Improving Production and Yield of Winter Greens in the Northeast

Progress report for LNE20-402

Project Type: Research and Education
Funds awarded in 2020: $84,948.00
Projected End Date: 12/31/2022
Grant Recipient: UMass Extension Vegetable Program
Region: Northeast
State: Massachusetts
Project Leader:
Susan Scheufele
UMass Extension Vegetable Program
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Project Information

Performance Target:

125 Northeast growers adopt at least one new best management practice in a total of 250 high tunnels. These farmers report an average yield of 0.5 lb/sq ft, and increased off-season revenue totaling $525,000 annually.

Introduction:

Problem and Justification: Consumer demand for fresh, local greens in winter is limitless, and production is not nearly meeting demand, representing a huge opportunity to increase financial sustainability of individual farms and sustainability of our Northeast regional food system.  Production of greens during winter is limited by three major factors: low-yielding production practices, poor stand associated with damping-off, and reduced yields caused by emerging diseases, especially downy mildews, which can cause 100% losses.

Downy mildews (DM) can be managed effectively by planting resistant varieties, but a gap in knowledge exists among growers and seed representatives, and the best varieties with broad DM-resistance are not being planted in the Northeast. Furthermore, intensive year-round production in high-tunnels leads to poor soil health and increased pressure from soil-borne diseases, especially damping-off, causing poor stand. Finally, growers could increase yields by increasing planting density, planting higher-yielding varieties, using more efficient irrigation and fertility practices, or modifying harvest systems.

Over 2,000 organic and conventional greens growers and agricultural service providers across the Northeast could benefit from education about emerging diseases, and more modern production systems. Other benefits include: generating off-season revenue, maintaining farming jobs and customer relationships over the off-season, lowering financial risk by increasing crop diversity, and improving soil health in high-tunnels.

Solution and Approach: On-farm surveys of current production practices and on-farm case studies on profitability of different production systems will provide a foundation for education on improving production and yield of winter greens. Connecting with technical advisers in major greens production areas will bring expertise about complicated diseases and knowledge about modern techniques to our region. Research will be conducted to assess productivity of DM-resistant varieties under Northeast winter growing conditions, impacts of seed priming on germination and stand, and use of green manures to increase soil microbial health, reducing soil-borne disease and increasing crop establishment and yield.

Milestones and Performance Target:

  • >2,000 growers and agricultural service providers learn about project activities and increase knowledge on winter greens production and profitability, current status of DM across the region, and disease management using resistant varieties
  • 350 growers and agricultural service providers attend or view webinars to increase knowledge on CA production practices, DM biology and management, and use of resistant varieties
  • 300 growers attend workshops and field days and increase knowledge of cost-effective production methods
  • 200 growers who attend educational programs express interest in improving their winter greens production efficiency and receive follow-up from project team
  • 125 growers plant a resistant variety or adopt another improved winter-greens production practice (e.g. increased plant density, more efficient harvest methods, etc.) in 250 high-tunnels across the Northeast, achieving yields up to 0.50 pounds/ft2, increasing off-season revenue by $525,000 and enhancing sustainability of year-round local food systems

Cooperators

Click linked name(s) to expand/collapse or show everyone's info
  • Genevieve Higgins (Educator and Researcher)
  • Jim Correll (Educator and Researcher)

Research

Hypothesis:

Profitability of winter greens production is directly related to plant establishment and disease prevention. Our research program is aimed at increasing yield by improving germination, increasing planting density, and reducing disease including damping-off and downy mildews. Replicated on-farm trials will address the following hypotheses:

  1. New varieties offer improved resistance to disease and improved growth under winter growing conditions.
  2. Increasing active soil organic matter can reduce damping-off and increase plant stand
  3. Increasing germination by priming seed before planting can increase plant stand
  4. Increasing plant density up to 4 million seeds/A can lead to increased yield
Materials and methods:

All experiments will be conducted at the UMass Crop and Animal Research and Education Farm in South Deerfield, MA, in an existing 30x96’ Rimol high tunnel. Soil will be prepared and fertilizers added based on soil test results in late-September and treatments will be planted in October. Spinach will be irrigated and side-dressed as needed according to soil moisture probes checked weekly and pre-sidedress nitrate tests taken monthly.

1. Variety trials, winter 2020-21 and 2021-22: In fall 2020, a spinach variety trial was set up to test this hypothesis at the UMass Crop & Livestock Research & Education Farm in South Deerfield, MA. This trial was managed by G. Higgins of UMass. We did not undertake a full variety trial for winter 2021-22 but instead incorporated the evaluation of 2 spinach varieties into the winter 2021-22 germination/stand trial.

