Tree Fruit: Horticulture Research Projects

Systems-based approaches to studying orchard agro-ecosystems

Over the past nine years, I have conducted a number of studies that aim to model whole-orchard ecosystems under different management programs, such as organic and integrated fruit production (IFP). Within these studies, I evaluate crop productivity, insect and disease control efficacy and damage, soil health, fertilizer and groundcover management practices, the maturity, phytochemical, and sensory quality of fruit, economic viability, and environmental impacts. These projects take on a multidisciplinary research approach to gain a deeper understanding of the complexity and interactions within farming systems.

Measuring soil quality in orchards using molecular, biological, physical, chemical indicators

This work explores the effects of groundcover and fertility management on soil health. Using PCR-based techniques, such as Terminal-Restriction Fragment Length Polymorphism (T-RFLP), I characterize changes in soil microbial community composition under different orchard management strategies, e.g., organic and integrated fruit production (IFP). In addition, I use a multitude of biological, physical, and chemical tools to understand the edaphic and soil quality features of treatments under study. These included microbial biomass, microbial respiration, potentially mineralizable nitrogen, aggregate stability, porosity, bulk density, organic matter, and mineral content.

Improving crop-load management for apples

In order for apple trees to produce high yields of marketable fruit year after year, crop-load needs to be adjusted by removing (thinning) flowers or fruitlets, or increasing/promoting the formation of flower buds for the following season. Growers often manage crop-load by applying plant growth regulators and other exogenous chemicals. These chemicals help improve fruit quality and prevent apple trees from only bearing fruit on a biennial basis. In my work, I aim to 1) improve our understanding of environmental interactions with chemical fruit thinners, and 2) gain improved knowledge of new tools and techniques that can increase a grower’s success in crop-load management.

Trialing crack-resistant cherry varieties

Although sweet cherries are a high-value tree-fruit crop, cherry production in Virginia has been limited due to production barriers, particularly the tendency for the fruit to crack just prior to harvest. In a trial initiated by Drs. Tony Wolf and Rongcai Yuan, we are evaluating a number of crack-resistant sweet cherry varieties, as well as exploring the possibility of growing cherry trees underneath screens or plastics to protect them from spring frosts and rain.

This project has received financial support from the Virginia Department of Agriculture and Consumer Services.