What You Need to Do for a Successful Blueberry Harvest This Summer

Our friends at Cornell Cooperative Extension have shared these important tips for ensuring the success of this season’s blueberry crop.

Blueberry harvest is underway and looks surprisingly good in most places – despite the May freeze, early drought, and occasional hail events around the region. Fruit is sizing very well and plant growth is great – these plants LOVE all this rain! But unexpected weather is when you will discover how effective your disease management program was.

Anthracnose fruit rot (Colletotrichum acutatum) is widely apparent in plantings. This disease should be prophylactically sprayed before and during bloom. You can spray now in hopes that you can thwart the spread of the disease, but look carefully at the REI and days to harvest all chemicals.   

This disease will present as a sunken spot on the fruit. In this humid weather, you will undoubtedly see the pink-orange fruiting spores that will grow on the sunken areas. Make a note to focus on next season to control this disease.

Mummyberry (Monilinia vacinii-corymbosi) is less widely apparent, but definitely out there. Mummyberry spores can be moved by pollinators, so even if you’ve never dealt with this disease before, there is always a chance. That is why we encourage growers to manage for it, despite the history in your own patch. This disease is controlled at the vegetative green tip – so pretty early in the spring. 

Blueberry tip borer moth (Hendecaneura shawiana) is a pest that we are seeing much more frequently than in the past. The pest doesn’t damage the fruit from this season. But the overall impact is more significant. The moth lays eggs in the tip of the newest canes, causing the cane to abort vertical growth and branch much lower than it normally would. This means that there is less opportunity for overall growth, the fruiting wood is too low, and over time the plant becomes less productive due to the architectural change. 

The small brown moth lays eggs in June, which hatch in July. The larvae drill down several inches, causing distortion and then death of the shoot tip. This flagging can look something like canker, but it’s more localized to the top 6” of the shoot. There are no labeled conventional insecticides. Use azadirachtin and pyrethrin products at petal fall for control.  

Japanese beetle (Popillia japonica) have started feeding on blueberry foliage. I’ve yet to get a report of fruit feeding, but that is when they become a problem worthy of spraying. Despite the foliar damage, they usually don’t do lasting damage to the plant. There are many pesticides that can be used on this insect, but don’t pull the trigger unless you really need to and make sure to read the label for Days to harvest. 

Canker diseases (Fusicoccum putrefaciens and Phomopsis vacinii) are exhibiting the tell-tale cane flagging. New shoots will wilt rapidly and die back from the tip towards the crown. Healthy vigorous canes will wilt and collapse. When you see this happen in an otherwise perfectly healthy plant, the likelihood is high that it’s canker. Fusicoccum canker forms bulls-eye type lesions on the stem, which is another diagnostic help. Prune the dead out as it appears and make a note to use a delayed dormant spray next spring.  

Entomology Update with Monique Rivera

This is a summary of the new Scaffolds Podcast, as featured on the CE Eastern NY Commercial Horticulture Program blog. Click here to listen to the podcast.

Well, folks, it looks like we're off to a weird start to the season with a week of summer weather and now in western New York, cooler and wetter conditions. Maybe a weird start is more like a stumbling start because it will warm up again for a day or two in western New York, and then go right back to cool and wet. But either way, we are collectively heading towards Pink, and there are, as always, some insects to consider and think about treatments for. 

If San Jose scale is a concern, it's not too late to include a treatment for this. There are still options until foliar development progresses to the point where coverage will decline. So the real aim of this treatment is to make contact with the woody parts of the tree and hopefully make contact with any eggs or immatures that are there. So if you're focused on getting an oil applied for this, there's still time for a 1% oil spray through tight cluster again to cover those woody surfaces. If you think you will need more control, there are other insecticidal options to add. In particular, I would consider Centaur or Esteem, both of which are insect growth regulators. 

So last week I spoke about the idea of bulletproofing IPM programs, and I think a good thought experiment about that would be to think about what your management program would look like if Organophosphates and Pyrethroids, for example, were eliminated. The idea of this is kind of ridiculous because organic management can use Pyrethrins, which are the direct plant extract, but in all honesty, at higher levels this is being considered.

And it's something that along our journey here on Scaffolds, I probably will continue to mention, because if we don't think about it now, I really think that it will sneak up on the industry as things start to be considered for elimination. And so it would be good to start to think about again what your program would look like if you could not use whole classes or mode of actions of insecticides. It would be really helpful to your future programs to start considering that. Not that I know that this is coming down the pike in New York State, but I do know that in California, before I left, I was asked to review the use of pyrethroids, which is the beginning of that consideration. 

Cornell’s Juliet Carroll Earns Excellence in IPM Award

Dr. Juliet Carroll, Fruit IPM Coordinator at Cornell University, earned the Excellence in Integrated Pest Management (IPM) Award from the New York State Integrated Pest Management Program (NYSIPM) at the Viticulture day of the B.E.V. (Business, Enology, Viticulture) conference in Rochester. The award honors individuals who encourage the adoption of IPM in their businesses, schools, communities, and farms, and who develop new tools and tactics for sharing these practices.

Dr. Carroll spearheaded the expansion of NEWA, a website and network that allows growers to understand how the weather will affect fungal and insect pests, and takes the guesswork out of their pest-management strategy. Carroll ran NEWA for over a decade. Under her leadership, NEWA went from 45 weather stations in New York State to over 500 in 12 states. Her work, along with Wayne Wilcox and Greg Loeb, on improving the user experience with the grape disease and grape berry moth models on NEWA, had an enormous impact on the implementation of grape IPM in New York.

Dr. Carroll also led the development of Trac software. Introduced in the early 2000s, the software simplified and digitized pesticide recordkeeping for large and small growers and processors alike. It allows farmers to input the information once, and generate customized reports for different processors. The software also includes reference to “IPM Elements” for grapes and other crops—a tool that helps growers assess their pest management practices.

Dr. Carroll built Trac software for five fruit crops, and partnered with a colleague to create TracTurfgrass for golf, lawns, sports fields and sod farms. Luke Haggerty, grower relations representative for Constellation Brands, calls Carroll’s TracGrape software “a true breakthrough” in recordkeeping. Of her work with NEWA, Haggerty says, “Julie has always been very proactive in developing and delivering the products needed for our growers to produce grapes in an environmentally and economically sustainable way.”

Tim Martinson, Cornell Cooperative Extension Viticulture specialist, noted, “IPM is built on information and decision-making tools. Juliet has built TracGrape and NEWA into useful, practical tools for growers.”

Dr. Carroll also co-edited organic production and IPM guides for grapes and several berry crops, and has regularly presented at Lake Erie Regional Grape Growers’ conferences and Coffee Pot meetings. She has conducted research on devastating pests, such as spotted wing drosophila (SWD), investigating whether hungry hummingbirds can provide meaningful control.

In addition, Dr. Carroll has chaired the Northeast IPM SWD working groups for the past decade, bringing research scientists, growers, industry reps, and extension educators from across the region together to help find solutions. Carroll has also helped fruit growers with bird management.

Learn more about integrated pest management at nysipm.cornell.edu.