Does zinc and boron fertilization enhance the physiological quality of maize (Zea maysL.) seeds?

Brazil is one of the largest maize producers in the world, ranking behind only the United States and China. In order to sustain the expansion of cultivated areas and achieve significant increases in maize production, the use of seeds with high physiological quality is essential. This quality is influenced by the availability of nutrients in the soil. Among these, zinc is the most limiting micronutrient for maize production, and boron also plays a crucial role in plant nutrition. Therefore, the objective of this study was to evaluate the physiological quality of maize seeds produced under different zinc and boron fertilization rates. The hybrid 30F53R was used, and fertilization was carried out with zinc (0.0, 2.0, 5.0, and 8.0 kg ha⁻¹) and boron (1.5 and 4.5 kg ha⁻¹). After harvest, the following parameters were evaluated: seed yield, thousand seed weight (TSW), germination, germination speed index (GSI), seedling length (radicle and shoot), and seedling dry mass. The results demonstrated that the micronutrients zinc and boron influence seed germination and the initial development of seedlings. Overall, as zinc application rates increased, there was an improvement in germination percentage, germination speed index (GSI), radicle length, and shoot length. Moreover, the greatest improvements were observed when zinc increments were applied in combination with the 4.5 kg ha⁻¹ boron rate.