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 What is it?
 Control of high sugar disease
 Significance of high sugar...






Group Title: Mimeo report - Bradenton Agricultural Research & Education Center - GC-1972-2
Title: High sugar disease of chrysanthemum, or, the excess phytosynthate syndrome
CITATION PAGE IMAGE ZOOMABLE PAGE TEXT
Full Citation
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Permanent Link: http://ufdc.ufl.edu/UF00067673/00001
 Material Information
Title: High sugar disease of chrysanthemum, or, the excess phytosynthate syndrome
Series Title: Bradenton AREC mimeo report
Physical Description: 2 leaves : ; 28 cm.
Language: English
Creator: Engelhard, Arthur W
Woltz, S. S
Agricultural Research & Education Center (Bradenton, Fla.)
Publisher: Agricultural Research & Education Center
Place of Publication: Bradenton Fla
Publication Date: 1972
 Subjects
Subject: Chrysanthemums -- Diseases and pests -- Florida   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
non-fiction   ( marcgt )
 Notes
Statement of Responsibility: A.W. Engelhard and S.S. Woltz.
General Note: Caption title.
General Note: "April, 1972."
Funding: Florida Historical Agriculture and Rural Life
 Record Information
Bibliographic ID: UF00067673
Volume ID: VID00001
Source Institution: Marston Science Library, George A. Smathers Libraries, University of Florida
Holding Location: Florida Agricultural Experiment Station, Florida Cooperative Extension Service, Florida Department of Agriculture and Consumer Services, and the Engineering and Industrial Experiment Station; Institute for Food and Agricultural Services (IFAS), University of Florida
Rights Management: All rights reserved, Board of Trustees of the University of Florida
Resource Identifier: oclc - 71837421

Table of Contents
    Copyright
        Copyright
    What is it?
        Page 1
    Control of high sugar disease
        Page 1
    Significance of high sugar disease
        Page 2
Full Text





HISTORIC NOTE


The publications in this collection do
not reflect current scientific knowledge
or recommendations. These texts
represent the historic publishing
record of the Institute for Food and
Agricultural Sciences and should be
used only to trace the historic work of
the Institute and its staff. Current IFAS
research may be found on the
Electronic Data Information Source
(EDIS)

site maintained by the Florida
Cooperative Extension Service.






Copyright 2005, Board of Trustees, University
of Florida







AGRICULTURAL RESEARCH &'EDUCATION CENTER
Bradanton, Florida

Bradenton AREC Mimeo Report GC1972-2 April, 1972

HIGH SUGAR DISEASE OF CHRYSANTHEMUM OR THE EXCESS PHYTOSYNTHATE SYNDROME

A. W. Engelhard and S. S. Woltz


What is it?

A physiological disease that occurs when more sugar or total carbohydrate is
being synthesized than the plant can use. It is very common in Florida.

Some cultivars of chrysanthemums are affected adversely by certain environ-
mental conditions, primarily the length and brightness of the days. Under these
conditions, plants synthesize more sugar than they can use. The excess sugar -
or excess total carbohydrates (there are several sugars and starch) results in
the development of a variety of plant symptoms. One or more symptoms may occur
on a given cultivar. The symptoms of the syndrome include leaves that may be
thick, leathery, brittle, crinkled, dark green in color, and downward cupped.
The leaves may have interveinal chlorosis, interveinal necrosis, interveinal
chlorotic spots, interveinal necrotic spots, leaf spots (may be indistinguishable
from those caused by disease organisms), and browning or blackening of tips and
margins of leaves. Magnesium deficiency symptoms may overlap those caused by
high sugar disease. Other apparent symptoms which may be related to excess
sugar are petal spots and petal tip necrosis on flowers. These symptoms vary
greatly among cultivars and do not all occur on a given cultivar. For example,
leaf spots are common on Explorer, Flamenco and Show Off, interveinal chlorosis
on Bluechip, downward cupped, thick, brittle leaves on Shasta, and crinkled
leaves on Indianapolis Yellow and Albatross. Some cultivars such as Belair
and Beauregard have flat, green leaves generally free of symptoms.

The symptoms are more prominent during certain periods of the year and at
definite periods in the development of the plants. Since light intensity and
day length are major contributors to the development of this physiological disease,
more symptoms are apparent in May than in December. Also, development of symp-
toms intensifies after plants nre pruned, i.e., after lateral buds and stems are
removed on standards or pruning to three stems on spray types. Pruning of the
"excess" growth removes growing plant tissues that use- the excess carbohydrate
the plant synthesizes. The excess carbohydrate thus accumulates and becomes
"toxic" to the plant. Each cultivar responds according to its own genetic
tolerance to the condition. Stock plants, where new growth is removed regularly,
are very susceptible to this disease. Growers report some varieties always look
bad in stock beds but look better in the field. Constantly removing the new
growth induces high sugar contents in older leaves.

