Bugs and weeds only slow the crops down. I will just ignore my farms if I'm busy and harvest them when they are ready. I check in on them once or twice a day, and whatever happens in-between, so be it. I still get whatever I'm growing just fine. Maybe the yield is less, I never checked, but it's not so much less that it makes a massive difference.

The yield is only reduced once the crop hits 0% moisture. This generally doesnt happen even if you ignore the crops all day unless its a really slow-growing one.