i'd like to step in with the correction that only a few select phenos of MM are actually true AFs, while some are just extremely photoperiod sensitive. if starting from seed, finding and isolating a true af mm can be a challenge in itself as it might take a few packs to find a suitable male and female. once the true af male and female MM's are found, it would be wise to make an f2 generation to isolate this trait and have plently of seeds available for breeding the several generations it is going to take to get a stable AF cross if crossing with a non AF plant.
I had an old thread on this over here in which there were a few discussions about mightymite
http://www.icmag.com/ic/showthread.php?t=66106&highlight=photo+period+sensitive
I had an old thread on this over here in which there were a few discussions about mightymite
http://www.icmag.com/ic/showthread.php?t=66106&highlight=photo+period+sensitive