Symposium: Advances in Integrated Pest Management Programs for Ornamental Plants: Exploiting Natural Resistance as a Management Tactic for Landscape Plants

Authors

  • David G. Nielsen

Abstract

Few native species of so-called pest organisms are capable of overwhelming vital woody plants to the point of causing significant damage. There is a larger number of secondary-action organisms that exploit weakened trees and shrubs, causing their further decline and eventual death. Entomologist and phytopathologists might be more helpful to the plant production and maintenance industries by adjusting their major thoughts from insects and pathogens to tree adaptation and adaptibility. Then, instead of considering how to directly control pest organisms we can begin to think in terms of what can be done for trees to reduce their susceptibility and vulnerability to pests. Classic tree improvement programs should be continued but require better coordination among disciplines for success. Traditionally, these programs have not received significant funding from Federal or State governments. An immediate and productive avenue for exploiting natural resistance might be to determine the influence of plant vitality on insect/disease-plant relationships. This work must be done in cooperation with plant physiologists to define physiological parameters associated with plant vitality. We must also work with landscape horticulturists to determine which cultural practices reduce vulnerability of landscape plants to important herbivores. A working hypothesis for this effort could be that most organisms that threaten survival of landscape plants are opportunists that exploit weakened hosts. Although the validity of this hypothesis requires rigorous testing, it is a conservative beginning, since there is evidence that improving tree vitality reduces impact of insects and fungal pathogens.

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Published

1989-09-01

Issue

Section

Literature Review Articles