Sustainable Strawberry Production in the Absence of Soil Fumigation

Funding provided by the National Strawberry Sustainability Initiative

Evalua&on of Compost on Strawberry Root Health and Plant Growth

Four commercial composts Five field sites

Disease suppression Root health

Plant produc7vity

Dr. Tom Gordon and Margaret Lloyd

Flat fumigation Bed fumigation

1. Change in fumigation materials: methyl bromide phaseout

2. Change in fumigation methods from flat to bed fumigation

1. Compost Characterization

2. Plant Productivity

3. Root Development

4. Disease Suppression

Introduction Compost characterization Plant productivity Root Development Disease suppression Conclusion

Evalua&on of Compost on Strawberry Root Health and Plant Growth

Material Name Descrip7on of source material

1 Yard Trimmings Compost

100% Yard trimmings

2 Manure Compost

20% steer manure 30-‐40% green waste fines 35-‐45% mix of: Waste + straw bedding from stalls <5% vegetable waste

3 Vermicompost 100% Composted dairy manure + rice hull bedding, fed to worms

4 Mushroom Compost

Spent mushroom compost from buPon mushrooms composted horse manure + straw Amended with gypsum and peat post-‐decomposi7on

The Composts

Yard trimming Manure Vermicompost Mushroom


PHYSIOCHEMICAL Mushroom Compost Manure Compost Yard Trimmings Compost Vermicompost

Nitrate-‐N* (ppm) 120 234 6.6 502

pH 7.3 8.1 7.6 7

EC (dS/m) 4.8 28 4.5 7.1

C:N 14:01 12:01 17:01 13:01

Cost $3-‐5/T $5/T $21/T $500/yd

Applica7on method Broadcast Broadcast Broadcast Apply to rootzone

OMRI Approved ✔ ✔ ✔ ✔

Compost Characteriza&on: Composi&on


Compost Characteriza&on


Microbial Activity

Total fungal and bacterial populations

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

Yard trimmings Mushroom Vermcompost Manure

FDA hydrolysis (ugFDA/gDw*m

in)

Microbial activity of each compost

Central Coast, CA (Santa Cruz & Monterey Coun7es) 4. Methyl bromide (MB)-‐ Fumigated, conven7onal field 5. Organic Commercial Field

North Coast, CA (San Mateo County) 3. Organic Commercial Field

Central Valley (Sacramento County) 1. Fumigated (non-‐MB), conven7onal field 2. Fumigated (non-‐MB), conven7onal field

Field Sites

1 2 3 4 5


Central Valley Central Coast ∨ ∨

North Coast

-‐0.05

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

Yard Trimmings Mushroom Manure Vermicompost Control

FDA hydrolysis (ug FD

A/gDw*m

in)

MB, Central Coast Conv, Central Valley Org, Central Coast Org, North Coast Conv, Central Valley



High

Intermediate

Low

Microbial ac&vity of field soil 2 weeks aSer compost incorpora&on

1.  Compost significantly increases microbial activity in field soil

2.  Regardless of the native soil, the effect each compost bestows on microbial activity is similar



Microbial ac&vity of field soil 10 weeks aSer compost incorpora&on

0 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.1

Yard Trimmings Spent Mushroom Manure Vermicompost Control

FDA hydrolysis (ug FD

A/gDw*m

in)

Conv, Central Valley MB, Central Coast Org, North Coast

1. Overall microbial activity is lower

2. Differences between composts is less

Day neutral Short day Cul7var name Albion Chandler

Seasonal growth curve Slow, steady produc1on for 6+ months

Peaks and troughs in produc1vity

Total fruit produc7on (per season)

Significantly higher Significantly lower

Root development and canopy growth

Slower, less vigorous ini1ally Strong early growth, large canopy


Strawberry Type and Cultivar

Plant Produc&vity

1.  Plants grown in methyl bromide fumigated field are significantly larger than those in organic fields.

2.  In organic fields, general trend shows greater growth in mushroom and vermicomposts.


Plant Produc&vity

1.


1.  Plant growth on the coast is significantly greater than inland in the central valley.

Plant Produc&vity

1.


1.  Plant growth on the coast is significantly more than inland in the central valley. 2.  Yard trimming and manure compost result is slightly less growth, whereas

vermicompost and mushroom tend to have slightly greater growth, along with control +N

ORGANIC FIELD, Central Coast

Effect of compost on strawberry yield

Plant Produc&vity


ORGANIC FIELD, Central Coast


Plant Produc&vity


YIELD CURVE

Weekly yield of two strawberry cul7vars grown in different composts



Plant Produc&vity ORGANIC FIELD, North Coast


Plant Produc&vity

Root development


Strawberry crown and canopy

Drip line

Root development


METHODS

• Albion

• Grown in 10% compost

• 3 weeks

• Greenhouse

• Ver1cillium dahliae microsclero7a infested sand inoculum

What is the effect of compost on root infec&ons by Ver$cillium dahliae?

