before sowing the soybean. inoculants and protectors, most variables related to biological nitrogen fixation are reduced. The application of inoculant + protector associated with Bayer's technological package is recommended as long as it does not exceed 14 days before sowing the soybean. inoculants and protectors, most variables related to biological nitrogen fixation are reduced. The application of inoculant + protector associated with Bayer's technological package is recommended as long as it does not exceed 14 days before sowing the soybean.