check when nights are ~10+ hours in your region or so and then add 9+ weeks. wihtout knowing exactly when it is "enough" for that plant, it's a bit of a guess. maybe, breeder has good info? find harvest month and work back from there 9+ weeks and see how long the nights are around then...
it's a mobile nutrient and yellowing from tip in. i'd guess nitrogen. give a good feed - noting extra or crazy. but if yo alternate or something, maybe double up one cycle -- type thing