Hit em with several UVB bulbs last several weeks & cut back on H2O…lower humidity to <35%, they’ll wish they had sunblock…they do
Trichomes!!!
Proven to increase THC not CBD, etc.
MaximumYield
“Like just about everything else on planet, cannabis plants are damaged by too much UV light. That’s why a cannabis plant will create more trichomes to protect itself if there is an increase in harmful
UV-B rays. As such, supplementing UV-B light using UV-B fluorescents (commonly sold at pet stores for reptiles) in a
flowering room can help boost trichome production, 2 power draw watts per sq/ft.)
OR
Article:
Horticulture •
Techniques
Cannabis Under Stress Produces More THC
April 3, 2020
Quote: UVB works
Another example is ultraviolet-B (UV-B) radiation, which can easily destroy plants in sufficient quantities. But in small amounts during flowering, UV-B light boosts THC accumulation in cannabis, an act of self-protection reminiscent of sunscreen. [2,3]
Mansouri et al [4] applied
abscisic acid (ABA), a sesquiterpene that acts as a plant hormone, to flowering cannabis plants. ABA inhibits growth and is produced by plants in response to environmental stressors, including (but not limited to) drought, UV radiation, cold, and salinity. [5] After exogenous application to cannabis, the researchers noted increased THC and α-tocopherol but decreased chlorophyll, carotenoids, and phytosterols. [4]
&
One recent study applied controlled drought to flowering cannabis plants. [1] The researchers withheld
fertigation for 11 days starting at week 7 of the flowering period. This increased tetrahydrocannabinolic acid (THCA) by 12% and cannabidiolic acid (CBDA) by 13% compared to the well-irrigated control. THC and CBD yields per unit growing area were 50% and 67% higher, respectively.
And finally a goody study done yrs ago:
UV-B RADIATION EFFECTS ON PHOTOSYNTHESIS, GROWTH AND CANNABINOID PRODUCTION OF TWO Cannabis sativa CHEMOTYPES
JOHNLYDON~.A*L, ANH. TERAMUaRnAd 'C. BENJAMICNOFFMAN~ 'Department of Botany, University of Maryland, College Park, MD 20742, USA,,2USDA-ARS, Southern Weed Science Laboratory, P.O. Box 350, Stoneville, MS 38776. USA and 'USDA-ARS,
Weed Science Laboratory, AEQ. I, Beltsville, MD 20705. USA
(Received 29 August 1986; accepted 24 February 1987)
Abstract-The effects of UV-B radiation on photosynthesis, growth and cannabinoid production of two greenhouse-grown C. sativa chemotypes (drug and fiber) were assessed.
Excerpt: “Only capitate-sessile and capitate-stalked glands contain cannabinoids, with stalked glands containing > 7 times more cannabinoids than sessile glands (Mahlberg et al., 1984). Capitate-stalked glands are only present on bracts (and associated leaves), cover over 70% of the surface area of bracts, and contain 100% of the cannabinoids in these tissues (Mahlbert et al., 1984). Thus, the UV-B absorbing cannabino- ids may be important in preventing this actinic radi- ation from penetrating ovary tissues. If so, populations of C. sativa which express UV-B enhanced cannabinoid production (as demonstrated with the drug chemotype) may have more repro- ductive success in high UV-B radiation environ- ments. This may account for the distribution of these chemotypes in temperate and tropical environ- ments as reported by Pate (1983). It should be pointed out, however, that one should be cautious when extrapolating from greenhouse to field con- ditions in UV-B studies. In addition, when consider- ing the distribution of C. sativa, one cannot overlook the fact that it is one of the oldest culti- vated plants known to man. Thus, its present distri- bution may possibly be an artifact of man’s cultural practices.
In conclusion, the A9-THC content in leaf and floral tissues of greenhouse grown drug-type C. saliva increased linearly with UV-B dose”
Here I MO our humidity is terrible six months out of the year, so I finally bought a dehumidifier for my flowering stage.
These are the UVB bulbs I use—I’ll runner four of them and Dual bulb hangers, about 12” from plants moving them daily for exposure.
UVB 150W $26 @Petsmart.
www.edrosenthal.com
www.google.com
