Incorporating a Cover Crop into Field Grown Nursery Production to Manage Flatheaded Appletree Borer with the Simultaneous Benefit of Improved and Sustainable Weed Management

View the project final report

• 2016 annual report

Commodities

• Agronomic: annual ryegrass, clovers
• Additional Plants: ornamentals, trees

Practices

• Crop Production: cover crops, nurseries
• Education and Training: on-farm/ranch research
• Pest Management: cultural control, integrated pest management
• Production Systems: agroecosystems

The purpose of this project is to investigate the use of cover crops to prevent flatheaded appletree borer (FAB), Chrysobothris femorata (Olivier) (Coleoptera: Buprestidae) attacks on maple trees and suppress competitive weeds in tree rows and middles. Flatheaded appletree borer has long been identified as a significant economic pest in orchards, nurseries and urban landscapes. Larval tunneling by FAB can girdle small trees, causing rapid decline of economically important hosts, with some nurseries reporting infestation rates of 30% or more on susceptible tree species. These infested trees can be killed outright by trunk girdling or rendered unmarketable due to borer damage. In production nurseries, red maples are one of the most problematic trees for FAB attacks in Tennessee.  Frequency of FAB attacks in nurseries varies for a number of reasons, including timing of protective sprays, size of trees at planting, site conditions, and localized borer populations.  Transplant stress alone does not explain attack frequency because FAB damage continues to be added to nursery blocks over time.  Since any FAB damage ruins the marketability of a nursery tree, the economic threshold for damage is essentially zero. Therefore, treatments or cultural practices that prevent FAB damage are very important to nursery growers to prevent economic losses.

Our preliminary research suggests that the presence of a winter cover crop may be a favorable option for nursery growers, acting as (1) a barrier to FAB oviposition in the spring and early summer, (2) an aid to preventing leaching of imidacloprid from the root zone of the trees and (3) as a natural suppression system for opportunistic weed species. We therefore propose a systems approach to in-field nursery tree production by incorporating a winter cover crop system combined with optimized pesticide use in order to simultaneously maximize FAB control and plant growth while minimize crop damage, weed competition and insecticide runoff.

For the performance period described here, objectives were to: 

• Establish 2015 winter cover crop
• Take initial maple tree measurements
• Transplant trees into the field
• Stake and fertilize trees
• Train masters student(s) in imidacloprid ELISA techniques
• Begin spring plot evaluations
• Treat insecticide plots