Winrhizo v 2005b

At the end of the cultivation period (166 days after transplantation), the growing medium was gently washed from the roots, and the plants were divided into shoots, leaves, flowers, and roots. These were then oven dried at 70°C until they reached a constant dry weight.
Five plants per treatment were harvested and their height, total shoot length, number of shoots, leaves, and flowers were measured. Total leaf area per plant was also determined by a leaf area meter (Delta-T, Decagon Devices, Pullman, Washington, USA). Total above-ground (shoot+leaves+flowers) and ground fresh and dry weight were calculated.
Fresh root systems were carefully washed with tap water after harvest, spread out on a transparent tray, and scanned at 400 dpi with a scanner (Epson Expression © 10000 XL, Japan). The captured images were then processed using image analysis software (WinRHIZO v. 2005b ©, Regent Instruments Inc., Québec, Canada) to determine total root length, average diameter, volume, tips, forks, crossings, projected, and surface area. For each replicate and treatment, roots of three plants were scanned.
Total leaf and root nitrogen content was measured using 1 g samples of foliar and root tissues, using the Kjeldahl method after 96% H₂SO₄ hot digestion.

Root morphology was assessed on the basis of root length, projected and total surface area, and number of tips, forks, and crossings on six plants for each treatment. The root system was separated from the aerial part and substrate. It was washed and scanned at 400 dpi (Epson Expression© 10000 XL scanner; Japan). The images were then processed using image analysis software (WinRHIZO v. 2005b©; Regent Instruments Inc., QC, Canada).

To analyze the quality of the root system, samples were taken at three different times: 20, 35 and 50 DAC. Six cuttings per experimental unit were taken on each sampling date. The substrate was gently washed away from the roots using first a hot bath and then a brush. The roots were scanned at 400 dpi using an Epson v700 Perfection (Japan) scanner. The captured images were then processed using image analysis software (WinRHIZO v. 2005b©, Regent Instruments Inc., Québec, QC, Canada, www.regentinstruments.com (accessed on 27 November 2021)) to determine total root length, root surface area, root average diameter, root tips, root forks and root crossings. The distribution of root length among the following root diameter classes was also determined [53 ]: very fine (VF, 0–0.5 mm), fine (F, 0.5–1 mm) and large (L > 1 mm).