Physiological quality of seeds of white oat cultivars in response to trinexapac-ethyl application

Efeito da dose e época de aplicação de trinexapac-ethyl na produtividade e qualidade fisiológica de sementes de aveia branca

“…A study carried out by Carvalho and Nakagawa (2012) reported that all batches of white oat seeds treated with trinexapacethyl exceeded the minimum germination rate requirement for sale (80%) set by the Brazilian Ministry of Agriculture, Livestock, and Food Supply (MAPA). By contrast, Bazzo et al (2018) reported that 100 g ha−1 trinexapac-ethyl applied to white oat crops between the first visible node and the second detectable node stages reduced the seed vigor of cultivars IPR Afrodite and IPR Artemis grown respectively in Londrina and Mauá da Serra, Paraná, Brazil. In a study investigating the effects of trinexapac-ethyl on wheat, Zagonel and Fernandes (2007) observed that application rate and timing must be specifically determined for each cultivar, particularly in the case of crops with high susceptibility to lodging.…”

“…When lodging occurs in the maturation phase, negative effects include exposure to diseasecausing conditions, germination losses, and seed rotting, as well as difficulties related to mechanized harvesting. Therefore, application of growth regulators has become a common practice to control lodging (Bazzo et al, 2018). Growth regulators reduce plant height and minimize the risk of lodging throughout the crop cycle, potentially contributing to the production of seeds with high physiological quality (Fernandes et al, 2023;McMillan et al, 2020).…”

Mineral composition of oat grains in response to nitrogen fertilization and growth regulator

“…different white oat cultivars in two contrasting environments regarding their soil and climatic conditions (Londrina and Mauá da Serra), Bazzo et al (2018) observed a significant reduction in the seed vigor with the regulator application. This result can be partially explained by the changes observed in the chemical composition of oat grains, since the grain/seed quality may be impaired due to a reduction in the content of important nutrients both in the germination process and the seedling emergence.…”

“…On the other hand, the expected was that trinexapacethyl o, by improving grain filling, would also promote greater translocation of Cu and Zn to the grains, which did not happened. Applying growth regulator results in the development of more compact plants, due to the reduction in their height, making the photoassimilates that would be destined for the elongation, in the absence of the growth regulator, be redirected to the formation and development of the grains, improving the filling of oat grains (Kaspary et al, 2015;Bazzo et al, 2018). However, in the present study, the reduction in the shoot volume may have kept stable the level of redox reactions and, consequently, the absorption and translocation of these nutrients in the plant.…”

“…When absorbed by the plant, trinexapac-ethyl selectively reduces the level of active gibberellin and induces the plant to temporarily inhibit or reduce its growth rate, depending on the applied dose and the environmental conditions (Guerreiro & Oliveira, 2012;Hawerroth et al, 2015). In addition to reducing lodging, the regulator can modify the plant morphology and its distribution of photoassimilates, with increased yield and quality of grains and seeds, due to changes in their chemical composition (Kaspary et al, 2015;Bazzo et al, 2018).…”