Uniconazole in seed treatment modifies the early growth of maize

In Brazil, corn crops are frequently affected by extreme temperatures and wide variation in water and radiation availability. These factors, coupled with the increasing incidence of pests and diseases and different management practices, limit crop yield. Alternatives that provide increased resilience in plants are of paramount importance, such as the use of growth regulators. This study aimed to investigate the effect of uniconazole (UCZ) applied to corn seeds on the germination, and growth of the shoot and root system at the initial stage of plant development. The experiments consisted of evaluating UCZ doses (0, 50, 100, 150, and 200 mg kg−1 seed) applied to seeds on the viability and vigor of seedlings. Moreover, the effect of UCZ doses on growth and biomass accumulation, root system morphology, contents of chloroplast pigments and nutrients, and leaf reflectance in plants grown up to the V4 stage was also evaluated. UCZ treatment on seeds promoted a delay in the germination process with increasing doses, also leading to a reduction in the shoot size and biomass without an influence on the root system. Vigor assessment showed that increasing UCZ doses applied to the seeds promoted reduction in the shoot size and biomass without changing germination. Plants grown in a greenhouse had inhibition of the initial shoot growth, with the height becoming uniform over time, regardless of the UCZ dose. Root data revealed that increasing the UCZ dose promoted an increase in root length and area with a reduction in diameter. Changes in chlorophyll a and b contents were also detected, in addition to the light absorption capacity depending on the UCZ dose. Seed treatment with UCZ at doses of 100 and 150 mg kg−1 seeds increased Fe, Si, K, Co, Ca, Mg, S, and Na contents in young plants. Lately, UCZ benefited the growth and development of young corn plants.