Metal Halide during flowering to increase potency.
by, 03-13-2011 at 11:55 PM (5373 Views)
Tricks of the tradeOriginally Posted by zues via riddleme
Delving through the history of marijuana cultivation you will find a myriad of techniques used to supposedly increase THC production. Much of this is little more than hippie folklore, but over the years some techniques have appeared which seem based on some amount of science.
Although some of the younger growers these days may never have used a metal halide light, many of the older set still swear by them as a complement to high-pressure sodiums in the flower room. With the advent several years ago of the Son-Agro HPS bulbs and others like it, which offer a higher amount of blue in the spectrum than standard HPS, many growers have felt that that they can do away with metal halides altogether. Growing strictly under sodiums has its advantages in terms of yield per watt, but is still lacking as far as a balanced spectrum when compared to a mix of HPS and halide.
Anyone that has ever seen a mixed light garden can testify that the healthiest, most crystallized buds occur where the two spectrums overlap. Again this brings us back to the UV factor, as metal halide bulbs emit a fair amount of UV while HPS emit almost none. Most growers employing halides in conjunction with HPS do so at a 2:1 HPS:halide ratio. Many growers, especially those restricted to one light, have been having good success using one of the new enhanced metal halide bulbs such as Sunmaster, which have a more balanced spectrum than either sodium or regular halide alone.
Glass and plastic materials used in greenhouses and air/water cooled light reflectors will block most useful wavelengths of UV from reaching plants. Luckily, recent research has shown that allowing UV to enter the greenhouse has many advantages on non-cannabis crops, and so some European greenhouses are beginning to switch to UV transparent glazing materials. Trade names for some of these products are Planilux, Diamant or Optiwhite. Plastic made from polymethylmethacrylate (PMMA) also transmits UV-B (the type that we are looking for). Traditional greenhouse coverings such as polyvinyl chloride (PVC), fiberglass, polycarbonate or regular glass allow little if any UV-B transmission.9
Harvesting in the morning ensures that your plant will be at peak THC content, as cannabis has shown THC fluctuations peaking in morning and dropping during the day. Some growers leave their lights off for several days before harvest to increase potency. This seems to have some scientific validity as light has been shown to degrade THC, hence the morning peaks. As light is the degrading factor and the plant still has the ability to manufacture THC during darkness, leaving the lights off for a day or two before harvest likely utilizes the plants stored potential for THC conversion without any opportunity for it to be degraded into cannabinol (CBN) and other breakdown products.8
Traditionally marijuana has been harvested when the pistils die and the calyx starts to swell into a false seed pod. These days the best growers are getting much more detailed in their harvesting criteria. They take a close look at the trichomes themselves to judge peak harvest. Evidence that this is the only real way to tell peak maturity is in Sagarmatha's strain Matanuska Tundra, which ripens resin glands while most pistils are still alive and white. This seems an odd twist of evolution but proves that the pistil color and ripe glands do not necessarily have any correlation.
A small 25x or more pocket microscope, which can be picked up inexpensively at any electronic store, works well for taking a closer look at trichome development. What we are examining are the capitate stalked glandular trichomes, which will be a round gland head supported on a stalk. The coloration of these gland heads can vary between strains and maturity. Most strains start with clear or slightly amber heads which gradually become opaque when THC levels have peaked and are beginning to degrade. Regardless of the initial colour of the resin head, with careful observation you should be able to see a change in coloration as maturity levels off.
Some cultivators wait for about half of the heads to go opaque before harvest to ensure maximum THC levels in the bud. Of course nothing tells the truth more than your own head, so try samples at various stages to see what's right for you. While you may be increasing the total THC level in the bud by allowing half of the glands to go opaque, the bud will also have a larger proportion of THC breakdown products such as CBNs, which is why some people prefer to harvest earlier while most of the heads are still clear.
Indica varieties usually have a 1-2 week harvest window to work with, while Sativas and Indica/Sativa hybrids may have a much longer period to play with.
With the growing popularity of personal hashmaking through precision screening, many growers are starting to pay closer attention to the development of glands. The use of different size screens to separate glands of different sizes can only broaden our knowledge of the subtle nuances of trichome quality.
Growers using the same clone line over many crops have an excellent opportunity to play with some of these different techniques, as the main variable will be the environment, not the plant. Keep in mind that different strains may react very differently to the same techniques so be careful about drawing general conclusions.
marijuana growers must look closer at their crop than the average farmer to achieve a premium product. Rows upon rows of beautiful plants are of no use if they do not glisten with the THC-laden trichomes that are the object of our quest.
Nurture your trichomes and feed your head!
WHAT I HAVE FOUND OUT IS THAT IF U USE A MH BULB ALL THE WAY THREW MEANING UR FLOWERIN WITH IT ALSO U WILL HAVE SOME CRAZY DANK STICKY ASS POTENT BUDS.
1) Starks, Michael. 1977. marijuana Chemistry Genetics, Processing and Potency. Ronin Publishing, Inc., Berkeley, CA pp. 17-86.
2) McParland, Clarke, Watson. Hemp Diseases and Pests; management and biological control, CABI Publishing, New York, NY
3) Pate, DW, 1994. Chemical ecology of Cannabis. Journal of the International Hemp Association 2: 29, 32-37.
4) Kutscheid, 1973. Quantitative variation in chemical constituents of marihuana from stands of naturalized Cannabis sativa L. in east central Illinois. Economic Botany 27: 193-203.
5) Bócsa, Máthé and Hangyel. Effect of nitrogen on tetrahydrocannabinol (THC) content in hemp leaves at different positions. 1997. Journal of the International Hemp Association 4(2): 78 -79.
6) Helen Philbrick and Richard B Gregg. Companion Plants and How to Use Them. 1996. Devin-Adair Company, Old Greenwich, CT.
7) Oldtimer1, 2001. Personal communication
Vic High, 2001. BC Growers Association. Web site and help desk.
9) Hoffman, Dr Silke. 2001. Ultraviolet radiation in the greenhouse. Floraculture International, May 2001. Ball Publishing, Batavia, Illinois. pp18-27.
• An excellent general reference is marijuana Botany, by Robert Connell Clarke. Ronin Publishing, Inc. Berkeley, CA