Nutrient and Weed Management Strategies for Organic Wild Blueberry Growers

Progress report for LNE19-374

Project Type: Research and Education
Funds awarded in 2019: $199,828.00
Projected End Date: 11/30/2022
Grant Recipient: University of Maine Extension
Region: Northeast
State: Maine
Project Leader:
Dr. Lily Calderwood
University of Maine
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Project Information

Summary:

The price of conventional frozen wild blueberries reached a record low $0.27/lb in 2017, a price that does not justify crop maintenance. Meanwhile the crop grown organically sells for $5.00/lb. Small organic growers are stuck with low yields and large organic-transition farms will struggle with low prices until effective organic fertility and weed management strategies are developed and disseminated effectively. At a pH of 4.0, most soil applied fertility is not available for blueberry plants, yet these nutrients feed weed species. Foliar nutrient uptake is not well understood for this crop and increases the risk for disease. The weed management tools available for organic growers are limited to sulfur applications, weed whacking, and hand weeding. Furthermore, the shallow blueberry root system is susceptible to drought conditions that non-irrigated fields have experienced over the last three seasons. While applied research has been conducted on wild blueberry for many years, it is time to focus on soil and plant health for a new market. 

Performance Target:

Fifty blueberry growers in Maine will adopt at least one new weed, nutrient, or irrigation management practice on  a total of 500 acres. Among these growers, 5 managing certified organic farms will increase their average yield  by 500 lbs/acre on a total of 100 acres. Additionally, 500 acres of conventional blueberry land will adopt practices  necessary to transition to certified organic production. 

Introduction:

Project A: Nutrient Management

Given the significant market declines for wild blueberries in the U.S. conventional market (USDA NASS 2018), interest in organic production is growing. Growing wild blueberries under certified organic standards is challenging because there are a limited number of fertilizer and pest management tools approved for use.

The effects of various organic amendments applied in wild blueberry systems have been previously studied. These include manure (Warman 1987), papermill sludge (Gagnon et al. 2003), gypsum (Sanderson and Eaton 2004), biosolids (Lafond 2004), municipal solid waste (Warman et al. 2009) and seafood-waste compost (Mallory and Smagula 2014). However, these studies produced variable results regarding blueberry productivity and marketable yield with few significant effects on soil organic matter or leaf nutrient concentrations. These studies demonstrate the need to investigate other organic alternatives at different rates and timings to better understand their cost-effectiveness and ability to aid in water retention and nutrient availability.

Factors that affect nutrient uptake in wild blueberries include weed presence, soil pH, water availability, and the presence of soil nutrients (Drummond et al. 2009). Wild blueberries compete with weeds for space, water, and nutrients, which can result in reduced crop yields and limited blueberry spreading if left unmanaged. Insects and disease pests can also benefit from nutrients applied to wild blueberry and in turn increase damage caused in blueberry plants. The low soil pH (4.0-4.5) of commercial wild blueberry fields does not allow critical nutrients like nitrogen, phosphorus, and potassium to be readily available to wild blueberry plants (Peterson 1982). Therefore, organic growers must rely on soil biology to break down applied organic matter in order to increase nutrient availability in crop fields. This study aims to identify materials that improve soil water holding capacity and nutrient availability for wild blueberries.

In this study we evaluate the efficacy of four organic soil amendments and one foliar spray treatment for their impact on wild blueberry growth and pest presence. This study focuses primarily on enhancing nutrient availability in organic wild blueberry systems rather than applying methods to directly manage pest populations. Because the materials applied may benefit pests, pest monitoring is a key aspect of this study. We seek to develop a better understanding of the relationship between wild blueberry nutrient inputs and pest presence in order to aid future recommendations for organic wild blueberry growers.

Project B: Weed Management

Due to the low prices of conventional frozen wild blueberries (2014-2018 mean = $0.40/lb) and increasing demand for organic wild blueberries, there are now 52 certified organic wild blueberry farms in Maine. While this group only accounts for 11% of all Maine wild blueberry farms, they are able to sell frozen berries at a higher price ($5.00 - $19.80/lb). Finding cultural and mechanical methods of weed management is important for all wild blueberry growers whether they are considered small, large, organic or conventional. Small organic growers are stuck with low blueberry yields because they do not have effective OMRI approved herbicides. Large organic-transition and conventional farms are in search of transition methods and low residue practices due to market demand.

To date, the University of Maine has found that removing weeds from a wild blueberry field can double yield in the conventional system (Yarborough 1997). Applying sulfur to reduce soil pH to 4.0 in the wild blueberry system is a very effective way of culturally reducing grass species (Saunders 2016 and Yarborough 1997). Soil pH reduction is a slow process which takes 2-3 years and one that does not reduce woody weeds as well as grasses. Removing woody weeds three times per season via mowing, weed whacking, and/or hand pulling is the most effective method of mechanical weed management to date (Drummond et al. 2012).

This four-year study will explore tine weeding and winter-kill cover crops as mechanical and cultural weed management tools for the wild blueberry system. A flex-tine weeder is a tractor attachment with metal fingers called “tines” that drag through the top one inch of

soil dislodging weed seedlings (Figure 1). Tine weeding is used on vegetable and small grain farms in early spring just as the first winter annual weed seedlings emerge. The stiffness of tines allows them to break through the soil crust and the vibration of tines uproots weed seedlings (Bowman 1997). Flex-tine weeders are designed to dislodge white thread stage weeds when the machine is run at a “fast” speed.

Cover cropping is defined as the planting of another plant species among or alternating with the cash crop. There are numerous benefits of cover cropping, a few of which include weed suppression, erosion management, soil organic matter builds up, increased soil water holding capacity, and habitat for natural enemy and pollinating insects. Several species of cover crop have been explored to meet the needs of different cropping systems. In wild blueberry production, planting a cover crop that would then become a weed would not be wise. Therefore, we are interested in “winter-kill” cover crop species that are planted in the late summer and die over the winter such as common oat (Avena sativa) or sorghum-sudan grass (Sorghum × drummondii). As the cover crop species grows in late summer through early fall, organic matter is created. After the plant dies, it falls to the ground creating a vegetative mat with the potential to suppress weeds (Clark 2007).

Cooperators

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  • Dr. Yongjiang Zhang (Researcher)
  • Dr. Seanna Annis (Researcher)

Research

Hypothesis:

We hypothesize that the execution of timely organic nutrient and weed management strategies will increase wild blueberry yields. In turn, this will improve the economic and environmental sustainability of this native crop. We seek to build upon recent research conducted (FNE14-808, ONE14-222) and expand our knowledge of the organic wild blueberry system for the long-term benefit of all berry growers in the Northeast.

