Evaluation of 12 Yellow Flesh Peach Cultivars for Organic Production in the Northeast

Evaluation of 12 Yellow Flesh Peach Cultivars for Organic Production in the Northeast

Summary

Selected yellow flesh peach cultivars were evaluated for the second year of a 2-year project in 2012 for their suitability for organic production in the Northeastern U.S. The 12 cultivars were selected based on their susceptibility to bacterial spot, and brown rot, and for good tree vigor, and fruit firmness. Orchard observations were recorded to determine each cultivar’s suitability for organic production.

Additionally, tree training as it affects tree and fruit exposure to sunlight and air circulation was managed utilizing the Perpendicular –V training system to optimize the successful production of organic peaches. Outreach for the information obtained from this project is occurring through extension newsletter articles, personnel communication and a final project handout summary which will include project goals, methods and a summary and analysis of the results will be prepared for distribution to interested growers through extension.

Objectives/Performance Targets

This project takes a broad approach to organic peach production understanding that quality peach production is a result of individual disease and pest organisms, the tree host response to pests based on the peach tree host’s health as supported or undermined by nutrition, training system and the environment both physical and biological. This project has observed, measured and recorded several contributing production inputs such as tree growth and vigor, soil and plant tissue nutrient levels, pest and beneficial insects in the orchard, and weather conditions that have contributed or detracted from the successful production of organically grown peaches in Adams County PA specifically with application for the Northeastern United States

Accomplishments/Milestones

Farm Operation Update: The first certified organic fruit was harvested in 2012 on the organic orchard planted in 2010 (Enterprise, Liberty, Goldrush, and Crimson Crisp and 12 cultivars of peach included in this study). Additionally, an organic apple orchard was established in 2012 which will increase organic fruit production on our farm to 7 acres including peaches and apples. We also lease 10 acres of mature wine grape vineyard (Chardonnay & Pinot Noir) on a near-by property. Our intention is to offer consumers both organic apples and peaches produced on our farm.

On both the bearing fruit orchard and newly planted orchard, tree training, nutrient and weed management advice is being provided by Dr. Robert Crassweller, Penn State University Extension Pomologist. Weed management consists of hand-pulling, a propane weed burner, and applications of Green Match herbicide which is approved for organic production. In 2011 and 2012, Dr. Rob Crassweller provided on-site instruction on tree pruning for the ‘V’ training system.

Project Activity for 2012: The 2011 annual report summarized the cultivar evaluations for organic production. Additional horticultural observations will be included in the final report submitted in February 2013. This annual report will briefly summarize the insect infestations and disease infections that occurred in the first bearing season of the orchard. Again, a full discussion of the insect and disease problems encountered with organically grown stone fruits will be presented in the final report in February.

Each cultivar was set up in two tree plots with five replications per cultivar. Insect counts and disease observations were made throughout the growing season. Bacterial spot, brown rot, and powdery mildew (rusty spot) were a focus of the project. Regular observations for bacterial spot on fruit and leaves were made across the replicated tree plots beginning just after bloom through harvest. No bacterial spot was observed. The peach cultivars were selected for low bacterial spot susceptibility so no bacterial spot disease was expected. No organic material controls were applied for bacterial spot control. Disease ratings for brown rot were made at bloom and 2 weeks before harvest. Weather conditions were dry until mid-July but then frequent rain showers increased the potential for brown rot disease development.

Brown rot was recorded on the later ripening cultivars where the fruit had been damaged by bird feeding and insect damage. Brown rot was 5% or less on damaged fruit of affected cultivars. Brown rot did not occur on undamaged fruit. Healthy fruit did not develop brown rot within one week in cold storage at 45 degrees F. Damaged and/or brown rotten fruit was picked from the tree and the ground when observed and removed from the orchard. Brown rot was not correlated with cultivar only damage and ripeness. Rusty spot caused by powdery mildew was observed at 5% to 10% levels across several cultivars beginning just after shuck split through harvest. No more than 2 spots were observed per fruit. By harvest the damage was slight on the fruit surface and did not affect fresh fruit quality in most cases.

Insects were observed across the peach cultivar plots from bud break through harvest. Pheromone traps and pheromone disruption was placed in the orchard in June for peach tree borer and oriental fruit moth. Peach borer traps caught 10 winged adults in one trap and 15 in another over a 7 day period immediately before the pheromone twist ties were placed in the orchard. No additional peach tree borers were caught in the traps after the twist ties were placed. Oriental fruit moth larvae were not found in any of the peach fruit harvested in 2012. No targeted pest control materials were applied specifically to control oriental fruit moth other than pheromone disruption.

Aphid colonies were recorded at a 5% level on new terminal growth in mid June. The colonies were controlled by lady bird beetles and larvae over the following four weeks with lady bird beetle adults and larvae reaching as many as 10 to 15 on the 5 aphid terminals observed per tree. Brown marmorated stink bugs, green stink bug insects and damaged fruit were first recorded in the third week of July. Damage from the green stink bug feeding was more severe and had a greater impact on fruit being eliminated for fresh fruit than Brown marmorated stink bug damage. Damage from both stink bugs was not higher than 10% on any of the peach cultivars. Generally, later cultivars had more stink bug damage.

Impacts and Contributions/Outcomes

The results of this project has improved the productivity of organically grown peaches in the Northeastern, reduced cost due to the natural resistance to disease of the cultivars and ultimately improve farm income by providing an approach for Northeastern farmers to grow and sell high quality organic peaches. There will also be a reduction in environmental and health risks since cultural and biological beneficial insect practices have reduced sprays and agricultural pollution.

Collaborators: