Yes this acually will throw the plant in an emergency crisis mode it will dump tricrome on those buds. Out door crops don't need the extended dark period, and it isn't a common practice with an outdoor grow because of the difficulty providing a compleatly dark enviroment outdoors. When creating darkness it needs to be as dark as night under a box, some light will find its way through, can you imagine someone trying to do this with a 100 plant patch? I understand we are talking about 1 plant, it will be benificial to some very small extent, try a 55 gl barrel if you are convinced it will do some good. I myself probably would concentrate more on getting it cut in the morning before sun-up, to prevent un flushed chem nutes stored in the roots, to travel. Get it before they make their journey back to the buds. This practice will probably benifit you more than a extended dark period on an outdoor grow. I have done it with a single plant, however it was not easy, like I said i flipped a 55 gal drum upside down and used that. The diffrence was a barely noticible. I have not repeated it.