Глава 27. Advanced Flowering

 

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 location. Every year the ratio of dark to light remains the same at a particular 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 enzyme 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 interrupted 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 variations 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, irregular 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 fully, 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 determinate” (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 triggers 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 affect 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 photosensitive 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.

 

 

 

 

 

 

 

 

 

 

 

 

Глава 28. Breeding

 

Humans have been breeding marijuana informally for thousands of years. The first farmers chose seeds from the best plants. Over many generations the plant was differentiated into varieties which had different uses and thrived under various environmental conditions. Scientific breeding did not begin until Gregor Mendel's experiments on inherited characteristics were discovered. Mendel crossed peas with differing characteristics and found that the off- spring plants inherited traits from their parents in a logical, predictable, statistical way. Today we know that each cell contains a set of chemical blueprints regarding every aspect of its existence. These chemical codes are called chromosomes and they consist of long double strands of sugar which have bases" consisting of one of four amino acids. Sets of three of these amino acid bases form genes which are read" by structures in the cell and direct it in its life processes. Chromosomes are found in pairs in most cells. Half of each pair of chromosomes is contributed by the male through pollen and half by the female. Marijuana has 10 pairs or 20 chromosomes. Each chromosome's genes are lined up in a specific order. The other member of the pair has a corresponding gene in the same location. Sometimes, a single gene is responsible for a characteristic. In other cases, several genes are responsible, often in a complex series of reactions. There has been very little formal genetic work on marijuana. Almost all of the research is the result of observation by cultivators. However, the cell and its chromosomes are easily observed using a high-powered microscope. Even an inexpensive instrument allows one to see the chromosomes during mitosis (cell division). The chromosomes line up in pairs and then reproduce themselves as the cell splits into two. When reproductive cells are produced, the pairs of chromosomes split and only one chromosome of each pair goes into each reproductive cell. (Photographs can be taken with the aid of a 35 mm SLR camera and an inexpensive adapter tube.) About 2% of the time, the genes jump" from one member of the pair of chromosomes to the other. This is a significant fact in breeding because it gives individual chromosomes a means of changing information regarding the characteristics for which they are coded. Breeding would be a relatively simple task if only one trait or characteristic were involved. However there are many factors to consider when choosing plants for breeding. These include: potency, taste, aroma, color, maturation time, yield, height, branching habits, adaption to low-light conditions, resistance to pests or diseases, leaf drop at maturity, and sterility. When a plant breeds true" it means that most of the corresponding genes on each of the pairs of chromosomes of the 10 pairs have the same information. However, plants of different varieties which are crossed are hybrids, and many of the corresponding genes on the two sets of chromosomes have information which is in conflict. For instance, the first generation cross (an F1 hybrid) may contain genes from one parent programmed for tall plants and genes from the other parent programmed for short stature. In this case the plants all have approximately the same height, intermediate between the two parents. When two F1 hybrids are crossed, however, the plants are either tall, intermediate or short. The reason is that some of the plants have genes for tallness, some for shortness and others for both. Many of the important characteristics of marijuana seem to be coded for partial dominance" as was just described. Aroma, taste, and potency seem to fall into this category.

When more than one gene is involved, there can be enormous numbers of possible combinations. Some characteristics are coded on genes which are either dominant or recessive. According to Robert Connell Clarke, author of Marijuana Botany, tall height, un-webbed leaves, green rather than purple coloring on calyxes (seed bracts), and large-size seeds are all dominant genes. A cross between two plants with conflicting genes would result in the F1 generation all showing the dominant trait. A cross between two F1 plants results in a majority of the plants indicating the dominant trait and only a few, those without the dominant gene on either chromosome, indicating the information found on the recessive gene. It is difficult for the hobbyist or grower to institute a scientific breeding program because thousands of plants must be grown to find one specimen which meets ideal breeding requirements. Growers have a limited amount of space to devote to the plants and thus have trouble sorting out the crosses. Cultivators can select the best plants in the garden for breeding. Sometimes a plant has one outstanding characteristic but is unexceptional in other respects. This characteristic can be introduced into the breeding pool and then the undesirable traits can be sorted out". Marijuana is especially difficult to breed scientifically because half the plants, those bearing pollen, carry genetic information for hidden factors. An observer has few means of judging the genetic potential of male plants regarding yield, bud structure, and even potency. There is some correlation between the male's potency and that of its daughters. One way to solve this problem is to induce male flowers on female plants. Then the characteristics of both parents are known and all the resulting plants have only female chromosomes. As in humans, gender in cannabis is determined by the X" and Y" chromosomes. The female has two X chromosomes and the male has one X and one Y. When the male plant produces pollen, half of the reproductive cells receive X and half Y. However, when male flowers are artificially induced in female plants, the pollen contains only X chromosomes, the only sex chromosomes the female plant has. All the resulting seeds contain two X chromosomes, one from each parent. To induce male flowers in female plants, the plants are sprayed with gibberellic acid or watered with an aspirin/water solution. Gibberellic acid is a plant hormone originally isolated from mold-infested rice. Symptoms of the infection include extraordinary vertical growth. Gibberellic acid affects plants in a variety of ways. In marijuana, it causes extension of all stems on which it is sprayed, and if used before flowers develop, it occasionally induces sex reversal" in females: male flowers develop on sprayed areas. The plant's genetic structure remains the same; however, the sex characteristics are altered. In a general way this is similar to a sex change operation; the genetic information contains information for one sex, but the hormones which are introduced by pill or injection artificially induce physiological changes in the body, including development of the other sex's sexual characteristics. Several correspondents have described the results of adding aspirin to their water. One grower used two aspirin in a gallon of water when the plants were in their third week of flowering. He said that the plants grew thousands of pollen sacs which contained fertile pollen. The most methodical way to breed marijuana using these substances is to allow the plants to flower after taking several clones from each plant. Once the plants are harvested, cured and tested, the cuttings of all except those plants selected as the best for breeding are eliminated. When the plants are large enough to pro- duce adequate amounts of seed for the breeder's purpose, some of the plants are kept as females, and male flowers are induced in others. Then the plants are bred. The first step involves gathering the pollen. Since cannabis is usually wind-pollinated, it produces an abundance of pollen which floats easily in the air. The male plants are placed in a separate draft-free location and the pollen drops onto unprinted paper placed underneath the plant. However, if there are several plants in the same room, the different plants' pollen may become contaminated with each other. If the plants are bent or turned on their sides so that the pollen has to drop through less air, more pollen collects. Plants placed in a cardboard box are even less susceptible to draft. Some growers collect pollen by cutting the flower spikes off the plants just as the flowers are to open. These spikes are placed in a paper bag so no pollen is lost. Pollen can also be collected by placing a white paper bag around flower spikes. White paper is used so that light rays are reflected rather than absorbed by the bag and turned into heat, which may damage the plant. Non-coated parchment paper breathes and eliminates humidity problems. Once the pollen is collected, the female flowers are fertilized. (If pollen is scarce, it is diluted 10-100 parts by weight with flour). Pollination can be accomplished simply by placing a bag filled with pollen around a bud and then shaking it. The pollen settles for a day or two and then is removed. Another method is to paint" the pollen onto the female flowers using a small watercolor brush. One grower insists that it is easiest to pollinate using your fingers. The best time to pollinate marijuana is when the flowers are well developed but still fresh, and have gone through several stages of growth and filling out. Breeding is a very detailed subject and this is just a cursory discussion of it. For more information, I recommend the book, Marijuana Botany by R.C. Clarke.

