Yes, deleted notes from an iPhone can be easily retrieved by using a data recovery software. I would recommend you TotalSaver for the ease of use and agility, as it helped me once when I was in a similar situation. Here's the link http:/www.recover-iphone-data.com
You can use iPhone backup extractor to retrieve the deleted messages. This application will extract all the files from the backups that iTunes automatically makes for ipad, as well as iPhone an iPod. See more details at ipadhelp.com/ipad-help/recover-lost-ipad-data/.
Retrieval from the iPhone/iPad DataBase If you have not been backup before deleted? No worries, the deleted files still can recover. You should note something before you recover the files as below: Some vital data likes Photos, Contacts, SMS, Notes, Call histories and more are stored in the dataBase. When you delete these files accidentally, those deleted feels are still stored in the dataBase. So you can recover those deleted files from iPhone/iPad database.
Step1: You can backup your iPhone/iPad and get the iPhone/iPad SQL Database off your iPhone/iPad. Step2: You can find your iPhone/iPad Database in /Users/~/Library/Application Support/MobileSync/Backup/, and analysis deleted records in SQL Database with some database tool.
Have you been used the Coolmuster Data Recovery for iPhone/iPad/iPod proglam?I have been use this tool to get back my deleted photos from my iPad,you can also use this tool to recover your iPad deleted notes too.
Do you sync your iPad 2 notes with iTunes, if you have, you just need the recover them from the backup, else you need a recovery app to scan your iPad and get the notes back, I recommend you this one, I try it before, visit http://goo.gl/XEYCWg to get it.