Integrated Management of Cranberry Insect, Weed - Disease Pests Using Fall - Spring Floods

Final Report for LNE98-107

Project Type: Research and Education
Funds awarded in 1998: $130,000.00
Projected End Date: 12/31/2002
Matching Non-Federal Funds: $146,766.00
Region: Northeast
State: Massachusetts
Project Leader:
Dr. Carolyn DeMoranville
UMass Amherst Cranberry Station
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Project Information


The overall objective of this project was to examine the use of flooding for the integrated control of cranberry weed, insect, and disease pests; to extend our current knowledge of what impacts flooding has on certain key pests, and to develop a strategy for reduced-pesticide management that minimizes adverse cranberry crop and plant impacts. Specifically we examined the effects of post-harvest and varied-duration spring floods on cranberry fruitworm, Rubus sp. weeds, fruit rot, and Phytophthora root rot.
Control of Rubus sp. weeds and cranberry fruitworm are of particular interest to growers because of the significant costs associated with their control. Due to their ability to spread quickly and substantially reduce yields, dewberries are considered to be of the highest priority in regards to weed control (Else, Sandler, and Schluter, 1995). Bog renovation is often the only means of management. Cranberry fruitworm, in its larval stage, has caused more damage to cranberry crops than any other pest in New England. IPM records indicate that fruitworm accounts for the majority of insecticides applied in Massachusetts cranberry agriculture. As any management for cultural control of pests must not only control the pests, but also have no adverse effect on crop productivity, we also examined the effects of pest-control floods on cranberry growth and yield.
While it is important to determine whether or not spring and fall flooding is a viable method of pest control, the physical mechanisms involved, or the reasons why or why not the practices in question work, are of interest. In-field data loggers were used to determine the abiotic factors present during flooding events. While not providing definitive answers to these questions, data gathered from loggers can at least help in creating new hypotheses for future studies.
In this research and demonstration project we were able to demonstrate excellent control of cranberry fruitworm with spring or fall floods and documented the duration required for efficacy. The spring flood or a 4-week fall flood also suppressed the perennial weed, dewberry. While we had previously shown large favorable impact on fruit rot disease with the use of a spring flood, fall flooding seemed to have little effect on this disease complex. Possible negative impacts of extended flooding were shown to be minimal – yield was unaffected by fall flooding as was incidence of Phytophthora root rot. However, we did document extreme yield impact if the practices were combined – extending the harvest flood to 3+ weeks followed with a flood in the spring. Grower participants and many other growers have adopted the extended harvest flood as a way to suppress cranberry fruitworm and dewberries, two key pests of Massachusetts cranberry.


Cranberries are the number one food crop in MA (farm gate value of approximately $40 million), grown on 14,000 acres. In addition, cranberry growers control more than 60,000 acres of support lands in association with their bogs. These farms represent a significant portion of the remaining open space in Southeastern Massachusetts, preserving valuable wildlife habitat and water recharge areas. However, as for many commodities, cranberry production remains dependent on the use of chemical pesticides.
Previous projects (ANE91.2; LNE94-50/ANE94.21) have focused on 30-day spring floods or ‘late water’. We have demonstrated that these floods can provide some control of key pests. However, in certain years, late water is associated with a poorly understood, serious reduction in yield. Preliminary observations have shown that post-harvest floods and shorter (2.5 week) late water floods have less impact on yield while seeming to offer some control of pests.
Spring floods (late water) have been shown to be effective in the control of cranberry fruitworm (Acrobasis vaccinii, Riley) and one particular dewberry species (Rubus hispidus). However, these floods have drawbacks including occasional severe crop reduction and can only be used once every two or three years. The use of fall floods has been shown to be a relatively low risk alternative to late water. Both practices offer pest control with reduced chemical inputs into cranberry production systems.
Post-harvest floods (fall floods) on cranberry beds have been reported by growers to suppress dewberry growth. Dr. Henry Franklin also reported that fall flooding reduced or eliminated cranberry fruitworm (Franklin 1924; 1959). Our research over the last four years has demonstrated that post-harvest floods have less impact on yield than spring floods yet still offer significant control of both dewberry and fruitworm. According to our data, shorter spring floods (2.5 – 3 weeks) have demonstrated less detrimental effects on cranberry growth and yield compared to standard 4-week late water, while offering some control of dewberry and cranberry fruitworm.

Project Objectives:

· Evaluate the effects of flooding for up to four weeks post-harvest [fall flood] on: a) cranberry fruitworm, b) perennial weeds, c) fruit rot disease, d) phytophthora root rot, and e) cranberry growth and yield.
· Determine optimum flood length required for control of cranberry fruitworm.
· Examine the use of a shorter duration (2.5 wk) spring flood for control of cranberry fruitworm, and determine impact of the flooding on incidence of fruit rot disease.
· Assess effectiveness of sequential fall-winter-spring flooding to control Rubus weed species.
· Determine the effectiveness of glyphosphate clipping in combination with a fall flood in the control of upright bramble (Rubus allegheniensis).
· Examine the impact of low and high rates of dichlobenil on cranberry and cranberry weed species.
· Evaluate the use of a short-term trash flood subsequent to dry-harvest as a cultural management tool against fruit rot disease.


Click linked name(s) to expand
  • Anne Averill
  • Susan Butkewich
  • Frank Caruso
  • Laura Romaneo
  • Hilary Sandler
  • Dan Shumaker
  • Martha Sylvia


Materials and methods:

Fall flood experiments:
Dewberry and cranberry growth: Ten one meter square plots were randomly established on flooded and non-flooded control bogs in August before the fall harvest. From 1998-2000, eight pairs were studied. Total number of R. hispidus crowns (rooted portion of plant) were counted and percent vegetative coverage of dewberry canopy was estimated in each plot. Five tissue samples consisting of 25 flowering and 25 vegetative cranberry uprights were taken randomly from both flood and control bogs and brought back to the lab to determine growth (length) and fruit set. Growers were instructed to leave their harvest floods on for up to four weeks post-harvest. Control pieces were picked according to normal harvest flood practices. In the year following the flood, dewberries, growth and fruit set were re-evaluated in August using the same methods.
Phytophthora root rot: In October 1999 and 2002, 3-week floods were held on ‘Early Black’ beds at three (2 in 1999, 1 in 2000) locations with previously diagnosed Phytophthora root rot infestations. Companion ‘Early Black’ beds with root rot were not flooded during that time. Damaged areas were surveyed in August 1999 (prior to the flood) and in July 2000 and July 2001 (post-flood) to determine the effect on the disease. Ridomil (standard fungicide treatment) applications were not made during these two growing seasons nor were attempts to improve the drainage made during that time. All chemical and cultural practices were identical in the paired beds. Lupine seedlings were germinated in the laboratory and floated in Styrofoam boats in six locations in these beds in May and August 2000 for 48 hr. Boats (five replicates) were floated in the holding pond, and in peripheral and internal ditches in each bed. Lupine roots (in contact with the water and exposed to Phytophthora) were excised, surface sterilized in 10% Clorox solution containing Tween 20, and plated on PARH selective medium. Plates were read for the presence of Phytophthora at 72 hr.
Fruit rot disease: The 2002 ‘Early Black’ pair of beds used to study root rot was used to determine whether the fall flood had any effect on populations of fruit rot fungi. The use of fungicides was identical in both beds during the 2000 and 2001 growing seasons. Beginning on August 18, 2000 (pre-flood) fifty healthy berries were sampled randomly throughout each bed. Five subsequent samples were taken at seven-day intervals. Berries were halved through the stem and calyx ends (one half was discarded), surface sterilized in 10% Clorox plus Tween 20, dried on sterile paper towels, and plated on acidified cornmeal agar. Fungi were evaluated at three weeks. Beginning on July 26, 2001 (post-flood season) fifty healthy berries were sampled randomly from the same areas sampled in 2000, and six subsequent samples were taken at seven-day intervals. Berries were plated as described for the pre-flood samples and fungi were identified at three weeks.
