Perceptions and outcomes of conventional vs. organic apple orchard management

Abstract

Organic farming can improve soil quality and provide effective pest control with reduced inputs compared to conventional farming. Although organic and conventional farming are often viewed as dichotomous, they may overlap in pest management and soil quality goals and outcomes. Here, we assessed similarities and differences between conventional and organic apple orchards in Washington State by quantifying pesticide program risk to natural enemies, soil quality, leaf nitrogen, and abundance of woolly apple aphid (Eriosoma lanigerum) and its natural enemies. We also interviewed orchard owners, managers, and consultants to learn about their practices and opinions of conventional and organic management for aphids and soil quality. Organic orchards used more insecticide applications than conventional orchards, but the insecticides used were rated as less harmful to natural enemies. Conventional and organic orchards had similar soil quality, pest abundance, and natural enemy abundance. Woolly apple aphid abundance was not correlated to soil, plant, or natural enemy measurements. Interviews revealed that management goals were similar in both systems. Overall, our results suggest that both conventional and organic styles of farming are heterogenous. For example, conventional farmers may simply follow recommendations for inputs of synthetic fertilizers and pesticides or go further by using some organic or integrated practices; at the same time, organic farmers can vary in their use of organically certified pesticide sprays and ecologically based management tactics. Our study suggests that integrated management strategies that use a mix of appropriate tactics may be more important than being strictly conventional or organic to achieve superior soil and pest management outcomes.