“What’s the strongest vegetable?”/“A muscle sprout.”

The Brussels sprout has a riddle:
 
Q: What’s the strongest vegetable?
A: A muscle sprout.
 
The “muscle sprout”  joke has been cited in print since at least 2002.
 
“What do you call weightlifting vegetables?”/“Muscle sprouts” is a related riddle.
 
 
Wikipedia: Brussels sprout
The Brussels sprout is a member of the Gemmifera Group of cabbages (Brassica oleracea), grown for its edible buds.
 
The leafy green vegetables are typically 2.5–4 cm (0.98–1.6 in) in diameter and look like miniature cabbages. The Brussels sprout has long been popular in Brussels, Belgium, and may have originated and gained its name there.
 
Google Books
Dude, Got Another Joke?
By Bob Phillips
Eugene, OR: Harvest House Publishers
2002
Pg. 11:
Agatha: Which vegetable is strong and green?
Abegayle: I pass.
Agatha: A muscle sprout.
 
Google Groups: alt.humor.puns
Puns of the Weak 09-29-03
Stan Kegel
8/29/03
(...)
What is the strongest vegetable in the world?
Muscle sprout (Danielle, 10 )
 
Google Books
Food Jokes
By Hugh Moore
Edina, MN: ABDO Publishing Company
2005
Pg. 21:
What is the strongest vegetable in the world?
A muscle sprout!
   
Twitter
A Joke a day
@Jokes_corner
Q: which is the strongest Vegetable in the world..? A: Muscle Sprout!! hoh hoh..
11:21 PM - 28 Dec 2009
     
Twitter
Sager Creek
@SagerCreek
What’s the strongest vegetable? A: A muscle sprout!
9:08 AM - 20 Jul 2010
 
Google Books
101 Amazing Food Jokes
By Jack Goldstein
Andrews UK Limited,
2013
Pg. ?:
What’s the strongest vegetable?
A muscle sprout!
 
Google Books
Justin’s Chuckle Time
By Justin Fletcher
London: Faber & Faber
2013
Pg. ?:
What’s the strongest vegetable?
A muscle sprout.