Hostname: page-component-cd9895bd7-lnqnp Total loading time: 0 Render date: 2024-12-27T13:47:38.386Z Has data issue: false hasContentIssue false

Effects of Fungi and Bacteria on the Decline of Arthropod-Damaged Waterhyacinth (Eichornia crassipes) in Florida

Published online by Cambridge University Press:  12 June 2017

R. Charudattan
Affiliation:
Dep. Plant Pathol. and Stat., Inst. of Food and Agric. Sci., Univ. of Florida. Gainesville, FL 32611
B. D. Perkins
Affiliation:
U.S. Dep. of Agric.–Agric. Res. Serv., Aquatic Plant Manage. Lab., 3205 S.W. 70th Av., Fort Lauderdale, FL 33314
R. C. Littell
Affiliation:
Dep. Plant Pathol. and Stat., Inst. of Food and Agric. Sci., Univ. of Florida. Gainesville, FL 32611

Abstract

A survey of the fungal and bacterial flora of waterhyacinth, [Eichornia crassipes (Mart.) Solms] infested with two arthropods, Neochetina eichhorniae Warner (weevil) and Orthogalumna terebrantis Wallwork (mite) was undertaken to determine the role of microorganisms in the decline of this host in Florida waters. Generally arthropod-infested plants were more diseased, had smaller laminae, lower numbers of live petioles and higher numbers of dead petioles per plant than noninfested plants. Several parasitic fungi, including some known pathogens of waterhyacinth, and soft-rot bacteria were isolated from arthropod-infested and noninfested plants. Higher numbers of microorganisms were present on arthropod-infested than on noninfested plants. The fungi and bacteria occurred randomly on arthropod-damaged waterhyacinth. No vector relationship was discovered between the arthropods and any fungus or bacterium. However, Acremonium zonatum (Saw.) Gams a virulent pathogen of waterhyacinth, and other necrotic leaf-spot diseases (‘disease B’) were predominant on arthropod-damaged plants. Disease B was independent of the arthropods, while A. zonatum incidence on waterhyacinth in sample sites was related especially to damage by adult mites. The origin of the observed association between A. zonatum symptoms and mite damage on laminae is unclear, even though field observations suggest a direct relationship between them. The weevil was also capable of aiding A. zonatum infections by creating points of entry for this pathogen into the host. In laboratory tests, waterhyacinths could be killed by the combined effects of the weevil and A. zonatum, although death did not ensue in the field under existing levels of this disease. The combined effects of arthropods and diseases led to reduction in the photosynthetic area of waterhyacinth and under severe stress, to root- and crown-rots. It is recommended that the process of biological control of waterhyacinth in Florida should include an integrated approach, using insects and pathogens.

Type
Research Article
Copyright
Copyright © 1978 by the Weed Science Society of America 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Literature Cited

1. Anderson, T. W. 1958. An introduction to multivariate statistical analysis. J. Wiley, Inc., New York. 374 p.Google Scholar
2. Barr, A. J. and Goodnight, J. H. 1972. A user's guide to the statistical analysis system. Sparks Press, Raleigh. 260 p.Google Scholar
3. Carter, W. 1962. Insects in relation to plant disease. Interscience Publ., New York. 705 p.Google Scholar
4. Charudattan, R. 1973. Pathogenicity of fungi and bacteria from India to hydrilla and waterhyacinth. Hyacinth Control J. 11:4448.Google Scholar
5. Conway, K. E. 1976. Cercospora rodmanii, a new pathogen of waterhyacinth with biological control potential. Can. J. Bot. 54:10791083.Google Scholar
6. Duncan, D. B. 1955. Multiple range and multiple F tests. Biometrics 11:142.Google Scholar
7. Freeman, T. E. and Charudattan, R. 1974. Occurrence of Cercospora piaropi on waterhyacinth in Florida. Plant Dis. Rep. 58:277278.Google Scholar
8. Kelman, A. 1967. Source book of laboratory exercises in plant pathology. W. H. Freeman & Co., San Francisco. 387 p.Google Scholar
9. Laemmlen, F. F. and Hall, D. H. 1973. Interdependence of a mite, Siteroptes reniformis, and a fungus, Nigrospora oryzae in the Nigrospora lint rot of cotton. Phytopathology 63:308315.Google Scholar
10. Perkins, B. D. 1973. Release in the United States of Neochetina eichhorniae Warner, an enemy of waterhyacinth. Proc. South. Weed Sci. Soc. 26:368.Google Scholar
11. Perkins, B. D. 1973. Preliminary studies on a strain of waterhyacinth mite from Argentina. Proc. Int. Symp. Biol. Contr. Weeds 2:180184.Google Scholar
12. Steel, R. G. D. and Torrie, J. H. 1960. Principles and procedures of statistics. McGraw-Hill Book Co., Inc., New York. 481 p.Google Scholar