This fall, the first full week of September saw overnight lows in the 70s on the 60,000 acres of land that is home to the cranberry bogs of southeastern Massachusetts. At this time of year, cranberry growers and the researchers at UMass Amherst Cranberry Station want to see nighttime temperatures in the 50s or lower in anticipation of harvest. 

Dean Mike Fox, Lynne McLandsborough, and Hilary Sandler standing in a cranberry bog
From left: Dean Mike Fox, Lynne McLandsborough, and Hilary Sandler

The red pigments that give cranberries their signature color—anthocyanins—are produced in the fruit as a response to environmental cues, like day length and temperature. Cool nighttime temperatures are key for pigment production. Without cooler temperatures, cranberries remain white or pink and growers are “chasing color” in a race against time—waiting for the berry to turn deep red so that it can be harvested and fetch a fair price by processors. Delaying collection of the berries for too long increases the risk of cranberry fruit rot (CFR) and this reduces the yield. 

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A team of UMass Amherst Cranberry Station researchers has received $1.19 million to explore sustainable solutions to address fruit rot and reduce the threat to cranberry production in Massachusetts. These scientists know that at least 15 fungal species are associated with the rot, and it is unknown how other microbes contribute to cranberry fruit rot (CFR), or how climate change will affect the disease and the cranberry industry, which contributes over $1.7 billion annually to the Commonwealth’s economy. 

Giverson Mupambi at UMass Amherst Cranberry Station
Dr. Giverson Mupambi in the bogs at UMass Amherst Cranberry Station

When a grower delivers a truckload of cranberries to a processor, a sample is collected in a long, clear tube to test the cranberries for color, firmness, and ripeness. Growers are paid for fruit based on a variety of factors—firm, red cranberries bring a higher market price than white or pink berries. Rotten fruit has no value to a processor like Ocean Spray® and is separated out in processing for use as compost. 

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Cranberry plants can survive for two hundred years with care and cultivation. Massachusetts cranberry growers average 60 years of age and are often the fifth or sixth generation working the land.

UMass scientists at Cranberry Station conduct vital work, in the labs and alongside growers in the bogs, to support the economic viability of the Massachusetts cranberry industry and to protect the environment for many generations to come. 


Annual Massachusetts cranberry industry in billions of dollars


Acres of land in Massachusetts that is home to the cranberry bogs and related industry


Number of years cranberry plants can survive with care and cultivation