Project Highlights
Fish extracts for integrated disease, insect, and fertility management in organic blueberries in the Southeastern U.S.
Investigator: Harald Scherm, University of Georgia, Athens, GA
Project location: south central Georgia
Summary
The purpose of this project is to develop a system for disease, insect, and nutrient management in organic blueberries centered around foliar applications of fish extracts, a renewable resource. Blueberry is the most important fruit crop in Georgia, and organic blueberry acreage is expanding rapidly in the state and in neighboring Florida. However, pest management options for organic blueberries are currently very limited. For example, sustainability of production is threatened by foliar diseases which cause premature defoliation in the summer, reduced flower bud set during the fall, and lower return yields the following year. In a recent field trial with a number of organic fungicides, two OMRI-approved fish extracts provided substantial control of Septoria leaf spot, the most important foliar disease on blueberry in Georgia. Based on these preliminary results, a primary goal is to compare and demonstrate the efficacy of several such products against the leaf diseases complex on organic blueberries.
Blueberry leaf beetle feeding on young shoots on organic rabbiteye blueberries. In fields where weed suppression is
sub-optimal, hordes
of beetles can move rapidly from senescing weeds to the crop and destroy large amounts of vegetative tissue in a short period of time.
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Foliar diseases such as Septoria leaf spot reduce photosynthesis of affected plants during the summer, and lead to premature defoliation in the fall, thereby severely reducing flower bud formation and yield in the following year.
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Insect and nutrient management are also major challenges in organic blueberries. The blueberry leaf beetle can destroy the tender new vegetative growth produced after berry harvest during the summer. Furthermore, nutrient supply is often inadequate, leading to reduced shoot growth and flower bud formation, thereby providing a poor foundation for next year’s yield. In a systems context, the added value of fish extracts as foliar fertilizers and/or insecticides or insect repellents would provide a powerful incentive for their use as summer sprays in organic blueberries. Thus, additional objectives are to evaluate leaf beetle suppression, foliar status, and plant growth in organic blueberries treated with fish extracts.
Project objectives are:
- Compare and demonstrate the efficacy of several fish products against foliar diseases of blueberry in a certified organic setting;
- Evaluate blueberry leaf beetle suppression in fish extract-treated plots;
- Determine the nutritional benefits of fish extract applications by measuring foliar nutrient status, plant growth, and flower bud formation in treated plots.
A final report describing the results of this project is expected in July 2011.
Contact:
Harald Scherm
Professor and Graduate Coordinator
Univ. of Georgia, Dept. of Plant Pathology
2311 Plant Sciences, 120 Carlton St.
Athens, GA 30602
tel. (706) 542-1258
E-mail: scherm@uga.edu
Skype: scher27205
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Collaborating producers:
J. Allen Miles, Sunbelt Blueberry Company and Miles Berry Farm, Baxley, GA
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OFRF funding awarded:
Fall 2008: $39,295 (2 years)
Funding category: Research
This project was funded in partnership with Stretch Island Fruit Company. |
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