Increasing the sustainability of Massachusetts cranberry production through cultural management of the bog habitat

Increasing the sustainability of Massachusetts cranberry production through cultural management of the bog habitat

Summary

The primary goal of this 3-year project is to develop, demonstrate, and implement grower-identified practices on MA cranberry farms that improve water and canopy management to reduce costs and improve pest management. On the grower-team farms, we will introduce low-cost practices with potential to increase fruit quality and contribute to pesticide reduction: pruning (and use as an alternative to sanding), irrigation scheduling, drainage improvement, bed sanitation, and integrated nutrient management. We expect that all of these practices will contribute to a more open, drier canopy and will improve air circulation, decrease duration of wetness events (reducing need for fungicides), improve penetration of biorational pesticides, promote better fruit color, enhance yield, and eliminate or reduce the need for sanding. The project will consist of the following components: initial survey of grower practices; applied research comparing sanding and pruning; on-farm demonstrations of water, canopy, and nutrient management practices, integrated in combinations; on-farm workshops, newsletters, and other educational opportunities; and final project assessment to include a follow-up survey and interviews.

Essential to the success of this endeavor is the reputation of the implementation team – a group of respected, forward-thinking growers who will provide project guidance, demonstration sites, and testimonials regarding what works. They are larger growers (manage >25% of MA acreage) with the resources to conduct on-farm research and the willingness to share results with the small farm operators who make up more than a third of the MA industry. By project’s end, the 5-grower team will have implemented an integrated suite of water and canopy management practices and will have helped an additional 15 growers adopt at least 2 of those practices.

Objectives/Performance Targets

At least 50 Massachusetts cranberry growers/farm managers will participate in on-farm educational opportunities regarding pruning, irrigation scheduling, nutrition management, and drainage enhancement practices. At least 20 of these will adopt two or more of the practices by the end of the project, 5 adopting the entire suite as project designer/participants. In so doing, participants will improve coverage of biopesticides, reduce insect pest refugia in lush vines, improve removal of leaf trash (which harbors disease inoculum), improve air circulation (which lowers fruit rot pressure and reduces need for fungicides), and increase penetration of light (which impacts fruit color and yield). Their farms will be designed and managed efficiently and with minimal environmental impact, both critical factors in long-term sustainability.

This project will contribute to the Northeast SARE outcome statement by demonstrating the effectiveness of easily integrated, low-cost practices, developed based on grower-identified needs. Project beneficiaries will improve the environment on their farms, managing resources wisely in such a way as to reduce the need for pesticides and maximize the effectiveness of those pesticides that must be used, while not sacrificing production.

Accomplishments/Milestones

This project began in the late spring of 2005. At year’s end we are at approximately Year 1.5.

Original milestones set forth for Year One were:
1) 160 farmers become familiar with the project and its goals by attending a grower meeting and documenting their current practices (completing the pre-survey).

The survey was conducted during a grower meeting in January 2006 (first opportunity after project start to reach a large audience at once). Prior to distributing the survey, we gave a presentation in which growers were informed about this project, its components, its grower team, and that opportunities to participate would be available.

Of the 230 meeting attendees, 186 completed the survey. The survey represented at least 2/3 of the industry acreage and 78% of respondents were the decision maker for that farm. The survey asked questions about current and planned activities in the areas of sanding, pruning, irrigation, drainage, and nutrient management. These responses will be compared to those at project’s end to monitor change in knowledge and practice.

Interesting highlight of survey responses included:
Ice sanding is the industry choice for canopy renewal — 93% have used this practice in the past 5 years; 73% sand their bogs every 3 years; 63% have beds that they sand but never prune while only 9% have beds that they prune but never sand.
Pruning is a part of canopy management for a larger than expected number of growers — 58% have beds that have been both pruned and sanded; 15% intentionally alternate the practices.
Growers use both practices for similar reasons — primarily for growth management/enhancement followed by pest management and light penetration.
These responses are encouraging, since a primary part of the demonstration research in this project involves inserting a pruning into a sanding regimen to extend the intervals between sanding (to reduce costs and use of non-renewable resources).

Much less encouraging was the fact that few growers schedule irrigation based on monitoring of soil moisture — 53% used a hand touch test (not considered very accurate) and 55% just applied according to an 1″ per week rule. Conversely, this allows room to change practice through this project (see year 2 milestones below).

2) 5 farmers (participation team) provide input into the final project design and establish (with the research team) the demonstration plots and replicated research elements on their farms

The project participation team met in early 2006 and discussed project design. At that meeting, we confirmed that the primary components of this project would be 1) sanding; 2) pruning; 3) irrigation scheduling; 4) nutrient management; and 5) drainage. It was agreed that the best way to compare sanding and pruning was in the originally proposed, replicated study of these two practices. To this end, a graduate student, Brett Suhayda began a Masters degree under the direction of Dr. Justine Vanden Heuvel. He has established the replicated study as part of his degree requirement. The study is sited at Rocky Pond Bog, a property managed by UMass as a demonstration site. Recently, Dr. Vanden Heuvel has left UMass. Dr. DeMoranville has replaced her as Brett Suhayda’s major professor but she will remain on his graduate committee.

