Is it permissible to distribute the zakat on crops directly to the poor without handing it over to the Zakat Fund, due to the large number of poor people and the Fund's failure to disburse the money in its rightful channels?

If you know that the Zakat (definition) office does not distribute zakat to its rightful recipients, and you are safe from harm by not paying it to them, then there is no blame upon you for distributing your zakat yourself. In fact, some jurists have gone so far as to say that zakat is not valid if the unjust ruler does not disburse it to its designated recipients.

The majority of jurists from the Hanafis and Malikis hold the view that it is impermissible to pay zakat to an unjust ruler if he does not disburse it to its lawful recipients. The Shafi'is, however, permit paying it to an unjust ruler. Meanwhile, the Hanbalis hold that paying zakat to an unjust ruler, or to rebels, or to Khawarij if they gain control of a land, is permissible, and the one who pays it is absolved of their duty.