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 have introduced 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 2.5.

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). Results of the survey are detailed in the 2006 annual report.

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 and Dr. Carolyn DeMoranville. 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 Dr. Vanden Heuvel 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 (with the two practices giving similar improvement over the controls). 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 were re-evaluated in 2007 to determine cumulative effects on yield. That data is currently being compiled.

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 were evaluated in 2007 for carry-over effects. Two years after treatment, all pruned areas had yield equal to or greater than that in the unpruned controls. This outcome is similar to that with sanding in previous studies: that is, treatment improves or modestly decreases yield in the first year but improves yield in the following year. In this study of pruning as an alternate to sanding, 4 of 6 fields that were followed for 2 years showed cumulative yield improved in the pruning treatment compared to that in the untreated controls.

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 presented information at our January 2007 grower meeting regarding the use of moisture sensors to auto start sprinklers. We also held a panel discussion with growers who are reducing water use by intermittent sprinkling for frost protection. Project team members participated. In July, we held a bogside workshop at a participant bog to show the implementation of water monitoring devices (sensors and water level floats). Attendance was 43.

An additional practice of interest to project participants is the use of a mowing cycle inserted into crop management at 3-5 year intervals as an alternative to both sanding and pruning. A grower participant reports that he has tried this practice and that the long-term cumulative yield more than compensates for the zero yield in the year of mowing. We have studied a demonstration site with part mowed (2004), part sanded (2005), and part pruned (2005). In 2005, yield was equal in sanded and mowed areas and lowest in the pruned area. In 2007, yield in previously sanded or pruned areas was equal, while yield was 33% greater in the mowed areas (compared to the other two treatments). This indicated that the ability to compensate for crop loss in the mowing year is real and warrants further investigation. We have sites lined-up for 2007 to further study this practice.

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.

There was no difference in adult survivorship between larvae that were in hibernacula constructed of sand or trash, nor did it make any difference if they were covered with a layer of sand or trash. Mortality of larvae was higher under deeper sand, but it had to be at least 4 cm to make an impact. This is not a realistic level of sanding that a grower would undertake. Therefore, substitution of pruning for standard sanding would have no impact on cranberry fruitworm management.

Populations of cranberry tipworm, another pest of interest, appeared to be reduced on pruned sites compared to those that were not pruned, a possible benefit to this practice.

Project participants have received grant funding for innovative bog renovations. As part of that undertaking, some are installing innovative drainage systems. These sites will serve as educational opportunities for studying the impact of improved drainage on the bog microclimate.

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

Our winter meeting took place on Jan 31, 2007. At that meeting preliminary results were presented from both the field demonstration sites (pruning as an alternate to sanding) and from the replicated trial of sanding and pruning. Due to weather, attendance was lower than previous years (164), so we held a make-up session in March — this was attended by an additional 50 growers.

3) 50 farmers attend an on-farm field day and learn how to implement the practices in the project demonstrations and research elements
In 2006, 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. Follow-up surveying (verbal) indicates that growers that attended have implemented the devices and are surprised that they are irrigating much less than previously. Our workshop on water monitoring, held at a grower site in July 2007, had 43 participants. Growers have signed up for a new project regarding water monitoring which will begin in 2008. Dr. DeMoranville will participate in that research along with Dr. Peter Jeranyama, Dr. Vanden Heuvel’s replacement on faculty at the Cranberry Station, and the Cape Cod Cranberry Growers Association. Interest for the new project comes directly from the educational efforts undertaken in this SARE project.

4) 10 farmers adopt 2 or more project practices (determined by surveys).
Numbers not determined to date. Preliminary mini-survey planned for January 2008.

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

We plan to meet early in 2008 to assess progress and formulate plans for the final field season.

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

Our next meeting is scheduled for January 24, 2008. We will report on the project and conduct a mini-survey to assess progress compared to the 2006 survey.

3) 50 farmers attend an on-farm field day and share experiences in implementing project practices

We plan to hold 2 field events in 2008. The exact format will be discussed at the project participant meeting.

4) A total of 20 farmers have adopted 2 or more project practices (determined by final survey)

Not yet done

5) Adopters have provided testimonials/experiences to encourage further adoption

Adopters have participated in panels and field days. In addition, we plan to record testimonials during the coming season.

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 2007, an additional 43 growers attended an on-farm workshop comparing the use of floats to that of moisture sensors. Growers are signing up for a moisture monitoring project to begin in 2008, with funding from the MA Department of Agricultural Resources.

By the end of 2007, demonstrations of sanding pruning sequence combinations were established at ten bog sites, these sites were followed into 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, there 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). Two years after pruning, yield remained equivalent or higher than those in unpruned areas.

The replicated sanding vs. pruning study is complete and only data handling and final writing remain. This graduate project will be complete by May 2008.

Based on information sharing within the grower community, we are receiving inquiries regarding the substitution of pruning for sanding. While the 2006-2007 winter provided excellent conditions for sanding, many growers did not sand and instead pruned their bogs in the spring of 2007. In addition, interest in implementing a mowing cycle for vigorous varieties such as Steven is increasing and several sites will be studied in 2008.

Collaborators: