Depleted pot tubers: The sprouts get smaller and skinnier and look like a poor excuse for a cutting. What happens next is disaster or you saved it. Some are so depleted they just die, perhaps they have some root rot but they are dead, dead, dead. Others respond to being given some liquid fertilizer and good growing conditions and grow well. Since, you took several cutting from this pot tuber, it has much less value to you as you will use one of the cuttings to make a pot tuber for next year. Really, it may not be worth saving. 
