Abstract:Objective: To evaluate the effect of chitosan (CH) and hydrogen peroxide (H 2 O 2 ) seed coatings and seedling sprinklings on two different maize varieties by measuring their phenology, the H 2 O 2 presence, the catalase (CAT) activity, and the protein quantity. Methods: Seven groups of ten seeds for each maize variety were treated with CH (2% (20 g/L) and 0.2% (2 g/L)) or H 2 O 2 (8 mmol/L) by coating, sprinkling, or both. Germination and seedling growth were measured. One month after germination, the presence of H 2 O 2 in seedlings in the coated seed treatments was evaluated. Protein content and CAT activity were determined under all treatments. Results: H 2 O 2 seed coating enhanced the germination rate and increased seedling and stem length in the quality protein maize (QPM) variety. Seedlings had a higher emergence velocity under this treatment in both varieties. CH and H 2 O 2 sprinklings did not have an effect on seedling phenology. Exogenous application of H 2 O 2 promoted an increase of endogenous H 2 O 2 . CH and H 2 O 2 seedling sprinkling increased the protein content in both maize varieties, while there was no significant effect on the CAT activity of treated seeds and seedlings. Conclusions: CH and H 2 O 2 enhance some phenological and biochemical features of maize depending on their method of application.