Current Projects

Alternative Management Strategy Development

Develop effective alternative management strategies for key insect pests. Specifically, our research emphasizes the development of beneficial entomopathogenic (insect-killing) nematodes for pest suppression.  These nematodes only attack insects and are not harmful to plants, humans or the environment. Our primary target pests are peachtree borer (Synanthedon exitiosa), lesser peachtree borer (Synanthedon pictipes) and plum curculio (Conotrachelus nenuphar). -Dr. David Shapiro-Ilan

Breeding

Breeding stone fruit adapted to the production environment of the Southeastern United States. -Dr. Chunxian Chen (USDA), Dr. Tom Beckman (USDA)

Germplasm collection of the North American Plums (Prunus, Rosaceae) and their Phylogeny. Dr. Dario Chavez (UGA), Dr. Tom Beckman (USDA), and Dr. Jose X. Chaparro (UF)

Stonefruit rootstock breeding and development for resistance to soilborne diseases and parasitic nematodes. -Dr. Tom Beckman (USDA)

Brown Rot Control

Fungicide trial to determine the best chemical management of brown rot on peach at the University of Georgia Horticulture Farm. Peach trees received various fungicide combinations prior to harvest. Peaches were harvested and monitored for the appearance of brown rot. -Dr. Phil Brannen

Disease management

Etiology and integrated management of diseases of fruit crops. -Dr. Harold Scherm

Theoretical and applied epidemiology. -Dr. Harold Scherm

Herbicide Damage Assessment

Trial to test the damage done to peach seedlings due to herbicide exposure. -Dr. Dario Chavez and Dr. Mark Czarnota

Hormone Application Effects

Plant growth regulators spray applications were made to two late-ripening varieties: ‘Ruston Red’ in Lane Southern Orchards, Byron, GA; and ‘Early August Prince’ in Pearson Farms, Marshallville, GA and in Lane Southern Orchards, Fort Valley, GA. The objective of this trial was to measure the effect of the plant growth regulators, ProGibb® and Retain®, in fruit firmness at harvest. Several other fruit qualities were also assessed including acidity, brix, and fruit size. -Dr. Dario Chavez

Lesser Peachtree Borer Control

Given that this pest attacks the tree above ground, it is a difficult target for beneficial nematodes because the nematodes are highly sensitive to UV radiation and desiccation. To overcome this obstacle, we developed an effective application approach that uses a sprayable gel (Barricade®) to protect the nematodes from adverse environmental conditions. Using the sprayable gel along with nematodes (S. carpocapsae) caused substantial suppression of lesser peachtree borer (Shapiro-Ilan et al., 2010).  In our current research, we are optimizing the formulation further to develop an improved tank mix. -Dr. David Shapiro-Ilan, Dr. Ted Cottrell, Dr. Dan Horton

Management Guide

Editing the annual revisions of the Southeastern Peach, Nectarine & Plum Pest Management and Culture Guide. -Dr. Dan Horton (UGA)

Mating Disruption for Peachtree Borer and Lesser Peachtree Borer

Mating disruption trials in commercial orchards continually indicate that larger test plots are required. During 2015 and 2016, about 1,000 acres of contiguous peach acreage will be put under mating disruption and monitored for efficacy both years. This demonstration study will address the issue of plot size and help determine the viability of mating disruption as a tool for SE commercial peach production. -Dr. Ted Cottrell, Dr. Dan Horton, Jeff Cook, Frank Funderburk

Peach Thinning Trial

Fruit thinning is a horticultural practice done by peach growers in order to obtain large fruit size and prevent branch breaking. The timing of this thinning determines whether the tree is bloom thinned, or fruit thinned. There are advantages to each of these practices. Trees at the USDA -ARS Fruit and Tree Nut Research Station were used to study the effects of different thinning practices on fruit size and quality. Trees received either bloom thinning, fruit thinning, or no thinning. Fruit size, total fruit weight per tree, and several other qualities were assessed. -Dr. Dario Chavez

Peachtree Borer Control

In our published research we have observed > 90% suppression of peachtree borer larvae when beneficial nematodes (Steinernema carpocapsae) are applied in the fall or in the spring (Cottrell and Shapiro-Ilan, 2006, Shapiro-Ilan et al., 2009). Currently, we are cooperating with University of Georgia and University of Florida scientists to determine irrigation requirements and the optimum method of application that the growers can use to control the pest, e.g., we are comparing application using a boom sprayer, trunk sprayer, handgun, etc. -Dr. David Shapiro-Ilan, Dr. Ted Cottrell, Dr. Dan Horton

Organic control of peach tree borer through application of entomopathogenic nematodes at organic peach tree grower located in Fayetteville, GA. -Dr. David Shapiro-Ilan, Dr. Ted Cottrell, and Dr. Dario Chavez

Plum Curculio Control

We discovered that the beneficial nematode, Steinernema riobrave, is highly virulent to the below-ground stages of plum curculio.  In the laboratory as well as in multiple field trials we have observed > 90% control of these insect stages (Shapiro-Ilan et al., 2004; 2008, 2011, 2013).  Our current research efforts are geared toward using nematodes in an integrated control program, e.g., we are exploring the potential to use sentinel trap trees to concentrate plum curculio within the orchard, and then kill them within those areas. Dr. Shapiro-Ilann, Dr. Ted Cottrell, Dr. Dan Horton

Root-feeding Weevil Control

An examination of peach roots has shown extensive feeding injury due to the larval stage of root-feeding weevils. The primary culprit were found to be two species of flightless weevils: Fuller’s rose beetle and the two-banded Japanese weevil. -Dr. Ted Cottrell, Dr. Dan Horton

Sap Beetle/Picnic Beetle Biology and Management.

The sap/picnic beetle complex is an emerging pest of peaches in both SC and GA. These beetles attack as fruit ripens, when it would be desirable to limit additional insecticide applications. The South Carolina Peach Council has funded our work to date.

a) Preliminary attract-&-kill trapping efforts in Meriwether County, GA and Edgefield County, SC showed promise. This technique has given control of Carpophilus dimidiatus sap beetles in Australian stone fruit. We are unaware of other use of this technique in the US.

b) Collections have been made season-long to begin the process of defining the species complex and its seasonality.

c) Joe McHugh, UGA’s insect systematist, is working to clarify Carpophilus taxonomy. The C. dimidiatus species group is particularly difficult to definitively ID, even for experts in this group of beetles. Joe is collaborating with Andrew Cline, California Department of Food & Agriculture, who is regarded as the authority on Carpophilus taxonomy.

d) Ted Cottrell is heading up laboratory toxicology work with both Carpophilus (sap) and Glischrochilus (picnic) beetles to determine their baseline susceptibilities to peach insecticides. –Dan Horton, Ted Cottrell, Joe McHugh, Greg Henderson, Trey Gafnea & Brandon Nolan.

Scab Control

Fungicide trial to determine the best chemical management of peach scab in middle GA at the USDA-ARS Fruit and Tree Nut Research Station. Peach trees received various fungicide combinations at shuck split and petal fall. Peaches were then collected and scab damage was assessed. -Dr. Phil Brannen

Stink Bug Control

Sampling has determined peach activity period for brown stink bug attacking peach and pesticide efficacy testing has helped determine which products to use against the brown stink bug. Current research is assessing the role of barriers and trap crops for preventing stink bugs from entering orchards. -Dr. Ted Cottrell, Dr. Dan Horton, Dr. Glynn Tillman-USDA, ARS, Tifton