Biological Control
Biological control, i.e. the suppression of pests or pest problems
by natural enemies such as parasites, predators, and pathogens, is
an area of major emphasis for research, teaching, and extension in
our state. The concept of biological control is that pests under
natural or undisturbed 
conditions are generally held in balance by
other organisms. Agricultural practices frequently create conditions
that upset this balance, enabling certain organisms to become pests.
The equilibrium between the pest and its natural enemies can be re-established
through manipulative techniques that promote the latter.
Several factors weigh in favor of a strong commitment to biological control in our state. Florida's ecosystems are rather delicate; its soils are mostly porous and pervious to a variety of agricultural chemicals which eventually pollute the fresh water resources. Certain pests have become resistant to chemical pesticides, in many cases without alternative controls. Florida also has been an inlet for several immigrant pests due to its geographic proximity to the Caribbean and Latin America . In addition, several minor crops are grown in the state for which no chemical pesticides are available due to high cost of registration. Finally, many pesticides, such as EBDC fungicides, are being withdrawn without suitable alternatives. These elements combine to make biological control an essential means of pest control.
Current and Ongoing Work in Biological Control
Field evaluation of bioherbicidal control of tropical signalgrass
Tropical signalgrass (Urochloa subquadripara) causes serious problems in turfgrass sod farms and golf courses in Florida. Currently there are very few options available to turfgrass managers to control tropical signalgrass in established bermudagrass, particularly with the loss of previously registered compounds like MSMA. Development of a bioherbicidal control strategy would supplement other cultural methods of weed management, while reducing the use of pesticides.
Dr. Carol Stiles and Dr. R. Charudattan, along with Dr. Yasser Shabana and Eduardo Canova (DPM graduate student), are collaborating on a project to assess the field-efficacy of Drechslera gigantea to control tropical signalgrass. In previous greenhouse tests by Dr. S. Chandramohan, this pathogen and two others in a mixture were shown to have restricted host range. The potential biocontrol agent did not cause significant damage to major crop plants or cultivated grass species tested. Field research will be conducted on bermudagrass and St. Augustinegrass turf infested with tropical signalgrass. This research is funded in part by the Florida Turfgrass Association and The Environmental Institute for Golf (Golf Course Superintendents Association of America).