The American Heritage® Dictionary of the English Language: Fourth Edition.  
2000.   
    
gunnysack   
    
SYLLABICATION:  gun·ny·sack 
<A HREF="http://www.bartleby.com/61/12.html">PRONUNCIATION</A>:    gn-sk 
NOUN:   Chiefly Western U.S. A bag or sack made of gunny. Also called 
Regional <A HREF="http://www.bartleby.com/61/69/C0756900.html">croker sack</A>, Regional <A HREF="http://www.bartleby.com/61/21/T0292150.html">tow bag</A>, Regional <A HREF="http://www.bartleby.com/61/50/T0295050.html">tow sack</A>. Also called 
regionally Regional <A HREF="http://www.bartleby.com/61/62/C0756200.html">crocus sack</A>. REGIONAL NOTE: A large sack made from 
loosely woven, coarse material goes by a variety of names in regional 
American English. The most general term is burlap bag, known everywhere but 
used especially in the Northeast. In the Midwest and West the usual term is 
gunnysack, which ultimately comes from the Sanskrit word gon, meaning “jute 
or hemp fiber.” In the Upper South such a sack is called a tow sack, and in 
Eastern North Carolina, a tow bag. (The word tow is another synonym for 
fabric made from jute or hemp and probably derives from an Old English word 
for “spinning.”) In South Carolina and adjacent parts of Georgia, it is 
called a crocus sack, and in the Gulf states, a croker sack, both terms 
deriving from the word crocus. According to Craig M. Carver, who draws on the 
research of Walter S. Avis, “Crocus is a coarse, loosely woven material once 
worn by slaves and laborers and common in colonial New England. It probably 
took its name from the sacks in which crocus or saffron was shipped.” Though 
the term crocus sack virtually disappeared from New England by the end of the 
19th century, it survives in the South
    

Growing up just prior to WWII, these sacks were generally not burlap but a 
rough white material that usually has print and other images.  They usually 
contained seed or other agricultural matter.   Called them crocus  sacks.

      Peter in Richmond