| Material Information
||Temperature affects severity of three foliar diseases of foliage plants
||CFREC-Apopka research report
||3 leaves : ; 28 cm.
||Chase, A. R ( Ann Renee )
Poole, R. T ( Richard Turk )
Central Florida Research and Education Center--Apopka
||University of Florida, IFAS, Central Florida Research and Education Center-Apopka
||Place of Publication:
||Foliage plants -- Effect of temperature on -- Florida ( lcsh )
Foliage plants -- Diseases and pests -- Control -- Florida ( lcsh )
||government publication (state, provincial, terriorial, dependent) ( marcgt )
bibliography ( marcgt )
non-fiction ( marcgt )
||Includes bibliographical references (leaf 2).
||Statement of Responsibility:
||A.R. Chase and R.T. Poole.
| Record Information
||University of Florida
||All rights reserved by the source institution and holding location.
||oclc - 70709260
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Copyright 2005, Board of Trustees, University
Temperature Affects Severity of Three FOddaI Science
Diseases of Foliage Plants Library
A. R. Chase and R. T. Pooie1
University of Florida, IFAS OCT 14 1987
Central Florida Research and Education Center Apopka
CFREC-Apopka Research Report ;H-87tiiversity of Florida
Temperatures play an important role in development and severity of
plant diseases. Some diseases, such as Botrytis blight are most severe
during the winter when temperatures are low and humidity is high in
enclosed greenhouses. In contrast Erwinia blight is known to be most
severe during the summer when high temperatures are favorable for disease
development. A recent report showed that Rhizoctonia aerial blight was
most severe on Boston fern when air temperatures were between approximately
85 and 95F and soil temperatures did not reach 90*F. The following
research was performed between December of 1986 and February of 1987 to
determine effects of air temperature on three common foliar diseases of
The plants and pathogens used for these studies were: Brassaia
actinophylla (schefflera) Alternaria panax; Calathea argentea (Silver
Portrait) Drechslera setariae; and Dracaena marginata (Red-edge) -
Fusarium moniliforme. Two series of studies were performed with each
combination. The first series evaluated effects of four minimum night
temperatures in a glasshouse on disease severity. The temperatures
included 60, 65, 70, and 75F. This test was completed four times for each
plant and pathogen listed. The second series evaluated effects of six or
seven continuous temperatures in growth chambers on severity of the
diseases. This test was performed twice for each plant and pathogen
combination and included 60, 65, 70, 75, 80, 85, and 90F.
All plants were inoculated using a standard method and evaluated for
disease severity approximately 7-14 days after inoculation. Alternaria
leaf spot ratings were estimated as the percentage of the plant foliage
showing symptoms while both Drechslera and Fusarium leaf spot were rated as
the number of lesions per plant.
Minimum night temperatures significantly affected development of all
three diseases (Table 1). Alternaria leaf spot was least affected by these
temperatures and developed best at temperatures between 60 and 70F
although significant disease developed at 75 as well. Optimal temperature
for development of Drechslera leaf spot on Calatheas was between 60 and 65
with significantly less disease developing at each temperature increase.
Fusarium leaf spot on Dracaenas was highest at 60F and failed to develop
significantly at all higher temperatures.
Results of the continuous temperatures study were similar. Optimal
temperatures for Alternaria leaf spot occurred between 65 and 75"F with a
dramatic decrease in development at temperatures of 80 or higher (Table 2).
Optimal development of Drechslera leaf spot was found at 60"F with higher
Associate Professor of Plant Pathology and Professor of Physiology,
respectively, Central Florida Research and Education Center, 2807 Binion
Road, Apopka, FL 32703.
temperatures resulting in decreased disease development. As in the
greenhouse trials, development of Fusarium leaf spot was best at the lowest
temperatures (60 and 65) and minimal above that level.
Optimal temperatures for development of these three diseases differed
considerably although all three developed at 60F. Alternaria leaf spot is
apparently less sensitive to temperature and developed over a relatively
broad range (60 to 75), compared to Fusarium leaf spot which developed only
at 60 and 65"F. Severity of Drechslera leaf spot can be reduced by
maintaining temperatures above 700F. Since relative humidities vary
considerably as temperature is raised, it may also play a role in disease
severity. However, plants in the growth chambers remained in plastic bags
until ratings were recorded and the effect of humidity on disease
development was minimal. These data suggest, that some diseases have a
narrower range of optimum temperatures than others, and that pesticide
applications should be concentrated at times when optimal temperatures
occur for each disease.
1. Chase, A. R. 1986. Effect of soil temperature on severity of
Cylindrocladium root and petiole rot of Spathiphyllum. AREC-Apopka
Research Report, RH-86-7.
2. Chase, A. R., and C. A. Conover. 1986. Temperature and potting medium
composition affect Rhizoctonia aerial blight of Boston Fern. AREC-
Apopka Research Report, RH-86-6.
3. Chase, A. R., and R. T. Poole. 1984. Development of Myrothecium leaf
spot of Dieffenbachia maculata 'Perfection' at various temperatures.
Plant Disease 68:488-490.
Table 1. Effect of different minimum night temperatures on severity
of three diseases of foliage plants.
% Area with
Mean number lesions
60 36**a 28* 5**
65 39 27 1
70 30 16 1
75 25 9 1
aSignificant at 5% (*) or 1% (**).
Table 2. Effect of different continuous temperature on severity
of three diseases of foliage plants.
% Area with
Continuous symptoms Mean number of lesions
temperature Alternaria Drechslera Fusarium
0 F (Schefflera) (Calathea) (Dracaena)
60 _a 29** 2**
65 37*b 15 3
70 34 7 1
75 38 2 2
80 6 3 0
85 6 0 0
90 2 0 0
Significant at 5% (*)
or 1% (**).