Materials and methods:

Project A: Nutrient Management

This project is replicated at three farm locations that were selected to represent three scales (small, medium, and large) and the three major wild blueberry growing regions (Mid-coast, Ellsworth, and Downeast) in Maine. The experimental design is a randomized complete block replicated six times. Each plot is 6’ by 30’ (180 ft2). A total of 54 plots and 9 treatments are located at each site (Table 1). The foliar fertilizer and chicken manure were applied at the recommended time and rate according to the label and company representative instructions. The Cobscook blend, mulch, and compost were applied according to recommendations from University of Maine Extension Educator Mark Hutchinson (personal communication, 2019). All products were applied one time except for the foliar fertilizer which was applied multiple times as recommended by the manufacturer.

All products were applied during the prune cycle of 2019. The foliar fertilizer was applied three times – once during the emergence, tip dieback, and bud development stages of wild blueberry growth at each site. It was applied on: June 19th, July 15th, and August 27th in Hope; June 24th, July 19th, and August 28th in Columbia Falls; and June 4th, July 18th, and August 30th in Surry. Chicken manure was applied on June 4th in Surry, June 5th in Hope, and June 12th in Columbia Falls. The Cobscook blend was applied on June 20th in Hope, June 24th in Columbia Falls, and June 26th in Surry. Mulch was applied on July 23rd and 24th in Columbia Falls and Surry, respectively. UMaine compost was only applied in Hope on June 19th. See Table 1 for product details. 

Table 1. Treatments tested at each of three organic farms in a randomized complete block design with 6 replicates.

 

Product

Rate

Rate Type

Crop Cycle

% NPK

Control

N/A

N/A

N/A

N/A

North American Kelp Co. Seacrop16 Foliar Fertilizer

1.2 L/242 gal. H2O/A

N/A

Prune

0.18% N

6.37% P

4.89% K

N/A

Crop

North Country Organics Cheep Cheep Chicken Manure 4-3-3

1089 lbs./A

Low

Prune

4% N

3% P

3% K

2178 lbs. /A

High

Prune

Coast of Maine Cobscook Blend Garden Soil

7.5 yd3/A

Low

Prune

0.4% N

0.14% P

0.12% K

15 yd3/A

High

Prune

*Mark Wright Disposal Dark Brown Mulch

7.5 yd3/A

Low

Prune

N/A

15 yd3/A

High

Prune

**University of Maine Compost

7.5 yd3/A

Low

Prune

0.41% N

0.11% P

0.10% K

15 yd3/A

High

Prune

*Only applied at Columbia Falls and Surry locations, % NPK analysis not completed

**Only applied at Appleton location

NPK represented as total nitrogen, phosphorus as P2O5, and potassium as K2O

Data Collection

Physiology

Two 0.37 m2 quadrats were placed in each plot to monitor percent tip-die back and physiological measures in the  vegetative year (2019). Within each plot, each of the two quadrats were placed in separate genets (plants). Six stems from each plot were randomly selected and marked to monitor stem length, chlorophyll content and anthocyanin content during June-October on a vegetative year (2019). Chlorophyll content was measured by a SPAD Chlorophyll Meter (SPAD 502; Minolta Corp, Osaka, Japan), anthocyanin content was measured by an ACM-200 anthocyanin meter (Opti-sciences, Hudson, USA). Photosynthetic electron transport rates were measured in leaves from 6 stems in each plot by a Y(II) meter (Opti-sciences, Hudson, USA) in August on a vegetative year (2019) between 10:00 and 14:00 h solar time. Ten random leaves from each genet in each plot (20 leaves as 2 samples in each plot) were collected in September of 2019 to measure leaf area and their dry biomass. Leaf area was determined using LI-3000A area meter (Li-Cor, Lincoln, NE, USA), then the leaves were oven-dried at 70ºC to constant mass and weighed.

Pest Pressure

Insects, weeds, and disease were monitored in the same 0.37 m2 quadrats (twice per plot) as pant physiology throughout the 2019, 2020 field seasons. In the 2019 prune-year pest scouting took place 3 times (once per month) from July to September at each of the three locations. In the following 2020 crop-year pest scouting took place 3 times May to July at each location. Pest severity (percent cover) for weeds, insect and disease were quantified using equal interval ranks between 0 and 6, where: 0 = not present, 1 = ≤1%-17%, 2 = 17%-33%, 3 = 33%-50%, 4 = 50%-67%, 5 = 67%-83% and 6 = 83%-100%. Weeds were identified into two groups in 2019 (grass and broadleaf) and in 2020 weeds were identified by genera and counted to obtain weed number per quadrat. In 2020 the number of wild blueberry stems with insect or disease damage were also identified and counted in addition to ranking.

Disease symptoms and leaf loss were rated in August and September using 0.25m2 quadrat in both 2019 and 2020.  Two quadrats were sampled per plot and percentages of blueberry cover, blueberry leaf loss, and blueberry leaf area with the following leaf spot diseases: Septoria leaf spot, powdery mildew, and leaf rust were estimated visually.  Symptoms of insect damage were also noted. August and September disease ratings were averaged across the 2 quadrats within the trial plot. 

Crop Productivity

Blueberry cover was quantified using the same equal interval ranking at the time of each pest scouting. Additionally, in the 2019 prune-year, stem heights and the number of buds per stem were recorded for 8 stems per plot at all locations late August to early Sept. In the following 2020 crop-year, fruit-set and fruit-drop were monitored with repeated measures on the same 4 stems per plot. Fruit-set measures included flower counts at peak bloom, green fruit counts prior to ripening, and blue fruit counts during ripening. Percent fruit-set was quantified by the number of green fruit relative to the number of flowers per stem, while fruit-drop was established through the number of blue fruit relative to the initial number of green fruit observed for each stem.

The first harvest of these plots took place on August 3rd, 6th and 11th, 2020 in Appleton, Surry and Columbia Falls, respectively. Harvest procedure included hand raking an exact quadrat in the flagged locations where repeated scouting had taken place, followed by hand raking the entire plot. Quality measures were also taken for each treatment including a 100-berry count to quantify average berry size and a brix measure of the relative sugar content.

Data Analysis

Physiology

The effects of the applied organic treatments on soil moisture, physiology (chlorophyll concentration and photosynthetic electron transport rate), and morphology (total leaf surface area per stem) of wild blueberry plants were statistically compared using a general linear model followed by LSD (least significant difference) post-hoc test in SPSS software (α = 0.05). In this model, the main effects of applied treatments were considered as a fixed factor, experimental blocks as a random factor, and a Bonferroni correction was also applied for confidence interval adjustment. Each site (Appleton, Surry, and Columbia Falls) was analyzed individually for the measurements taken in the prune year 2021.

