“Why shouldn’t you tell a secret in a cornfield?”/“Because the corn has ears.”

A corn riddle is:
   
Q: Why shouldn’t you tell a secret in a cornfield?
A: Because the corn has ears.
 
The corn pun is an old classic. “Tell not your secrets in a corn-field; it has thousands of ears” was printed in the New York (NY) Ledger on October 24, 1863.
   
             
24 October 1863, New York (NY) Ledger, “Wit and Wisdom,” pg. 3, col. 5: 
TELL not your secrets in a corn-field; it has thousands of ears.
 
28 January 1864, The Perry County Democrat (New Bloomfield, PA), pg. 2, col. 6:
Tell not your secrets in a corn-field; it has thousands of ears.
 
30 July 1868, The Youths’ Companion (Boston, MA), pg. 124, col. 3:
AN AGRICULTURAL CONUNDRUM. Why should a man never tell his secrets in a corn-field? Because it has so many ears.
 
4 September 1869, The Saturday Evening Post (Phlaldelphia, PA), pg. 6, col. 3:
Never tell your secrets in a cornfield, for it has a thousand ears.
 
Google Books
15 July 1870, To the Stranger in the Tyrol, pg. 11:
Never tell your secrets in a cornfield, for it has a thousand ears.
   
Google Books
Encyclopedia of Wit and Wisdom:
A Collection of Over Nine Thousand Anecdotes
BY Henry Hupfeld
Philadelphia, PA: David McKay, Publisher
1897 (Originally published 1877)
Pg. 232:
WHY should a man never tell his secrets in a corn-field ? Because it has so many ears.
 
Google Books
American Proverbs:
A Study of Texts and Contexts
By Wolfgang Mieder
Berlin, Germany: P. Lang
1989
Pg. 94:
Never tell a secret in the cornfield ‘cause the corns got ears.
   
Google Books
Happy Smile:
Jokes for Kids
By Adam Smith
Lulu Press (Lulu.com)
2017
Pg. ?:
Q: Why should you never tell a secret in a corn field?
A: Because there are too many ears.
 
Twitter
On Reflection‏
@onreflectweets
Where should you never tell a secret?
Near a cornfield. There are ears everywhere.
@edfringe #BadJokeFriday #NationalPopcornDay
9:02 AM - 19 Jan 2018