Interest rates and economic growth Are interest rates the cause of economic growth?

For example there is no money in the system and bank a is lending company A a loan Y with X interest.

how can company A pay back the loan Y with interest X when the system is just loaded with loan Y? 

My conclusion is the Loan Y can only be paid back with interest when the economic is growing by other loans?
Let's consider a simpler example.

You have 10 apples. With that, you can eat $x$ apples and "invest" in the rest $10-x$ apples, plant them, and each would yield two apples tomorrow. Let's say that with some optimization, you decided to eat 4 apples, saving the other 6 apples so that you could have 12 apples tomorrow. GDP would grow by 2.

Is this a result of "interest rate"? No. There's not even a bank here.

Now imagine that there is a bank that ask you to deposit your apples there for a day. What would you demand in return? 2 apples tomorrow for every apple you save today. That's the interest rate. The assumption is that the borrower can do something at least as productive with the money he/she borrowed, and the apples would go to those who can most efficiently use them.