so you knew about pollinating aspects of it, huh? i just read this:
While plants under high-enhanced UV-B produced over 40% more flowers than plants under the two lower UV-B treatments, whole-plant production of viable pollen was reduced under low-enhanced UV-B to 34% of ambient controls.
...
Seed abortion rates were higher in plants pollinated with pollen from the enhanced UV-B treatments, than from ambient UV-B. Despite this, seed yield (number and mass) per plant was similar, regardless of the UV-B exposure of their pollen source. Our findings demonstrate that enhanced UV-B levels associated with springtime ozone depletion events have the capacity to substantially reduce viable pollen production, and could ultimately reduce reproductive success of B. rapa.
American Journal of Botany ; VOL. 83 ; ISSUE: 5 ; PBD: May 1996
about the kind of panels that are being used for greenhouses:
Trade names for some of these products are Planilux, Diamant or Optiwhite. Plastic made from polymethylmethacrylate (PMMA) also transmits UV-B. Traditional greenhouse coverings such as polyvinyl chloride (PVC), fiberglass, polycarbonate or regular glass allow little if any UV-B transmission (*most light shields on grow lights and the glass of many grow bulbs do not allow it's tranmission).
Hoffman, Dr Silke. 2001. Ultraviolet radiation in the greenhouse.
Floraculture International, May 2001. Ball Publishing, Batavia,
Illinois. pp18-27.
*my note
Most of the theory behind UV causing resin production in cannabis had to do first with the geographical origins of cannabis>the stronger varieties come from high UV latitudes. but then the relationship got backed up further with info on the chem constituents of the resin and the refractory properties of the round resin heads. and now they are saying that the light acts as an element in the conversion of a precursor into THC.
The concentration of cannabinoids in Cannabis sativa L. is correlated with high ultraviolet-B (UV-B) radiation environments.^..delta../sup 9/-Tetrahydrocannabinolic acid and cannabidiolic acid, both major secondary products of C. sativa, absorb UV-B radiation and may function as solar screens.^The object of this study was to test the effects of UV-B radiation on the physiology and cannabinoid production of C. sativa.^Drug and fiber-type C. sativa were irradiated with three levels of UV-B radiation for 40 days in greenhouse experiments.^Physiological measurements on leaf tissues were made by infra-red gas analysis.^Drug and fiber-type control plants had similar CO/sub 2/ assimilation rates from 26 to 32/sup 0/C.^Drug-type control plant had higher dark respiration rates and stomatal conductances than fiber-type control plants.^The concentration of ..delta../sup 9/-THC, but not of other cannabinoids) in both vegetative and reproductive tissues increased with UV-B dose in drug-type plants.^None of the cannabinoids in fiber-type plants were affected by UV-B radiation.^The increased level of ..delta../sup 9/-THC found in leaves after irradiation may account for the physiological and morphological insensitivity to UV-B radiation in the drug-type plants.^However, fiber plants showed no comparable change in the level of cannabidoil (CBD).^Resin stripped form fresh fiber-type floral tissue by sonication was spotted on filter paper and irradiated continuously for 7 days.^Cannabidiol (CBD) gradually decreased when irradiated but ..delta../sup 9/-THC and cannabichromene did not.
I am told that this means that "high levels of UV-B cause a photomorphogenic reaction in the trichs which produces the fully developed form of THC. and that otherwise, without the high levels of UV-B, the girls use compression forces in the trichs to produce the pre-cursor form of THC".
and also to add a bit more to the OP's question about the UV-A of "blacklights" a bit, all these mj guys also say that UV-A is most definitely good for psychoactive compound manufacture in mj.
but about the UV-B, some growers say the herb is better, some say no. others say it depends on strain as to whether it will have an effect; and that the strains origin, be it from a high UV area or not, is linked to UV's effectiveness.
one well recommended UV-B light to use is the UVB 10 by reptisun but there are whole threads on recommend lights, both at herb forums (hg420, treatingyourself and also the big ones i am sure) and at reptile forums (shelled warriors and idk).
One hypothesis regarding the global decline in frog populations concerns sensitivity to UV-B radiation. Biologists from the University of Joensuu (Finland) looked at the effects of solar UV-B on 3 anurans -- the common frog (Rana temporaria), moor frog (R arvalis) and common toad (Bufo bufo). Embryo survival was unaffected by exposure to solar UV-B for R temporaria and B bufo. For R arvalis, protection from solar UV-B reduced embryo mortality, but hatching success was lower in both treatment and control groups. For B bufo, tadpole survival was increased with protection from UV-B. The scientists concluded that UV-B had no effect on R temporaria but affected R arvalis and B bufo at different stages of development.
Hakkinen J et al. 2001. The effects of solar UV-B radiation on embryonic mortality and development in three boreal anurans (Rana temporaria, Rana arvalis and Bufo bufo). Chemosphere 44:441-446.
So that means (to me) that although adults can benefit from having an area where they can voluntarily migrate to soak up the rays, it is bad to expose your babies.
It's important to remember in bufo husbandry or for other dudes like turtles and lizards, the glass of their aquarium will block UV-B<<so their lights need to be placed accordingly. also the glass of house windows will not let in the right light unless it is replaced with one of those panels.
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