Leaf growth and development of sugarcane irrigated and fertilized with different sources and doses of nitrogen

Abstract

The objective of this study was to evaluate the effects of N sources and doses on the leaf growth and development of sugarcane irrigated (CTC-4 variety), in the cane-plant cycle, cultivated in a Red Oxisol of Cerrado (savannah) phase. The experiment was carried out under field conditions at Fazenda Rio Paraiso II, belonging to the Raízen Usina, in the municipality of Jataí, GO, southwest region of Goiás, Brazil. The experimental design used for the biometric growth assessments was a randomized block design, with three replicates, in a 4 × 2 × 4 subdivided scheme. The treatments were four doses of N (0, 60, 120 and 180 kg ha^-1), two N sources (urea and ammonium nitrate) and four evaluation periods (210, 250, 290 and 330 days after planting - DAP). The increase of the nitrogen fertilizer rate provided an increase in leaf area. The highest leaf area was reached at 250 DAP. At 330 DAP, the dry mass of the pointer occurred. The sugarcane leaf area is greater with ammonium nitrate at a dose of 180 kg ha^-1.