Yield and flowering of onion fertirrigated by NPK drip irrigation under phosphorus doses at different plant densities

• Autor(a) principal: Menezes Júnior, Francisco Olmar Gervini
• Data de Publicação: 2023
• Outros Autores: Higashikawa, Fábio Satoshi, Gonçalves, Paulo Antonio Souza
• Tipo de documento: Artigo
• Idioma: por
• Título da fonte: Vértices (Campos dos Goitacazes. Online)
• DOI: 10.19180/1809-2667.v25n22023.20582
• Texto Completo: https://editoraessentia.iff.edu.br/index.php/vertices/article/view/20582
• topic: Allium cepa; adubação fosfatada; fertirrigação; Allium cepa; adubación fosfatada; fertirrigación; Allium cepa; phosphorus fertilization; fertigation

The study aimed to observe the phosphorus dose and plant density that maximize bulb productivity and to record the flowering of onions in a drip irrigation system. The treatments were at four plant densities (300, 400, 500 and 600 thousand plants ha-1) submitted to five doses of phosphorus (0, 40, 80, 120 and 160 kg of P2O5 ha-1), weekly distributed along the vegetative cycle of the crop via fertigation. The doses of phosphorus and fixed doses of nitrogen (150 kg N ha-1) and potassium (105 kg K2O ha-1) were divided weekly. Productivity of classes 2, 3 and 4 and flowering were evaluated. Doses of 150 kg N ha-1, 120 kg P2O5 ha-1 and 105 kg K2O ha-1 are sufficient to obtain yields greater than 50 t ha-1 of bulbs in Cambisol with high level of phosphorus and average levels of organic matter and potassium. It is suggested that current recommendations be reviewed for yields greater than 30 t ha-1, especially for fertirrigated systems. It is recommended to use populations of 400 to 500 thousand plants ha-1 to obtain class 3 and 4 bulbs. One third of the SCS 373 - Valessul onion plants flower when subjected to average minimum temperatures below 13 ℃ for more than ninety days.