Question:

missed this little nit: Sulu's hobby was supposed to have been botany way back in The Man Trap, and yet he knew nothing about farms in this show? Is Sulu getting old and senile?

Answer:

And yet in the very next line Sulu notices that there are no cows and that the barn isn't even built for them. Botany is the study of plants, not farming, and by Star Trek's time was probably done in greenhouses with lots of automated equipment. The colonists in this episode had built what appeared to be a late 19th to early 20th century farm. Most botanists today probably wouldn't know what was "right or wrong" about such a farm unless it was something obvious, such as the absence of livestock and its associated equipment.

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