Pest Pressure & Productivity

Due to the nature of count data collected in the field (which often has a high number of zeros creating a skewed distribution) much of our data failed the assumptions of normality and equal variance often required to run parametric statistical tests. All data was transformed with a square root transformation prior to any statistical testing. Ranked data and pest count data visually improved following transformation, but the data continued to statistically fail for normality. Statistical tests were carried out despite non-normality after establishing there were no serious problems with the data.

Ranked blueberry cover and pest cover data were transformed to their corresponding percent mid-point. Ranked blueberry cover, pest cover and pest counts (#/m2) were compared across all years (2019-2021) using a full-factorial repeated-measures mixed model design in JMP (JMP®, Version 15.2). Here, the full factorial tested the effects of date, treatment, and any interaction between date and treatment for the ranked response variables.

Project B: Weed Management

In April 2019, the site location for this study was selected at Blueberry Hill Farm in Jonesboro, ME. This ongoing trial is a randomized complete block design replicated six times with 6’ by 30’ plots and 3’ wide buffers between plots. The trial is located on one acre that is now managed organically although it is not an organically certified piece of land. One soil sample was taken of the site location before the project began.

In March 2020 we conducted a lab experiment to test the ability of cereal cover crop species to germinate in acidic wild blueberry soil. The effects of low pH were tested using a water and buffer solution. In the lab, common oat (Avena sativa, Blue Seal) and pearl millet (Pennisetum glaucum F1, Johnny’s Selected Seeds) were germinated in petri dishes (100 seed/dish) with 4 watering treatments: a control using distilled water only (pH: 7.0) and 3 water/buffer solutions (pH: 4.0, 4.5 and 5.0) . Each watering treatment was replicated 3 times for each species. Seeds were sprayed daily using a spray bottle for 5 days. The number of seeds germinated per petri dish was recorded and average percent germination was calculated. Because successful germination occurred in the lab, common oat and pearl millet cover crop seed was planted via broadcast in the field on September 1st, 2020 after harvest. Four cover crop treatments were planted: common oat and pearl millet each at a low and a high rate (Table 1).

Treatments are listed in Table 1. Two controls were employed; no weeding and hand weeding on one date. On May 13th and June 12th prune year tine weeding treatments were completed. Tines on a Williams flex-tine weeder were set to have the greatest down pressure (setting 8)(Image 1). The tractor was run slower than recommended at 1 mph due to the bumpy field and our learning curve. The hand weeded treatment was completed on June 12th.

Table 1. Weed management treatments used in the 2019 prune-cycle and the 2020 crop-cycle. All tine weed treatments had 2-passes per date and cover crop seeds were planted on September 1, 2020 after harvest.
Williams flex-tine weeder at Blueberry Hill Farm, May 2019.

Measures of weed and blueberry crop growth were collected using two 0.5m x 0.5m quadrats per plot. Two quadrats were placed per plot and flagged for repeated measurements in the same locations throughout the study.

Weed control efficacy was evaluated within each quadrat by ranking overall weed cover using the Daubenmire scale of 0-6 (Table 2). In 2019, weeds were identified into two groups; grass and broadleaf, each of which were also given a severity rating on the same 0-6 scale and sampled twice throughout the season (June 27th and August 28). In 2020 we took a slightly different approach by counting the total number of weeds per quadrat with an overall rank of cover using the Daubenmire scale and listing the top three weeds that covered the most area within each quadrat. These measurements were taken three times throughout the 2020 crop-year (May 14th, May 27th and July 2nd).

The response of the blueberry plant to tine weeding in 2019 was monitored through repeated observations of blueberry cover as well as physical measures of stem height, bud number per stem and ramet density (Figure 2). In 2020, six random stems were flagged per treatment and monitored repeatedly for fruit-set and fruit-drop for the 3 tine weed treatments and the 2 controls. Fruit-set measures included bud counts in the late spring, flower counts at peak bloom, green fruit counts prior to ripening, and blue fruit counts during ripening. Percent fruit-set was calculated from the number of green fruit and the number of flowers per stem, while fruit-drop was calculated from the number of blue fruit and the original number of green fruit observed for each stem.

Harvest occurred on August 17th, 2020 for the tine weed treatments and both controls. Harvest procedure included hand raking exact quadrats in the flagged locations where repeated measurements were taken throughout the season. Then a walk behind harvester, harvested a 3ft strip down the center of each plot. The two modes of harvesting provided an ‘exact’ yield and a more ‘realistic’ yield (accounting for % loss that may occur with a mechanical harvester) for each treatment. Quality measures were also taken for each treatment including 100-berry weight to quantify average berry size and a brix measure of the relative sugar content using a hand-held Atago brix-acid meter.

Cover crop emergence was evaluated on October 9th, 2020 by counting the number of emerged plants within two quadrats/plot and measuring the heights of 6 random cover crop plants per plot.

Common oat (top) and pearl millet (bottom) cover crop seedlings at Blueberry Hill Farm in October.

Table 2. Daubenmire ranking scale (1-6).

 

Percent Coverage

Rank

Range

Midpoint

1

0-5%

2.5%

2

5-25%

15.0%

3

25-50%

37.5%

4

50-75%

62.5%

5

75-95%

85.0%

6

95-100%

97.5%

Data Analysis

Blueberry health and recovery after tine weeding were evaluated using blueberry stem height, bud counts (per stem), blueberry plant cover and number (ramets/m2). The continuous data (stem height, plant and bud number) were evaluated using a one-way ANOVA with a Tukey’s Pairwise comparison in JMP (JMP®, Version 14.3) across all weed management treatments (α = 0.05). Ranked (ordinal) data for blueberry plant cover and weed severity by type (broadleaf and grass) were compared using Chi-Squared test in JMP across all treatments (α = 0.05).

Research results and discussion:

Project A: Nutrient Management

Effects of Organic Amendments on Soil Moisture

Overall, no significant differences were found in seasonal average soil moisture among the treatments in any of the studied locations. However, on average in the Appleton field, all the treated plots except the high rate of the Coast of Maine Cobscook blend treatment showed a trend towards higher soil moisture compared to the control plot. In contrast, in the Surry field, only the low rate of mulch-treated plots showed comparatively higher soil moisture on average than control plots whereas other treated plots had similar soil moisture as the control. In Columbia Falls field, all treatments showed comparatively higher soil moisture content than the control where the highest soil moisture was found in the high rate of mulch followed by Cheep Cheep-treated plots.

