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

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

Summary

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 pathogenicity 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. SARE funding for 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.

Objectives/Performance Targets

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 pedalfall 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 sevenday 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.

Accomplishments/Milestones

The funded project has a start date of 03/01/2014. Biocontrols listed in proposal are currently being grown at large scale to insure the avaiblitly of these for the start of the blueberry growing season. I have located where to purchase materials stated in the proposal. A student worker, as descibed in the proposal, has been recruited for the summer of 2014.

Impacts and Contributions/Outcomes

 Projected OUTREACH

1. 2014 National APS meeting. National/international plant disease community. This is important for two reasons, blueberries are growing in popularity as an agricultural crop in new areas and the pathogen of topic affects many more systems than just blueberries.

2. 2014 NE Division of APS meeting. Regional plant disease community. The Northeast portion of this country grows numerous blueberries; both high and low-bush varieties. New Jersey is a great location to study the blueberry anthracnose pathosystem due to blueberries center of origin being the Pine Barrens of New Jersey. (Funding requested to attend this meeting)

3. Face-to-face with farmers at Rutgers Extension twilight meetings. This portion is what the whole proposal is getting at, actual engagement of the people who are going to use this information to make more money. The biocontrols created in this proposal do not use chemistry-based fungicides so it is safer for the farmers and anyone else out in the field. (Funding requested for semi-gloss computer paper for pamphlet construction)

4. Online via an instructional video for the Plant Management Network. Synthesis of this video will enable hardcore plant pathologist and growers alike to understand the biological mechanics, preparation, application and storage. (Funding requested for publication not fabrication of the video)

Projected IMPACTS

1. Core understanding of a fungal pathogen’s response to floral extracts and the overall bloom period on highbush blueberry.

2. Increased knowledge of bactreial biocontrols that can be utilized by organic, transition and commerical (non-organic) blueberry farmers. Increased number of bacterial biocontrols that can be utilized by growers.

3. Recomondations for commerical and synthesised (this project) bacterial biocontrol strategies.  

Collaborators: