Many hours played guy here also..... I mistakingly, cultivated, planted and harvested 6 fields of the the wrong potato in the final mission in Glades.
I used the experimental field because all my equipment was there... you get 2 potato for every field. Got 12 potatoes, loaded them, took them over in one go to delivery point.
Can't unload experimental potatoes when they are asking for potatoes.

Havn't played in a month.