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

Abstract

Aims: The present study evaluated the efficiency and response to phosphorus (P) use of corn cultivars in the tropical climate in southern Para State, Brazil.
 Study Design: Two experiments were carried out, in low P (50 kg ha-1) and high P (200 kg ha-1) applications in Randomized block design (RBD), three replicates, and fourteen cultivars were used for the experiment.
 Place and Duration of Study: The experiment was carried out in the 2019-20 harvest at Sitio Vitoria (8º18'32" S, 50º36'58" W), located in the municipality of Santa Maria das Barreiras, a southern region of Para state, Brazil.
 Methodology: Phosphate fertilization was used in the sowing groove. In low P, 50 kg ha-1 of P2O5 were applied, and in high P were 200 kg ha-1 of P2O5. The source was simple superphosphate (18% P2O5). The dose in high P was defined to achieve high yields and considering the nutrient content in the soil, in low P the dose was well below. Nitrogen and potassium fertilization in cover were divided: 50% in V4 and 50% in V8. Doses of 150 kg ha-1 of N and 90 kg ha-1 of K2O were used, and fertilizers were used: urea (43% N) and potassium chloride (60% K2O).
 Results: The highest means were: 8,710 kg ha-1 efficiency and 29.78 kg kg-1 response. The efficient cultivars were: ORION, BR 2022, CR 120, AL BANDEIRANTE, M 274, BRS 3046, and AG 8088. And those considered responsive were: BM 3061, BR206, CATIVERDE 02, BR 205, ANHEMBI, BR 2022, and BRS 3046.
 Conclusion: The cultivar BR 2022 and BRS3046 showed high efficiency and also a response to phosphorus use.