All perfect praise be to Allah the Lord of the Worlds. May His peace and blessings be upon Prophet Mohammad and upon all his family and companions.
The jurists have agreed that it is not permissible to sell fruits for two years or more, because the fruits are non-existent at the time of the contract, and the sale of non-existent goods is invalid according to the text (Quran and Sunna) and the consensus of scholars. As narrated by Jabir Bin Abdullah (may Allah be pleased with him) what follows: "The Messenger of Allah, peace and blessings be upon him, forbade Al-Muhaqala, Al-Muzabana, and Al-Mu'awama." [Moslim]. Al-Mu'awama is the sale of fruits for several years.
Sheikh Al-Islam Al-Nawawi (may Allah have mercy on him) said: "The sale of non-existent goods is invalid by consensus, and Ibn Al-Mundhir and others have conveyed the consensus of Muslims on the invalidity of selling fruits for two years and the like" [Al-Majmu' Sharih Al-Muhadhdhab/Vol. 9/P.258].
In conclusion, it isn`t permissible to sell fruits for two years and more. And Allah The Almighty Knows Best.