The effect of fluctuating light intensity on plant growth.
Young plants of 5 species were grown in pots for 8-16 days in daylight under shades constructed of 6-mm strips. The shades were fixed or were made to move laterally so as to subject any part of a leaf to alternate conditions of high and low light intensity for cycles of 86, 16 or 2.2 sec. Differences between treatments were almost absent in cotton and were <5% for white mustard. Tobacco grown under 'rapidly' moving shades produced 8.5% more DM than under 'slowly' moving shades. Plants under 'slowly' moving shades always yielded less than under fixed shades but the difference was less than 5% except in tobacco. None of the treatment differences were statistically significant.-R.B.