I don't know the details, but anecdotally I can say two things:
1. Produce produced in collective farms was notoriously atrocious. "Moldy" sounds like bullshit, but in general quality was bad. (Not like now! Kaluga chicken is delicious.) I know that agriculture hit a real crisis in 1991, but this is probably because Gorbachev had fucked the economy up. :) (Just as an aside, wrecking Georgian and Moldovan agriculture is one of many things that Gorbachev is disliked for.)
2. About half of Soviet agriculture was PRIVATE. After having finished work at the collective farm, a farmer was allowed to farm his/her own land plot. They would then take the produce to town and sell it in the market. This produce was of much better quality.