Conclusions of Caplan's thesis 117 pages long or so
Caplan
Cannabinoid concentration and yield in the dry floral material of cannabis exposed to drought stress at week seven in the flowering stage. T
Conclusions
This study suggested that controlled drought stress can increase the concentration of major cannabinoids THCA, CBDA and the yield of THCA, CBDA, THC, and CBD in chemovar II cannabis without reducing dry floral weight (yield) and irrespective of decreased Pn. These results were achieved by gradually drying the substrate over eleven days until plant WP reached around -1.5 MPa during week seven in the flowering stage. Comparable results can be expected using leaf wilting as a drought stress indicator with fertigation triggered at a leaf angle 50% higher than in its turgid state. This method for administering drought-stress and the results of this study should be applicable for similar varieties of chemovar II cannabis; however, other chemovars or varieties may respond differently.
Yield in the control was 178 ± 9.4 g·m-2 and was 232 ± 18.5 g·m-2 in the drought treatment but yield did not differ statistically between the two treatments (P = 0.06; n = 3). The moisture content of the dried and cured floral material was 8 ± 0.1 % in the control, 11% lower than that in the drought treatment, at 9 ± 0.1 % (P = 0.01; n = 3). Henceforward, the floral dry weight and cannabinoid contents are corrected to zero percent moisture.
Of the analyzed cannabinoids, all were detected in at least one sample, these included: THC, THCA, CBD, CBDA, CBG, CBGA, and CBN. In the drought treatment, only one sample had a detectable concentration of CBG and CBN, and in the control there were no samples with detectable CBN; therefore, comparisons could not be made for these cannabinoids, and the means for CBN were not presented.
The drought treatment elicited a 12% increase in THCA concentration and a 13% increase in CBDA concentration but had no effect on the concentrations of the other detected cannabinoids Drought had substantial effects on cannabinoid yield, expressed as grams of cannabinoid from floral material per unit growing area (g·m-2). In the drought treatment, THC yield was 50% higher, THCA yield was 43% higher, CBD yield was 67% higher, and CBDA yield was 47% higher than in the control
I'd want at least 2 weeks if I could get it.
