What is the shortest night that will keep plants flowering. I am using a 12/12 cycle now. I am wondering if it would hurt anything if I opened my closet to work on the plants near the end of their night.
well this is actually an interesting physiological plant question; at what point does a short season plant flower? there are a few different things to look at. first, MJ is an annual and will partially flower when its good and ready, light time be damned. this is based on genetics and u will have a hard time stopping those genes. but more importantly to your direct question, plants dont have a clock per se but what they tell is the difference between yesterday's light vs todays light. true to their name, short day plants (inwhich MJ is one, corn is another) start to turn on flowering mechanisms when yesterdays light is longer than todays light. as the light time gets shorter, the short season plant flowers more and more because yesterdays light is always longer than todays in the fall of the year. so to answer your question, i dont know what the shortest night will be. i think that question is moot because of the two reasons i give above. hope that answers your question.
So, by your (froggy) reasoning, it would seem that opening the closet near the end of their night would make one day have more light than the previous. Would this slow/stop the flowering? Furthermore, is it sufficient to simply put the plants on a 12/12 cycle for flowering? Would it be better to gradually increase the length of the nights?
well its not MY reasoning but just a fact of plant pathology. with that said, ill say that plant path was many many years ago and the details are fuzzy but let me try to tease ur q a bit. first, a plant has 2 modes, on sun and off sun. there is no partial. ur plant is either on or off, or better yet, day on and night off. so a little bit of sun doesnt just turn a little bit of flowering on, the plant is either in flower mode or its not. second, i dont know if there is any way of totally turning off flowering. u can try to go to 24hrs on/0 hrs off but once u put it into flowering, ive found that its unlikely that one can turn it off unless one wants to chop it down to a nub. i have taking a plant that was once in flower and then harvested then chopped to about 3 inches of stalk. that was thrown under 24hrs light and that reverted back to veg. but to try this with a full grown plant is different. lastly, as to the gradiant of going from light to dark, ive found that there is no diff. in nature, the each different plant has a point at which it switches to flowering from veg state. and with a plant like MJ and all the vari's that it has, i would assume that even vari's have their own point. some plants wont need 12 and some will need 10. what most people do with a hi degree of success (and i have been doing it for many years) is just go from my veg bench of 24hrs to the flowering bench of 12 hrs. no middle ground. the shock doesnt hurt anything that i can tell.