You should get out of the habit of copying and pasting. Instead use Set Variable script steps and then populate the new target field with theSetField script step using your chosen $var result.
Also, instead of your steps 2 and 3, I personally would combine those two step intoone:
Set Field [Plant Databas::Harvesting date: Get(CurrentDate)]
Copying and pasting is potentialy dangerous and problematic (in my experience).
HI Mark, thanks a lot for the suggestion. It works brilliantly and I will get rid of the copy/paste habit.