I grew up on a farm, and worked pretty much all the time growing. I never detassled in my life, and I actually think it's more common work for kids who grow up in rural areas, but not ON a farm, as most farmers don't really plant commercial seed corn. Another thing I noticed is that the jobs that sucked when I was 12 became enjoyable by the time I was 18.
Worst job: cleaning out an elevator scale pit. The pit was 4 feet high, so you were bent over the whole time. We were scooping out the 2 foot high layer of rotten corn and mud. One guy scooped it into a bucket, and another guy outside of the pit, hauled the bucket out of the pit on a rope. It was August, and about 90 degrees outside, and we were doing it in the afternoons after football 2-a-days. Ugh.
Best job: current one. I work at a driving range, and when I'm not groundskeeping, I'm sitting behind a counter doing about an hour's worth of real actual work every day. Lot's of time to read.