Am I alerted when I exceed the maximum concentration / dosage when recording a spraying?
Yes, you are alerted. You are only not alerted if the selected product does not have a maximum concentration and/or dosage configured; when you record the operation in field activities, we issue an alert. If you want to disable the alerts, you can do so by clicking 
Settings.
To configure maximum concentration and/or dosage limits for a product, go to
Settings > Catalogs.