Wild Blueberry Plant Physiology and Morphology

Overall, no significant differences were observed in the wild blueberry leaf sizes in any of the three organic wild blueberry fields. In the Appleton field, both low and high rates of coast of Maine cobscook blend treated plots and the control plot had comparatively higher leaf size than the other treatments. In the Surry field, the control plot, plots with the low rate of cobscook blend and chicken manure, and the SeaCrop16 treated plot in the prune year (2019) had higher leaf size compared to the other treated plots. In contrast to the leaf sizes observed in the Appleton and Surry fields, the high rate of chicken manure and SeaCrop16 in the crop year (2020) at Columbia Falls had higher mean leaf size compared to the control and other treatments. In 2021 (second prune year) at the Appleton field the average leaf chlorophyll concentration was the highest in the low rates of Cheep Cheep and the Coast of Maine Cobscook blend treatments, but this was not significant. Again, in the Surry and Columbia Falls fields, average leaf chlorophyll concentration was the highest where the low rate of Cheep Cheep was applied.

Regarding the wild blueberry leaf dry biomass, significant differences were observed among the treatments in Appleton and Columbia Falls fields but not in the Surry field. In the Appleton field, higher leaf dry mass was observed in the control plot and the treated plots with both low and high rates of Coast of Maine Cobscook blend, SeaCrop16 applied in the prune year (2019), high rate of chicken manure compared to the other treated plots. In contrast, in the Surry field, the observed leaf dry mass was almost similar among the different treatments including the control plot. However, in the Columbia falls field, the high rate of chicken manure treated plot had significantly higher leaf dry mass compared to the control plot.

Effect of Organic Amendments on Blueberry Cover and Pest Incidence, 2019, 2020, and 2021

Looking at all three years of this study at all three locations together, blueberry cover responded well to all organic amendments with 2% to 4% greater coverage than the control. While the blueberry exhibited a positive response to all amendments, only the SeaCrop16 foliar spray applied in the prune year (2019) exhibited significantly greater blueberry cover relative to the control. Other strong responses, although not significant, include SeaCrop16 applied in the crop year, Cheep Cheep, and mulch.

Pest Incidence

Weed cover observed across all three locations over the three-year period was significantly higher where Cheep Cheep was applied at the higher rate. Here, the high rate of Cheep Cheep had on average 6% more weeds than the control and 19% more weeds than the treatment with the lowest weed pressure, University Compost. The treatments that exhibited fewer weeds were the University Compost (both rates), the SeaCrop16 applied in the crop year, and the high rate of mulch. All four treatments listed had significantly less weed coverage than the control by as much as 7% to 13%. Weed number (#/m2) showed similar results to that of the weed cover above where Cheep Cheep had significantly more weeds per area compared to the control. Looking at weed number, only SeaCrop16 applied in the crop year had significantly fewer weeds than the control.

When evaluating the weed population by the general categories of grass and broadleaf, there was a consistent trend with higher frequencies of grass species relative to broadleaf species. The control, Coast of Maine Cobscook blend, and University compost-treated plots showed an expected trend where greater weed frequency were present in the prune years (2019 and 2021) and reduced weed frequency was observed in the crop year (2021), due to greater blueberry leaf coverage in the crop year. The Cheep Cheep- and mulch-treated plots, however, showed a steady increase across all three years with an increase in weed frequency in the crop year despite competition from the blueberry. SeaCrop16 did not follow either trend. Across treatments and all years grass species consisted primarily of: poverty oat grass, witchgrass, barnyard grass, rushes, sedges, and other unidentified grasses. Broadleaf species’ frequency varied by year. Top broadleaf species in 2020 consisted of: cow wheat, Canada mayflower, aronia, bracken fern, and red sorrel. In 2021 top broadleaf species were primarily: red sorrel, aronia, toadflax, wintergreen, and dogbane. Weeds were not identified to genera in 2019.

Weed number (#/m2) averaged across all three locations (Appleton, Surry and Columbia Falls) over three years (2019-2021) under organic amendment treatments. The least squares mean estimates are presented following a square root transformation. Letters indicate significance at the 0.05 level of significance. Error bars indicate the standard error of the mean.
Weed cover representing the area of weed pressure measured across all three locations (Appleton, Surry and Columbia Falls) over three years (2019-2021) under organic amendment treatments. The least squares mean estimates are presented following a square root transformation. Letters indicate significance at the 0.05 level of significance. Error bars indicate the standard error of the mean.

Insect coverage, a spatial measure of insect pressure generally indicated by pest damage to leaves or observation of the actual culprit, was significantly higher in the Cheep Cheep plots (both rates) and in the mulch (high rate), relative to the control. Here, the mulch (high rate) amendment had the greatest insect pressure, 6% greater than the control; followed by the the Cheep Cheep high rate and low rate, 5% and 4% greater than the control, respectively. The University compost (both rates) presented relatively low insect pressure, although, no treatments were significantly less than the control. Insect numbers, however, did show the highest concentrations in the mulch treatments at both rates relative to all other treatments and the control. The top three insects across all three years (2019 to 2021) were tip midge (54% frequency), red striped fireworm (26% frequency) and flea beetle (22% frequency).

Disease coverage, including leaf spot species, mummy berry, and phomopsis, as indicated by a spatial measure of disease pressure, was relatively similar across all treatments with the exception of Cheep Cheep (high rate), which exhibited 5% less disease than the control (Figure 10). The number of stems with disease showed fewer trends than the ranked coverage, however it is worth noting that the SeaCrop16 applied in the crop year was the only treatment with significantly greater disease (number) with this measure (Figure 11). High disease with SeaCrop16 applied in the 2020 crop year may be a function of applying foliar fertilizer in peak drought conditions experienced in 2020. Reduced disease with the higher application of Cheep Cheep suggests increased crop resilience with added nutrients

Effect of Organic Amendments on Harvest Yield and Quality

Harvest will occur again and for the last time in this project in 2022. The 2020 harvest yield of the wild blueberry did not exhibit significant treatment differences across all three locations. Despite no statistical significance, every treatment that received organic amendments yielded higher than the control. Berry quality measures taken at the time of harvest included brix as a measure of berry sugar content and 100 berry weight as a measure of berry size. Berry sugar content was highest in the chicken manure treatments and lowest with University Compost, although treatment differences were nonsignificant. Berry size was significantly lower in both mulch treatments than the University compost (low-rate). All other treatments showed no significant differences from one another in berry size. It is worth noting that while University compost exhibited large berry size, it also had the lowest sugar content, suggesting the berries had a higher water content.

Project B: Weed Management 

Impact of Tine Weeding

Observationally, we saw that two tine weed passes were more effective than one pass per date at uprooting white thread stage weed seedlings. The first pass loosened up the soil required to then dislodge weeds in the second pass. Preliminarily, Canada mayflower, horse weed, and red sorrel were uprooted (Image 2). Loose and dead wild blueberry ramets were pulled up in some cases. The most damage to wild blueberry occurred from driving over the field on the second tine weed date, June 12th (Image 3). On the first tine weed date, May 13th, wild blueberry leaves were not out yet and therefore less damage to wild blueberry from tractor tracks was observed.

