Production Components and Agricultural Productivity of Corn under Nitrogen Doses and Planting Times

Aims: The objective of this study was to evaluate the best time for planting and nitrogen dose during the dry season that provides better yield to corn crop in the Alagoas Coastal Tablelands region.

Study Design: The experimental design was in randomized blocks, in the split plot scheme with four repetitions.

Place and Duration of Study: The experiment was developed at the Center of Agrarian Sciences of the Federal University of Alagoas in 2016.

Methodology: The plots consisted of 20 lines with seven meters in length and received the four sowing seasons (E1: 28/05/16, E2: 11/06/16, E3: 25/06/16, E4: 22/07/16). The subplots contained 5 lines of 7 meters each and received the nitrogen doses (0, 75, 150 and 225 kg ha-1). The variables analyzed were: Number of grains per ear (NGE), grain mass per ear (GME) and agricultural yield obtained from the weighing of all grains harvested in the useful area of each plot.

Results: The variables agricultural productivity and number of grains per ear of corn adjusted to the quadratic regression model, while for the mass of 1,000 grains the linear was better. Grain mass per cob, number of grains per cob, weight of 1,000 grains and yield are influenced by nitrogen rates. The E1 season was the one that provided the highest grain mass per turn (235 g), number of grains per ear (675) and agricultural yield (9.6 t ha-1). For the mass of 1,000 grains, season E2 obtained the highest result (263 g).

Conclusion: Maximum corn yield can be achieved by applying 209 kg ha-1 of N, which corresponds to a yield of 9.55 t ha-1 if planted until 06/11/16.