Nutrition decisions

This week we once again hosted Dr. Joan Davenport of Washington State University. Joan, a former researcher for Ocean Spray, works with Pine Island Cranberry to provide guidance on fertilizer, water, and nutrients, as well as general PIICM management. Joan comes to see us in the spring during the bloom period and again in the height of summer to discuss fertilizer needs for bud set (defined below).

Additional nutrition is necessary because while cranberries have adapted (and thrive) in their native sandy soil, nutrients are taken from the bog through the harvest of fruit. The three main elements usually added for nutrition are nitrogen, phosphorus, and potassium. According to “Cranberry plant demand for nitrogen is highest during three stages of the lifecycle critical to cranberry development–early growth, fruit set and bud set. Early growth is when the plant grows vegetatively through vining and root growth and produces a flush of new leaves. Fruit set is when the flower becomes pollinated and fruit begin to form. Soon after fruit set comes bud set when nitrogen is needed for both fruit development and production of the next year’s flower bud.”

Joan and our PIICM team visit several bogs to check growth and fruit set in order to best determine nutritional needs. They also take into account the sanding schedule, as sanding helps improve growth and yield by stimulating the development of new uprights (covering the base of the roots strengthens the root system and creates a more healthy vine) while also reducing insects (by burying insect eggs) and improving soil drainage. This lowers the need for additional plant nutrition.

“This late in the growing season, we are assessing the new plantings for nutritional needs but also for when to stop fertilizing, so that the plants will enter dormancy,” Joan says. “For established beds, we are evaluating the plants for how much crop they are holding and the bud potential for next year to develop recommendations for applications for the remainder of the growing season, including post-harvest and some guidance for roughneck in the spring of next year.” (The roughneck stage is when the stem elongates significantly and all flower buds are visible, being held tight to the stem.) To do this, Joan and the PIICM team look at the amount and size of fruit, the length and color of both new and upright growth, and the amount of buds already set.

Once Joan and the team tour the bogs, she makes specific recommendations based on their findings, such as the sand level needed in certain beds or where to adjust for deficiencies.

“It’s going to take eyes on the beds,” Joan says. “But here, there are always eyes on the beds.” And as always, our PIICM team is out doing whatever it takes to make sure our growing season gives us good results.

1. Fertilizer Use in Cranberry Production:
2. Workmaster, Beth Ann A., Jiwan P. Palta, and Teryl R. Roper, “Terminology for Cranberry Bud Development and Growth”,

New planting: updates

One of our April blog entries was on planting bogs at Sim Place. Planting was completed in May, but continuing care for the young bogs is under the supervision of Tug Haines, the fifth generation of the Haines family working at Pine Island and currently serving as a foreman in our PIICM program.

Once the plants are in, it is important to monitor the young bogs frequently to ensure that they are rooting well and remain healthy. Last week, Tug met with Bill, PIICM manager Cristina Tassone, and Dan Schiffhauer of Ocean Spray to check the bogs and discuss their nutritional needs.

The consensus was “so far, so good”; we’re not getting much leaf drop and the plants seem to be thriving. We’re not seeing many runners yet, but according to Schiffhauer, that’s just fine. “You don’t want kudzu,” he says. “The important thing the first year is for the roots to establish before they start running, and that’s what we’re seeing.” The PIICM team will continue to watch color and leaf size on the new growth in order to determine fertilizer needs and then modifying the plan if necessary. As soil and nutrition consultant Dr. Joan Davenport always reminds us: “It is ineffective to put fertilizer onto the beds until the root mass around the [new plants] is at least the diameter of a standard #2 pencil.”

As with the established bogs, heat is also a consideration. A ride with Tug overseeing the young bogs is very much like a night monitoring for frost; we check for the bog temperature (the thermometer is protected by a shade canopy for more accurate readings) and soil moisture before deciding if running the water is necessary.

You cannot always rely on tensiometer readings, however; you also need to get out in the bog and check for yourself. On her last visit, Joan also noted that “when leaves are young and tender, relying strictly on the tensiometers could result in a false sense of security about what the plant water demand is.” Yesterday the soil seemed particularly hardened and dry, so Tug decided to run the water for a couple of hours. Again, as with frost, it’s not just as simple as turning on some sprinklers. Once the irrigation is going, it may also be necessary to let more water in from the reservoirs to keep the pump supplied.

Then, of course, we ride around to monitor both the soil and the equipment in order to fix any possible sprinkler malfunctions. “You have a little more margin for error than you do with frost,” Tug says. “It’s urgent, but you don’t need to move quite as fast.” He needs to make sure the sprinklers are both running at capacity and rotating completely in order to get the best cooling effect.

Even on young bogs, however, maintaining a balance is crucial in order to avoid phytophthora. If it infects and damages the root system, it could take more than one growing season for the bogs to recover.

signs of phytophthora in established bed

effects of phytophthora on roots

One of the strategic drivers to achieve our mission is increasing production over time through bog renovation and decreasing the time to achieve full production, which is essential to accomplish our growth objectives. And, like everything else we do here at Pine Island Cranberry, the key to achieving our goals is attention to detail. All of the things on this week’s tour shows our drive to be the very best and the amount of attention to detail that implementing our strategy takes.

Plant nutrition

One of the goals of our Pine Island Integrated Crop Management (PIICM) program is to continuously improve our decisions: we often do this through learning opportunities via advice from specialists.  Last week, we had a visit from Dr. Joan Davenport, of Washington State University. Joan, a former researcher for Ocean Spray, works with Pine Island Cranberry to provide guidance on fertilizer, water, and nutrients, as well as general PIICM management.

Joan comes to work with us at this time of year, as adjusting nutrition is most vital just prior to bloom (and again in late July/early August for bud set) in order to help production for the current as well as successive years.

Joan goes out into the bogs with our PIICM manager Cristina Tassone (as well as Dan Schiffhauer of Ocean Spray) in order to best determine the nutrition needed for optimum crop yields and quantity. Another one of the keys to our PIICM program is giving vines the nutrients they need, when they need it; the amount of fertilizer to be applied is determined by variety, soil conditions, and past practices, requiring constant evaluation of current conditions, history, and trends. Nutritional needs are different for young vines as opposed to established plantings, as well.

Joan’s expertise as a soil scientist with a specialization in perennial fruit crops is invaluable to our PIICM program. In established beds she looks for growth as well as amount and color of old leaves from as far back as two seasons. This means that it is critical to keep accurate, detailed records on past practices.

After surveying both new planting and established beds, Joan will send us a report with her findings and suggestions for scheduling and fertilizer amounts. We use this report as a guideline as we continuously evaluate crop conditions throughout the growing season.