Canada mayflower uprooted from tine weeding on May 13, 2019.
The late tine weeding date damaged wild blueberry under tractor tracks and was not as effective at pulling weeds out.

Blueberry Health

In 2020, four passes with the tine weeder resulted in a visual reduction in blueberry cover, blueberry development, and accumulated vegetative growth (Figure 1). The image below, taken over a month after tine weeding, shows the disturbance from four passes of the tine weeder with a dark strip consisting of large patches of bare ground, undeveloped stems, uprooted rhizomes, and less green vegetation than the surrounding treatments. In 2021 the tine weeded treatments had become less distinguishable apart from unhealed, uprooted rhizomes.

Post-tine weeding blueberry cover and blueberry stem number measured across 2020 and 2021 showed a reduction with increased passes with the tine weeder (Figure 2). Blueberry cover was significantly greater in the control than both tine weed treatments by as much as 10% and 17% compared to the tine with two passes and with four passes, respectively. Blueberry stem number showed significant reduction with four passes of the tine weeder relative to the control. Here, four passes with the tine weeder resulted in 20% fewer stems.

Average total bud number in the spring of 2021 presented little difference in bud number between treatments with a slightly larger standard error in the tine weeded treatments, meaning greater variation in bud numbers between stems. Other reproductive stages varied by treatment with the greatest average flower number and the lowest green fruit occurring in the tine treatment with four passes, perhaps suggesting poor pollination in this treatment or a more likely scenario being reduced nutrient or water availability. Green fruit and blue fruit counts were highest on average in the tine treatment with two passes, possibly reflecting differences in development rate.

Fruit development (% stage by treatment), evaluated for July 29, 2021 (the day of harvest), suggests the fruit developed slower in plots tine weeded with two passes than plots tine weeded with four passes relative to the control. This is clear through the ratio of green fruit to blue fruit on the day of harvest.

Average bud number, flower number, fruit numbers for green fruit and blue fruit measured on May 7, June 3, June 16, and July 29, 2021, for each peak stage respectively. Treatment differences were nonsignificant for all reproductive stages. Error bars indicate the standard error of the mean.

Comparing Before and After Tine Weeding in 2020

When comparing the single date pre-tine measures to the average post-tine measures collected throughout the season, a percent change can be generated to show the difference between the two time periods by treatment. Here, comparing pre- and post-tine measures for 2020, there was little difference in blueberry cover in the control (-2%), while the tine weed treatments exhibited a 17% and 21% decrease in blueberry cover for treatments that received two passes and four passes, respectively. Weed cover increased by 23% in the control treatment as weeds emerged throughout the season, but weed number decreased (see discussion). Both tine weed treatments experienced a decrease in weed cover and weed number with the greatest decrease in the tine treatment with four passes. Here, more passes with the tine weeder led to a 14% decrease in weed cover and a 65% decrease in weed number (#/m2) following tine weeding.

Changes in blueberry cover, weed cover and weed number following tine weeding is calculated by the difference (%) between pre-tine weed measures taken on May 6, 2020, and post-tine weed measures taken May 14 to September 1, 2020.

Effects of Tine Weeding on Weed Pressure

When comparing the types of weed species present across treatments, tine weeded with four passes had the lowest diversity of weed species present but the highest occurrence of grass. Tine weeded treatments had a higher percentage of broadleaf weeds than the control. Overall, red sorrel was the top broadleaf species in all treatments (post-tine weeding), followed by St. John’s wort and violet. When evaluating weed presence by life cycle, treatment differences were non-significant, but an interesting trend occurred. Tine weeding resulted in a visible increase in annuals and grasses while exhibiting a decrease in perennial weeds relative to the control. This shows that tine weeding may impact weeds differently based on their growth and reproductive patterns. When evaluating the effect tine weeding on weed cover and weed number there is a visible reduction with the increasing number of passes when compared to the control. In 2020, weed numbers (#/m2) were significantly less in the 2 and 4 pass treatments relative to the control. When evaluating 2020 and 2021 together, both weed cover and weed numbers are not significantly different between treatments suggesting the weed pressure may have rebounded slightly in 2021. Overall, weed presence was considerably less in the plots that were tine weeded relative to the control. Compared to the control, weed covers (%/m2) were 25% and 31% less and weed numbers (#/m2) were 36% and 37% less with 2 passes and 4 passes, respectively.

Blueberry cover (%/m2) and blueberry stem number (#/m2) by treatment following tine weeding, measured in 2020 and 2021. Treatment differences were nonsignificant for weed cover and weed number. Letters indicate significance at the 0.05 level of significance for blueberry stem number. Error bars indicate the standard error of the mean.

In 2020, preliminary results on cover crop establishment showed the oat outperformed the millet in height (for both rates) and germination (high rate only). In August 17, 2021 two high rates of common oat were applied (500 and 1000 lbs/ac) and results will be shared in the 2022 report. 

Germination and height of cover crops pearl millet and common oat at two seeding rates. Letters indicate significance at the 0.05 level of significance for germination and plant height, capital letters are to be compared separate from lowercase letters. Error bars indicate the standard error of the mean.
Research conclusions:

Project A: Nutrient Management

From the three years of data collected so far from this four year study, some soil amendments may be able to improve the condition of organic wild blueberry plants. In the third year, treatment effects seemed to decline in wild blueberry physiology and morphology since no significant differences in those parameters were found among the treatments from the second year. This may mean that treatments should be applied every few years to achieve consistent improvements in physiological and morphological performance, and thus yield. This observation requires another year’s observation and data collection to support or refute it.

However, blueberry cover and pest data has begun to show patterns in the third year indicating that plant cover and pest response to soil amendments is delayed until the next cycle. In the first three years of this trial, blueberry cover was significantly higher in all treatments excepting Coast of Maine (high rate), mulch (high rate), and University Compost (both rates); the greatest blueberry cover was observed after the application of Cheep Cheep, resulting in visibly taller, fuller, and greener plants. Cheep Cheep-treated plots also had the highest weed cover (predominantly grasses) and there was a significant correlation between weed pressure and reduced yield in the Cheep Cheep (high rate) plots. Cheep Cheep’s high macro- and micro-nutrient concentration (N-P-K is 4-3-3 & Fe, Cu, S, Ca, Mg, Zn, Mn are present) benefits weeds as much as wild blueberry. 

