anaerobic soil disinfestation (asd): updates on research...
TRANSCRIPT
Anaerobic Soil Disinfestation (ASD): Updates on Research and Implementation
C. Shennan1, J. Muramoto1, G. Baird1, M. Mazzola6, M. Bolda4, S. T. Koike4, O. Daugovish4, M. Mochizuki4, S. Dara4, K. Klonsky5, E. Rosskopf3, N. K. Burelle3 , D. Butler2,3
1Univ. of California, Santa Cruz, 2Univ. Tennessee 3USDA-ARS, U.S. Horticultural Research Lab, Florida, 4Univ. of California Cooperative Extension 5 Univ. of California, Davis 6USDA ARS Wenatchee, WA.
Funded by USDA-NIFA MBTP 2012-51102-20294 and CA Strawberry
Commission
Acknowledgements Margherita Zavatta, Lucy Toyama, and student workers, interns, and volunteers of
the Shennan lab, UCSC
Monise Sheehan, Kat Kammeijer, Laura Murphy, Patty Ayala at UCCE
Hillary Thomas, Alex Orozco, Mark Edsall, and Dan Legard, CA Strawberry Commission
Steve Fennimore, UC Davis.
Thomas Flewell and crew, Dole Food Company, Inc.
Dave Peck, Manzanita Berry Farms
Jenny Broome, Dan Chellemi, Natalia Neerdaels, Emily Paddock and Marty Madesko, Driscoll’s
Mike Nelson, Patti Wallace and Luis Rodriguez, Plant Sciences
Rod Koda, Shinta Kawahara Farm
Bryan Gresser, Central West Produce
Will Doyle, W.D. Berry Farms
Jonathon Winslow, Stephanie Bourcier, Farm Fuel Inc. and Frontier Ag Company Inc.
Outline – Anaerobic Soil Disinfestation What we know:
ASD and V. dahliae suppression Yield responses in past field trials Economics
Recent trials: N issues and pre-plant fertilizer C-source makes a difference Efficacy against different pathogens? Issues with scaling up and site differences
Future needs and ongoing trials
ASD: Some Target Pests and Crops Soil-borne pathogens Verticillium dahliae1,2,4
Fusarium oxysporum1,2,3 Fusarium redolens2
Macrophomina phaseolina3 Ralstonia solanacearum2 Rhizoctonia solani1
Sclerotium rolsfii3
Nematode Meloidogyne incognita1 Pratylenchus fallax2
Weed Nutsedge3
Crops tested Welsh onion2
Tomatoes2,3 Strawberries2,4 Eggplant2, 3 Spinach2
Peppers3 Maple1 Catalpa1
• Cut flowers3
1 Dutch studies; 2 Japanese studies; 3Florida studies; 4 California studies
ASD: Three Steps
1. Incorporate organic material
Provides C source for soil microbes
2.Cover with oxygen impermeable tarp
3. Irrigate to saturation and maintain field capacity for 3 weeks
Water-filled pore space
Create anaerobic conditions and stimulate anaerobic decomposition of incorporated organic material
Total irrigation rate: at least 3 acre-inches
Findings to 2012
1. Good yields obtained with 9ton/ac rice bran 1. Salinas 2010 - equal to MeBr (and UTC) yields 2. Watsonville 2010 - within 15% of MeBr yields 3. Ventura 2011 – 75% increase yield over UTC 4. Castroville 2011- as good or better than Pic-Clor 5. Watsonville 2011 – equal to Pic-Clor and steam 6. Santa Maria 2012 – equal to Pic-Clor 7. Watsonville 2012 – lower yield than steam/Pic-Clor
but higher than UTC – poor anaerobic conditions 2. Got consistently good V. dahliae suppression - 80 to 100%
decrease in # microslerotia in soil, using a range of C sources provided good anaerobic conditions
3. Weed suppression limited in the central coast of CA
Findings to 2012 (contd): 4. Need to accumulate 50,000 mV hrs of Eh below