 

Глава 29. Сбор урожая

 

Женское растение конопли при цветении проходит несколько стадий. Сперва возникает несколько цветков, остальные появляются вокруг них. Цветы также появляются также везде, где черенки листьев отходят от веток. Бутоны увеличиваются, так что целые участки ветвей (те самые шышки!) становятся толстыми из-за торчащих во все стороны пестиков (длинные ворсистые нити). Пестики обычно белые или бледно розовые, иногда бледно-лиловые. Они выглядят свежими и влажными. Некоторые вянут, окрашиваясь в красный, багровый или коричневый цвет. Как только участок принимает завершенный вид начинается новая волна цветения, обычно на более-менее свободных участках. Такие волны могут наблюдаться в течении нескольких недель, потом цветы закрываются и их чашечки начинают набухать. Это «ложные семена», т.к. цветы не опылялись и нормальное семя произвести не могут. Эти стручки покрыты капельками смолы, которые после достижения полной зрелости блестят под лампой как драгоценные камни. Отдельные капельки под увеличением выглядят прозрачными. Когда они станут янтарного цвета – пора собирать урожай.

 

Разные сорта достигают зрелости по-разному: некоторые сразу полностью, другие постепенно, начиная сверху или снизу. Один заслуженный садовод сказал как-то: «Большинство моих растений созервали снизу вверх, последней – основная верхушка». Под искуственным освещением созревание идет наоборот, сверху вниз. Кстати, наружная сторона ветвей созревает быстрее внутренней. Всего может пройти около месяца пока урожай не будет полностью собран. Если срезать небольшие участки за раз, то на следующие за ними попадает больше света и они быстрее дозревают.

 

Проблемы с урожаем

 

Некоторые экваториальные разновидности требуют так много света для окончательного созревания, что практически невозможно обеспечить эту потребность с помощью только искусственного освещения. В таких случаях цветы вырастают, но их меньше и они полностью открываются в течении нескольких месяцев. Они даже могут не образовывать плтную шишку, а достаточно редко располагаться на стебле. Эта проблема решается только улучшением освещения. Один садовод заметил, что снижение температуры в помещении также способствует образованию более плотных шишек. Из-за вышеперечисленых недостатков ваши шишки могут иметь меньшую коммерческую ценность, но они будут такими же сильными.

 

Обычно растения выращиваемые в помещении менее компактные чем те, которые росли в открытом грунте, но зато они сильнее. Окружающая среда в помещении гораздо мягче и ТГК производится без помех.

 

Плесень

 

Плотные шишки часто атакуются плесневыми грибками, споры которых постоянно находятся в воздухе. В подходящих условиях споры быстро прорастают, а подходящими для них являются: высокая влажность, малая освещенность и температура около 60 F. В открытом грунте эти условия чаще всего реализуются во время сбора, когда температура ниже, а высокая влажность и низкая освщенность реализуются в плотных шишках без проблем. Любое загрязнение или область повышенной влажности легко притягивают споры, и чудесные шишки могут превратится в грибницу или слизь (фу!) всего за одну ночь. При выращивании в помещении образованию плесени также немало способствует низкая освещенность и повышенная влажность. Есть несколько способов осложнить плесени жизнь: выдерживать температуру около 70 F, использовать генератор отрицательных аэроионов для очистки воздуха от спор. Также помогает снижение влажности с помощью осушителя воздуха или просто усиленной вентиляции.