As you can see from the two screenshots below, from left to right are the crops that farmer villagers harvest upon reaching their final stages of growth.
However, upon harvesting said crops, they do not pick up any leftover seeds from Wheat and Beetroots, yet they DO pick up the leftovers from potatoes and carrots.
This wasn't the case from previous updates, and certainly shouldn't be happening.
Baby farmer villagers can now harvest the crops (intentional?) and the same effect happens.
As of 188.8.131.52, Farmer Villagers (adult/baby) can't re-plant any crops and they only pickup Beetroots and Wheat.