Hi, this song drives me crazy!  The one line I kind of remember is
"sweetest on the vine" or something like it and the song is about a
guy and two sisters.  And yes, you guessed it one of the sister was
the "sweetest on the vine"

Thank you

Hi just4fun! 

The song you have in mind is Mary's Vineyard by the artist Claude King.

Here are part of the lyrics to the song Mary's Vineyard:

?The grapes in Mary's vineyard are the sweetest on the vine
Old man Oscar Dill lived back in the Tennessee hills
He's got him two or three stills and he makes heavy water
Oh I worked for him one time runnin' sour mash across the line
And he warned me to pay no mind to his three daughters
Yeah one was eighteen and one was twenty two one was just my age
One by one I opened the door to the gilded cage (yes I did now)
He don't know and I ain't gonna tell him what I've done one time
Cause he thinks he raised three little angels ah I think that's fine
I made love to his sweet Martha and pretty little Caroline
But the grapes in Mary's vineyard are the sweetest on the vine?

See the complete lyrics here:
http://www.stlyrics.com/songs/c/claudeking22815/marysvineyard616368.html

Or here
http://64.233.167.104/search?q=cache:n4H6ZcI8NaoJ:www.lyrics007.com/Claude%2520King%2520Lyrics/Mary%27s%2520Vineyard%2520Lyrics.html+%22sweetest*+*+vine%22+LYRICS&hl=en


Buy the CD at Amazon
Wolverton Mountain: Very B.O. Claude King 
Track 15: Mary's Vineyard
http://www.amazon.com/exec/obidos/ASIN/B00000JWR7/qid=1092859578/sr=ka-1/ref=pd_ka_1/103-4687575-5498207
 
Search terms used:
"sweetest* * vine" LYRICS

I hope this helps!

Best regards,
Bobbie7

YEAH THAT'S IT!!  The time I have spent thinkin' about that song.......  Great job!

Thank you very much for the nice rating and generous tip!

Regards,
Bobbie7