Biological Control of Blueberry Anthracnose and Cranberry Fruit Rot: Exploiting Fungal Responses to Blueberry and Cranberry Bloom in Biocontrol Treatments

View the project final report

• 2013 annual report
• 2014 annual report

Commodities

• Fruits: berries (blueberries), berries (other)

Practices

• Crop Production: biological inoculants
• Education and Training: extension, networking, on-farm/ranch research
• Pest Management: biological control, chemical control
• Production Systems: organic agriculture

The problem: blueberry anthracnose, the driving force behind blueberry fungicide regimes in the northeast, cannot be controlled without the use of chemical fungicides. I am investigating alternative control methods using novel information on the pathogens life cycle discovered during my MS research on this disease. Utilizing data collected from blueberry floral-extracts I have discovered that host floral extracts have a significant stimulatory effect on sporulation and appressorium formation of the causal agent C. acutatum. Inclusion of the floral extract in pathogenicity assays significantly increased disease. These results have led to the conclusion that aqueous floral extracts provide a vital signal to increase virulence and enhance disease. In this project I will test several potential biocontrol agents to compete for and deactivate the stimulatory effects of floral extracts and evaluate the efficacy of these organisms in field trials. The project will give the opportunity to develop a bioassay for testing and evaluating biocontrol agents for anthracnose control and validate the bioassay through field trials. Among the biocontrol agents being tested Serenade® MAX is already labeled for use on blueberry and has been shown to have activity against anthracnose in some field trials. Thus, if successful improved recommendations on the timing and use of Serenade® MAX would be in place by the conclusion of this SARE grant. It is also likely that proposed uses would be compatible and could enhance the traditional chemical-based programs and ultimately help reduce fungicide use.

1. Develop bacterial bioassay to test whether or not the biological control candidate
bacteria are suitable to use in the field.
2. Develop new biocontrol solutions using Paenibacillus sp. isolated from cranberry,
two bacterial isolates cultured from grape cultivars, GCF and GT.
3. Compare efficacy of 1. Standard Rutgers Extension recommendations (multiple
fungicides) 2. Serenade® MAX 3. Paenibacillus sp. isolated from cranberry 4. GCF 5. GT 6. Combination treatment of biocontrols at [1:1:1]; Paenibacillus sp., GCF and GT 7. Water only 8. Non-treated, in the control of blueberry anthracnose. Anthracnose amounts will be visually assessed by collection of immature fruit post pedal-fall then collections of mature fruit through the rest of the growing season.
4. Microscopy will be performed on representative fruit from all treatments at every developmental stage at seven-day collection intervals. Graduate student will be assessing number of conidia present as well as appressoria formation.
5. A storage test will be preformed once bushes start producing mature fruit. Fruit will be collected every seven days and visually assessed for anthracnose 1wk, 2wk, 3wk and 4wk post collection.
6. Outreach: Results will be disseminated at 2014 National APS meeting, 2014 NE Division of APS meeting, face-to-face with growers at Rutgers Extension twilight meetings and online via an instructional video concerning the synthesis, application and efficacy of newly described biocontrols and lifecycle of blueberry anthracnose.