Cranberry fruitworm (CFW): From 1998 to 2000, prior to harvest, five packets of 25-35 CFW hibernacula (over-wintering stage) were placed approximately one inch beneath the surface of both control and flooded bogs (total of 8 pairs, including the dewberry sites described above). Packets were collected the following spring and placed in 50°F incubators for one month. Hibernacula were then held at room temperature and allowed to emerge. Percent larval emergence was then calculated.
To determine optimum flood length required for control of CFW, 20 mesh packets containing 30 cranberry fruitworm hibernacula (over-wintering stage) were placed beneath the surface of both control and fall flooded cranberry bogs prior to harvest in 2001. Groups of four packets were taken from flood and control pieces weekly for 4 weeks and placed in 50ºF incubators. One group of four remained in the field over the winter. These were collected and placed in incubators in early April 2002. One month later, all hibernacula were moved to room temperature and allowed to emerge. Percent larval emergence was calculated.
Shortened vs. traditional late water:
In the spring of 2000, four paired were used to study the effectiveness of a shortened late water flood versus the traditional 4 week flood on control of CFW. Prior to flooding, six packets containing 10 fruitworm hibernacula were placed randomly on control and flood bogs approximately one inch below bog surface. In two pairs, the treated bogs were flooded for 4 weeks — hibernacula were removed at 2.5 weeks and 4 weeks in one and at three and four weeks in the other. In the remaining two pairs, the flood was only held for 2.5 weeks. Packets were collected from the flood or after the flood and handled as described above.
Weed experiments:
Glyphosphate clipping experiment: Three bog sites (one later subjected to fall-flood) were studied in August of 1999 to determine the effectiveness of using clippers dispensing glyphosphate to control upright bramble (Rubus allegheniensis). Plots were established (the number of plots was variable depending on amount of bramble present), and plants in each plot were subjected to one of three treatments: clipped, clipped with glyphosphate dispensed, or non-clipped control. Clipped plants were dried and weighed. The following August, all plants within the plots were clipped at the base, dried, and weighed.
Effect of low and high rates of dichlobenil on cranberry health and weed species: This research was conducted at two sites. At each site plots were established in areas of high and low weed pressure. Within each area, three treatments were established: no herbicide, 40 lb/a dichlobenil, 100 lb/a dichlobenil. Treatments continued for 4 years. In each year, growth, weed species and yield were evaluated in the plots.
Short-term ‘trash’ flood:
A pair of dry-harvested ‘Howes’ beds were used in this project. A trash flood consists of flooding the bed, allowing leaf litter and stray berries to float, and removing that trash from the flood water. One of these beds (8#1) received a three-day postharvest trash flood in October 2000. The other bed (8#2) did not receive the trash flood. Both beds were managed in identical fashion. Starting on August 4, 2000 (pre-flood) fifty berries were randomly sampled from the entire bed weekly through September 29. Beginning on July 19, 2001, weekly samples of fifty berries were randomly taken from each bed through September 13. Berries were processed as described under fall flood – fruit rot evaluations.
Else, M. J., H. A. Sandler, and S. Schluter. 1995. Weed mapping as a component of integrated pest management in cranberry production. HortTechnology 5(4): 302-305.
Franklin, H. J. May 1924. Managing Cranberry Fields. Summer and Fall Flooding. U. S. Department of Agriculture, Farmers’ Bulletin No. 1401, Page 3.
Franklin, H. J. October 1950. Cranberry Insects in Massachusetts, Bulletin No. 445, Part II-IV. p. 19-23.