200mV to get V. dahliae suppression, and for soil temps to be above 65oF for at least first week of ASD treatment
-500 -400 -300 -200 -100
0 100 200 300 400 500 600
9/8 9/15 9/22 9/29 10/6
Eh m
V
Changes in Soil Eh (mV )
Aerobic
Anaerobic
0
50,000
100,000
150,000
200,000
250,000
0 10 20 30 ASD treatment (days)
Cumulative Eh mV Hours
threshold
2012-2013 Replicated Trials 1. Watsonville: Driscoll’s and Plant Sciences
ASD w/rice bran 6 t/ac and 9 t/ac, ASD w/molasses 6 t/ac and 9 t/ac, ASD w/rice bran 4.5 t/ac + molasses 4.5 t/ac, and UTC
2. Watsonville: MBA
ASD w/rice bran 9 t/ac, ASD w/molasses 9 t/ac, ASD w/rice bran 4.5 t/ac + molasses 4.5 t/ac, Rice bran 9 t/ac w/o water, Water w/o C-sources, and UTC
3. Watsonville: Cassin Ranch (MeBr buffer zone) and Driscoll’s
ASD w/rice bran 9 t/ac, ASD w/molasses 9 t/ac, Steam, Steam + MSM, and UTC
4. Santa Cruz: UCSC Organic Farm
ASD w/rice bran 4.5 t/ac + molasses 4.5 t/ac w/ and w/o compost, MSM, and UTC
Location C-source/treatments type
Watsonville Rice bran 6, 9 t/ac Molasses 6, 9 t/ac RB 4.5 + Mol 4.5 t/ac UTC
2x Conventional
Watsonville Rice bran 6, 9 t/ac Molasses 6, 9 t/ac RB 4.5 + Mol 4.5 t/ac Controls: UTC, Water only, Rice bran 9 t/ac – no water
Conventional - MBA
Watsonville Rice Bran 9 t/ac Molasses 9 t/ac Steam Steam + Mustard Seed meal UTC
Conventional
Santa Cruz RB 4.5 + Mol 4.5 t/ac +/- compost Mustard Seed meal UTC
Organic
2012-2013 Demonstration Trials –Monitoring
Location C-source Acreage
type
Watsonville 9t/ac Rice Bran or 4.5t/ac RB+4.5t/ac Molasses +/- preplant fertilizer
1 0.5
Organic Conventional
Salinas 9 t/ac Molasses 0.5 Conventional
Salinas 9 t/ac Molasses 1 Conventional
Santa Maria 9 t/ac Molasses 0.5 Conventional
2013 - 0.5 -1ac Demonstration Sites – Sandy Soil Good ASD Established
-500
-400
-300
-200
-100
0
100
200
300
400
500
600
9/8 9/15 9/22 9/29 10/6
Eh m
V Changes in Soil Eh (6" depth)
(Conventional Site)
-500
-400
-300
-200
-100
0
100
200
300
400
500
600
9/15 9/22 9/29 10/6
Eh m
V
Changes in Soil Eh (6" depth) (Organic Site)
RB9-Fert
RB9+Fert
RB4.5+Mol4.5-Fert
RB4.5+Mol4.5+Fert
Aerobic
Anaerobic
• Fertility management?
ASD with 9ton/ac Rice Bran equal yields to MeBr in conventional site
Little effect of pre-plant fertilizer in conventional (slow release 18-6-12 600 lbs/ac) or organic site (feather meal 1000 lbs/ac)
RB+Molasses worked well at organic site – better with pre-plant?
0
20,000
40,000
60,000
80,000
Cum
ulat
ive
mar
keta
ble
fruit
yiel
d lb
s/ac
re
Cumulative Marketable Fruit Yield (PSI. Albion. Mean ± SEMs)
A AB ABC ABCD BCDE CDE DE E
a a a ab
bc cd de
e
But ……. Strong pre-plant fertilizer effect at another site… Yields in ASD w/RB, or RB+Molasses same or better than MeBr or Pic-Clor
Efficacy against other pathogens:
Watsonville 2011
% roots from which Rhizoctonia was isolated
Pythium spp.
Cylindrocarpon spp.
% roots from which fungi was isolated Watsonville 2011
6/21/2013 5/08/2013 8/02/2013
Progress of Fusarium wilt at MBA 2013
• Fall Bed ASD does not control Fusarium
• Works elsewhere when soil temperature higher
Threshold 86 deg F (30 deg C)
Summer flat ASD w/ clear TIF MBA 2013
Summer flat ASD w/ clear TIF MBA 2013 – control Fusarium?
