'Greetings, Name. I have heard of your great skill as a farmer, and I believe you might find some use in this book. It will impart to you great secrets of your profession.
'When you have read it, return to me, and we will speak again.'
Your skills as a farmer have gone beyond your previous mastery.
Use the Farmer's Guide
You have been given a book of gem-lore by a Master Craftsman. You should read it and study the secrets contained within its yellowed pages.
Talk to the Master Craftsman
Master Craftsman can be found in Esteldin, Michel Delving, Thorin's Hall, and Rivendell.
You should speak with the Master Craftsman, now that you have read the book of farming lore.
Master Farmer Proficiency
Completes master farmer proficiency and allows supreme crafting
Sets Completed Proficiency to 5
Sets Open Crafting tier to 6