Fig. 13

Assessing trichome maturation in cannabis. a Changes in translucency and b changes in red score in trichome heads of genotype “Hash Plant” progressing from 3 weeks to 7 weeks of the flowering period. A sharp reduction in translucency and a rise in red score can be seen. c Bract tissues in week 8 of the flowering period in which reddish-brown stalked-capitate glandular heads can be seen (arrow), especially on the lower half of the bract. d A representation of the proportion of glandular heads that are clear (blue circles), translucent (white circles) and red-brown (red circles) using the CIELAB color space. e Comparison of the appearance of stalked-capitate glandular heads under visible light (left) and under UV light (right) showing blue autofluorescence that is associated with the glandular head. f Close-up of glandular heads with an enhanced exposure showing autofluorescence under UV light. Some aggregation of the glandular heads due to resin secretion can be seen (arrow)