A current flowering technique becoming more common amongst growers is called light deprivation. Also known as ‘blacking out’ , ‘light dep’ and inducing photoperiod. To ‘light-dep’ a plant is to shorten the duration of the its sun’s light cycle, (done in many different ways) so as to encourage the plant to flower in a time of year that wouldn’t naturally trigger plants to flower outdoors. For instance, by reducing the summer sun to only 12 hours of light to your plant it would trigger the plant to recognize that the end of it’s life cycle is coming and therefore begin it’s flowering/seed production phase of it’s life. Another cycle coming to an end sending the plant into its innate urge to reproduce. Obviously this method of farming is only beneficial growing plants whose flowering cycle is determined by the amount of hours it gets of light and the number of hours it gets to rest and process its food. This technique affords the farmer several benefits. In environments that have a short growing season due to early/late frosts light deprivation allows an outdoor crop to start flowering earlier than ‘full season’ plants therefore allowing for an earlier harvest. Eliminating the detrimental effects of cold and frost to the crop. Multiple crops can be grown each year outdoors in the same amount of space that one crop would be grown in. The third and fourth cycles seem to have a considerably less quantity of flower mass produced than the first two due to the decreasing potency of the autumn/winter sun and warmth. This method also gives the grower the ability to implement supplemental lighting and heating within this new growing environment allowing them the ability to extend their daylight hours when there is less than twelve hours of sunlight whether just to add some extra flowering hours or add even more hours of light to simulate the summer vegetative sun cycle. Some light deprivation supply companies offer lumen meters that automatically turn on your supplemental lighting when light levels go to low sue to foggy mornings, cloudy/rainy days and/or timer systems to control the lighting cycle. There is now the ability to keep your growing situation private under your choice of greenhouse covering materials. Overall , light deprivation gives you the best choice for low energy consumption growing using the free power of the sun while allowing for multiple high yield, high quality crops.
These days growing has a lot to do not only with quality and variety but the time of the season in which you can market your products. Nothing like having a bumper crop of tomatoes at the same time every other farmer just harvested their crop. Instead, by using the control that light deprivation offers to the farmer you can have a high quality crop available when everyone else is just looking at their flower sites just starting to develop and/or your second crop harvested when all the long season growers are just starting to get prepared for the harvest season.
Ok. Sounds great. Whats the drawback? The farmer has to be VERY aware as to make sure that the cycle stays the same every day. This means that if one is to choose a dark period of 7pm to 7am that the plant has to be blacked out EVERYDAY at 7pm and opened at 7 am. EVERYDAY. Let me stress that point. It is the same as an indoor growing environment. When it’s night time, its night time. What you put in to it is what you will get out of it. As well one needs to make sure that there are no ‘light leaks’ in this artificially induced dark room. Lumen meters show that what the human eye sees is not necessarily what the plant sees. Zero lumens, what a plant generally considers very dark, can be achieved while still being able to see things with the human eye. As a matter of fact , the industry standard for blacking out a crop still allows an individual to be able to read a newspaper in! Some of the hardships light dep deals with as well is trying to keep the heat and humidity levels in check in the dark phase so as to not make the plant stretch, mold or get mildews and other diseases due to these levels getting out of check.
Again, it is similar to an indoor growing environment. Sometimes you will need to add exhaust fans or circulation fans to create air movement when the blackout is closed. A good technique is to choose a flowering time that allows you to close the blackout just as it is getting dark and then an hour after it is good and dark retract the blackout. In the morning close the blackout an hour before it gets light out. This allows the plants to be in fresh air the majority of the night and decreasing the amount of time that they are closed in a space. When a grower is choosing a design one should consider a company that automates their systems under greenhouse material or creating a manual system themselves that is covered by an outer layer of greenhouse material. The reason I mention this is that there is nothing like trying to manipulate a long cumbersome piece of plastic that is soaking wet from the rain and keeping it from not snagging and ripping and the like. Some companies offer automated systems to make sure that the timing stays constant and control the hours of the blackout system allowing one to take advantage of this method of allowing fresh air all night to the plants while not tying the grower to the needs of the plants an extra four times everyday.
Breathable, to cut down on high heat and humidity levels, and non breathable blackout fabrics are available by some companies as well. When choosing a blackout material keep in mind the choice of longevity. There are cheap pieces of black plastic that hardware stores sell that can do the trick. But consider that they will trap in all of your humidity and heat and at the end of the season you have a big piece of plastic to throw away. There are materials available on the market that create a superior growing environment and have the benefit of lasting multiple seasons. They are usually more of an investment but good, successful businesses make investments. The idea is that although your lighting is now free from the sun you are still trying to create the ideal ‘indoor’ growing environment. Affording the grower the best of both worlds; the efficiency and quantity of outdoor growing and the control, consistency and quality of indoor growing. Irregardless of the size or level of automation, in today’s market with everybody and their grandmother learning of the self sustaining and viable techniques of farming it is most important for the educated and experienced farmer to look into the future of timing, control, quality and the ability to expand both their crop and their market. From my point of view I feel that light deprivation, and the automation of it so as to create a more abundant, less labor growing situation is the wave of the future. Steer towards the light but come check out what’s happening on the dark side. Maximum results, minimum effort.