Applications of Cheep Cheep appear to have increased the soils’ water-holding capacity as well (albeit not significantly), since this fertilizer added organic matter to the soils (Gould, 2015; Bot & Benites, 2005). Cheep Cheep treatments resulted in higher leaf chlorophyll concentrations and greater leaf area than other treatments (though not significant) which may be due to the higher nitrogen content in chicken manure (Cheep Cheep’s N-P-K is 4-3-3) than in other amendments studied; nitrogen is the single most important nutrient for building leaf chlorophyll, which improves photosynthetic performance and results in improved crop production (Taiz et al., 2015). A better understanding of the leaf nutrient concentrations will better explain the contradictory responses of photosynthetic electron transport rates when compared to applied treatments; these results will be explained in next year’s report.

When including the third year of data (2021) in the repeated measures’ statistical analyses, blueberry cover waned in all organic amendment treatments except for SeaCrop16 applied in the 2019 prune year. SeaCrop16 contains cytokinin, a plant growth hormone that can potentially protect plants from drought and frost damage and promote photosynthesis (Novakova et al., 2007). In 2020, wild blueberry fields experienced warmer temperatures and drought conditions making plants stressed in these fields that are not irrigated. The SeaCrop16’s mode of action may have led to the high performance of the blueberry with this treatment.

Insect presence was greater where mulch had been applied when compared to all treatments, this effect was especially prominent with insect ‘cover’ in response to the high rate of mulch. While future research into this trend is necessary, the mulch may be improving the structural habitat for insect pests, especially over winter when insects take refuge in the duff below the plants. This ‘effect’ of mulch on insect pressure may also be due to site-specific tendencies, since mulch was not applied at all locations.

Disease cover across all three years was significantly lower where the high rate of Cheep Cheep had been applied relative to the control, and a number of other treatments. Here, lower disease occurrence in response to a high application of both macro- and micronutrients is likely a result of reduced plant stress.

Recommendations to Growers

Organic growers should consider applying a lower rate of chicken manure (Cheep Cheep) IF they have excellent weed management practices already in place. SeaCrop16 or other liquid kelp product can be applied during the prune year to increase blueberry cover. Compost or mulch may be used to build organic matter and suppress weeds. Importantly, all composts have slightly different nutrient and organic matter content based on the materials used. Apply compost in a small area of the field to test impacts in your field.

Cost of Products

The cost of products used plays a critical role in implementation by wild blueberry growers (Table 2). The Coast of Maine Cobscook Blend was the most expensive product, followed by North Country Organics Cheep Cheep. Both the North American Kelp Seacrop 16 foliar fertilizer and Mark Wright Disposal mulch had lower costs per unit and were also applied at lower rates compared to the chicken manure, thus resulting in overall lower costs compared to all other treatments. No cost was given for compost because it was donated by the University of Maine for this study.

Table 2. Cost comparison of 2019 prune-cycle treatments. Cost is based on one application. Prices may vary based on quantity purchased, grower size, and retailer.

Product

Rate

Cost ($/acre)

Cost/unit

 

Control

N/A

N/A

 

 

N/A

 

North American Kelp Co. Seacrop16

Foliar Fertilizer

1.2 L/242 gal. H2O/A

$14.70

 

$245/5 gal.

 
 

North Country Organics Cheep Cheep

Chicken Manure 4-3-3

1089 lbs./A

$814

$37/50 lb.

 

2178 lbs. /A

$1628

 

Coast of Maine

Cobscook Blend Garden Soil

7.5 yd3/A

$2025

$270/yd3

 

15 yd3/A

$4050

 

Mark Wright Disposal

Dark Brown Mulch

7.5 yd3/A

$240

$32/yd3

 

15 yd3/A

$480

 

*University of Maine Compost

7.5 yd3/A

N/A

N/A

 

15 yd3/A

N/A

 

Project B: Weed Management 

Effects of Tine Weeding on Blueberry Health: Before and After Tine Weeding in 2020

Our comparison of blueberry cover, weed cover, and weed numbers before and after tine weeding showed that this method was an effective weed reduction technique. Two passes with the tine weeder controlled certain weeds, yet wild blueberry yield and blue fruit count was not significantly different than the control.

The control plots saw an increase in weed cover (but not number) as the weeds in these plots were not stressed by the tine weeding. Both two and four passes with the tine weeder reduced weed cover by 9-14% and weed number 52-65%. It also reduced blueberry cover by 17-21% for two and four passes, respectively. These reductions prove the hypothesis that multiple passes with the tine weeder effectively dislodge and remove more and more weed roots with each pass; reasonably, rhizomes of wild blueberry are also dislodged, particularly with multiple tine weeder passes.

Effect of Tine Weeding on the Crop

Disturbance stimulates wild blueberry growth, and this knowledge has been integrated into crop management in the form of mowing or burning to prune the plants and encourage future growth in addition to some more advanced methods of disturbance on some farms (DeGomez, 1988). One of our hypotheses was that tine weeding would stimulate wild blueberry plant production. Over the course of two tine weeding trials in both cycles over 3 years we can conclude that this type of disturbance does not increase plant production. We did see an increase in flower number when prune plants were tined twice and four times yet this increase did not continue into green fruit and blue fruit at harvest. There were significantly more green fruit at harvest indicating that fruit development was delayed in tined plots. We saw a decreasing trend towards smaller berry size, lower Brix content, and lower yield from control to two and four passes. These delays may be due to a “late pruning” event or from dislodged rhizomes that reduced the plants’ ability to take up nutrients and water.

Effects of Tine Weeding on Weed Presence

Comparison of which weed species were present across treatments made clear that four passes with the tine weeder decreased diversity of weed species present. This may be due to some weed species being more susceptible to tine weeding than others. Interestingly, the most frequently identified top broadleaf species under each of the treatment conditions were exactly the same: red sorrel, St. John’s wort, and violet. The tine weed treatments presented a higher occurrence of broadleaf weeds relative to the control suggesting greater species diversity and more consistent presence across all plots and sample dates. The average occurrence of the annual violet species were 3x higher in tine weeded plots relative to the control. Annual plants may have been planted by the tine weeder, which moved seeds from parent plants and dropped the seeds in the top layer of duff, where they lay dormant until the right conditions occurred. Grasses and broadleaf perennials may have grown more numerous as the tine weeder physically broke apart clusters of grasses and rhizomes, thereby stimulating more growth.

Recommendations to Growers

Generally, we do not recommend tine weeding because our study has found a decrease in several wild blueberry health parameters even though yield itself did not significantly decrease the year after tine weeding. Growers seeking to manage weeds using tine weeding will find two passes with the tine weed sufficient for reducing perennial broadleaf weeds in their fields, IF the field is level, with minimal adverse impacts on fruit yield and quality. Tine weeding is not recommended for growers with grasses and annual weeds. The speed and pressure settings for the tine weeder will need to be adjusted based on localized conditions, such as field rockiness and levelness. Growers interested in tine weeding are encouraged to do an assessment of what weeds are present in their fields prior to tine weeding in order to make sure tine weeding is right for their field and to measure the impact of tine weeding at your location.

