The Cannabis Grow Bible. Greg GreenЧитать онлайн книгу.
research shows that the average potency of cannabis in the United States has increased very little. According to the Federal Potency Monitoring Project, in 1985 the average THC content of commercial-grade marijuana was 2.84 percent, and the average for high-grade sinsemilla in 1985 was 7.17 percent. In 1995, the potency of commercial-grade marijuana averaged 3.73 percent, while the potency of sinsemilla in 1995 averaged 7.51 percent. In 2001, commercial-grade marijuana averaged 4.72 percent THC, and the potency of sinsemilla in 2001 averaged 9.03 percent.40
Breeding for Desirable Traits
Because of the large-volume, high-yielding, resinous, potent, high calyx-to-leaf ratio, and high trichome production of a dioecious population of female-only plants for sinsemilla there is accordingly an increase in and refinement of the strains available to the cultivator—although tried and tested clones are maybe far more appropriate for those who want to get going immediately. For this reason, most growers are concerned with obtaining gynodioecious-resistant clones that meet the standards the grower wants from the genetic material. The grower will probably not want to be concerned with breeding for cannabis seeds (nuts or achenes) but is interested in C. indica species or subspecies indica/sativa hybrids; they will probably exclude most sativa because it is an expert plant to work with and unsuitable for anything less than a very sizeable growing area with longer flowering times. The cultivator will automatically stay away from hemp or from “auto-flowering” ruderalis in order to have sinsemilla results, although there is consideration for outdoor ruderalis/indica hybrids where the grower can only grow an auto-flowering cannabis strain because of short flowering seasons.
After harvesting growers manicure their bud. This is a tight cut that even ends up revealing some stem.
Working with dioecious populations is the common practice. A high calyx to leaf ratio of female flowers is the telltale sign of useful drug cultivars, if potent. Taste, smell, observable attractive traits, yields, and ease of manicuring are usually secondary appreciations after potency. The existence of the monecious types is for the production of hemp-related products, while dioecious types include both recreational and medical drug uses, and are also used in textile production for fiber. Note that there is a danger of casually associating some de-drugged hemp with normal cannabis hemp. We do not want to deal in detail with monecious individuals or populations.
Understanding Sex Determination Systems
Cannabis has been widely studied with regards to its sexual systems because of observable and repeatable sex reversal conditions.41 The usual expectancy of an XY sex-determination system was confirmed in 1924 by K. Hirata,42 but was disputed by J. H. Schaffner in 1925, who found through his own sex reversal studies in hemp that an X:A system was present and highly influenced by environmental conditions. 43 There is doubt over how the XY system occurs in cannabis, with statements that the Y chromosome is slightly larger than the X being difficult to distinguish.44 What is important to understand is that cannabis may be stressed to express all forms of sex within the same population.
Most strains that you will come across are the result of human intervention. Breeders try to produce strains that are tasty, smell good, and give the user different types of highs. Good strains are widely sought after by growers because you can be guaranteed that the seller of the seeds knows a great deal about the plant and its particular history.
Sativa
Height—Tall, averaging between 4 and 15 feet
Nodes—Long internodes between branches, 3 to 6 inches
Leaves—Thin, long, and pointy leaves with no markings or patterns
Blades—Usually between 6 and 12 blades per leaf
Indica
Height—Small, averaging between 6 inches and 4 feet
Nodes—Short internodes between branches, 3 inches and less
Leaves—Wide, short, and rounded leaves with marble-like patterns
Blades—Usually between 3 and 5 blades per leaf
Ruderalis
Height—Small, averaging between 6 inches and 4 feet
Nodes—Very short internodes with much branching
Leaves—Small and thick
Blades—Usually between 4 and 6 blades per leaf
Ruderalis is hardly used today. Sativa and Indica are extremely common and these two species will be the main focus of this book. Indica and Sativa species produce different forms of high. The high of each species can be controlled by the time at which you harvest. In addition, they can be crossed to produce Indica/Sativa hybrids. This may sound confusing, but it is in fact quite simple and will be further explained in Chapter 15.
LEAF TYPES
Indica
Mostly Indica
Indica / Sativa
Mostly Sativa
Sativa
Ruderalis
A Word About Male Potency
In general, the male plant is considered inferior. This, however, may not be true in all cases. Male plants from some strains can produce more THC or be more potent than females from weaker strains. Most male plants from good genetics are stronger than the Ruderalis female. Males can also be smoked45 (not advised) or made into hash oil.
The Life Cycle of the Marijuana Plant
The marijuana plant grows in three main stages: germination, vegetative growth, and flowering. There are also three additional sub-stages in the marijuana plant’s life cycle. Here we describe the complete life cycle of the cannabis plant in brief.
Germination
PLANT TYPES
Sativa
Ruderalis