Effects of irradiance on growth and winter bud production by Vallisneria americana

Korschgen, C. E., W. L. Green, and K. P. Kenow. 1997. Effects of irradiance on growth
and winter bud production by Vallisneria americana and consequences to its abundance
and distribution. Aquatic Botany 58:1 9. Reprinted by U.S. Geological Survey,
Environmental Management Technical Center, Onalaska, Wisconsin, March 1998.
LTRMP 98-R005. 9 pp.    (NTIS #PB98-134695) 


ABSTRACT

Number, total biomass, and individual mass of winter buds of Vallisneria americana was
significantly related to the depth of the 1% of surface irradiance (Z) and the photosynthetic
photon irradiance calculated for each shading treatment imposed during this study.
Between the range of 23.8 and 111.2 cm depth for the 1% Z, total biomass of winterbuds
produced ranged from 0.63 to 0.01 g, counts ranged from 3.5 to 0.1, and mass of
individual winterbuds ranged from 0.18 to 0.04 g. Total biomass of winter buds produced
was reduced when plants were exposed to a 14-day period without irradiance during the
middle of the growing season. Applying the results of the culture experiments to
conditions found in Navigation Pool 8 of the Upper Mississippi River suggests that
irradiance may indeed limit the distribution and abundance of Vallisneria americana by
reducing the number and size of winter buds.   1997 Elsevier Science B.V.


KEYWORDS

Growth, irradiance, Mississippi River, Vallisneria americana, wild celery, winterbuds