Image shows a male plant after 24 days of vegetative growth at 18/6 day/night. Staminate flowers are located at the node between the stipule and emerging branch.
This is another view of the same pre-flowering male plant so you can get a better view.
out a crop of outstanding buds every six to ten weeks all year long.
Inducing flowering in cannabis grown from seed with a 12/12 day/night photoperiod will cause plants to show sex, male or female. Once the sex of the plant is guaranteed, males are almost always harvested before they shed pollen, and females are coaxed into higher yields. Once the photoperiod is set, disrupting it will cause plants to suffer stress. If they suffer enough stress, hermaphrodite tendencies increase.
Water intake of flowering plants is usually somewhat less than in the vegetative stage. Adequate water during flowering is important for plants to carry on internal chemistry and resin production. Withholding water to "stress" a plant will actually stunt growth and diminish yield.
Removing large fan leaves to allow more intense light to reach small buds or to stress plants is crazy! Large leaves are necessary to keep plants healthy. Indoors and in greenhouses where the hours of darkness are controlled, cannabis flowers for six to ten weeks or longer. This is a very short time. Hacking off branch tips to initiate more budding sites diffuses floral hormones and retards growth. Remove only leaves that are 50 percent or more damaged by diseases, pests, and cultural practices.
Upon pollination, one of the many, tiny grains of pollen from the male (staminate) flower pod, lands on a pistil of the female (pistillate) flower. Female flower tops are a mass of calyxes with each calyx harboring an ovule and a protruding set of pistils. Actual fertilization takes place when the grain of male pollen slides down the pistil and unites with the female ovule deep within the female calyx. Once fertilization takes place, pistils turn brown and a seed forms within the seed bract. Seeds are the result of this sexual propagation and contain genetic characteristics of both parents. In nature there is
The red arrow shows where pre-flowers develop on both male and female plants.
a 50/50 chance for a seed to [produce a male or female plant. Once fertilized with male pollen, female plants put the bulk of their energy into producing strong, viable seeds. When flowers are full of ripe, mature seeds, the female will die, having successfully completed her life cycle. The male completes his life cycle and dies after producing and dispersing all of his pollen into the wind, in search of receptive female pistils.
Pre-flowers, described by Robert Clarke in Marijuana Botany as "primordial," are the first indication of a plant's sex. The pre-flowers grow at branch internodes just behind the leaf spur or stipule about the fourth week of vegetative growth, when the plant is six to eight weeks oid. This is the point of sexual maturity, the first sign a plant is preparing for flowering-the next stage in life.
You can see pre-flowers with the naked eye, but a 10 to 30X magnifier will make viewing easier. You can accurately determine plant sex after eight weeks. Using this method, you can distinguish sex before incucing flowering.
Male pre-flowers are normally visible when plants are six to eight weeks old, after the fourth week of vegetative growth. The pre-flowers emerge behind the stipule at the fourth to fifth branch internodes and generally do not turn into full flowers. But, according to Bongaloid (www.overgrow.com), "a male plant will develop mature staminate flowers after prolonged periods of vegetative growth."
Always wait to induce flowering until after pre-flowers appear. Inducing flowering with 12 hours of uninterrupted darkness and 12
Male pollen sacks hang like little balls Each pollen sac has enough pollen to pollinate all the females in the average grow room.
Early male flowers are easy to spot with the naked eye. They are located at branch internodes.
Botanical drawing of all male parts and overall view of the male flower.
Male flowers develop quickly on the tip of this male plant. Keep an eye out for male plants, and separate them from females as soon as they are spotted.
This male plant is in full bloom. Flowers open over the course of a week or longer to ensure females are completely pollinated.
hours of light before pre-flowers develop will stress the plant. This stress could cause peculiar growth, and plants might develop into hermaphrodites. Inducing flowering before pre-flowers form will not expedite flowering. In fact, flowering will occur at about the same time as if you had waited for pre-flowers to show!
