Zakaah on grapes

Zakaah is due on grapes if they reach the nisaab, which is
five wasqs (i.e., 300 saa’s), because of the report narrated by al-Bukhaari
(1405) and Muslim (979) from Abu Sa’eed al-Khudri (may Allaah be pleased
with him), that the Messenger of Allaah (peace and blessings of Allaah
be upon him) said: “There is no zakaah on anything less than five wasqs.” 

Half of one-tenth of the grapes should be given if they were
irrigated at a cost, such as if they were irrigated by machines. But if they
were not irrigated at a cost, such as if they were irrigated by rainfall or
rivers, then the full one-tenth must be given. 

Al-Nawawi said in al-Majmoo’ (5/440): Zakaah is not
due on dates and grapes unless their dry weight reaches the nisaab, which is
five wasqs. 

The Scholars of the Standing Committee for Issuing Fatwas
said: If the grapes reach the nisaab, which is five wasqs, then zakaah is
due on them, so one half of one tenth should be given on grapes. If he sells
them he should pay one half of one tenth of their price. This applies if
they were irrigated at a cost, such as if they were irrigated by machines or
channels or sprinklers. But if they were not irrigated at a cost, such as if
they were irrigated by rainfall or rivers, then the full one-tenth must be
paid. End quote. 

Fataawa al-Lajnah al-Daa’imah
(9/229) 

And Allaah knows best.