  • Treatments: 18 spinach varieties were chosen for evaluation, taking into consideration recommendations by seed production and distribution company representatives. Varieties were chosen for their downy mildew resistance and for their growth speed under winter tunnel conditions. 
  • Methods: All varieties were seeded on October 18, 2020, at a rate of 3 million seeds/A, with 4 replications of each variety in a randomized complete block design. Plots were 2'x4' and there was 1' between plots in-bed. Pre-sidedress nitrate tests were taken monthly and indicated that the spinach should be sidedressed in late February - because the trial was almost complete at that point, no additional fertilizer was added. Downy mildew was not found in this trial.
  • Data Collection and Analysis: Germination, stand, vigor, and disease severity (%) were assessed weekly October 21-March 30, and marketable yield was evaluated 6 times throughout the winter, with each variety being harvested 2-4 times between December 22 and March 30. All data were analyzed using a general linear model and means were compared using Tukey’s honestly significant difference test (P = 0.05) in SAS.
  • Spinach high tunnel variety trial at the UMass Research Farm, before the first harvest. December 8, 2020.
    Harvesting spinach from the high tunnel variety trial. December 22, 2020.

2. Improving plant stand, winter 2021-22: In fall 2021, a trial to evaluate the effects of seed priming, spinach cultivar, and incorporation of buckwheat cover crop on spinach stand was set up at the UMass Crop & Livestock Research & Education Farm in South Deerfield, MA. This trial is being managed by G. Higgins of UMass. 

  • Treatments: The impact of cover crop residue as a pre-plant soil amendment on seedling emergence and suppression of damping off caused by Rhizoctonia solani, Pythium spp., and Phythophthora spp. is being evaluated compared to an untreated control and a compost-amended soil. The effect of seed priming is being evaluated as a split-plot factor in this full factorial design, and half the seed was primed before planting and the other half was planted without priming.
  • Two spinach cultivars were chosen for evaluation as well - Kolibri is a cultivar commonly grown in winter high tunnels in the Northeast, and Crosstrek is a newer variety that performed well in the spinach variety trial conducted under this grant over winter 2020-21.
  • Methods: Buckwheat was seeded into half of the tunnel on July 30, at a rate of 90 lbs/A. The buckwheat residue was incorporated on September 10, three weeks before seeding spinach into the tunnel. The spinach seed was primed on September 30 - the seed was soaked in 0.3% hydrogen peroxide solution for 3 hours, then drained and placed in an airtight container for 16 hours at approximately 65F. Spinach was seeded into the tunnel on September 31, at a rate of 3 million seeds/A (70 seeds/sq ft). Plots were 2'x6', with 1' between plots in-bed, and were arranged in a split-plot design, with cover crop as the whole plot factor and variety and priming as subplot factors.
  • Data Collection and Analysis: Total number of plants germinated and number of plants damped off were counted twice a week beginning October 6, and plot vigor was rated twice a week beginning October 8. Plot vigor will be rated through the winter and first harvest data will be collected for all plots. All data will be analyzed using standard statistical analyses such as ANOVA or General linear models with appropriate post-hoc tests.
  • Buckwheat growing in half of the high tunnel
    Buckwheat cover crop growing in half of the high tunnel (right), summer 2021. A cucumber trial was underway in the other half of the tunnel (left)
    Full spinach germination/stand trial, October 22, 2021. The two left-hand beds received the buckwheat cover crop treatment.

Farmer Input: Input from growers on our project advisory board, from our UMass Extension Stakeholder Group, and also from other projects e.g. NE-SARE project LNE15-343 and the Frozen Ground Grower Network was solicited before developing these experimental questions and methods.

Research results and discussion:

Variety Trial, winter 2020-21: Two varieties, 'Platypus' and 'Viroflay' had significantly lower germination rates than all other varieties in the trial (<15%) and were excluded from the dataset for the vigor and yield analyses. 'Crosstrek', 'Dallas', and 'Patton' were the most vigorous varieties on December 22 (before any varieties were harvested) and when vigor was averaged over the entire season.

Some notes about some varieties that stood out:

  • 'Dallas' had the highest yield (0.921 lb/ft2), significantly higher than about half of the varieties trialed. 'Crosstrek' and 'Nembus' also had high yields, around 0.8 lbs/ft2.
  • 'Auroch' and 'Bandicoot' had the lowest yields, both less than 0.5 lbs/ft2, and low vigor ratings, potentially caused by high rates of post-emergence damping off in both varieties.
  • 'Nembus' was among the highest-yielding varieties, but had a middle-range plot vigor.
  • 'Sculptur' had a high seasonal vigor rating, but a middle-range yield.
  • Spinach varieties trialed in 2020-21
  • Graph showing yield per square foot from spinach varieties
      • Spinach variety trial, winter 2020-21: Yield per square foot. Statistical significance was determined using analysis of variance. Means were separated using Tukey's HSD at α-level 0.05. Varieties that share one or more letters are not significantly different from each other.

