Is zakat obligatory on grapes?

Zakat is obligatory on grapes if they reach the nisab, which is five awsuq (300 sa's), based on the Prophet's (peace be upon him) saying: "There is no sadaqa on less than five awsuq." Half of one-tenth (5%) is due if irrigation involves cost (such as machinery), and a full one-tenth (10%) if irrigation is without cost (such as rain and rivers). Zakat is not obligatory on grapes unless their dried equivalent reaches the nisab.