𝓞 is extant here and reads “in the fruits of my labors”. Oliver Cowdery, when he copied from 𝓞 into 𝓟, replaced the plural fruits with the singular fruit. As explained under Alma 29:17, the original text seems to have number agreement in collocations of fruit(s) and labor(s); thus “in the fruits of my labors” is quite appropriate. For a more extensive discussion regarding the number for fruits, see under Jacob 5:74. Generally, we follow the earliest textual sources, thus fruits (the reading here in 𝓞) for Alma 36:25.
Summary: Restore the plural fruits in Alma 36:25, the reading of the original manuscript.