Improving plant stand, winter 2021-2022: Data from this trial will be analyzed over winter 2021-22.

Research conclusions:

Variety Trial, winter 2020-21: Of the varieties trialed in 2020-21, 'Dallas' and 'Crosstrek' would be excellent choices for winter growing as they had high germination rates, high vigor throughout the season, high yields, and resistance to spinach downy mildew races 1-17. Some of the varieties that we trialed in 2020-21 may not appear in seed catalogs but seed reps may be able to special order unlisted varieties from producers, especially if smaller-scale growers collaborate to meet minimum order requirements.

Participation Summary

Education

Educational approach:
  • Webinar on spinach downy mildew: A Virtual Winter Greens Field Day was held on January 14, 2021, and was attended by 179 commercial growers, home gardeners, and agricultural service providers J. Correll (University of Arkansas) presented on spinach downy mildew and G. Higgins (UMass) presented on the UMass high tunnel spinach variety trials. We ran out of time for S. Scheufele's (UMass) presentation on other diseases of winter greens, but this presentation was disseminated to attendees via email after the webinar. Attendees who responded to the program evaluation reported that they increased their knowledge of spinach downy mildew by an average of 36.6% and using resistant varieties for spinach downy mildew management by an average of 41.2%. This webinar was recorded and is available on the UMass Vegetable Program YouTube channel here: https://www.youtube.com/watch?v=IDtJO8lKiCg
  • Field Days: Results from the 2020-21 spinach variety trial and plans for the 2021-22 spinach germination and stand trial were presented at the July 27, 2021 Annual UMass Extension Field Day at the UMass Crop & Livestock Research & Education Farm in South Deerfield, MA, attended by 79 commercial farmers, agricultural service providers, and students. On a scale of 1-5, with 1 being the least and 5 the most knowledge gained, attendees who completed the field day evaluation reported an average of a 1.0-point increase in knowledge about reducing damping off in high tunnel spinach. On a scale of 1-5, with 1 being the least and 5 the most likely to implement a damping off reduction practice on their farm, attendees who completed the field day evaluation reported an average of 3.67.
  • On-Farm Production Survey: 4 farms signed on to be winter spinach production case-studies. These farms completed an extensive intake form with information about their winter spinach production practices. During the winter 2020-21 growing season, they each tracked their spinach labor, inputs, and yields for 1 spinach high tunnel, and were visited biweekly by G. Higgins of UMass. The information from these farms was used to create a narrative case study and an enterprise budget for each farm's winter spinach production. The case studies and enterprise budgets were presented by G. Higgins along with two of the case study growers (Danya Teitlbaum of Queens Greens and Ryan Karb of Many Hands Farm Corps) in a webinar (Economics of Winter Spinach: Three Case Studies, September 1, 2022, available here: https://www.youtube.com/watch?v=o_AaLBVjK6I). Due to a technical error, we don't have program evaluation results from this webinar.
    • Seeding spinach at one of our case study farms for this project. October 12, 2020.
      A farmer harvesting a spinach leaf by hand, pinching a leaf off at the stem. The farmer holds a handful of harvested spinach leaves in the other hand.
      Harvesting spinach at one of our case study farms in this project. January 19, 2021.
  • Downy mildew consultations and diagnostic support: As of December 2021, 8 growers have reached out for support identifying the race of spinach downy mildew on their farms. We sent out samples from 6 of these farms, and 3 have been race typed so far.
  • Fact sheets: Wrote fact sheet on Cladosporium leaf spot of spinach and posted online and distributed through Veg Notes newsletter (3500 subscribers).
    Fact Sheet: Spinach, Cladosporium Leaf Spot
  • Newsletter articles:

Milestones

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

1,680 growers, agricultural service providers, and industry representatives learn about project activities, educational programs, and read newsletter articles on results of spinach variety trials and increase knowledge on current outbreaks of DM across the region, and learn about higher-yielding, disease-resistant varieties of lettuce and spinach. Of these, 250 growers and 25 ag service providers sign up to receive future notifications and information about ways to get involved including educational events and participation in the on-farm production survey.

