Susceptibility of Brassaia actinophylla and B. actinophylla 'Amate' to Alternaria leaf spot

Material Information

Susceptibility of Brassaia actinophylla and B. actinophylla 'Amate' to Alternaria leaf spot
Series Title:
AREC-Apopka research report
Chase, A. R ( Ann Renee )
Agricultural Research and Education Center (Apopka, Fla.)
Place of Publication:
Apopka Fla
University of Florida, IFAS, Agricultural Research and Education Center-Apopka
Publication Date:
Physical Description:
2 p. : ; 28 cm.


Subjects / Keywords:
Amate (Plant) -- Diseases and pests -- Control -- Florida ( lcsh )
Fungal diseases of plants -- Florida ( lcsh )
Alternaria diseases -- Florida ( lcsh )
Alternaria ( jstor )
Mites ( jstor )
Leaf spot ( jstor )
government publication (state, provincial, terriorial, dependent) ( marcgt )
bibliography ( marcgt )
non-fiction ( marcgt )


Includes bibliographical references (p. 2).
General Note:
Caption title.
Statement of Responsibility:
A.R. Chase.

Record Information

Source Institution:
University of Florida
Rights Management:
All applicable rights reserved by the source institution and holding location.
Resource Identifier:
70922499 ( OCLC )


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-/ Susceptibility of Brassaia actinophylla and B. actinohylla
'Amate' to Alternaria leaf spot r ,p ,
Central! Sc'eice
A. R. Chase1 Library
University of Florida, IFAS
Agricultural Research and Education Center Apopk CT 1 4 1987
AREC-Apopka Research Report RH-86-1

Colijn and Lindquist recently reported on levels of resi-stai--to --
two-spotted spider mite for Brassaia actinophylla (schefflera) and the
cultivar B. actinophylla 'Amate (Amate schefflera) (1). They found that
mites feeding on Amate produced fewer eggs, had poorer survival and took
longer to mature than those feeding on the standard schefflera.
Scheffleras are also hosts of a variety of fungal and bacterial pathogens
under most production situations. The following report summarizes work on
susceptibility of these two selections to Alternaria panax, the cause of
Alternaria leaf spot.

Ten plants each of Amate and the standard schefflera were obtained
from commercial producers as liners. They were planted into a
steam-treated potting medium consisting of 50% Canadian peat and 50% pine
bark amended with 10 lbs Osmocote 19-6-12, 7 Ibs dolomite, and 1 lb
Micromax per cubic yard. Plants were grown in 4" pots on a greenhouse
bench receiving approximately 1000 ft-c. and temperatures between 70 and
100 F for 3-4 weeks prior to inoculation. Plants were placed under
intermittent mist (5 sec/ 30 min from 8:00 am to 8:00 pm daily) starting 1
day prior to inoculation and continuing until test completion. Plants were
inoculated with a conidial suspension of Alternaria panax and placed in
polyethylene bags for 3 days. The number of lesions per plant was recorded
between 7 and 10 days after inoculation. This test was performed 3 times.

Results from these tests were similar and showed that Amate was
significantly less susceptible to A. panax than the standard schefflera
(Table 1). In most tests, Amate developed 1/3 the number of lesions found
on schefflera. In addition, these lesions were smaller and caused less
damage on Amate than on the standard schefflera.

Many growers are interested in producing Amate since the plant is more
compact, sturdier and many feel more attractive than the standard
schefflera selection. Amate is also more tolerant of interiorscape
conditions. The fact that Amate is also more resistant to two serious
problems, two-spotted spider mites and Alternaria leaf spot, further
enhances its suitability for use by the foliage plant industry.

Associate Professor of Plant Pathology, University of Florida, IFAS,
AREC-Apopka, 2807 Binion Rd., Apopka, FL 32703.


1. Colijn, A. C., and R. K. Lindquist. 1986. Mites and moisture stress on
Brassaia. Florida Foliage 12(2):53-56.

Table 1. Severity of Alternaria leaf spot on Brassaia
actinophylla (schefflera) and B. actinophylla
'Amate' (Amate schefflera).

Number of lesions/plant
Plant Test 1 Test 2 Test 3

Schefflera 27.0 ax 26.5 a 33.0 a

Amate schefflera 10.3 b 3.4 b 9.6 b

XNumbers in the same column followed by the same letter
were not significantly different at the 5% level
(Duncan's New Multiple Range Test).