My 2 year old has already gotten a great start on growing his train, my 17 month old only has a couple tiny eye feathers, i have learned from observasion that peacocks can grow a train even before the age of 2 as mine did while others may have a different outcome with their peacocks.
I would say if you are not yet seing eye feathers he may not grow many till nexxt year.
This is my 2 year old. he also had a train last year but not as pretty as this year.
My older one didn't have any eye feathers until his 3rd year, his son is going to be two this summer (hatched July 5, 2010) and doesn't look like he has any yet so will probably have them his third year also. Other people have peacocks with eye feathers as 2 year olds, some just a few and some with nice looking trains so every bird is different.