Research results and discussion:
Outcomes – experiment results:

Dewberry: Eight pairs of fall-flood sites were studied from 1998-2000. A 4- week flood duration appears to be required for dewberry control (table 1). A 3-week flood was only successful in one of three attempts and in that case, no control bed was evaluated. In five of six 4-week pairs, dewberries declined more or increased less in the flooded bed. Though the number of crowns increased in both flooded and control beds in the summer of 2001, plots on non-flooded control beds produced about three times more new crowns than did plots on flooded pieces. We can conclude that, while fall floods do not control dewberry completely, a four week flood appears to suppress populations of the weed.
Table 1. Effect of fall flood on dewberry populations
Year Site # Flood length(weeks) Change in dewberry crowns (number)
Flooded Control
1998 1 4 +1.6% -35%
2 4 -30.8% +2.6%
3 4 -19.5% —
1999 1 4 -27% +3%
2 4 -31% +3%
3 3 +7% -3%
4 3 -41% —
5 3 +2% -35%
2000 1 4 +27% +96%
2 4 +8.6% +29%

An additional flood in the spring (sequential 4-week fall, winter, 4-week spring flood) did not afford additional control of dewberry and resulted in severe crop reduction compared to the control bog and the fall-flood-only bog.
Phytophthora root rot:
In October 1999 and 2000, 3-week floods were held on paired ‘Early Black’ beds at three locations with previously diagnosed Phytophthora root rot infestations. All chemical and cultural practices were identical in the paired beds. The fall flood did not increase or decrease the degree of root rot damage (visual observations) in any pair of beds. There were no differences in the incidence of the pathogen between any of the paired beds, based on the lupine bioassay. We conclude that a fall flood does not increase the incidence of Phytophthora root rot.

Fruit rot disease:
At the Phytophthora pair studied in 2000-2001, fruit rot observations were also recorded and fungal populations for this disease were evaluated. Tables 2 and 3 show 2000 populations of fungi that can cause fruit rot disease, unidentified fungi and non-infected fruit. Populations were roughly similar on the two beds prior to the fall flood.
Table 2. Non-flooded control – Pre-flood fungal populations

Fungus 8/18 8/25 9/01 9/08 9/15 9/22 total
Allantophomopsis 2 4 2 8
Fusicoccum 2 8 14 8 8 10 50
Gloeosporium 4 4 2 4 2 16
Phomopsis 18 8 10 6 34 30 106
Phyllosticta elongata 2 12 4 2 20
Phyllosticta vaccinii 28 2 2 32
Physalospora 24 46 66 60 60 256
Unidentified, other 36 60 26 26 14 16 178
Sterile 18 12 10 4 4 4 52

Table 3. Fall flood – Pre-flood fungal populations

Fungus 8/18 8/25 9/01 9/08 9/15 9/22 total
Allantophomopsis 2 6 2 10
Coleophoma 4 2 2 4 12
Fusicoccum 4 2 14 22 18 28 88
Gloeosporium 2 2 2 2 8
Phomopsis 8 6 14 14 10 26 78
Phyllosticta elongata 12 4 6 6 28
Phyllosticta vaccinii 6 2 2 10
Physalospora 20 32 74 48 56 38 258
Unidentified 38 38 8 28 14 14 140
Sterile 26 16 8 2 10 10 72

Tables 4 and 5 show the same evaluations in the year following the fall flood. In both beds, fewer fruit were infested by fungi. Incidence of identified pathogenic fungi was greater in the flood bed. Notably the Phyllosticta species were both elevated compared to the control bed. Table 4. No fall flood – 2001 Post-flood fungal populations

Fungus 7/26 8/02 8/09 8/16 8/23 8/30 9/06 total
Allantophomopsis 2 2 2 6
Colletotrichum 2 2 4 8
Fusicoccum 6 2 2 6 6 8 12 42
Gloeosporium 2 4 6
Phomopsis 4 6 8 8 16 24 28 94
Phyllosticta elongata 4 2 4 10
Phyllosticta vaccinii 10 10
Physalospora 6 8 4 20 24 14 14 90
Unidentified, other 32 36 34 32 52 38 24 248
Sterile 54 50 52 36 14 28 20 254

