it was made to increase spinach comsumption due to his low price, easeness of serving/packaging and nutritive values. AFAIK, this wasn't made up by farmers, but US government itself. Popeye was the stereotypical propaganda hero, later, he was used by UK propaganda as well
http://www.imdb.com/title/tt0152556/
http://www.mtcnet.net/~bierly/popcarball.htm
http://www.abc.net.au/science/k2/moments/s301760.htm
however, there's a theory about spinach being another name for marijuana, which is quite funded. Either way, the first Popeye's strips had little use of spinach, and it became a central feature of the character in 1931
woot-wooooot!!
