Faculty contact:  Ian Merwin

Orchard agroecology studies focus on alternative strategies in orchard weed and soils management, effects of water and nutritional stress on fruit trees, interactions between cover crops and soilborne plant pathogens, orchard replant problems, and the agroecology of perennial crop systems.

Recent studies include:

• Comparisons of Organic and other Sustainable Fruit-growing Systems - A systems-level comparison of organic and IFP (integrated fruit production-also known as "green" or "ecological" production in Europe) apple production in a representative commercial orchard. We are evaluating tree physiology and fruit yields, insect and disease pest incidence, soil quality, nutrient uptake by trees, nutriceutical attributes of fruit, consumer perceptions and preferences of Organic vs. IFP apples, and the economic costs and returns of each system.
• Bio-based Management and Etiology of Apple Replant Disease - Apple replant disease (ARD) is a common problem typified by stunted growth and reduced yields in successive plantings of apple at old orchard sites. We are testing several methods of controlling ARD and exploring the causation and ecology of this soilborne disease. Methods include preplant soil treatments, using different rootstocks and replanting in the old rows vs. old grass lanes.
• Long-term Studies of Alternative Orchard Groundcover Management Systems (GMSs) - Soil and groundcover management systems are important in perennial crop systems because of their effects on soil conditions, nutrient availability, tree growth and yields. We are taking a multi-disciplinary approach to study including measures of soil microbial abundance, activity and community composition, to study the long-term effects of different GMS on biotic and abiotic factors in an orchard soil.
• Vineyard Management to Minimize Winter Cold Damage and Maximize Fruit Quality - We are pursuing several lines of research involving vineyard floor management systems such as reflective geotextile and organic mulches, root pruning and cover cropping, over-wintering protective strategies for cold-tender vinifera winegrapes, and the effects of irrigation and soil drainage on vine establishment and berry quality.