Improving Fumigant Efficiency and Reducing Fumigant Emissions in Plastic Mulch Raided-Bed Systems for Strawberry Production
Improving Fumigant Efficiency and
Reducing Fumigant Emission in
Plastic Mulched Raised-Bed
Systems for Strawberry Production
Oleg Daugovish, Suduan Gao, Brad
Hanson, James Gerik and Husein Ajwa
Raised-bed strawberry production
• California strawberries are grown mainly in raised-bed
systems tarped with standard polyethylene film (PE).
• Over 55% of strawberry fields are treated with
fumigants applied through drip irrigation lines buried
near the bed surface prior to planting.
• Soil fumigation is an important tool in controlling soil-
borne pathogens, nematodes, and weeds.
• Use of fumigants are highly regulated by governmental
agencies because of fumigant emissions.
Pest problems of strawberry production
• Increasing number of
• Weed problem.
• Difficulty in controlling
pests at bed-center or
• Traditional tarp:
– Polyethylene tarp (PE)
• Low permeable tarp:
– Virtually Impermeable Film (VIF)
– Totally Impermeable Film (TIF)
• Tarp permeability:
– PE > VIF > TIF
Fumigation in raised-beds
• Can totally impermeable film (TIF) covering and/or deep
application improve fumigant distribution, fumigation
efficacy, and reduce fumigant emission?
• Will the emission from the uncovered furrow be a
concern? If true, can water seal control the emissions
Develop effective fumigation strategies that increase
fumigation efficiency, sustain strawberry production,
and reduce environmental pollution by TIF covering
and deep drip-fumigation in raised-beds of the coastal
Time: August 16-30, 2013
Location: Strawberry field in Camarillo (coastal area of
Soil: Sandy loam
Bed dimension: 47 inch W, 14 inch H.
Bed center-center: 69 inch.
Setting up beds
Installing drip tape
Two drip tapes
Four drip tapes
1) Two shallow drip lines - non-fumigation under TIF
2) Two shallow drip lines - full rate under TIF
3) Two shallow drip lines - 1/2 rate under TIF
4) Four drip lines (2 shallow & 2 deep) - full rate under TIF
5) Four drip lines (2 shallow & 2 deep) - 1/2 rate under TIF
6) Two shallow drip lines – full rate under PE
* Deep drip lines at 7 inch deep spaced 27 inch in apart beneath shallow
drip lines installed at 2 inch deep.
** 24 tarped beds including 6 treatments and 4 replicates.
** PE plots and TIF plots are not at same location.
• Fumigant: Pic-Clor 60 EC (a mixture
of 56.7% CP, 37.1% 1,3-D, and 6.2%
• Full rate: 25 gallon/ac (300 lbs/ac).
• Application: On August 16 over a 4-h
• Flushing and water seal.
Surface two drip tape
Four drip lines
Measurement during fumigation
• Emission (passive chamber): Full rate TIF treatments
(bed and furrow).
• Soil gas sampling.
• Fumigant concentration under tarp.
• Residual fumigant at the end of trial.
• Pathogen survival.
• Deep- vs. shallow-application:
Fumigant concentration time exposure index
(g cm-3 h-1)
• Fusarium was detected
in 3 non-fumigated beds,
especially at the bed-
• All the fumigation
100% control on
fusarium, both at bed-
center or near bed edge.
• One month after
• Early flowering strawberry
variety, San Andreas
(Lassen Canyon Nursery,
• The planting intensity:
• 4 rows of plants/bed.
• Irrigation and fertilization
was applied regularly to
promote plant growth.
No difference was found on plant growth
among TIF treatment during the early
Plant cover on bed
Leaf greenness Stomatal conductance
Marketable berry yields
during 8 harvest from
January 30 to March 18
were slightly higher in
* The measurement was on 20 plants per beds.
• Low emissions occurred from the TIF mulched
• TIF retained fumigants more effectively than PE; half-
rate fumigant under TIF may achieve same pest
control result as full rate fumigant under PE.
• Deep application provided better emission control
and contributed to more uniform fumigant
distribution than shallow application.
• Data on pest control, plant growth, and berry yield
further suggest that deep fumigation and TIF
covering will be the optimized fumigation technology
in raised-bed production systems.
• Regular communication with the cooperating growers, the principle
stakeholders (e.g., California Strawberry Commission, Trical, Inc.).
• Annual International Research Conference on Methyl Bromide
Alternatives and Emissions Reductions on November 4-6, 2013 in San
• Organic Strawberry Workshop on January 21, 2014 in Tennessee State
• California Plant & Soil Conference on February 4-5, 2014, in Fresno, CA.
• Field day entitled “Water management in strawberry” on March 26, 2014
in Ventura, CA.
• Central Coast California Association of Pest Control Advisers (CAPCA)
Chapter’s Spring CE Meeting on May 1, 2014, at Santa Maria, CA.
• Ventura CAPCA members meeting on June 11, 2014, San Paula, CA.
• American Society for Horticultural Science Annual Conference on July
27-August 1, in Orlando, FL.
• ASA, CSSA & SSSA International Annual Meetings on November 2-5,
2014 in Long beach, CA
• This project is funded by a grant from the Walmart
Foundation and administered by the University of
Arkansas System Division of Agriculture Center for
Agricultural and Rural Sustainability.
• Cooperating growers, Steve Imoto, Glen Imoto, and their
field crew providing the tested field, field equipment, and
• Crop Production Service (CPS) provided fumigation
• Technical assistance was provided by Water Management
Research Unit, USDA-ARS, Parlier, CA and the
Department of Plant Sciences, UC Davis.
• Ruijun (Ray) QIN
• University of California-Davis/
• 9611 S. Riverbend Ave., Parlier,
• Tel: 559-596-2904
• Cell: 559-905-9286
• Email: email@example.com