The use of native perennial wildflowers and alfalfa trap crops to increase pollination and biological control in strawberries

The use of native perennial wildflowers and alfalfa trap crops to increase pollination and biological control in strawberries

Summary

The purpose of this project is to provide small fruit growers in the Northeast with a simple and effective management strategy for enhancing biodiversity and ecosystem services (biological control and pollination) using native perennials and alfalfa in companion plantings. We expect that planting wildflower-alfalfa strips will increase abundance and diversity of native bees resulting in greater pollination services and higher fruit yields. Similarly, we expect the wildflower-alfalfa strips to increase parasitism rates of the tarnished plant bug resulting in decreased fruit damage and higher yields. Additionally we will measure the relative benefits of using wildflowers or alfalfa alone or together to determine the role of each in enhancing ecosystem services and to explore potential synergistic effects.

Objectives/Performance Targets

My objectives are to:
1. Quantify the influence of wildflower-alfalfa strips on pollinator community composition and pollination services in strawberry.
2. Investigate P. digoneutis biological control of tarnished plant bug to determine
a) if parasitoids near Wildflower-Alfalfa strips achieve a higher parasitism rate and,
b) if high parasitism correlates with reduced pest damage in the field.
3. Disentangle the relative benefits provided by either wildflowers or alfalfa through increased pollination and/or biological control on strawberry yield.

No objectives fully accomplished yet.

Accomplishments/Milestones

To accomplish these objectives we have established 36 paired 15’x20’ plots of Jewel, a June bearing variety of strawberry on 15 farms in the finger lakes region of NY. Half of the plots had a strip (3X20’) of native perennial wildflowers (10 species, we were unable to successfully grow the late figwort and alum root) planted as plugs parallel to an end row in October 2012. These plots also had a strip (2×20’) of alfalfa planted between the wildflowers and the end row of strawberry. All other sides of the plots had grass seeded with control plots at each site receiving grass on all sides. At three of the 15 farms two additional strawberry plots were established with either wildflowers only, or alfalfa only to address objective 3.

Now that plots are established we can begin our field projects starting in the spring of 2013. The project is progressing as planned and establishment of plots including wildflower-alfalfa strips has been better than expected. The survival of these plots through the first winter will be critical to the success of the project and we are making every effort to ensure their survival. The only change in plan so far was that the two above mentioned wildflower species were not in the mix and the yellow coneflower did not germinate however we were able to substitute Indian hemp (Apocynum canabinum)

Impacts and Contributions/Outcomes

If successful this project has the potential to significantly reduce pesticide use and reliance on managed honey bees for northeastern strawberry farmers. The adoption of wildflower-alfalfa strips for ecosystem services presents not only an economic gain for farmers but can also assist in the conservation of out native beneficial insects. As we have not yet started collecting data our impacts have been limited. Thus far, I have been in regular contact with the owners and managers of the farms where my research plots are located. Through these interactions I have raised awareness about the potential for biological control of tarnished plant but and the negative impact pesticides can have on its natural enemies. I have also called attention to the necessity of insect pollination of strawberry flowers and the current decline on abundance and diversity of our native bee species. Additionally, my preliminary field work suggests that native bees a more important than honey bees as strawberry pollinators.

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