0
25,000
50,000
75,000
100,000
125,000
150,000
175,000
200,000
225,000
8/4 8/14 8/24 9/3 9/13 9/23
Cum
Eh
mV
hrs
Summer flat ASD RB9t/ac Summer flat ASD RB4.5t/ac
Changes in Cumulative Eh mV Hours (MBA 2013)
Threshold to kill Verticillium dahliae at 25 °C
15.0
20.0
25.0
30.0
35.0
40.0
45.0
8/10/13 8/17/13 8/24/13 8/31/13 9/7/13 9/14/13 9/21/13 9/28/13
Soil
tem
p °C
Changes in Soil Temperature at 6" depth (MBA 2013) UTC
Summer flat ASD RB9t/ac
Summer flat ASD RB4.5t/ac
Threshold to kill Fusarium oxysporum
Oct. 2012 Sugarcane Molasses Injection (1:1 to 1:3 dilution with H2O)
C sources and efficacy?
Efficacy of molasses not good in CA, although works in Fl and Japan Fruit yield ~70% of fumigated control Temperature issue? Distribution issue? Short-lived anaerobic conditions - split applications
needed to sustain anaerobic conditions at lower temperatures?
Mix molasses and rice bran - promising?
Need to assess different C sources on various organisms at different temperature regimes
Spence Field - Salinas Fall 2012
-300
-200
-100
0
100
200
300
400
500
10/13 10/20 10/27 11/3 11/10 11/17
Eh m
V
Changes in Soil Eh (6" depth) (Spence, Salinas. 2012)
Aerobic
Anaerobic
1st molasses injection
2nd molasses injection (10/23/12 3 ton/ac)
C- Source efficacy? Differential effects of Molasses versus Rice Bran ASD on fungal communities
0.00E+00
1.00E+06
2.00E+06
3.00E+06
4.00E+06
5.00E+06
6.00E+06
7.00E+06
8.00E+06
9.00E+06
UTC Mol 6 Mol 9 RB 6 RB 9 RBMol PicChlor MBPic
cfu
g-1 s
oil
M. Mazzola 2013
ASD effects on fungal community composition also depends on C source (T-RFLP analysis)
Fumigant UTC and Molasses RB or RB + Mol
M. Mazzola, 2013
Practical issues to be addressed
Scaling up: 2012; 120 acres under ASD 2013; 430 acres under ASD – 29 ac Conventional
401 ac Organic 67% of growers who did ASD in 2012 continued to use
it in 2013 Variability in achieving good anaerobic conditions
• Porous soil structure in heavy soil (large clods) prevented good ASD conditions
• Macrophomina and other pathogens not controlled
When Verticillium levels in soil very high (30+ microsclerotia/g soil), ASD may not completely eliminate disease
Watsonville field
0
10000
20000
30000
40000
UTC ASD molasses 9
tons/ac
ASD rice bran 9
tons/ac
Steam Steam + MSM
Cum
ulat
ive
mar
keta
ble
fruit
yiel
d (lb
s/ac
re)
Marketable Fruit Yield Proprietary variety. 8/17/13. Mean ± SEM A
AB BC
CD D
Alternatives to rice bran as C source?
Bed application costs with 9 ton/ac rice bran typically around $2000-2400 per acre compared with about $1200/ac for Pic-Clor
High total N addition – about 360lb/ac
Other C-sources to reduce costs and N application? Flat application and reduced rate options? Reduce fertility applications to account for C source
nutrients
Future work Effectiveness for controlling different pathogens needs much more
work – what temperature, anaerobic thresholds and C-sources work for each pathogen
Cost and nitrogen issues – other options for C-sources: Molasses – can efficacy be improved? Grape pomace not promising - other options? Summer cover crops may work as partial C-source Flat application may allow reduction of RB application rate? Degree of N2O emission?
Limitations of bed application – challenges of creating anaerobic conditions in heavier soils. Options for flat application and reduced C input rates?
Possible combination of ASD with other strategies? Sequential with MSM? With low rate of fumigants?
