Monoecious Strains

Marijuana plants are often hermaphrodites. Male flowers will frequently sprout forth on female plants, particularly under adverse conditions, and strains are known in which nearly every plant contains both sexes. Such monoecious strains have been specially developed for fiber production because they yield a uniform crop which matures simultaneously (the males of dice-, cious strains usually die about one month earlier than females). The monoecious strains contain little THC even hermaphrodites from mostly dioecious strains are of the low THC, high CBD variety (see tables 4 and 5). It seems that it should be possible to develop high THC monoecious strains as well. One monoecious female Thai plant had 2.5% THC and 0.3% CBD, while a male of the same strain had 2.1 and 0.4%, respectively. 

It should also be kept in mind that the designation of a plant as monoecious is often rather arbitrary, since fnany individuals have few male flowers. Hemp breeders have also developed seeds which will yield nearly 100% females (produced by crossing two highly inbred strains). 

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It is possible, by selective pollination, to obtain seeds which yield all (or nearly all) males or females. This can be done by crossing with certain monoecious strains, or by a simpler method available to almost anyone. If the male flowers that arise on a female plant are used as the pollen source, the resulting seeds will all be females. If the plant does not do this naturally, there are various techniques for inducing the monoecious conditions, such as low light, low night temperatures, stress, and spraying with Ethrel. These techniques will be discussed in more detail in future chapters. 

Comparison of Monoecious Plants with Females of Same Strain... 

Medium and low THC strains of monoecious fiber hemp cultivated in France showed approximately parallel changes in CBD and THC during growth [Physiologia Vegetale 1 349 (1980)]... 

A study of five monoecious fiber strains grown in France showed two cannabinoid types one with 0.34% THC and... 

Chestnut trees are typically monoecious, but chestnut is self-incompatible, which makes cross-pollination a necessity for crop production. Recognition of the incompatible and compatible strains in an early stage of development is essential for the planting of economically valuable chestnut gardens. 

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