The replicated experiment was established in May 2006. Vine cover, light penetration, and spray penetration were determined during the summer and in the fall, areas from each plot were sampled to estimate fruit production. Low intensity sanding (~1/2 inch) or low intensity pruning (single pass) was associated with highest fruit yield. At higher intensities, fruit production declined to less than that in untreated plots. All sanded or pruned plots had greater light penetration compared to controls but spray penetration was unaffected by sanding or pruning — even control areas showed complete penetration during a simulated chemigation event. The plots will be re-evaluated in 2007 to determine cumulative effects on yield.

During our first team meeting, the growers identified the following as the primary question of interest to them regarding these practices: “Can pruning be integrated into sanding cycles in order to reduce the need for sanding?” To answer this question, they have established pruning demonstrations on their farms as follows: 1) prune ½ of an area sanded two years previously; 2) prune ½ of an area sanded three years previously; or 3) prune ½ of an area sanded four or more years previously. Options to prune in the year of sanding or the year following sanding were not included, since if the two practices accomplish the same thing, and sanding is done on a three-year cycle normally, there would be no need for additional treatment in those years. By tackling all three treatment combinations at multiple sites in each year of the project, at the end of three years we will have multiple repetitions of the following protocols: 1) sand-no treatment-prune; 2) sand-no treatment-no treatment-prune; 3) four or more years since sanding, then prune. The first and second of these protocols mimic the substitution of pruning in the most common sanding cycles currently used.
At the end of 2006, we have 6 sites for protocol 1; 3 sites for protocol 2; and 1 site for protocol 3. Effects of pruning on yield were variable (prune in spring, evaluate crop that fall): 3 of 6 sites that were 2 years out from sanding had improved yield in pruned areas; 2 of 3 sites that were 3 years out from sanding had improved yield in pruned areas; and the >4 years since sand site had equal yield in pruned and unpruned areas. Fruit rot was more correlated with yield (greater yield – greater rot) than with pruning treatment. All sites will be evaluated in 2007 for carry-over effects.

Original milestones set forth for Year Two were:
1) The 5 farmer participation team evaluates practice outcomes with the research team and suggests modifications and improvements to project practices.

The project team met and agreed to keep the project focus on alternating pruning into sanding regimens. In addition, interest is building in the use of irrigation automation. We will present information at our 2007 grower meetings regarding the use of moisture sensors to auto start sprinklers. We will also begin to explore reduction in water use by intermittent sprinkling for frost protection with the project team. Interaction with nutrient management will be a part of this as well.

Based on preliminary indications that some of the project practices may impact insect populations, we established a field study in 2006 to look at our key insect, cranberry fruitworm. This study will also help determine any negative impacts of reducing the use of the sanding practice.

Cranberry fruitworm (larvae in hibernacula—this stage overwinters on the bog floor) were placed under different conditions in semi-natural and natural settings to determine the direct effect of how a change in cultural practices (increased bed sanitation, change in sand and trash levels) may make the system more/less favorable to this key insect pest.

Field trials were set up at in September and October 2006 using hibernacula (there were two hibernacula treatments: formed of either sand or trash) placed in alternating blocks covered with 2 cm of sand, cranberry leaf trash, or sand/trash mix. We hypothesize that phenolics in the cranberry leaf trash may reduce fungal inoculum and thus enhance overwintering survivorship. The hibernacula will be collected in the spring of 2007 and assessed for survivorship and fungal infection. Greenhouse trials were established to evaluate the possible ramifications of removing the sanding practice on cranberry fruitworm populations. Sand hibernacula (10 replicates of 10 hibernacula) were placed under differing (0, 1.5 cm, 3.0 cm, 4.5 cm, and 6.0 cm) sand layers in 13 cm pots are being held in a cold frame greenhouse over the winter. A portion will be assessed for survivorship and fungal infection in the spring of 2007. The remainder will be held until May 2007 when moth emergence will be assessed.

2) 160 farmers learn (at a winter meeting) about preliminary impacts of the project practices at the participant farms.

Our winter meeting will take place on Jan 31, 2007. At that meeting preliminary results will be presented.

3) 50 farmers attend an on-farm field day and learn how to implement the practices in the project demonstrations and research elements
We held 2 workshops regarding irrigation scheduling using water-level floats. These were held on-farm and participants (36) built their own device to take back to the farm. In addition, we made another 45 floats that we sold to growers. These devices are used to monitor water table in the cranberry bog and that information is used to schedule irrigation. Followup surveying (verbal) indicates that growers that attended have implemented the devices and are surprised that they are irrigating much less than previously.

4) 10 farmers adopt 2 or more project practices (determined by surveys).
Numbers not determined to date.

Impacts and Contributions/Outcomes

To date 36 growers have attended hands-on workshops at the Cranberry Station Farm regarding how to construct a water-level float, a device recommended for use in irrigation scheduling. Each participant left with a float ready to install and was provided with a contact person for follow-up instruction regarding installation. Growers have reported implementation and are pleased with the reduction in irrigation when using the floats as a basis for scheduling.

In by the end of 2006, demonstrations of sanding pruning sequence combinations were established at ten bog sites, additional sites will be established in the spring of 2007. At each site, project scientists gathered information regarding canopy density, productivity, and crop quality. Pruning appeared to have little (if any) negative impact on yield. However, their was no apparent reduction in fruit rot disease with pruning. At one site, pruning appeared to drastically decrease incidence of insect damage (compared to unpruned adjacent areas).

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