Participation Summary
5 Farmers participating in research

Education

Educational approach:

A collaborative research and outreach program continues to reach both organic and conventional wild blueberry growers. In the first year of this project, the research team worked with collaborating farmers to finalize treatments and set up research trials on three farms. In 2019 we shared this project at the Annual Wild Blueberry Field Day held in Jonesboro ME (91 attendees), Organic Wild Blueberry Growers Field Day in Dresden ME (20 attendees), and Western Maine Wild Blueberry Field Meeting in Otisfield ME (14 attendees). 

First year results were presented at the 2020 Wild Blueberry Conference which was held in Bangor ME on February 22 which had 90 attendees, 45% of which identified as organic. Throughout the winters of 2020 and 2021 education and outreach related to this project had to be conducted virtually due to the Covid-19 pandemic. In the spring of 2020, from April through June on Friday mornings "Wild Blueberry Coffee Hours" were held as a way to engage growers and allow for further education as the season began (34 total attendees). Four virtual field days were held in July 2020 that covered disease, insect, weed, and nutrient management for both organic and conventional growers (61 total attendees). In September 2020 we were able to hold 2 in-person field meetings that were socially distanced and with masks where results from this project were shared on big posters outside (24 total attendees). Our wild blueberry newsletter regularly reaches 735 recipients (486 online and 249 in print) where important project updates are shared.

In 2021 the Wild Blueberry Conference was held virtually and included an Organic Wild Blueberry Production session which had 83 attendees live and the recording can be found here. A total of 1168 attendees called in to all 17 virtual sessions. Over the summer of 2021 five field meetings were held for organic and conventional growers where organic weed and nutrient management were topics covered. In 2021 there were a total of 169 attendees in person.

Lily Calderwood presenting the tine weeding trial at the 2019 Maine Wild Blueberry Field Day in Jonesboro, ME.
Co-PI Seanna Annis explaining how to identify leaf spots on wild blueberry at the 2019 Organic Wild Blueberry Growers Meeting in Dresden, ME.
Calderwood and growers learning about organic weed management during an outdoor 2020 field meeting.
Farmers at a 2021 field meeting in Ellsworth, ME.

Milestones

Milestone #1 (click to expand/collapse)
What beneficiaries do and learn:

1. Four farmers give feedback on research trial design and treatments.

Proposed number of farmer beneficiaries who will participate:
4
Actual number of farmer beneficiaries who participated:
4
Actual number of agriculture service provider beneficiaries who participated:
5
Proposed Completion Date:
July 31, 2019
Status:
Completed
Date Completed:
August 1, 2021
Accomplishments:

From discussion with members of the advisory group the chicken manure treatments of the fertility trial are of interest and further study was suggested to look at lower rates of chicken manure which may cause less of a weed problem. Mulch is also a material of great interest after the 2020 drought conditions. Without water, plants can't take up the nutrients they need. 

Findings on tine weeding experiment are not promising for reliable weed management. Advisory group was pleased that mechanical weeding was looked at in this manner. "It is valuable to know that tine weeding reduced perennials. Those are the most common weeds in my fields but I have a bumpy field so it might not be the best option" - Wild Blueberry Farmer

Milestone #2 (click to expand/collapse)
What beneficiaries do and learn:

2. Three farmers host the three replications of the nutrient research trial on their farm.

Proposed number of farmer beneficiaries who will participate:
4
Proposed number of agriculture service provider beneficiaries who will participate:
1
Actual number of farmer beneficiaries who participated:
4
Actual number of agriculture service provider beneficiaries who participated:
3
Proposed Completion Date:
August 31, 2019
Status:
Completed
Date Completed:
August 31, 2021
Accomplishments:

Trials were established in 2019 and continued through 2021. The trials will remain in place for reduced data collection and harvest in 2022. 

The 4 farm locations as planned hosted research trial replications (Jonesboro, Surry, Appleton, and Columbia Falls).  An additional mulching trial began in 2020 as a spin off from this project with the goal of understand what particle size of mulch would be best for nutrient and water holding capacity in wild blueberry. The funded grad student on this project also worked on the mulching project which was held at yet another organic wild blueberry field in Stockton Springs, ME. 

IMG_2207

Milestone #3 (click to expand/collapse)
What beneficiaries do and learn:

3. One farmer hosts the irrigation demonstration.

Proposed number of farmer beneficiaries who will participate:
15
Proposed number of agriculture service provider beneficiaries who will participate:
5
Actual number of farmer beneficiaries who participated:
85
Actual number of agriculture service provider beneficiaries who participated:
15
Proposed Completion Date:
September 30, 2021
Status:
Completed
Date Completed:
July 8, 2021
Accomplishments:

An irrigation demonstration was competed at the UMaine Wild Blueberry Field Day in Jonesboro, ME on July 8th 2021. This is our biggest field day with the most attendance from both farmers and ag service providers. Attendees found it very helpful to see the current irrigation system at the UMaine farm.  The above ground piping is typical of what some wild blueberry farms in Maine currently have. Moving forward newer irrigation technology will be discussed. Irrigation is seldom used on small and medium wild blueberry farms yet recent drought conditions have forced the topic to surface again. New irrigation systems would have to be partially funded by NRCS or another federal agency as this infrastructure is too expensive for most family farms to invest in. Therefore, it was especially valuable to have NRCS present at this demonstration to share how wild blueberry can be irrigated and have farmers who attended demonstrate the need for irrigation. 

This demonstration spurred a later Ag Service Provider event specific to irrigation at Wyman's of Maine. Wyman's - a large wild blueberry company- does irrigate using several different guns and water sources. People who attended included myself (UMaine Extension), Eric Venturini (Wild Blueberry Commission of Maine), Amanda Beal, Commissioner of Ag (State of Maine Dept of Agriculture), Wyman's agronomists, and several District Conservationists from NRCS in addition to Tony Jenkins the Resource Conservationist. 

Milestone #4 (click to expand/collapse)
What beneficiaries do and learn:

4. Four trial host farmers collect production and sales data and report their 2018, 2020, and 2022 average blueberry yield/acre and average price (excluding trial plots, organic acres).

Proposed number of farmer beneficiaries who will participate:
4
Proposed Completion Date:
November 30, 2019
Status:
In Progress
Accomplishments:

Yield has been reported for 3 of the farms for the 2020 harvest and we will need to compare this to the next crop year which is 2022.