Total root length analysis

3 week growth period

V. dahliae root assay

Compost Amendment Field Soil V. dahliae inoculum

0% 100% ✔

10% Steer manure 90% ✔

10% Mushroom 90% ✔

10% Vermicompost 90% ✔

10% Yard trimming 90% ✔

Effect of compost on suppression of plant pathogens

with strawberries

Treatment pots planted with strawberries


3 weeks

V. dahliae root assays Total root length is analyzed

Treatment pots planted with strawberries

Effect of compost on suppression of plant pathogens


Control (-) P.ultimum

Control (+) P.ultimum

Mushroom compost

(+) P.ultimum

Vermicompost (+) P.ultimum

Manure compost

(+) P.ultimum

Yard trimmings compost

(+) P.ultimum

Pythium ultimum surrogate assay for disease suppression

•  10% compost + Sunshine potting mix •  Soil mix is inoculated with P. ultimum. •  After 5 days, 7 cucumber seeds are sown per pot


Summary

Root Development: • Vermicompost led to significantly more root development in field and potted trials

Yield • Control + Nitrogen has the highest yield at this point • Vermicompost and mushroom compost are also showing greater productivity early in the season

Root infection • Manure compost is showing suppression of both Pythium ultimum and Verticillium dahliae • Vermicompost led to reduced frequency of infection from V. dahliae

All composts significantly increased microbial activity All composts led to greater root development in the field All composts reduce infection by Pythium ultimum

WEBSITE AND BLOG



This could not have been possible with out the following support


Funding provided by

UC Davis Dr. Tom Gordon, advisor

Dr. Dan Kluepfel, USDA, thesis committee Dr. Mike Davis, thesis committee

Sharon Kirkpatrick, Gordon lab manager

Team Green: Emmi Koivunen, lab technician Lola Quasebarth, lab technician Peter Henry, lab technician Ana Maria Pastrana Leon, visiting scholar Athina Ruangkanit, lab intern

North Coast Field Trial Matt Quinn, North Coast field harvester Tim Campion , grower collaborator Jim Cochrane, grower collaborator

Central Coast Don Yoshimura, grower collaborator Gina Colfer, Earthbound Asso. collaborator Ian Greene, grower collaborator Jack Anderson, field support

Sacramento Field Trials Chuck Ingels, UCCE farm advisor Sacramento Co. Kyle Garrett, UCCE field assistant Luke, UCCE field assistant Anthony and Sidney Saetern, grower collaborator Lo Saetern, grower collaborator

Compost Collaborators Tom Ford, Central Coast Compost Alex Sharpe, Z Best Jack Chambers, Sonoma Valley Worm Farm Greg Tuttle, Monterey Mushroom

Margaret Lloyd [email protected]

Funding provided by the National Strawberry Sustainability Initiative

Group 1 (smallest)

Group 2

Group 3

Group 4 (largest)

How does each compost influence strawberry root growth?

How does strawberry root growth differ in each compost?

0

500

1000

1500

2000

2500

3000

1 2 3 4

Total Roo

t Len

gth (cm)

Group #

ALBION CROWNS AT PLANTING

WHEN? 1.Crown size at planting 2. Roots at harvest –March 3. Roots mid-harvest (July) 4. Roots at end (Sept)

HOW? Destructive sampling 3 plants per rep Hydropneumatic root elutriator + root scanner

CHANDLER CROWNS

AT PLANTING

DEL REY CROWNS at PLANTING

0

500

1000

1500

2000

2500

3000

3500

Tota

l roo

t len

gth

Compost type

Effect of Compost on Root Growth Total Root Length

Root Infection Trial 1 (Rep1, 2, 3)

M. LLOYD AND THE QUESTIONNAIRES

The industry-‐wide shij in strawberry produc7on from tradi7onal fumiga7on methods generates a tremendous need for knowledge transfer and grower support. Accordingly, as a complement to the biological research, we are conduc7ng a social network analysis and grower-‐iden7fied needs assessment, to iden7fy pathways of knowledge transfer among strawberry growers and to bePer understand grower percep7ons of their goals, needs and management styles to best develop MB-‐alterna7ve outreach.

Approach 1.  Establish # of growers in region (community profile) 2.  Reach growers (determine # that’s good enough)

1.  Phone 2.  Mail 3.  Meetings 4.  Individuals

QUESTIONNAIRES

Microbial Community Analysis

Soil samples from each field site are taken for DNA extrac7on four 7mes: (1)  Plan7ng, (2)  Harvest (March), (3)  Midharvest (July) (4)  End of harvest (Sept)

Does field soil amended with compost suppress Ver$cillium dahliae microsclero&a viability?

In the absence of a plant host, biological control by compost could be affec7ng microsclero7a viability through mechanisms of fungistasis. To elucidate the role of the amendment on microsclero7a viability, field soil is amended with 50% compost, spiked with V. dahliae microsclero7a and put in 4” pots in a greenhouse for 9 months. Every three months, soil is assayed for V. dahliae viability.

50% compost 50% field soil Sand inoculum (104 million/g sand) Assay every 3 months Greenhouse

Pythium ul$mum Surrogate Assay

In this trial, field soil is taken from the field trial, sieved to homogenize par7cle size and spiked with P. ul1mum. For five days, this mixture is maintained in the growth chamber with moisture before 20 Cherry Belle radish seeds (P.ul1mum-‐suscep7ble) are sown per pot. Ajer 14 days, the number of surviving seedlings is counted and used as a proxy to compare disease suppression by each treatment.

Does field soil amended with compost suppress pathogens?

METHODS

1.  Field soil from trials 2.  Sieve 3.  Mix with P. ul1mum 4.  Wait 5 days 5.  Sow with radish or cucumber

seeds 6.  Wait 14 days 7.  Count surviving seeds

4. Effect of compost on suppression of plant pathogens

Science

Sustainable Strawberry Production in the Absence of Soil Fumigation