Difference between Put something back and Put something behind

put something back—delay smth. till a later time or date:

• The subsequent events put back the development program by some three years.

put something behind—

1. = put something back:

• The cold weather has put the crops behind by a month.

2. try to forget smth. bad; regard smth. as no longer important:

• The boys have put behind those early season mishaps in hopes of something better.