Plants grown from seed under an 18/6 day/night photoperiod will generally show pre-flowers before plants that are given a 24/0 day/night photoperiod. Once pre-flowers are distinguishable as male or female, plants can be induced to flower with a 12/12 day/night photoperiod.
Crains of pollen are miniscule. This close-up of a grain of male pollen is magnified 4000 times. Eirik (www.overgrowxom) captured this image on a scanning electron microscope.
A word of caution from bc-trichome-farmer (www.overg row.com): "Do not try to sex a seedling based on the very first pre-flower. Wait and make sure. The time between using a 25X (loupe) to spot the very first pre-flower and the plant dropping pollen is at least 10-1-days awav, so it's safe."
When given a 12/12 day/night photoperiod, male cannabis reaches maturity and flowers one to two weeks before females. However, male plants do not necessarily need a 12/12 day/night photoperiod to dawn flowers and shed pollen. Males can flower under long days and short nights as well, but they generally produce fewer flowers. Once male calyxes show, pollen develops quickly and can disperse within a very short time. There is always an early opener that sheds pollen, often within 24 hours or less! To avoid pollination problems, remove males as soon as they are distinguished. If growing male plants, always isolate them from females, so they will not be pollinated. See Chapter 5, "Harvest," for more information on harvesting males.
Males continue flowering and shedding yellowish, dust-like pollen from bell-shaped pollen sacks well into the females' flowering stage, which ensures pollination. If you are making seeds, pollinating females too early, before the girls have developed many receptive female pistils, will result in a small seed crop. See Chapter Seventeen, "Breeding," for more information.
Male flowers are about one quarter-inch (6 mm) long and pastel green to yellowish in color. Flowers first develop near the top of the plant. Pollen sacks develop on a short spike and hang in clusters at the base of branches. Gradually, flowers develop towards the bottom of the plant. After two to six weeks of the 12-hour photoperiod, fully formed floral sacks split open and shed pollen.
Males are usually taller than females and have stout stems, sporadic branching, and fewer leaves. In nature, wind and gravity carry pollen from taller males to fertilize (pollinate) receptive females. Male plants produce fewer flowers than females, because one male plant can pollinate many females. Males also contain less THC and overall lower cannabinoid levels.
Males fertilize females, causing them to stop high THC production and start seed formation. Remove and destroy males, except those used for breeding, as soon as their sex has been determined. The instant they show sax, separate male plants used for breeding from females. Do not let them shed pollen. Premature pollen sacks often form and open early or are hidden under foliage and go unnoticed until it is too late. If growing from seed, take special care to ferret out male flowers and plants.
Growers have reported that bouncing the photoperiod around and dynamically raising or lowering the temperature have the effect of producing more male plants. Note that each stimulus involves creating a climate that
This drawing shows the main parts of a female cannabis plant causes plants to suffer stress. Also, the stressful environment does not necessarily turn the entire plant male; it turns it hermaphrodite. The most susceptible plants already have a predisposition to hermaphrodism. See Chapter Sixteen, "Breeding," for more information.
There are several ways to promote male or female plants during seedling growth. (See "Grow More Female Plants from Seed" in Chapter Two). During vegetative growth you can get a good idea of a plant's sex from its genetic background and growth characteristics. The most dependable way to deduce sex is "Cloning for Sex" (see Chapter Three). For a complete discussion, see Chapter Sixteen, "Breeding."
Near the end of norma! vegetative growth, plants grown from seed develop pre-flowers. This is when female calyx formation initiates, and it is not contingent upon photoperiod. It occurs when a plant is old enough to show signs of sexual maturity, about the fourth week of vegetative growth, or six to eight weeks from germination. The pre-flowers emerge behind the stipule at the fourth to fifth branch internodes.
A pre-flower looks like a regular female flower; most have a pair of white fuzzy pistils. Pistils normally form after the light green seed bract part of the pre-flower has formed. Wait until pistils have formed to ensure the plant is a female and not a male. The pre-flowering stage lasts from one to two weeks. A little patience is in order now!