Table 5. Fall flood – 2001 Post-flood fungal populations

Fungus 7/26 8/02 8/09 8/16 8/23 8/30 9/06 total
Allantophomopsis 2 2 2 6
Colletotrichum 4 4
Fusicoccum 4 2 4 8 22 26 66
Gloeosporium 2 2
Phomopsis 4 10 10 8 18 12 62
Phyllosticta elongata 10 6 6 2 12 12 4 52
Phyllosticta vaccinii 18 24 42
Physalospora 6 8 6 8 14 10 10 62
Unidentified, other 16 22 26 60 20 30 18 192
Sterile 58 60 54 22 44 16 16 260

The flood seemed to depress the incidence of Physalospora (although levels decreased somewhat in the control as well), Fusicoccum and Coleophoma compared with the previous growing season. Conversely, the incidence of Phyllosticta vaccinii was greater in the year after the flood. Percent fruit rot at delivery to the handler in the year following the flood was greater in the bed that received the fall flood (7.80% poor vs. 0.99% poor). We conclude that the fall flood certainly does not suppress fruit rot organisms. Whether this practice increases fruit rot incidence remains an open question. No other growers in the project reported elevated deductions for rot.
Cranberry fruitworm:
Based on the data collected from 1998-2000, fall floods are effective in the suppression of CFW on the flooded bed (table 6). Even in control pieces, mortality is high over the fall and winter. However, 100 percent mortality was achieved in every complete fall flood. It should be noted that this insect may re-infest beds by flying in from other locations in the following season.
Table 6. Effect of post-harvest flood on survival of cranberry fruitworm
Year Site # Flood length (wks) CFW mortality (%)
Flooded Control
1998 1 4 100 97
2 4 100 80
1999 1 4 100 80
2 4 100 80
3 3 100 88

4 3 100 —
5 3 100 —
2000 1 4 100 71.3
2 incomplete 95.3 92
3 4 100 48.7

Flood length and fruitworm mortality:
Based on excellent results with 3- and 4-week floods (above), we next examined flood duration vs. CFW mortality starting with one week. Based on data collected in 2001, it appears that less than a three week flood gives inadequate fruitworm control. Hibernacula removed from the bog after only one or two weeks emerged at a much higher percentage than did ones removed after three weeks (figure1). By week three, oxygen levels in the flood had repeatedly dropped below 4 ppm (figure 2). This may account for the increased mortality over time.

Figure 1. Relationship between flood duration and CFW mortality.

Figure 2. Dissolved oxygen in flood water. Post-harvest flood with CFW hibernacula.
Cranberry growth and yield:
Effects of fall floods on cranberry growth and yield were studied at two paired sites (comparing pre- and post-flood years for length and fruit set and comparing to previous 4-year average yield). While yield was lower on the flood bed compared to the control bed at Site 1, yield was greater than the previous 4-year average (pre) for that bed, indicating no substantial negative yield effect. However, the decline in fruit set in the post-flood year bears investigation.
Table 7. Effect of fall flood on cranberry growth and yield.
Site Yield (bbl/A) Upright length (mm) Percent fruit set
4 yrs Pre Post Pre Post Pre Post
1 (Flood) 143 161 64 67 42.3 32.5
1 (control) 182 231 79 71 44.7 45.7

2 (Flood) 111 79 82 62 50.1 37.7
2 (control) 113 75 57 78 65.7 56.

Short late water (spring) floods:
Four pairs of short spring flood sites were studied for effect on CFW mortality. At two sites, comparison to a 4-week flood was made. Short floods increased CFW mortality somewhat compared to un-flooded sites but the traditional 4-week flood afforded much better control (Table 8). Based on these data, a short flood would not be a recommended practice for CFW control.
Table 8. Effect of spring flood duration on CFW mortality.
Site Flood length CFW mortality
Flooded Control
1 2.5 weeks 50% 28%
2 2.5 weeks 45% 13%

3 2.5 weeks 40% 34%
4 weeks 98% 20%

4 3 weeks 41% 37%
4 weeks 94% 71%

Glyphosphate clipping to control upright bramble:
Clipping and clipping in combination with glyphosphate herbicide was not successful in controlling upright bramble and in fact, seemed to stimulate growth the following season in comparison to non-clipped plants (table 9). Plants in the flooded sites however, had less growth the following season in comparison to the control site. This study did reinforce the utility of fall flooding as a method for dewberry suppression.
Table 9. Effect of fall flood and clipping on average bramble weight (g) in plots.
1999 clipped plots – 2000 clip +glyphosate 2000 no clipping – 2000 all combined 2000
Control bed 24.7 36.9 32.7 27.8 32.5
Flood bed 26.7 22.8 34.3 24.1 27.1

Effect of dichlobenil on weed control and cranberry.

