Location: Southern Horticultural Research2010 Annual Report
1a. Objectives (from AD-416)
Develop strategies for controlling insects that are problematic in nursery settings (e.g., fire ants, tree borers, Japanese beetles) in the southeastern United States and/or develop strategies for implementation of low-residual pesticides.
1b. Approach (from AD-416)
1) Elucidate the physiological chemical ecology of fire ants and other insects that are problematic in greenhouses, container pads, fields, and other environs suitable for growing ornamental crops. 2) Develop spray strategies to best use pesticides (specifically fungicides) that have low residual acitivity.
3. Progress Report
Research addressing a number of plant pest issues affecting the nursery industry was conducted. New treatment regimes for control of imported fire ant have been tested for possible adoption as quarantine treatments. Preliminary results indicate a 100% control utilizing a banded application of bifenthrin coupled with individual treatment of large fire ant mound. In the tests to date, this treatment regimen provides a 5 month ant-free window. This is a significant change to the current treatments which are labor intensive, costly and provide only a 84-day window. After replication, the new procedures will be proposed to APHIS for adoption as a regulatory treatment. This new option will provide growers with the means of using fewer pesticides and lower labor costs to achieve their business objectives. New procedures have been developed for inducing attack by buprestid beetles on nursery trees. The development of these procedures will make testing control strategies more efficient. Previously, researchers had to rely on natural attacks of these insects to test new treatment options, natural attacks are sporadic and not predictable. Much more rapid advances in treatment efficacy trials are now possible for this important nursery insect. Measures of population shifts among imported red, black, and hybrid fire ant have been conducted. The three species exist in Tennessee; this research provides an assessment of the inter-species dynamics and is particularly important in the area of biological control. Most biological control agents for fire ant are species-specific, and it is important to determine which species will dominate in given environments. In the area of plant pathology, we continue an emphasis in disease control in flowering dogwood, continuing long term research to improve dogwood production through improved host resistance, development of biorational products, implementation of biological control methods, and improved timing of treatments. Identification of microorganisms cultivated from feral environments has progressed, a number of organism have been identified that have potential to exclude the mildew pathogen from its intended host plant. These organisms have potential as biopestides. Research continues in field surveys to document important soil and water-borne pathogens in Tennessee soil and plant tissues, identify Verticillium, Fusarium and others pathogens and determine their incidence, hosts and economic significance, and to develop an educational tool on Phytophthora diseases for nursery growers to help them make informed decisions on disease management strategies. In response to stakeholder concerns, an examination of a defoliation problem in Flowering Cherry led to the identification of a pathogen not previously known to occur in Tennessee. Research has identified control measures for this disease. Testing is underway to confirm the efficacy of treatments in commercial nursery production settings. The ADODR or his representative meets regularly with the cooperating scientist, and these meetings include site visits.