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Copyright 2005, Board of Trustees, University
of Florida

ERWINIA SPP.-- SYMPTOMS AND FOLIAGE PLANT HOSTS

A. R. Chase
University of Florida, IFAS ... ;
Agricultural Research Center Apopka
ARC-A Research Report RH-83-13 .

One of the most serious and destructive foliage plant diseases is caused

by either Erwinia carotovora pv. carotovora or E. chrysanthemi. These bacteria

have been problems in the foliage industry for many years. Symptoms of Erwinia

infections differ somewhat from one host to the next, but several major types

of symptoms are common. Leaf spots or blights are characteristically water-

soaked and rarely discrete (their borders are not clearly confined). The

spots may occur on any part of the leaf and in the case of a blight these

spots enlarge and spread throughout the leaf and into petioles and stems. The

most common indication of stem rot caused by Erwinia spp. is yellowing of lower

leaves followed by wilting and lodging of the cutting or stem that is infected.

Examination of the cut end of the stem generally reveals a soft-to-mushy rot

which commonly smells like rotten fish. The tissue in the area looks like it

is disintegrating and bacterial exudate may occur.

The practice of trimming and resticking rotted cuttings is not advisable

because stem rot can recur and kill the cuttings even though they have rooted.

This practice is especially undesirable in stock plants because the Erwinia

stem rot will be perpetuated and spread to plants started from these stock

plants. Successful prevention of this disease remains dependent upon securing

and maintaining Erwinia-free plants since chemical control methods have not

always been satisfactory. Erwinia-free plants may be most easily secured by

purchase from a tissue culture laboratory which produces them and maintained

by strict sanitation measures in the growing area. These measures involve

removal and destruction of all infected plants as well as frequent examination

of stock and production plants for symptoms. Once Erwinia enters the growing

area (especially on asymptomatic plants or contaminated pots or potting medium)

it is very difficult to control since it is not always evident in infected

plants. For example, symptoms of stem rot of dieffenbachia may not be present

in stock plants, but they develop in cuttings started from these stock plants.

Keeping the foliage dry is another important control method for the foliar

phase of this disease since bacteria require free water on leaves to spread

and infect new sites.

Erwinia has a very broad host range, that is, it may infect many plants.

Knowing which plants are susceptible to Erwinia spp. is important in developing

control strategies because all new plants brought into the growing area are

potential sources of Erwinia contamination. Many of the known foliage plant

hosts of Erwinia are given in the table along with the most susceptible plants

in each group and the type of symptom which is generally encountered. There

are undoubtedly many other foliage plants which are susceptible to Erwinia

spp. and their absence from this list should not be taken as a statement of

their resistance to this serious bacterial pathogen. A list of references is

included at the end of this article for further information concerning specific

hosts of Erwinia spp.

References

1. Brown, J. G. and A. M. Boyle. 1943. Bacterial soft rot of sansevieria.

Phytopathology 33:350-351.

2. Dickey, R. 1979. Erwinia chrysanthemi: A comparative study of phenotypic

properties of strains from several hosts and other Erwinia species.

Phytopathology 69:324-329.

3. Griffith, L. 1982. Common problems with aglaonemas. Florida Nurseryman

29(9):10,69.

4. Haygood, R. A. and D. L. Strider. 1979. Influence of temperature, inoculum

concentration, and wounding on infection of Philodendron selloum by Erwinia

chrysanthemi. Plant Dis. Reptr. 63:578-580.

5. Haygood, R. A. and D. L. Strider. 1981. Influence of moisture and inoculum

concentration on infection of Philodendron selloum by Erwinia chrysanthemi.

Plant Disease 65:727-728.

6. Haygood, R. A. and D. L. Strider. 1982. A comparison of inoculation methods

of Erwinia chrysanthemi in greenhouse ornamentals. Plant Disease 66:461-463.

7. Haygood, R. A., D. L. Strider, and E. Echandi. 1982. Survival of Erwinia

chrysanthemi in association with Philodendron selloum, other greenhouse

ornamentals, and in potting media. Phytopathology 72:853-859.

8. Knauss, J. F. and J. W. Miller. 1974. Bacterial blight of Saintpaulia

ionantha caused by Erwinia chrysanthemi. Phytopathology 64:1046-1047.

9. Knauss, J. F. and J. W. Miller. 1972. Description and control of the rapid

cutting decay of Scindapsus aureus incited by Erwinia carotovora. Proc. Fla.

State Hort. Soc 85:348-352.

10. Knauss, J. F. and C. Wehlburg. 1969. The distribution and pathogenicity

of Erwinia chrysanthemi Burkholder et al. to Syngonium podophyllum Schott.

