ABSTRACT
Because Cannabis is a difficult plant in which to fix traits through selective breeding, and often only the fem ale plants are of econom ic importance, m odern m arijuana growers have found that it is advanta geous to clone exceptional plants by rooting stem cuttings. In this way practically unlim ited num bers of identical select plants can be grown. Besides circum venting the vagaries o f genetic recom bination, cloning can produce uniform crops of female plants in one genera tion. Clones of valuable m ale plants can also be preserved for pollen production in breeding program s. Vegetative clone libraries are m aintained under artificially created long day length.