On 8 Oct 1996, Janice M. Glime wrote:
>> Ross,
> I enjoyed your answer to this, and so many other of your responses. I
> am curious about item 4 - providing sucrose. I read this somewhere and
> put it in the botany book I wrote for the course I teach here. When I
> sent the book out for review, the reviewer jumped all over me, saying that
> the sucrose would encourage the growth of bacteria. We have ignored the
> advice in our lab experiments, but we really haven't seen any differences
> in those with sucrose and those with none. Can you give any specific
> advice on concentration? Some have suggested putting aspirin with it to
> prevent bacteria. Sorry I'm not looking for this myself in the
> horticulture journals, but the nearest library with horticulture journals
> is at least 100 miles away (more likely 400) - or in some unknown person's
> basement.
> Thank you,
> Janice
> ***********************************
> Janice M. Glime, Professor
> Department of Biological Sciences
> Michigan Technological University
> Houghton, MI 49931-1295
>jmglime at mtu.edu> 906-487-2546
> FAX 906-487-3167
> ***********************************
>>>>Dear Janice,
I thought I would add my two cents worth.
As far as I understand, sucrose is only useful for flowers that still
have some expansion to go (ie: flowers that are bought while in bud and
open in the vase). In sprays of woody plant flowers (I'm talking
Australian native plants here) sucrose can actually enhance senescence.
Presumably the increased carbohydrate is used as a signal to begin
vegetative growth.
As Ross and the reviewers suggested, sucrose will encourage bacterial
growth. From my experience at home the major cause of flower senescence
is bacterial growth which blocks the stem of the flower leading to poor
water uptake. I always recut stems and remove leaves which may be
submerged (these provide ideal sites for bacterial growth) immediately
before placing flowers in the vase and to the vase I add a dash of
household bleach. The bleach contains chloride which stops bacterial
growth but in dilutes solution seems to have little harmful effect on the
flowers.
I too have heard that aspirin has a beneficial effect on flower longevity
but have not read any scientific proof.
Jamie Day
Department of Biochemistry
University of Otago
P.O. Box 56
Dunedin
New Zealand
Ph: 64-3-4795149
Fax: 64-3-4797866
Email: jamie at sanger.otago.ac.nz