Long term applications of dichlobenil at low (40 lb/a) or high (100 lb/a) rates did not adversely impact cranberry growth or yield (Figure 3). However, the study did show the adverse yield effects of high weed populations. The herbicide was effective in reducing the weed population in the study area (Figure 4).

Figure 3. Effect of dichlobenil and weed pressure on cranberry yield. Data collected at end of year 4.

Figure 4. Effect of dichlobenil and initial weed pressure on weed incidence (% mean species change) in cranberry bogs after 4 years.

Short term trash flood – impact on fruit rot:
Fungal populations were compared in two beds of fresh-harvest cranberries in 2000 (tables 10 and 11). After harvest, one bed was subjected to a ‘trash’ flood for 4 days during which fallen leaves and berries floated to the surface and were removed from the bed. In the following year, fungal populations were again surveyed in the paired beds (tables 12 and 13).
Table 10. Trash flood – 8#1 – 2000 Pre-flood fungal populations
Fungus 8/04 8/11 8/18 8/25 9/01 9/08 9/15 9/22 9/29 total
Allantophomopsis 2 2
Botrytis 2 2
Coleophoma 2 2
Colletotrichum 0
Fusicoccum 2 2 8 6 10 10 8 6 22 74
Gloeosporium 6 12 2 16 2 6 4 48
Phomopsis 6 8 2 2 4 12 10 2 54
Phyllosticta elongata 4 6 8 4 6 16 14 58
Phyllosticta vaccinii 0
Physalospora 12 12 24 18 12 36 30 40 30 214
Unidentified, other 32 28 36 26 30 16 8 12 6 194
Sterile 48 44 32 32 38 32 36 24 30 314

Table 11. No trash flood – 8#2 – 2000 Pre-flood fungal populations

Fungus 8/04 8/11 8/18 8/25 9/01 9/08 9/15 9/22 9/29 total
Allantophomopsis 2 2 4
Botrytis 0
Coleophoma 2 2
Colletotrichum 2 2
Fusicoccum 4 12 4 6 20 16 24 24 110
Gloeosporium 8 2 10 14 2 8 2 6 52
Phomopsis 8 2 6 10 4 12 8 4 54
Phyllosticta elongata 2 2 2 2 10 4 8 12 8 50
Phyllosticta vaccinii 10 2 6 2 20
Physalospora 10 28 18 38 38 40 52 52 40 316
Unidentified 28 20 22 26 24 14 12 14 16 176
Sterile 46 46 34 28 20 14 12 6 16 222

As was the case with the long post-harvest flood pair, there were more sterile berries in 2001 than 2000 in the trash flood pair. That is, incidence of pathogenic fungi was lower in general in 2001. The trash flood seemed to lower the incidence of Gleosporium and Phyllosticta elongata. However, incidence of Gleosporium was also reduced in the non-flooded bed. Incidence of Physolospora was slightly increased in the year following the trash flood but strongly reduced in the control bed. None of the changes were striking and we can conclude that the trash flood had little impact on the incidence of fruit rot fungi in the year following the flood.
Table 12. Trash flood – 8#1 – 2001 Post-flood fungal populations

Fungus 7/19 7/26 8/02 8/09 8/16 8/23 9/06 9/13 total
Allantophomopsis 2 4 6
Colletotrichum 2 2 10 2 16
Fusicoccum 4 2 6 8 22 14 56
Gloeosporium 8 2 2 6 8 2 28
Phomopsis 4 10 10 10 8 16 58
Phyllosticta elongata 4 6 4 8 16 38
Phyllosticta vaccinii 2 2
Physalospora 22 18 14 6 52 62 18 34 226
Unidentified, other 24 28 6 22 24 16 22 20 162
Sterile 46 54 60 60 18 8 20 20 286

