Influence of the harvesting time in the level of nitrate in hydroponic lettuce

• Autor(a) principal: Tsuruda, Junior Hideu
• Data de Publicação: 2011
• Outros Autores: Ianckievicz, Alessandra, Rodini, Fernando Ken Yti Onodera Kikuchi e Ianicelli, Basso, José Marcelo, Takahashi, Hideaki Wilson
• Tipo de documento: Artigo
• Idioma: por
• Título da fonte: Semina. Ciências Agrárias (Online)
• Texto Completo: https://ojs.uel.br/revistas/uel/index.php/semagrarias/article/view/3610
• topic: Lactuca sativa L.; Light intensity; Nitrate reductase; Lactuca sativa L.; Intensidade luminosa; Nitrato redutase.

The broadleaves vegetables have high ability to accumulate nitrate in the leaves and petioles, and the ion accumulation that can cause harm to human health by forming carcinogens and cause a disease in the liver, known as methaemoglobinaemia. Thus the study was to evaluate in hydroponic lettuce, the levels of nitrate at different harvesting time and in three different parts of the plant. The harvest was held at 6:00, 9:00, 12:00, 15:00 and 18:00 hours, and the plants have been divided into three parts for consideration, and these leaves external, leaves internal and stalk. The results were submitted to compare Tukey a 5% probability, obtaining an average of the highest levels of nitrate in portions of stalk harvested at 12 hours, with 2702.40 ppm of nitrate in the fresh matter. The average achieved by internal leaves were higher at 9 am, with 1879.28 ppm of nitrate in the fresh matter, as the external leaves had no significant difference between different times, and also the body of minor accumulation of nitrate in the plant.