Thank you Michael.
No secrets !
A) On the cutting start up, I believe that the willow tea solution soaking helps..
B) Then when moving to the first up-potting, have used a mix of roughly 70% universal potting soil, 20% worm castings and 10% perlite plus two coffee spoons flat of soluble iron oxide wrapped in 2 pieces of kitchen paper, 4 inch deep diametrically opposed and near the pot wall...Early spring ALL new figs react very positively to this treatment with good visible growth...
C) Two to three week later, some fertigation (every other week) a solution of 5-8-10 + micros - 30 ml per 12 litre water applied on the moist soil
D) Optionally, instead of (C), I am using on other figs 60%-30%-10% + the iron as above and for fertigation a solution of P-K 13/14 + micro elements , same 30 ml per 12 litre water, on moist soil
I am inclined to believe that the worm castings and the iron oxide together seem to boost plant growth and some degree of robustness and immunity (?) to the plants.
Next season on next up potting I shall be adding some natural limestone.
Francisco