The Effect of Ultra-Violet Radiation Upon Higher Plants

On the Influence of Ultra-violet Rays upon the Frequency of Nuclear Division in Plants

“…This result coincides with the results obtained by ELTINGE (1928) and JACOBI (1928) from their experiments on the influence of ultra-violet rays upon germination and growth in some higher plants. According to them, for a certain period of time after exposure the growth of the plants is generally accelerated, if the time of exposure is suitably long, but when it is too long, the rays act injuriously upon the plants.…”

The Killing of Plant Tissue and the Inactivation of Tobacco Mosaic Virus by Ultraviolet Radiation

“…Eltinge (10) observed that a series of commercial glasses, Quartzlite, Vita, and window glass, did not transmit injurious rays from a quartz-tube mercury-vapor arc. The ultra-violet component transmitted by the Vita glass used (limit at wave length 289 me), seemed beneficial to some plants but without visible effect upon others.…”

“…The work was started with some pieces of Corex A which had previously been used as a roof covering TEXT F.20 " F, 10 Open arc without filter. The work was started with some pieces of Corex A which had previously been used as a roof covering TEXT F.20 " F, 10 Open arc without filter.…”

“…A filter transmitting one percent at wave length 249.7 mJL will protect the plant for about 10 minutes on single exposures. Radiation from the quartz tube mercury arc without a filter will cause a rapid killing of the whole upper surface of young tomato seedlings in one minute as exposed in this investigation.…”

“…That is, a plant which is only slightly injured by a single to-minute irradiation through a certain filter will receive very little further injury when irradiated through that same filter each day for several weeks provided that each single exposure never exceeds 10 minutes. That is, a plant which is only slightly injured by a single to-minute irradiation through a certain filter will receive very little further injury when irradiated through that same filter each day for several weeks provided that each single exposure never exceeds 10 minutes.…”