“Kill the body and the head will die” (boxing adage)

A saying in agriculture is “Kill the root and the head (of the plant) will die.” In boxing, a saying is “Kill the body and the head will die.” That is, punch the other fighter in the midsection to slow him down, and then go for the head and knock him out.
 
The saying has been used in boxing since at least 1935, when heavyweight Joe Louis used the strategy to defeat Primo Carnera.
 
 
Google News Archive
11 May 1935, The Afro American, “Louis in Tip-Top Form on Eve of Carnera Bout” by Russell J. Cowans, pg. 20, col. 2:
Asked by the writer how he intended to fight Carnera, Louis declared, “I will concentrate my attack on the mid-section for the first three rounds and then switch to the head.”
 
This will be following the advice given to him by his trainer, Jack Blackburn, himself a noted fighter of bygone days, and old Sam Langford.
 
Sam told Joe to “kill the body and the head will soon die.” This method was pursued by Langford when he bowling over heavy weights fifteen or twenty years ago.
     
24 October 1946, New Orleans (LA) Times-Picayune, “Hayes Looks Good in Gym” by Pete Baird, pg. 15, col. 5:
“I (Charlie Hayes, a Detroit fighter—ed.) like to punch to the body—you know the old saying, ‘Kill the body and the head will die.’”
 
Google News Archive
23 February 1954, Spokane (WA) Daily Chronicle, “Mario Trigo Favored to Defeat Bob Woods,” pg. 15, col. 1:
Operating on the theory that if you can “kill the body the head will die” Mario Trigo counted heavily on his body attack to cut Bobby Woods of Spokane down to size in the 10-round main event of Promoter Guz Cozza’s boxing card tonight at the armory.
   
2 December 1955, New York (NY) Times, “Sports of The Times” by Arthur Daley, pg. 33:
The farmers have an axiom that boxers have adapted for themselves.
 
“Kill the root and the head will die,” say the agronomists. The Cauliflower Industry has changed it slightly to “Kill the body and the head will die.” Or as they inelegantly yell from the corners, “Sock him in the belly.”
 
Google Books
Victory Over Myself
By Floyd Patterson with Milton Gross
New York, NY: Pelham Books
1962
Pg. 64:
But there’s another battle cry that always should be remembered in the ring. “Kill the body and the head must die.”
 
Google Books
The Complete Book of Boxing
By Gene Brown
New York, NY: Arno Press; Indianapolis, IN: Bobbs-Merrill
1980
Pg. 177:
In the tremendous tempo, Frazier was fulfilling his strategy to “kill the body and the head will die.”
 
OCLC WorldCat record
Kill the body, the head will fall : a closer look at women, violence, and aggression
Author: Rene Denfeld
Publisher: New York : Warner Books, ©1997.
Edition/Format:  Book : English
 
Google Books
The Fight of the Century:
Ali vs. Frazier March 8, 1971
By Michael Arkush
Hoboken, NJ: Wiley & Sons
2008
Pg. 157:
Frazier adhered to the boxing axiom “You kill the body, the head will die.”