Table 13. No trash flood – 8#2 – 2001 Post-flood fungal populations

Fungus 7/19 7/26 8/02 8/09 8/16 8/23 9/06 9/13 total
Allantophomopsis 2 2 4
Colletotrichum 2 2 8 2 14
Fusicoccum 4 8 4 8 10 8 36 26 104
Gloeosporium 4 2 2 2 4 14
Phomopsis 4 2 2 6 10 6 16 46
Phyllosticta elongata 2 10 2 2 4 2 20 42
Phyllosticta vaccinii 2 2 4 8
Physalospora 6 14 12 48 48 16 20 164
Unidentified, other 40 40 18 22 30 8 18 20 196
Sterile 46 36 74 58 10 22 22 16 284

Participation Summary


Educational approach:

Appendix 2. Resources
Title: A good year to try a fall flood (newsletter article)

Author: Dan Shumaker and Carolyn DeMoranville Release date: September 2000

Type of resource: Online (web-based) newsletter Available in quantity: NO
Cost: none Shipping and Handling? no
How to order:
Web address:
(click on “September 2000” for this article)
Title: Reducing Management Costs in Cranberry Production

Author: Carolyn DeMoranville Release date: Spring 1999

Type of resource: Fact Sheet Available in quantity: limited
Cost: none Shipping and Handling? no for single copies
How to order:
Deb Cannon
UMass Cranberry Station
P.O. Box 569
East Wareham, MA 02538
Phone: 508-295-2212, x10; FAX: 508-295-8387; e-mail:
Web address:
Title: Utility of fall and spring floods in cranberry pest management

Authors: Carolyn DeMoranville, Dan Shumaker, Hilary Sandler Release date: Spring 2003

Type of resource: Color Fact Sheet Available in quantity: limited
Cost: $5.00 Shipping and Handling? included on domestic orders
How to order (after May 2003):
Deb Cannon
UMass Cranberry Station
P.O. Box 569
East Wareham, MA 02538
Phone: 508-295-2212, x10; FAX: 508-295-8387; e-mail:
Web address:

Appendix 3 — Events

Annual Cape Cod Cranberry Growers Association Winter Meeting and Environmental Workshop, Plymouth, MA, March 1-2, 2000.

Panel discussion (breakout session), repeated twice in the afternoon sessions 3/2/00:
Post Harvest Management of Cranberry Beds

Approximate attendance 100.

The Project leader (C. DeMoranville) and a grower participant (K. Gilmore) from SARE project LNE 98-107 participated in a panel discussion on cranberry post-harvest management. Highlighted was the use of the fall flood as an alternative pest control practice. Most attendees indicated that they would be willing to try this practice.

UMass Cranberry Station Annual Cranberry Research and Extension Update, Falmouth, MA, March 7, 2000

Panel discussion of the use of spring floods for pest control – emphasis on cost savings by reduction in pesticide use.

Approximate attendance 125.

Project participants discussed the benefits in the use of spring floods for control of cranberry fruitworm, southern red mites, perennial weeds, and fruit rot disease.

Annual Cape Cod Cranberry Growers Association Winter Meeting and Environmental Workshop, Plymouth, MA, March 2, 2001.

Panel discussion:
Low Cost Cranberry Management

Approximate attendance 200.

The Project leader (C. DeMoranville) and participant (H. Sandler) from SARE project LNE 98-107 participated in a panel discussion on low-cost alternatives in cranberry management. Highlighted was the use of the fall and spring floods as alternative pest control practices.

UMass Cranberry Station Annual Cranberry Research and Extension Update, Wareham, MA, March 17, 2001.

Poster Presentation:
Integrated Management of Cranberry Insects and Weeds Using Fall and Spring Floods

Approximate attendance 50

Poster was authored by D. Shumaker, C. DeMoranville, H. Sandler, A. Averill, and M. Sylvia. Results from this project were presented to cranberry growers.

