Figure 10.

Recovery of fungal species from samples of unsterilized coconut fiber (coco) used in the hydroponic cultivation of cannabis plants. Samples were diluted in water and plated onto PDA+S. (A) A diverse range of Penicillium and Aspergillus species were recovered from unused coco bags. (B) Colonies of Aspergillus niger (black) and Aspergillus terreus (pink) present in coco samples. (C) Proposed scheme through which molds found in growing substrates could be air-borne and spread to the inflorescences, or grow internally in the pith tissues of the stem. (D, E) Microbes present in coco substrate at the beginning and end of the production cycle include species of Aspergillus (red colonies), Penicillium (blue-green colonies) as well as a range of uncharacterized bacteria. (F) Colonies of Fusarium oxysporum emerging from coco substrate used in cannabis production, showing complete colonization of the medium by the end of the 10-week production cycle as a result of build-up of inoculum.