Proposed number of farmer beneficiaries who will participate:
250
Proposed number of agriculture service provider beneficiaries who will participate:
25
Actual number of farmer beneficiaries who participated:
1800
Proposed Completion Date:
June 1, 2020
Status:
Completed
Date Completed:
January 1, 2022
Accomplishments:

The following were distributed via the Vegetable Notes newsletter (3600 subscribers): 2020-21 Spinach Variety Trial results, May 6, 2021 issue; Timely alerts of spinach downy mildew outbreaks over 2020-21 winter season; Event listings for the January 28, 2021 Virtual Winter Greens Field Day (also advertised in other regional Extension newsletters), July 27, 2021 UMass Extension Field Day, and September 1, 2021 Economics of Winter Spinach webinar. 2021 spinach germination trial results will also be published in spring 2022.

12 growers signed up to adopt new spinach production practices and provide us with information on how the changes impacted their inputs and yields.

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

Attend or view webinars to increase knowledge on winter greens production methods, downy mildew biology and management through use of resistant varieties, and other common greens diseases and issues such as damping-off

Proposed number of farmer beneficiaries who will participate:
300
Proposed number of agriculture service provider beneficiaries who will participate:
50
Actual number of farmer beneficiaries who participated:
110
Actual number of agriculture service provider beneficiaries who participated:
35
Proposed Completion Date:
March 1, 2021
Status:
Completed
Date Completed:
September 1, 2021
Accomplishments:

January 28, 2021 Virtual Winter Greens Field Day: 60 farmer and 20 agricultural service provider attendees. Attendees who completed the program evaluation reported averages of 36.6% and 41.2% increased knowledge on the topics of spinach downy mildew and using resistant varieties to manage spinach downy mildew, respectively. Recorded webinar has 139 views as of February 8, 2022.

September 1, 2021 Economics of Winter Spinach webinar: Approximately 50 farmer and 15 agricultural service provider attendees. Recorded webinar has 68 views as of February 8, 2022.

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

Attend on-farm workshops and field days and increase knowledge of downy mildew resistant-varieties and cost-effective production methods (results of regional high tunnel production survey)

Proposed number of farmer beneficiaries who will participate:
200
Proposed number of agriculture service provider beneficiaries who will participate:
30
Actual number of farmer beneficiaries who participated:
79
Proposed Completion Date:
July 31, 2021
Status:
Completed
Date Completed:
July 27, 2021
Accomplishments:

July 27, 2021 UMass Extension Field Day: 79 attendees. On a scale of 1-5, with 1 being the least and 5 the most knowledge gained, attendees who completed the field day evaluation reported an average of a 1.0-point increase in knowledge about reducing damping off in high tunnel spinach. On a scale of 1-5, with 1 being the least and 5 the most likely to implement a damping off reduction practice on their farm, attendees who completed the field day evaluation reported an average of 3.67.

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

Growers who attend educational programs and express interest in improving their winter greens production efficiency receive resources to help them implement and track changes including yield, and receive follow-up from project team in-person or by phone and email.

Proposed number of farmer beneficiaries who will participate:
125
Proposed number of agriculture service provider beneficiaries who will participate:
30
Proposed Completion Date:
March 31, 2022
Status:
In Progress
Accomplishments:

As of November 2021, 12 growers who attended educational programs and read about spinach downy mildew in Vegetable Notes expressed interest in improving their winter greens production efficiency and have been contacted by us to receive resources.

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

Growers receive diagnostic support in the event of winter greens disease outbreaks on their farms. Samples are collected and shipped to collaborating labs for typing, and the results are communicated back to growers and shared with the Extension community to document emerging disease outbreaks.

Proposed number of farmer beneficiaries who will participate:
20
Proposed number of agriculture service provider beneficiaries who will participate:
30
Actual number of farmer beneficiaries who participated:
4
Proposed Completion Date:
March 31, 2022
Status:
In Progress
Accomplishments:

As of November 2021, 8 Northeast growers have reached out for spinach downy mildew diagnostic support. Of those, 6 were sent out for race identification. 2 were identified as the same novel strain and 1 as race 14. We have not received identification for 3 of the strains.

Milestone Activities and Participation Summary

Educational activities:

5 Consultations
1 Curricula, factsheets or educational tools
1 Published press articles, newsletters

Performance Target Outcomes

Target #1

Target: number of farmers:
125
Target: change/adoption:

Northeast growers adopt at least one new best management practice in a total of 250 high tunnels. These farmers report an average yield of 0.5 lb/sq ft, and increased off-season revenue totaling $525,000 annually.

Target: amount of production affected:

250 high-tunnels across the Northeast

Target: quantified benefit(s):

Achieve yields of up to 0.50 pounds/sq ft, resulting in an increase in off-season revenue by $525,000.

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.