Planting represents doing things that end in some kind of result, and gathering in represents experiencing the results of what one has done. Alternate translation: "for just as a farmer gathers in the fruit of whatever kind of seeds he plants, so everyone experiences the results of whatever he does" (See: [[rc://en/ta/man/jit/figs-metaphor]])
Paul is not specifying males here. Alternate translation: "whatever a person plants" or "whatever someone plants" (See: [[rc://en/ta/man/jit/figs-gendernotations]])