کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
31099 44542 2009 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Serious complications in experiments in which UV doses are effected by using different lamp heights
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی بیو مهندسی (مهندسی زیستی)
پیش نمایش صفحه اول مقاله
Serious complications in experiments in which UV doses are effected by using different lamp heights
چکیده انگلیسی

Many experiments examining plant responses to enhanced ultraviolet-B radiation (280–315 nm) simply compare an enhanced UV-B treatment with ambient UV-B (or no UV-B radiation in most greenhouse and controlled-environment studies). Some more detailed experiments utilize multiple levels of UV-B radiation. A number of different techniques have been used to adjust the UV dose. One common technique is to place racks of fluorescent UV-emitting lamps at different heights above the plant canopy. However, the lamps and associated support structure cast shadows on the plant bed below. We calculated one example of the sequence of shade intervals for two common heights of lamp racks and show the patterns and duration of shade which the plants receive is distributed differently over the course of the day for different heights of the lamp racks. We also conducted a greenhouse experiment with plants (canola, sunflower and maize) grown under unenergized lamp racks suspended at the same two heights above the canopy. Growth characteristics differed in unpredictable ways between plants grown under the two heights of lamp racks. These differences could enhance or obscure potential UV-B effects. Also, differences in leaf mass per unit foliage area, which were observed in this experiment, could contribute to differences in plant UV-B sensitivity. We recommend the use of other techniques for achieving multiple doses of UV-B radiation. These range from simple and inexpensive approaches (e.g., wrapping individual fluorescent tubes in layers of a neutral-density filter such as cheese cloth) to more technical and expensive alternatives (e.g., electronically modulated lamp control systems). These choices should be determined according to the goals of the particular experiment.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Photochemistry and Photobiology B: Biology - Volume 97, Issue 1, 6 October 2009, Pages 48–53
نویسندگان
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