By: Karen Cahill, Cape Cod Cranberry Growers Association
Summer may be vacation season for most, but for cranberry growers it is one of the most important times of the year. The work done in June and July, along with the weather, will have a massive impact on the size and quality of the cranberry harvest in the fall.
Right now, the cranberry buds, which came out of dormancy and cracked open in the spring, are in bloom. [Side note: European settlers believed these small pink flowers to resemble the head and neck of a crane, dubbing them “crane berries”.] On most farms, commercial bees are brought in, usually 1-2 hives per acre, to assist native bees with pollinating the cranberry plants. Honeybees are hard workers, but they do prefer a dry day. Bumble bees will work earlier and later in the day and when cranberry bogs are wet. From mid-June to mid-July, the bees do their work, and fruit set occurs, meaning tiny green berries start to grow.
While the bees manage pollination, growers are managing critical input decisions to provide optimal nutrition for their plants and to fight off disease and pest pressures. Years ago, growers would make their input decisions based solely on the calendar. Now, the industry relies on Integrated Pest Management (IPM), which is not a single method but a continuous cycle of evaluations and actions. Workers sweep different areas of the bogs with butterfly nets weekly to get a sense of what insects are present and at what life stage. Leveraging the expertise of UMass Cranberry Station researchers, growers will determine at what threshold an intervention is necessary. Crop protection can come in the form of biological controls (natural predators, parasites or pathogens), chemical controls (pesticides or herbicides), or cultural controls (short-term floods, sanding or pruning).
Public concerns about chemical controls are understandable, but the way they are used in agriculture is subject to extensive oversight. The products themselves are regulated by the U.S. Environmental Protection Agency (EPA), with strict rules on the timing, rate and method of application. After EPA approval, the Massachusetts Department of Agricultural Resources (MDAR) undergoes a separate acceptance process for all pesticide use in the state. Finally, commercial application requires licensing that is provided by MDAR, which involves testing and subsequent training and education to maintain licenses.
Growers strive to use crop protection products only when needed. Careful, targeted applications help protect the crop while minimizing unnecessary inputs, and because these products are expensive, there is both an environmental and economic incentive to avoid overuse. Most pesticides are applied through the irrigation systems at night or early morning, never in the presence of wind, and not before or after heavy rain. To supply essential nutrients needed for growth, fertilizers are applied to cranberry bogs via drones, helicopters, irrigation, rotary spreaders, or motorized vehicles.
While the bees and the growers are working overtime, Mother Nature is not exactly cooperating at the moment. As of June 9, the Massachusetts Executive Office of Energy and Environmental Affairs declared a Level 2 - Significant Drought in the Southeast, Cape Cod, and Islands Regions due to worsening dry conditions. The lack of rain requires growers to draw down on their water supply, as cranberry plants require about one inch of water per week during the growing season. Additionally, cranberries are susceptible to scald, a physiological breakdown of the fruit caused by intense heat, solar radiation, and low humidity. To prevent crop loss, growers may irrigate the bogs in these conditions. These vital irrigation decisions are balanced with the need for water for frost protection and harvest come fall. So, while the rest of us are reveling in all this sunshine, cranberry growers are praying for rain.
From a distance, a cranberry bog in summer looks like a bucolic green pasture, but upon closer inspection, there is a literal buzz of activity marked by constant attention and countless decisions. With a little cooperation from Mother Nature, we’ll be reaping the benefits of all this activity come harvest.
