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 4-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.

In 2008, the 5 growers of the implementation team met with the research and extension professionals and reviewed progress. As a result, a bogside workshop (attendance 33) was held at one of the team’s farms to showcase the use of mowing and pruning as an alternative to sanding. Data handling was completed for the replicated sanding/pruning study and a manuscript is in preparation. The replicated sanding vs. pruning study showed that light pruning or sanding (a single pass with a knife-rake pruner or 1.5 cm of sand) can be a useful tool for cranberry canopy management as both practices can open up the canopy resulting in decreased wetness duration and improved light interception. Light severity treatments appeared to have had a positive effect on yield and net returns compared to that in untreated controls.

Based on a mini-survey conducted in January 2008, we can state the following regarding project implementation: irrigation scheduling has gone from zero to ~25%, use of pruning as an alternative to sanding has gone from 15% to ~30%, and more than 30% have implemented improved nutrient management.

A follow-up mini-survey and reporting on project results are planned for the UMass cranberry winter meeting (January 2009) and a grower exchange regarding water conservation will be held as part of the Cape Cod Cranberry Growers Association Winter Meeting (March 2009). In late winter, we will conduct the final project survey and grower interviews to document adoption of project 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 3.5 (project will end in June 2009).

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). Of the 230 attendees, 186 completed the survey. Results of the survey are detailed in the 2006 annual report. Important highlights included: 93% had sanded some acres of their bogs within the past 5 years; 15% intentionally alternated sanding and pruning; virtually all scheduled irrigation by touch testing or just applying 1 inch per week.

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. The replicated experiment was established in May 2006. A manuscript of the results of the replicated study is in preparation for HortTechnology.

This study compared the effects of varying levels of sanding and pruning in April 2006 on vine canopy characteristics and yield over the course of two growing seasons. Each practice was applied at four levels: sanding application directly onto the vines at four depths: control (0 cm), light (1.5 cm), moderate (3.0 cm), or heavy (4.5 cm); pruning at four severities with a commercial pruner: control (not pruned), light (1 pass with pruner), moderate (2 passes), and heavy (3 passes). Based on the study results we can state the following:

Light pruning or sanding (a single pass with a knife-rake pruner or 1.5 cm of sand) can be a useful tool for cranberry canopy management as both practices can open up the canopy resulting in decreased wetness duration and improved light interception. Light severity treatments appeared to have had a positive effect on yield and net returns compared to that in untreated controls. Sanding is more risky than pruning due to its greater negative impact on yield when treatments are heavy and because nonuniform application of sand may not provide the intended benefits. Further, sanding is more expensive than pruning. On average, pruning plots had higher yield than sanding plots in the year of treatment. Heavy pruning treatments were able to recover after the first year, whereas heavy sanding treatments still had lower yields in the second year. This is an important consideration since the pest management benefits of sanding are only effective with the equivalent of the moderate or heavy treatments used in this study. The prolonged decrease in yield may make sanding an impractical pest management option. Due to the potential benefits of light pruning and the reduced risk of over-treatment compared to sanding, it may be a viable option for cranberry growers as a replacement for or as a supplement to sanding for canopy management.

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 established multiple demonstration repetitions of the following protocols (yearly actions in sequence): 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: 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 (attendance 164) 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 initiated a long-term study of this practice at 5 paired (mow-no mow) sites, 3 of these sites are growers who are not participants in the planning team.

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.

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 (normal maximum is 1 inch (2.5 cm)). 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. Initial results are so good that several growers plan to participate in an additional study using these drainage systems as a means to irrigate from the subgrade (as opposed to overhead sprinkling.

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. Several growers have signed up for a new project regarding water monitoring which began 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 was conducted in January 2008. See Year 3 Milestone 2.

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.

The project team met in March 2008 to evaluate progress. Farmers agreed that the project was on target. The use of mowing in canopy management continued to be an area of interest. Participant Garrettson offered to host a bogside workshop regarding water conservation and canopy management using mowing (this workshop was held in July). Participant Beaton related his positive experiences in mowing, noting that he often integrated this practice with a very light application of sand (equivalent of less than 0.5 inch). He also noted the increasing attention to water quality as it interacts with nutrient management. He is implementing low phosphorus (P) fertilizers and is encouraging adoption by his peers. This topic was covered at two winter meetings in 2008 (attendance 281 in January; 275 in March).

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

The Cranberry Station hosted a grower meeting on January 24, 2008 (attendance 281). The program included a report on this SARE project (sanding vs. pruning and mowing studies), a presentation by Dr. DeMoranville on P reduction, and a presentation by plant physiologist, Dr. Jeranyama, on soil moisture monitoring. During the meeting, we conducted a mini-survey regarding sanding, pruning, fertilizer use, and irrigation management. 156 attendees completed the survey, however, results were only compiled for the 135 identifying themselves as the decision-maker for their farm (representing 8,292 acres). Results were as follows:

70% of respondents (35% of the reporting acres) sanded in the winter of 2006-2007, 89% on the ice; and a similar percent planned to sand in the 2007-2008 winter. About half of those who sanded in 2006-2007 believed that their 2007 crop was reduced as a result of the sanding.

33% indicated that if they could not sand, that they would use pruning as an alternative (up from 15% in the initial survey). However, in 2006 only 785 acres were reported as pruned and in 2007 only 600 acres (compared to 2,930 acres sanded), this did represent ~35% of respondents for each year. Of the 600 aces pruned in 2007, growers indicated that for 23%, the pruning was done as an alternative to sanding.

In this initial year of education and peer recommendation to reduce fertilizer phosphorus (P), 36% indicated that they will develop or had developed a plan for P reduction and 33% were exclusively using materials with a N:P ratio of 1:less than 1.

It was most encouraging to see that in the two years between surveys, use of technology to plan irrigation increased from virtually zero to 11% using water level floats and 14% using sensors or tensiometers. In addition, 10% of respondents are using irrigation cycling to conserve fuel and water during frost protection.

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

We held one field event in 2008. This was a bogside workshop held at participant Garrettson’s farm (33 attendees). The focus was an opportunity to compare areas that has been pruned, sanded, or mowed in the past 3 years. Growers were able to observe the canopy and the crop and note that mowing (in the previous year) had evened the canopy and that crop was similar to that in unmowed areas. An additional early season bogside workshop is planned for 2009. This will cover frost management (cycling of sprinklers and frost tolerance). A follow-up grower exchange regarding irrigation scheduling and cycling for frost protection will be held at the winter workshops of the Cape Cod Cranberry Growers Association on March 5-6, 2009.

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

We plan a follow-up mini-survey at our January 22, 2009 grower meeting. A final project survey will conducted in May 2009 (by mail) with personal interviews as follow-up. However, based on the 2008 mini-survey, we can state that irrigation scheduling has gone from zero to ~25%, use of pruning as an alternative to sanding has gone from 15% to ~30%, and more than 305 have implemented improved nutrient management.

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 over the winter and into the spring of 2009.

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. Four growers signed up for a moisture monitoring project that began 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 showed that light pruning or sanding (a single pass with a knife-rake pruner or 1.5 cm of sand) can be a useful tool for cranberry canopy management as both practices can open up the canopy resulting in decreased wetness duration and improved light interception. Light severity treatments appeared to have had a positive effect on yield and net returns compared to that in untreated controls.

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 Stevens is increasing and 5 growers provided paired sites for a comparison mowing study that began in 2008.

Based on our 2008 mini-survey, we can state that irrigation scheduling has gone from zero to ~25%, use of pruning as an alternative to sanding has gone from 15% to ~30%, and more than 30% have implemented improved nutrient management.

Collaborators: