This is plant variaties, a catalog from which you can pick one when entering the planting information.
You have the option to add any number of attributes to it with the “choose a field…” option, where you can manually enter both the key and value.
e.g.: Resistances HR: ToMV:0-2/TSWV/TYLCV/Ff:A-E/Fol:0,1/Va:0/Vd:0/Si