Fla. State Hort. Soc. 82:370-373.

References (continued)

11. Knauss, J. F. and J. W. Miller. 1974. Etiological aspects of bacterial

blight of Philodendron selloum caused by Erwinia chrysanthemi. Phytop

64:1526-1528.

12. Lai, M., S. Shaffer, and K. Sims. 1978. Bacterial blight of Syngonium

podophyllum caused by Erwinia chrysanthemi in California. Plant Dis. Reptr.

62:298-302.

13. McFadden, L. A. 1961. Bacterial stem and leaf rot of Dieffenbachia in

Florida. Phytopathology 51:663-668.

14. Miller, H. N. and L. A. McFadden. 1961. A bacterial disease of Phil .....

Phytopathology 51:826-831.

15. Miller, J. W. 1972. Leaf rot of Philodendron selloum caused by Erwinia

chrysanthemi. Plant Path. Circ. No. 124. 2 pp.
16. Miller, J. W. 1980. Bacterial stem and leaf rot of Dieffenbachia. Plant

Path. Circ. No. 216. 2 pp.

17. Miller, J. W. 1982. Bud rot of Dracaena deremensis caused by Erwinia

carotovora. Phytopathology 72:977 (Abstr.).

18. Miller, J. W. and J. F. Knauss. 1974. Bacterial blight of African violet.

Plant Path. Circ. No. 149. 2 pp.

19. Munnecke, D. E. 1960. Bacterial stem rot of Dieffenbachia. Phytopathology

50:696-700.

20. Roberts, B. J. 1977. Susceptibility of certain Saintpaulia species and

cultivars to bacterial blight. Plant Dis. Reptr. 61:1048-1050.

21. Suslow, T. and A. H. McCain. 1979. Etiology, host range, and control of

a soft rot bacterium from cactus. Phytopathology 69:8 (Abstr.).

1. Foliage plant hosts of Erwinia spp. and the most common symptoms) of
infected plants.

name of
group

violet

nas

ims

nest fern

:'ads

-as cacti

nes

.bachias

S .as

oes

ias

'lodendrons

host
i '

Specific plant
species

Many cultivars

Many species

Several species

Several species

Asplenium nidus

Aechmea fasciata

Gymnocalycium spp.

Many cultivars

Schlumbergera spp.

C. terminalis and
others

All species

D. marginata
D. deremensis

D. sanderana
D. godseffiana

K. blossfeldiana

P. argyreia
Watermelon)

P. selloum

Other cultivars
(P. hastatum)

Symptom type

Blight of the crown, petioles and leaves.

Both stem rot of cuttings and leaf spot
symptoms occur on aglaonemas.

Leaf spots are common.

Leaf spots and blights.

Leaf blights extending into the petioles.

Crown and stem rot occur on rotting cuttings.

Stem rot is common.

Stem rot occurs occasionally.

Stem rot starts at the base of the leaf
cutting primarily and extends upward.

Severe loss of cuttings through stem rot
which also extends into the lower leaves.

Stem rot is very severe on cuttings of this
plant if the stock plants are infected. The
leaf spot phase is also a problem for plants
watered from overhead.

Both plants are very susceptible to stem rot.

These species are most commonly afflicted with
leaf spot that may extend down into the stems.

Leaf and stem rot occur.

Leaf spots can develop under wet conditions.

This is one of the most susceptible plants to
the foliar phase. Infection of leaves starts
as tiny spots but commonly enlarges to encompass
the entire leaf and petiole and causes complete
collapse of the leaf.

Most of the other cultivars are susceptible to
Erwinia spp. and show discrete leaf spots and
stem rot at times.

Table 1 (continued)

Common name of
host group

Pothos

Sansevierias

Scheffleras

Succulents

Syngoniums

Wax plant

Yucca

Specific plant
species

Epipremnum aureum

S. trifasciata

Brassaia actinophylla
Schefflera arboricola

Crassula argentea

S. podophyllum

Hoya carnosa

Soft tip yucca.

Symptom type

Leaf spots and cutting rots occur
on this plant during propagation.

Leaves turn yellow and wilt and spots
develop, especially at their bases. The
entire plant may collapse as the i
progresses into the upper portions of

The most common symptom is a watery leaf
which is black or tan. Petioles and
may also become infected.

Leaves and stems are both affected.

Severe blight of the leaves can occur on
plants being watered from overhead. The
lesions commonly spread along the veins
leaves are water-soaked and collapse.

All portions above ground may be i

Leaf spots and rot of cuttings occurs
occasionally, especially during pr,