*2.1. Experimental Location*

The experiment took place in Marathon, Greece (42 km north from Athens), in a commercial organic vegetable production unit (Megafarm Gaia mas). This region is specifically known for its horticultural production, being the main vegetable provider for Athens. The timing of the data acquisition flights was specifically designed to be performed a few hours prior to the first wave of selective harvesting. This was desired for two reasons: (1) to ensure that the entire field was intact (no broccoli heads were harvested), maximising the

sample density in every image and the generated field orthomosaic; and (2) to make sure that individual plants of different maturity levels were present across the field, as it was at the very start of the harvesting season. The selected experimental parcel was located in the south-west part of the production unit, and occupied an area of approximately 1 ha. The segmen<sup>t</sup> on which the ground truth targets were deployed covered slightly more than half of it (Figures 2 and 3).

**Figure 2.** The experimental location in Marathon, Greece.

**Figure 3.** The field segmen<sup>t</sup> where the experiment took place.