Plants grown from seed under an 18/6 day/night photoperiod will usually show pronounced pre-flowers before plants given a 24/0 day/night photoperiod. And, under a 16/8 day/night regimen pre-flowers show more quickly and are often more
Pre-flowers on this ]Puna Budder' from THSeeds are nearing the end of the pre-flow-ering stage that lasts about two weeks.
The green calyx supports two very small pistils on this pre-flowering 'Flo' from DJ Short.
The pre-flower on this 'Mr. Bubble' female is very easy to spot with the naked eye.
pionounced. Once pre-flowers are distinguishable as male or female, plants can be induced to flower with a 12/12 day/night photoperiod.
Always wait to induce flowering until after pie-flowers appear. Inducing flowering with 12 hours of uninterrupted darkness and 12 hours of light before pre-flowers develop will st'ess the plant. This stress couic cause odd growth, and plants might grow into hermaphrodites. Inducing flowering before pre-flowers form will not speed flowering. Flowering will occur about the same time as if you had waited for pre-flowers to show!
Female cannabis is prized for heavy, potent resin production and weighty flower yield. Ideal female plants grow squat and bushy with branches close together on the stem and dense foliage on branches. In most strains, the first signs of female flowers appear one to three weeks after inducing flowering with the 12-hour photoperiod. Female flowers initially appear near the top of the terminal bud and gradually develop on lower branches starting at the tips and moving downward. Flowers have two small one-quarter to one-half inch (6-12 mm) fuzzy, white hairs, called pistils that form a "V." The set of pistils is attached at the base to an ovule, which is contained in a light green pod, called a calyx. Pistil-packed calyxes form dense clusters or buds along stems. A cluster of buds is often called a top or cola. The masses of calyxes develop rapidly for the first four or five weeks, after which they grow at a slower rate. Buds put on much of their harvest weight as they swell during the last two or three weeks of growth. Pure sativas, including Thai varieties, can flower for four months or longer! Once the ovule has been fertilized by male pollen, rapid calyx formation and resin production stow, and seed growth starts.
'Chocolate Chunk' in early flowering
'Flo' in early flowering
'C/ioco/aie Chunk' in full flower liFTlfi liFTlfi
'Haze Heaven' in early flowering
'Haze Heaven' in full flower
When females' flowering is at their zenith, pistils swell and swell. Soon they change in color, most often from white to amber and, eventually, to reddish brown.
Sinsemilla (pronounced sin-semiya) is derived from two Spanish words: "sin" = without and "semilla" = seed. Sinsemilla is the word that describes flowering female cannabis tops that have not been fertilized by male pollen.
Highly prized sinsemilla buds are the most potent part of any strain, with a proportionately large volume of THC per flower bud,
'Mr. Bubble' in early flowering
'Nebula' in early flowering
'Stinky Pinky' in early flowering
'Shaman' in early flowering
'Nebula' in full flower and it's all smoke, no seeds! Unpollinated female plants continue to flower until calyx formation and resin production peak out; six to ten weeks after turning the lights to 12 hours. During six to ten weeks of flowering, calyxes develop and swell along the stem, yielding more high quality buds than pollinated, seeded flowers.
Make any female marijuana sinsemilla by removing male plants as soon as they are identified. Removing males virtually guarantees that male pollen will not fertilize succulent female pistils. Sometimes a few early grains of pollen are shed by premature male flowers. Pollen dispersed from wild or cultivated male cannabis plants could also be floating in the air. Sometimes a hermaphrodite with a few male flowers will sprout on a predominately female plant. See "Hermaphrodites" in Chapter Sixteen, ^pp Breeding. ; B \
Warfoc/c Passion' in early flowering
Warfoc/c Passion' in early flowering
'Stinky Pinky1 /n full flower
'White Russian ' in early flowering
'Warlock' in full flower
'White Russian' in full flower
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