Research assistant Caleb Slemmons helps to set up one of a network of weather stations used to monitor conditions to help blueberry growers across Maine. Photo courtesy of University of Maine

by Enrico Villamaino

The University of Maine’s School of Biology and Ecology was recently endowed with a grant from the USDA to enable pomologists to research means of promoting blueberry cultivation in the State of Maine.

The grant was awarded by the USDA’s Specialty Crop Research Initiative (SCRI). SCRI grants fund the work of professionals in the specialty crop industry. To be eligible for a grant, a proposal must address at least one of five general areas of study: plant breeding and genetics, addressing threats from pests and diseases, improving production and processing efficiency, new innovations and technology and food safety hazard prevention and response.

Dr. Seanna Annis has worked as an associate professor of mycology and associate Extension professor at the University of Maine since 1998. Her research has largely focused on fungi as plant pathogens (in particular the genetic diversity, physiology and molecular biology of various fungal pathogens) and applied aspects of the controlling of fungi that attack lowbush blueberry plants.

Annis’s grant proposal delineated her plan to collect, format and distribute valuable data about blueberry crop health and conditions to growers in a timely manner. She is continuing the work she began eight years ago and submitted for review in mid-2020. The Maine Department of Agriculture, Conservation and Forestry, which makes the final decision on who will receive SCRI grants, allocated $79,994 for her project.

Annis explained, “Starting in 2012, we set up a network of 15 weather stations. These stretch all the way from Waldoboro to Crawford, covering the region of the state best suited for growing blueberries.” Using a cellular network, the station relays weather information to Annis’s lab. The data are then processed and relayed to subscribing farmers across the state. “We look at things like the air temperature as well as the level of and duration of wetness in the air. We then use algorithms to calculate the risk of the likeliest infections to blueberry plantings.”

To maximize the amount of growers she’s able to assist, and realizing that not all farmers are easily reached by any one method, Annis disseminates her findings through an app, a website, email updates, blog posts and recorded voicemail notifications.

Outlining what she believes are currently the two biggest threats to blueberry farms in Maine, Annis called attention to a pair of diseases.

“Mummy berry disease is our biggest challenge,” she said. Caused by the pathogen Monilinia vaccinii-corymbosi, mummy berry disease results in the replacement of blueberry fruit with a fungal mass which can often lead to considerable crop loss. “Mummy berry attacks leaf buds just as they’re opening. And the real problem with mummy berry is that it’s gone native. It’s adapted to our climate, so it doesn’t die off during the winter.” Early symptoms of the disease include the wilting of leaves and newly formed pinkish leaves will often turn a rosy brown.

Botrytis blossom blight is a condition caused by the pathogen Botrytis cinerea. “It’s on open flowers and nearly open flowers, so you really have to look out for it as your plants are getting ready to bloom,” Annis said. Botrytis is an excellent colonizer of dying plant tissues, and can cause leaf spots and crown rot. Growers on the lookout for this disease should keep an eye out for the wilting of tender shoots.

Annis hopes her project will help growers stay vigilant and treat these diseases in their earliest stages. At the conclusion of her research, Annis will submit a final report to the Wild Blueberry Commission of Maine’s advisory board.

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