Abu Hurairah radiyallahu anhu reports, When the people saw (picked their) new fruit, they used to come and present it to Rasoolullah sallallahu alaihe wasallam. Rasoolullah sallallahu alaihe wasallam then recited this du'a:
Transliteration: Allahumma baarik lana fi thimaa-rina wa-baarik lanaa fi madinatinaa wa-baarik lanaa fi saa-'i-naa wa-fi muddinaa-Allahumma-inna Ebraahima 'ab-duka wa-kha-li-luka wa-nabiy-yuka wa-inna ab-duka wa-nabiy-yuka wa-in-nahu da'aa-ka li-makkata wa-inni ad'u-ka lil-madinati bi-mith-li maa da'aaka bihi li-makkata wa-mith-lahu ma'a-hu.Translation: O Allah! Bless us in our fruits. Bless us in our city. Bless us in our Saa', and bless us in our Mudd' (these are two measures used in Madinah to measure dates, etc.). O Allah verily Ibrahim alaihis salaam is Your servant, friend and Nabi (since it was an occasion for humbleness Sayyidina Rasoolullah sallallahu alaihe wasallam did not mention here his being the habib - beloved - of Alah.) And (whatever) he has supplicated to You for (colonising) Makkah. (Which is mentioned in the aayah, ...so incline some hearts of men that they may yearn towards them, and provide Thou them with fruits in order that they may be thankful. - Surah Ibrahim, 37) I supplicate the same to You for Madinah."He then called a small child, to whom he gave that fruit.
English reference: Book 29, Hadith 192
Arabic reference: Book 30, Hadith 201