North American Cranberry Research and Extension Workers Conference, Becancour, Quebec, Canada, October 4-6, 2001.

Poster Presentation:
Integrated Management of Cranberry Insects and Weeds Using Fall and Spring Floods

Approximate attendance 65.

Poster was authored by D. Shumaker, C. DeMoranville, H. Sandler, A. Averill, and M. Sylvia. Results from this project were presented to cranberry researchers and extension professionals from throughout North America. This extends the project outreach beyond MA.

UMass Cranberry Station Cranberry Management Update, Plymouth, MA, January 14, 2003.

Oral Presentation:
Management of perennial weeds in cranberry

Approximate attendance 275

Project participant Hilary Sandler presented the results of the dichlobenil study and data showing the impact of spring and summer floods on weed populations.

Project Outcomes

Impacts of Results/Outcomes

Seven farms provided land for the demonstration experiments funded by this project. Certainly, those farmers have been directly affected by the project. All have seen the positive benefits in insect and weed control afforded by the use of flood in the spring and fall. Likewise, they have seen that using these practices did not adversely impact yield or increase disease incidence. As a result, these farmers have adopted spring and fall flooding as part of their cranberry farm management. While we did not demonstrate a significant impact of ‘trash’ flooding on incidence of disease organisms, growers remain committed to the practice as a good method of sanitation, preventing the buildup of a ‘duff’ layer that may harbor insects and diseases. In fact, the prevalence of this practice may explain the failure to show more dramatic results as the control bed was trash flooded in all years previous to the study and had not developed a serious buildup of trash.
Through the educational activities conducted during this project, additional farmers have also adopted these practices. The testimonials provided by project participants at meetings as well as informally on the ‘coffee-shop circuit’ has played a large role in general adoption. Presentations at professional gatherings of cranberry researchers and extension providers has led to inquiries and potential transfer of these practices to other cranberry growing regions.

Farmer Adoption

See also – Impact of results – outcomes section.

Appendix 4 — Farmer involvement, comments

Kirby Gilmore
Benson’s Pond Cranberry, Inc.
P.O. Box 190
Rochester, MA 02770

“I had previously experimented with the holding of my harvest flood and had observed impact on dewberries. I communicated this to scientists at the Cranberry Station and became involved in this project. I have been pleased with the impact of this practice on weed infestations on my bogs. I was happy to participate in a presentation for other growers regarding the results of this project and continue to use this practice.”

George Rogers and Bob Conway
AD Makepeace Company
158 Tihonet Road
Wareham, MA 02571

The Makepeace company has adopted spring and fall floods as well as short-term in-season floods for pest control as a cost-savings strategy. They continue to work with team members from the Cranberry Station to evaluate additional uses of flooding in cranberry pest control. As the largest grower in MA, their adoption of these practices has great impact directly and in its influence on other farmers in the region.

Keith and Monika Mann
Mann Farms
810 Head of the Bay Road
Buzzards Bay, MA 02532

The Manns communicated satisfaction with the use of spring floods particularly and continue to use them on their organic acres. (Their farm consists of organic certified properties as well as traditional bogs).

James Paduch
Crystal Lake Cranberries
26 Highland Street
Middleboro, MA 02346

David Nolte
Decas Cranberry Co.
4 Forge Drive
Carver, MA 02330

Hiller Cranberry Co.

265 Mary’s Pond Road
Rochester, MA 02770

Areas needing additional study

Of academic interest would be a study looking at the long-term effects of failing to use a ‘trash’ flood following dry harvest. However, since most growers have adopted this practice, the study would not be likely to lead to further change in farming practices. Of more interest is to follow-up on the apparent decrease in fruit set following a 3-4 week post-harvest flood. Preliminary investigations indicate that carbohydrate resources in the plant may be depleted during harvest flood. Sever depletion may relate to reduced fruit set the following season. While this is of concern, we were not able to document any decrease in yield associated with the use of the post-harvest flood for pest control.

Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.