CONTROL 07 HIGH SUGAR DISEASE

There are a number of ways this physiological disease can be minimized. One
of the ways is to reduce the sunlight intensity on the plants. Shading with
cloth providing up to 50% shade reduces the symptoms. The rapid development
of the symptoms in the final month of the crop season suggests that shading
would be most effective at that time. Denser plantings with standards or with
cultivars that have "thin" foliage (such as Flamenco) also reduces the symptoms.







AGRICULTURAL RESEARCH &'EDUCATION CENTER
Bradanton, Florida

Bradenton AREC Mimeo Report GC1972-2 April, 1972

HIGH SUGAR DISEASE OF CHRYSANTHEMUM OR THE EXCESS PHYTOSYNTHATE SYNDROME

A. W. Engelhard and S. S. Woltz


What is it?

A physiological disease that occurs when more sugar or total carbohydrate is
being synthesized than the plant can use. It is very common in Florida.

Some cultivars of chrysanthemums are affected adversely by certain environ-
mental conditions, primarily the length and brightness of the days. Under these
conditions, plants synthesize more sugar than they can use. The excess sugar -
or excess total carbohydrates (there are several sugars and starch) results in
the development of a variety of plant symptoms. One or more symptoms may occur
on a given cultivar. The symptoms of the syndrome include leaves that may be
thick, leathery, brittle, crinkled, dark green in color, and downward cupped.
The leaves may have interveinal chlorosis, interveinal necrosis, interveinal
chlorotic spots, interveinal necrotic spots, leaf spots (may be indistinguishable
from those caused by disease organisms), and browning or blackening of tips and
margins of leaves. Magnesium deficiency symptoms may overlap those caused by
high sugar disease. Other apparent symptoms which may be related to excess
sugar are petal spots and petal tip necrosis on flowers. These symptoms vary
greatly among cultivars and do not all occur on a given cultivar. For example,
leaf spots are common on Explorer, Flamenco and Show Off, interveinal chlorosis
on Bluechip, downward cupped, thick, brittle leaves on Shasta, and crinkled
leaves on Indianapolis Yellow and Albatross. Some cultivars such as Belair
and Beauregard have flat, green leaves generally free of symptoms.

The symptoms are more prominent during certain periods of the year and at
definite periods in the development of the plants. Since light intensity and
day length are major contributors to the development of this physiological disease,
more symptoms are apparent in May than in December. Also, development of symp-
toms intensifies after plants nre pruned, i.e., after lateral buds and stems are
removed on standards or pruning to three stems on spray types. Pruning of the
"excess" growth removes growing plant tissues that use- the excess carbohydrate
the plant synthesizes. The excess carbohydrate thus accumulates and becomes
"toxic" to the plant. Each cultivar responds according to its own genetic
tolerance to the condition. Stock plants, where new growth is removed regularly,
are very susceptible to this disease. Growers report some varieties always look
bad in stock beds but look better in the field. Constantly removing the new
growth induces high sugar contents in older leaves.

CONTROL 07 HIGH SUGAR DISEASE

There are a number of ways this physiological disease can be minimized. One
of the ways is to reduce the sunlight intensity on the plants. Shading with
cloth providing up to 50% shade reduces the symptoms. The rapid development
of the symptoms in the final month of the crop season suggests that shading
would be most effective at that time. Denser plantings with standards or with
cultivars that have "thin" foliage (such as Flamenco) also reduces the symptoms.










The symptoms are more severe on the more exposed south and west sides of the beds
than on the north and east sides and interiors of the beds. Therefore, plant-
ing to obtain the least plant exposure, such as orienting of beds in a north
to south rather than east to west direction is helpful.

Nitrogen and magnesium nutrition can affect the high sugar disease. High
levels of nitrogen nutrition temporarily alleviate adverse effects of the high
sugar, especially when nitrogen is supplied mainly in the nitrate form rather
than the ammonium form. Magnesium deficiency can accentuate the disease.
When high sugar in the plants adversely affects quality, steps should be taken
to insure an adequate magnesium supply.

Significance of high sugar disease

The obvious significance of this physiological disease is that its presence
reduces the quality of the product and competitiveness on the market. Growers
should strive to produce plants that have flat, green, flexible leaves free of
any excess cupping, thickening, brittleness, crinkled shapes and physiological
leaf spots.




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