Organic wild blueberries are sold for $13.00/lb fresh and $5.00/lb frozen (average market values) and it costs approximately $3.00 to produce each pound with an average yield of 2,000lbs/acre.

For organic growers who sell their berries to the organic frozen commodity market in Maine, prices were $1.64/lb in 2017 and are now $1.04/lb due to the lack of marketing. However, demand for organic blueberries (both wild and cultivated) increased 12.6% (USHBC 2018). This trend is prominent in the Northeast and relevant to local businesses and the wild blueberry industry. RAS Wines, a large local purchaser of lowbush blueberries, has indicated that they plan to increase their annual purchase of organic lowbush blueberries from 18,000 lbs in 2020 to 32,000-40,000 lbs in 2021. Three prominent organic farms in Maine have already begun to engage with the trend, making online sales of organic lowbush frozen berries, powder, chips, and tea, where 12oz of powder is sold for $64.00 ($5.30/oz).

The number of certified organic wild blueberry acres in Maine has increased from 1,800 acres in 2018 to 2,635 acres in 2020, with current production of approximately 5 million lbs (2,000lbs/acre) of berries per year. 

Milestone #5 (click to expand/collapse)
What beneficiaries do and learn:

5. 10 farmers receive individual assistance with adoption of a new management practice through phone
consultations and/or site visits.

Proposed number of farmer beneficiaries who will participate:
10
Actual number of farmer beneficiaries who participated:
19
Actual number of agriculture service provider beneficiaries who participated:
1
Proposed Completion Date:
December 31, 2019
Status:
Completed
Date Completed:
January 28, 2022
Accomplishments:

Calderwood has documented individual consultations with 19 organic growers or interested-in-organic growers over 3 years of this project. Communicating best organic management practices with these 19 producers impacts the management of 1000 wild blueberry acres in Maine.

 

Milestone #6 (click to expand/collapse)
What beneficiaries do and learn:

6. 200 blueberry farmers attend the Maine Wild Blueberry Conference.

Proposed number of farmer beneficiaries who will participate:
200
Actual number of farmer beneficiaries who participated:
400
Actual number of agriculture service provider beneficiaries who participated:
33
Proposed Completion Date:
March 31, 2022
Status:
Completed
Date Completed:
March 17, 2022
Accomplishments:

In 2019 there were 160 attendees at the UMaine Wild Blueberry Conference. 

In 2020 there were 90 attendees at the UMaine Wild Blueberry Conference. 

In 2021, the conference occurred virtually for two hours on Wednesdays and Fridays from January-March. A total of 1168 attendees signed on for all sessions but these are repeated people. 200 individuals attended at least one conference session in 2021 with 183 people attending sessions that specifically covered organic crop management. 

 

Milestone #7 (click to expand/collapse)
What beneficiaries do and learn:

7. 40 blueberry farmers from ME, MA, NH, and Canadian provinces who attend at least one of two field days or the conference report learning about a new management practice.

Proposed number of farmer beneficiaries who will participate:
40
Actual number of farmer beneficiaries who participated:
326
Actual number of agriculture service provider beneficiaries who participated:
10
Proposed Completion Date:
December 31, 2020
Status:
Completed
Date Completed:
July 8, 2021
Accomplishments:

20 organic growers attended the 2019 Organic Field Day in Dresden ME. 

91 growers attended the 2019 Annual Wild Blueberry Field Day in Jonesboro ME (approximately 20% were organic)

61 growers attended the 2020 Virtual Wild Blueberry Field Meetings (approximately 30% were organic)

30 growers indicated that they learned about weed management at the 2021 Wild Blueberry Field Day (2021 Field Day Survey)

17 growers indicated that they learned about weed management at the Virtual Wild Blueberry Conference in 2021 (Conference Survey)

An additional 17 growers indicated that they learned about nutrient and pH management at the Virtual Wild Blueberry Conference in 2021 (Conference Survey)

 

 

 

 

Milestone #8 (click to expand/collapse)
What beneficiaries do and learn:

9. 200 blueberry farmers from ME, NH, MA, and Canadian provinces watch at least one of 6 webinar/conference videos posted to our YouTube channel.

Proposed number of farmer beneficiaries who will participate:
200
Proposed Completion Date:
November 30, 2022
Status:
In Progress
Milestone #9 (click to expand/collapse)
What beneficiaries do and learn:

10. 600 Northeast (ME, NH, MA, and Canadian provinces) blueberry farmers receive the Lowbush Blueberry Management Guide.

Proposed number of farmer beneficiaries who will participate:
600
Proposed Completion Date:
November 30, 2022
Status:
In Progress

Milestone Activities and Participation Summary

Educational activities:

120 Consultations
1 Curricula, factsheets or educational tools
1 Journal articles
4 On-farm demonstrations
5 Online trainings
3 Published press articles, newsletters
1 Tours
2 Webinars / talks / presentations
12 Workshop field days

Participation Summary:

483 Farmers participated
35 Number of agricultural educator or service providers reached through education and outreach activities

Learning Outcomes

134 Farmers reported changes in knowledge, attitudes, skills and/or awareness as a result of their participation
10 Agricultural service providers reported changes in knowledge, skills, and/or attitudes as a result of their participation
Key areas in which farmers reported changes in knowledge, attitude, skills and/or awareness:

Fifteen new and transitioning growers asked about managing wild blueberry organically in 2019 - 2021. 

Three organic growers let me know that they are taking on new organic acreage. The only wild blueberry growers buying land are currently organically certified. 

One wild blueberry grower wanted to discuss the difficulty in getting a farm loan for wild blueberry due to the lack of market for wild blueberry in general. 

One grower wanted to learn more about managing pollinator habitat on organic wild blueberry land.

Service providers ask about mulching, applying sulfur for weed management, and if burning actually helps to manage mummy berry. 

Survey data provides the # who have changed a management practice. 

Performance Target Outcomes

Target #1

Target: number of farmers:
50
Target: change/adoption:

adopt at least one new weed, nutrient, or irrigation management practice

Target: amount of production affected:

500

Target: quantified benefit(s):

5 managing certified organic farms will increase their average yield by 500 lbs/acre on a total of 100 acres

Actual: number of farmers:
19
Actual: change/adoption:

Adopted weed management especially, how and when to apply sulfur to reduce soil pH which is a known grass management tool. Adopted different burn-pruning practices that allow for mummy berry management while saving organic matter. Applied Entrust as organic SWD control around field edges rather than whole field.

Actual: amount of production affected:

1,000

Actual: quantified benefit(s):

Waiting on 2022 yield data.

19 Farmers changed or adopted a practice

Participants

No participants

Information Products

    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.