Agronomic Performance of Corn Cultivars as a Function of Phosphorus Use

Abstract

Aims: The research was carried out to evaluate the agronomic performance of corn cultivars in contrasting phosphorus environments in the state of Pará, Brazil.
 Study Design: The experimental design was randomized blocks with ten treatments and three replications. The treatments were composed of ten cultivars: AG 1051, AG 8088PRO2, BR 206, BRS 3046, PR 27D28, 2B655PW, AL BANDEIRANTE, ANHEMBI, CATIVERDE 02 and ORION
 Place and Duration of Study: In the 2017/18 crop, two competition trials of corn cultivars were carried out at Sítio Vitória, municipality of Santa Maria das Barreiras, state Pará, Brazil.
 Methodology: Two competition trials of corn (Zea mays L.) cultivars were carried out under contracting conditions of phosphorus: high P (100 kg ha-1 of P2O5) and low P (50 kg ha-1 of P2O5), using simple superphosphate (18% P2O5) as the source. The agronomic efficiency of phosphorus use was obtained by the difference between grain yield in both levels, divided by the difference between doses. The variables evaluated were: ear height, plant height, ear diameter, number of rows per year, number of grains per rows and grain yield.
 Results: The mean grain yield of the cultivars ranged from 5,446 kg ha-1 (low P) to 11,486 kg ha-1 (high P), and the means of all cultivars were higher in high P. The means agronomic efficiency ranged from 25.1 kg kg-1 (AL BANDEIRANTE) to 96.6 kg kg-1 (AG 1051).
 Conclusion: The highest phosphorus dose (100 kg ha-1 of P2O5) resulted in higher values in the variables studied. The cultivars that stood out the most, under high and low phosphorus, were AG 8088PRO2, AG 1051 and BRS 3046, the last two being agronomically efficient.

Efficiency and Response to Phosphorus Use of Corn Cultivars in the Tropical Climate

“…Subsequently, they acquire a reddish-purplish color (anthocyanin accumulation) at the tips and margins of the leaf blade, which may extend to the culm. The plant also shows reduced growth [5][6][7][8][9][10][11].…”

“…And as the raw material for the manufacture of these fertilizers is finite, it is necessary to search for cultivars with efficient use and responsive application of phosphorus. Within this context, several researchers have sought to obtain these cultivars with greater efficiency and use of P for the cultivation of corn [4][5][6][7][8][9][10][11][12].…”