USE OF THE PRACTICE OF COINOCULATION VIA SEED TREATMENT IN UP TO 60 DAYS BEFORE SOY SOWING (Atena Editora)

Abstract

Inoculation of seeds before commercialization, that is, inoculated or coinoculated a few days before sowing, are technologies used for different crops, in addition to soybeans, consolidating themselves as a practice that tends to be increasingly carried out in soybean crops in Brazil. Thus, the objective was to evaluate agronomic traits in soybean cultivated in the field in Pindorama-SP, 2021/22 season, submitted to different treatments via seeds with commercial inoculant for coinoculation at different times before soybean sowing. The treatments tested were: T1 = Control (without addition of biological inputs), T2 =. Nitrogen fertilization (200 kg of N/ha); T3= Inoculum based on Bradyrhizobium applied at planting and T4, T5, T6, T7, T8 and T9 = Commercial inoculant for co-inoculation based on Bradyrhizobium and Azospirillum bacteria applied via seed treatment respectively at 0, 7, 15, 30, 45 and 60 days before soybean planting. At the R8 stage, the following traits were evaluated: plant height at maturation (APM) and insertion of the first pod (AIV) in cm, average number of grains per pod (NMGV) and grain yield (PG) in kg.ha-1. From the results obtained, it was verified for the APM and AIV characters that the tested treatments did not differ statistically from each other, with, respectively, general average of 81.04 and 18.38 cm. As for the NMGV, T2 was the highlight with the highest average of grains per pod of 2.62, although it did not differ significantly from T4 and T5 with respectively average values of 2.58. In terms of PG, treatments T5, T3, T4, T2 and T6 did not differ statistically from each other and stood out providing higher values of respectively 3056.1, 2971.3, 2940.1, 2841.1 and 2789.20 kg.ha-1. Thus, it can be concluded that the practice of coinoculation can be applied via commercial inoculant in the treatment of seeds up to 15 days before the soybean sowing date, without compromising grain productivity.