Baud mentions that fig need mainly potassium. Adding nitrogen will encourage vegetative growth and slow down or even completely prevent ripening. I am also looking for high P-K ratio fertilizers for next season, as on my in ground unknown this year i had one single fig get close to ripening, while the bush has 7ft branches and many green figs that will not make it. I was feeding it a 14:7:21 ratio water soluble since it had severe frost damage last winter, but now I think that nitrogen was too much.
My potted plants are too small to produce fruit so i gave thrm the same fertilizer to grow leaf.