In terms of naming, you can just add a -d at the end of the name

E.g 01-CHA-006-32-d - block 1, chardonnay, row 6, vine 32 is diseased

Currently you can't add new vines whilst out in the vineyard, so if you will only be identifying diseased vines whilst out in the field, then this is one approach:

Add vines on the web app called disease 1, disease 2, disease 3, disease 4.

Ensure you have property types of Row, vine no.  for samples.

Then when you are out in the field and come across a diseased vine, you can put a tag on it, write the tag with ‘disease 1’ and select the row, and vine number.

Once back home, Sync, and you will see all the info on your computer. At this point, if you want to rename them based on their row and vine number you can.

(Click on the name ‘disease 1’ > Edit button >  e.g ‘01-CHA-006-32-d’

If you do already know the diseased vines exact location in advance, then you can add them on the web app before going out to the field. Just make sure you sync the phone before going out to the field, so that the information is transferred to the phone.