In a normal season, without particular atmospheric difficulties (drought, hail, wind, cold, heavy rain etc) this is on average 20% of the total production of the field. Physiologically, in fact, each plant produces some vegetables or fruits that are more or less small than the average, with an uneven color or with some shape or skin defect.
On the other hand, in an unstable season at an atmospheric level (which is now almost the norm) the part of the crop that is aesthetically not compliant and therefore to be discarded can reach up to 70-80%.
All this leads to two substantial problems, both heavy and unjustifiable.