Gabriel Barbosa da Silva Júnior, Cid Naudi Silva Campos, Paulo Eduardo Teodoro, Rafael Ferreira Barreto, Sylvia Letícia Oliveira Silva, Renato de Mello Prado, Leónides Castellanos, Luiz Cláudio Nascimento dos Santos, Federal University of Piauí, Universidade Estadual Paulista (Unesp), Federal Institute of Maranhão, Federal University of Mato Grosso do Sul, Universidad de Pamplona, and Paulo Donato Castellane
Made available in DSpace on 2020-12-12T01:29:44Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-10-01 Despite the importance of nitrogen (N) supply to plants, there are still doubts concerning the optimal relations of ammonium and nitrate in the nutrition of yellow passion fruit seedlings. This study aims to evaluate the interaction between nitrogen concentrations and ammonium and nitrate proportions in the nutrition, growth, and dry matter production of passion fruit seedlings grown in a substrate with a nutrient solution. The experiment was conducted in a greenhouse in randomized complete block design with three replications in a 4 × 5 factorial design, consisting of four N concentrations (2.5, 5.0, 10.0 and 20.0 mmol L−1) and five ammonium proportions (0, 25, 50, 75 and 100% in relation to the total N supply). At 60 days after transplanting, green color index; accumulation of N, potassium, calcium, and magnesium in roots and shoots; stem diameter; leaf area; root length; nitrogen use efficiency (NUE); and dry matter of roots and shoots were evaluated. For the formation of seedlings of yellow passion fruit, the nutrient solution should have 13 mmol L−1 of N, with 40% of this nutrient in the form of ammonium. The passion fruit is a plant tolerant to ammonium. However, a critical concentration above 5.7 mmol L−1 of NH4+ in the nutrient solution decreases absorption of cations, NUE, and production of dry matter. Department of Plant Science Research Center of Agricultural Sciences Campus of Ministro Petrônio Portella Federal University of Piauí Department of Soils and Fertilizers Faculty of Agriculture and Veterinary Sciences São Paulo State University São Paulo State University (UNESP) School of Agricultural and Veterinarian Sciences Department of Agronomy Federal Institute of Maranhão Department of Agronomy Federal University of Mato Grosso do Sul Campus Chapadão do Sul Department of Agronomy Universidad de Pamplona Paulo Donato Castellane Department of Soils and Fertilizers Faculty of Agriculture and Veterinary Sciences São Paulo State University São Paulo State University (UNESP) School of Agricultural and Veterinarian Sciences