Interruption of flowering at 5 weeks

Discussion in 'Advanced Growing Techniques' started by pgrowsoul, Jul 29, 2009.

  1. I read in some random ScrOG guide and have heard that Ed Rosenthal also says that in some cannabis strains bud size can be increased by putting them on a 24/0 or 20/4 regime for 1-2 days at 5 weeks into flower. Anyone ever tried this? Picture comparisons would be sweet!
     
  2. From The SOG/ScrOG Bible(Not sure who wrote it):

    Interrupted flowering

    Also known as ``buddus interruptus'', the procedure is to switch the lights to 24/0 for a day or two about at the end of the fifth week of flowering, when the buds seem to stall out. It should only be done once during the crop, and for no more than two days. The best technique is to switch for one day, wait a couple of days to observe the effect, and then give it one more day if the buds haven't responded. This is not the same as ``double budding'', as the plant is never actually kicked into vegetative growth.

    If the plants react well, you will see tufts of additional flowering parts standing out from the sides of the buds like little towers. Done early enough, these extra parts should finish in time, and they will add extra weight to the crop. This technique can be particularly valuable in scrog, given the large number of smaller buds.

    A caveat is in order, not all plants respond well. Some don't react to the light change at all, and a very few may be disturbed into uncontrolled growth from the tops of the buds. You might be concerned with a tendency for male parts to be produced, but I've been practising this method for a long time, and I've never seen a ``hermie''.
     
  3. Advanced Flowering
    Created by Sam Selgnij
    Copyright 1986 Ed Rosenthal and Sam Selgnij
    In Chapter 25 (Flowering), marijuana's photoperiod response
    was described. Most varieties of cannabis flower in response to
    changes in the light cycle. This is a foolproof method for a plant to
    determine when to flower when it is adapted to a particular loca-
    tion. Every year the ratio of dark to light remains the same at a par-
    ticular date. Scientists think that plants measure the number of
    hours of darkness by producing a hormone, tentatively named
    florigen. This hormone has not actually been discovered. The
    theory is that when the level of this hormone reaches a critical level,
    the plant goes into its reproductive mode.
    Through simple experimentation, we know some interesting
    things about this plant response. It is a localized response by the
    plant. This was discovered by shading one branch of a plant but
    leaving the rest of it without a daily dark period. Only the branch
    that was shaded flowered. (This is a viable technique to use to sex
    plants).
    Researchers think that the hormone is produced by the plant
    continuously. However, it is destroyed or metabolized by an en-
    zyme or hormone which is produced only in the presence of light.
    Under natural conditions, the critical level builds up only with the
    onset of long nights in the autumn. When the dark cycle is inter-
    rupted by light, even for a few minutes or less, the florigen is
    destroyed by the plant and the plant starts the buildup to the critical
    level over again.
    The response to different light cycles is a graduated one. Plants
    that initiate flowering at one light/darkness routine flower more
    heavily when the amount of darkness is increased. This response is
    more pronounced on plants originating from a higher latitude
    where the light cycle changes more.
    Chrysanthemums are also long night-flowering plants, and
    their growth patterns have been studied extensively for use by the
    greenhouse industry. Researchers found that the largest flowers
    with the highest total weight were grown when the dark cycle
    routine was provided each night. When the plants were shaded 6

    nights a week, there was a slight diminution of flower size and total
    weight. With each additional unshaded night, flower size and
    weight dropped.
    Cannabis is one of the most widespread plants. It is naturalized
    everywhere from the equator to the arctic. (Private cannabis
    gardens have also been documented as being grown by scientists
    stationed at outposts in the Antarctic - it's not illegal there since
    no country has sovereignty). The plant has developed many varia-
    tions on the photoperiod response to adjust to different climactic
    and latitudinal conditions.
    Female plants from equatorial or sub-equatorial zones such as
    Colombia, southern Mexico, central Africa, and south India are
    absolute photo-determinate (APD). These plants are acclimated to
    latitudes in which there is little variation in the light cycle
    throughout the year. As long as the dark period falls below a
    minimum trigger period, the plant remains in the vegetative growth
    cycle. This can go on for years under continuous light conditions.
    When the dark period lengthens to a trigger point, the plant
    changes its growth pattern to sexual development. If the dark
    period falls below the trigger level when the plants are flowering,
    the plants easily revert back to vegetative growth.
    APD plants are good candidates to flower and regenerate.
    Since they respond to the light cycle in a relatively simple way, ir-
    regular or interrupted cycles alter growth significantly. Buds are
    smaller, leafier, fluffier, looser, and may run. They look a bit like
    low-light flowers.
    Flower size can be increased by allowing the plants to ripen ful-
    ly, then placing them in a continuous light regimen for a few days.
    Flowering is triggered again and the plants produce new clusters of
    flowers.
    Some cannabis varieties are "relative photoperiod deter-
    minate" (RPD). These plants have a trigger that they respond to
    under normal growing conditions, but when they receive an unusual
    light regimen, they respond to the change in the light conditions in
    unusual ways. For example, an early flowering indica normally trig-
    gers at 10 hours of darkness, but if it is grown under continuous
    light and then the darkness cycle is increased to 8 hours, the plant
    triggers. Once these plants are triggered, the light cycle has less af-
    fect upon them than upon the absolutes. The developing flowers are
    not as sensitive to occasional interruption of the darkness cycle.
    RPD varieties include mid-and high-range latitude-adapted
    plants including Moroccans and southern Africans, early indicas,
    commercial hemp and hybrids developed for early harvest
    (September or earlier).
    RPD varieties are harder to manipulate using the light cycle.
    Plants placed into flowering do not revert to vegetative growth as
    easily as APD varieties. The plants are harder to regenerate. Light
    stress promotes hermaphroditism in these varieties. They are harder
    to clone; they take longer and have a lower success rate.
    Most males and some extreme northern varieties including the
    ruderalis strains fall into a third category which is not photosen-
    sitive at all. Both age and development seem to play a role in deter-
    mining when these plants flower. For example, a Hungarian
    ruderalis developed flowers under continuous light after 8 weeks.
    Most varieties of males indicate under continuous light after 3-9
    months. Thais and some equatorial sativa males are exceptions and
    will not flower until the dark period is increased. Under 18 hours of
    light, males indicate sooner than under continuous light.
    Cold may hasten sexual expression but not flower development
    of some northern varieties.
    Some varieties, especially indicas, respond to unnatural light
    cycles by showing of photo-period response disorder. Genetic
    females turn hermaphroditic when exposed to long dark periods
    during early growth.
     
  4. do you understand how easily that could HERMIE your plant(s)...

    i would guess not too many ppl have tried this method.

    i've eardr of leaving your plants in complete darkness for the last day or 2 before harvest to promote more resin production...
     
  5. #5 pgrowsoul, Jul 29, 2009
    Last edited by a moderator: Jul 29, 2009
    Yes, I think hermie-ism is more likely in plants with unstable genetics but if your using a true breeding F1 strain it would not be likely to occure. I think anyways. I like to experiment so I will give this ago on my FourWay to see what happens. Might not do shit since it is about 1/2 indica/skunk, and a 1/4 rudie, but the rest is sativa so who knows. I will post pics once underway.
     

Share This Page