Robert Stewart

Project overview

Robert, a graduate from Queen’s University Belfast, gained his degree in 2017 with a BSc (Hons) Biological Sciences, before immediately beginning his PhD project entitled: Ecosystem Based Approaches to Apple Orchard Management. Carrying on from previous research he explored during his undergraduate studies. Robert’s project focuses on exploring and developing ecological approaches to ensure the sustainable management of apple orchards.

While these systems are intensively managed, to control pests, disease and plant-life competing for resources, it is recognised that orchards require pollinators, that the orchard provides a habitat for natural enemies that can control pest species, and that the soils in orchards contain many small microarthropods, fungi and bacteria that are essential for maintaining plant and ecosystem health. Healthy trees and healthy ecosystems translate into more fruit and higher profits. How the networks of pollinators, natural enemies and soil invertebrates integrate together to maximise the functioning for the system is the primary focus of Robert's PhD

The project will test a range of simple management interventions to minimise the total number of sprays required by the grower to ensure a profitable crop is collected, while incidence of loss due to pest/disease is kept to a minimum.

He is developing a “Smart Orchard” approach to orchard management using specially tailored wildflower seed mixes that will allow for new populations of solitary bee species, and other pollinators to colonise the orchards and be localised throughout the year, with a constant food source, while being able to deliver an increased pollination service during the apple blossom period.

Furthermore, the historical effects of the intensive management strategies will be examined in relation to both the above-ground and soil communities from orchards of varying ages, to create a dynamic understanding of how these communities can undergo dramatic changes through the consistent management strategies employed by apple growers over the lifespan of a natural apple orchard.

The project will survey the pollinator biodiversity within the orchards, and measure their pollination potential to detect any pollination shortfall caused by their lack of abundance. Management regimes in the orchards that might benefit and sustain pollinator populations year round is a major focus for the study.

Furthermore, the project will also investigate the relationship and create a platform for local beekeepers raising the Irish black honey bee, Apis mellifera mellifera, and the growers within Armagh, as these native bees are better adapted to dull and drizzly weather, a hallmark of Northern Irish climate.