Figure 2.

Influence of foliar application of Ca²⁺ on sugar beet leaf coverage area shape and height under drought stress. (A) Representative image-based detection of leaf coverage area; (B) plant height estimation based on lateral imaging; and (C) leaf coverage area. Plants were grown in pots for a duration of 8 weeks. Five-week-old sugar beet plants were kept at 90% field capacity as control or exposed to drought stress (30% field capacity) for a duration of 3 weeks. Ca²⁺ was applied at BBCH14 and BBCH18 in concentration of 5 L ha⁻¹ corresponding to 540 g Ca ha⁻¹. Plants were imaged every four days from first Ca²⁺ application. Bars indicate means ± SD.