The effect of cultivar type, time of cultivation, and biostimulant treatment on the yield of spinach (Spinacia oleracea L.)

The aim of the present study was to investigate the influence of spraying with Aminoplant on the yield of two spinach cultivars in the spring and autumn cultivations. The experiment was carried out in 2008 and 2009 in the experimental station of the University of Agriculture in Krakow, Poland. Three factors were taken into consideration: (1) cultivar: ‘Rembrandt F₁’ and ‘Spiros F₁’; (2) time of cultivation: spring and autumn; (3) dose of Aminoplant: control (without Aminoplant), 1.5 dm³ ha^-1 and 3.0 dm³ ha^-1. The spinach yield was dependent on the time of production and cultivar type, and ranged between 18.6-44.8 t ha^-1. Both cultivars yielded better in autumn cultivation. Spraying with Aminoplant had no effect on spinach yield. Dry matter content in spinach leaves was between 6.3-11.2 g 100 g^-1. Spinach grown in the autumn had a greater content of dry matter in comparison to the spring cultivation. In 2009, ‘Rembrant F₁’ was characterized by greater dry matter content than ‘Spiros F₁’. Aminoplant in a dose of 3.0 dm³ ha^-1 lowered dry matter content in spinach leaves as compared to the control. The nitrate content in spinach was differentiated (558-3506 mg NO₃ kg^-1 f.m.) and depended on the time of cultivation, the cultivar, and the Aminoplant dose.