Physiological quality of oat seeds produced by plants treated with mesotrione or tembotrione

Selective herbicides may cause plant stresses as a result of changes in plant physiology or seed formation and development processes, thus affecting the quality of seeds. Thus, the aim of this study was to assess the effect of application of increasing doses of mesotrione or tembotrione on the physiological quality of white oat seeds from different cultivars. It is a field experiment carried out in two crop years (2019 and 2020), in a split split-plot randomized block design. The main plots consisted of the cultivars: FAEM 007, IPR Afrodite, UPFA Fuerza and URS Monarca. The subplots were mesotrione and tembotrione; and sub-subplots were doses of each herbicide: 0x;1/4x; 1/2x, 1x and 2 x (x= recommended commercial doses for maize, equivalent to 168.0 g a.i. ha-1 for mesotrione and 88.2 g a.i. ha-1 for tembotrione). Seed germination was 1% lower after application of the 2x dose of the herbicides, compared with control, i.e., there was a slight reduction in the germination of seeds produced in 2019. There was a significant effect of cultivar on germination and vigor. The cultivar UPFA Fuerza showed better performance than the other cultivars, with 96% germination index (GI) and 94% accelerated aging (AA) in 2019, while the best performance in 2020 was achieved by URS Monarca, with 98% GI and 97% AA. It was concluded that the oat seeds had high physiological quality in all treatments tested. The germination and vigor of oat seeds depended on the genotype being used, especially UPFA Fuerza (2019) and URS Monarca (2020), but they were not affected by the herbicides and doses tested