Anaerobic Soil Disinfestation (ASD): Updates on Research and Implementation

Transcription

1 Anaerobic Soil Disinfestation (ASD): Updates on Research and Implementation C. Shennan 1, J. Muramoto 1, G. Baird 1, M. Mazzola 6, M. Bolda 4, S. T. Koike 4, O. Daugovish 4, M. Mochizuki 4, S. Dara 4, K. Klonsky 5, E. Rosskopf 3, N. K. Burelle 3, D. Butler 2,3 1 Univ. of California, Santa Cruz, 2 Univ. Tennessee 3 USDA-ARS, U.S. Horticultural Research Lab, Florida, 4 Univ. of California Cooperative Extension 5 Univ. of California, Davis 6 USDA ARS Wenatchee, WA. Funded by USDA-NIFA MBTP and CA Strawberry Commission

2 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.

3 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

4 ASD: Some Target Pests and Crops Soil-borne pathogens Verticillium dahliae 1,2,4 Fusarium oxysporum 1,2,3 Fusarium redolens 2 Macrophomina phaseolina 3 Ralstonia solanacearum 2 Rhizoctonia solani 1 Sclerotium rolsfii 3 Nematode Meloidogyne incognita 1 Pratylenchus fallax 2 Weed Nutsedge 3 Crops tested Welsh onion 2 Tomatoes 2,3 Strawberries 2,4 Eggplant 2, 3 Spinach 2 Peppers 3 Maple 1 Catalpa 1 Cut flowers 3 1 Dutch studies; 2 Japanese studies; 3 Florida studies; 4 California studies

5 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

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8 Total irrigation rate: at least 3 acre-inches

9 Findings to Good yields obtained with 9ton/ac rice bran 1. Salinas equal to MeBr (and UTC) yields 2. Watsonville within 15% of MeBr yields 3. Ventura % increase yield over UTC 4. Castroville 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

10 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 65 o F for at least first week of ASD treatment Eh mv Changes in Soil Eh (mv ) Aerobic Anaerobic /8 9/15 9/22 9/29 10/6 250, , , ,000 50,000 0 Cumulative Eh mv Hours threshold ASD treatment (days)

11 Replicated Trials Location 1. Watsonville: Driscoll s C-source/treatments and Plant Sciences type ASD w/rice bran 6 t/ac and 9 t/ac, ASD w/molasses 6 t/ac and 9 t/ac, Watsonville ASD w/rice bran Rice 4.5 t/ac bran + 6, molasses 9 t/ac 4.5 t/ac, and UTC 2x Conventional Molasses 6, 9 t/ac 2. Watsonville: MBA RB Mol 4.5 t/ac ASD w/rice bran UTC 9 t/ac, ASD w/molasses 9 t/ac, ASD w/rice bran 4.5 t/ac Watsonville + molasses 4.5 t/ac, Rice Rice bran bran 6, 9 t/ac 9 t/ac w/o water, Water Conventional w/o C-sources, - MBA and UTC Molasses 6, 9 t/ac RB Mol 4.5 t/ac 3. Watsonville: Cassin Ranch (MeBr buffer zone) and Driscoll s Controls: UTC, Water only, ASD w/rice bran Rice 9 bran t/ac, 9 ASD t/ac w/molasses no water 9 t/ac, Steam, Steam + MSM, Watsonville and UTC Rice Bran 9 t/ac Conventional 4. Santa Cruz: UCSC Molasses Organic 9 t/ac Farm Steam ASD w/rice bran 4.5 t/ac + molasses 4.5 t/ac w/ and w/o compost, MSM, Steam + Mustard Seed meal and UTC UTC Santa Cruz RB Mol 4.5 t/ac +/- compost Mustard Seed meal UTC Organic

12 Demonstration Trials Monitoring Location C-source Acre age type Watsonville 9t/ac Rice Bran or 4.5t/ac RB+4.5t/ac Molasses +/- preplant Organic Conventional fertilizer Salinas 9 t/ac Molasses 0.5 Conventional Salinas 9 t/ac Molasses 1 Conventional Santa Maria 9 t/ac Molasses 0.5 Conventional

13 ac Demonstration Sites Sandy Soil Good ASD Established Eh mv Changes in Soil Eh (6" depth) (Conventional Site) Eh mv Changes in Soil Eh (6" depth) (Organic Site) Aerobic Anaerobic RB9-Fert RB9+Fert RB4.5+Mol4.5-Fert RB4.5+Mol4.5+Fert /8 9/15 9/22 9/29 10/ /15 9/22 9/29 10/6

14 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 lbs/ac) or organic site (feather meal 1000 lbs/ac) RB+Molasses worked well at organic site better with pre-plant?

15 But. Strong preplant fertilizer effect at another site Yields in ASD w/rb, or RB+Molasses same or better than MeBr or Pic-Clor Cumulative marketable fruit yield lbs/acre 80,000 60,000 40,000 20,000 0 E e BCDE Cumulative Marketable Fruit Yield (PSI. Albion. Mean ± SEMs) de DE cd ABCD ab AB a A a ABC bc CDE a

16 Efficacy against other pathogens: % roots from which Rhizoctonia was isolated Watsonville 2011

17 Pythium spp. % roots from which fungi was isolated Watsonville 2011 Cylindrocarpon spp.

18 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) 5/08/2013 6/21/2013 8/02/2013

19 Summer flat ASD w/ clear TIF MBA 2013

20 Summer flat ASD w/ clear TIF MBA 2013 control Fusarium? Cum Eh mv hrs 225, , , , , ,000 75,000 50,000 25,000 Changes in Cumulative Eh mv Hours (MBA 2013) Summer flat ASD RB9t/ac Summer flat ASD RB4.5t/ac Threshold to kill Verticillium dahliae at 25 C 0 8/4 8/14 8/24 9/3 9/13 9/23 Soil temp 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 /10/13 8/17/13 8/24/13 8/31/13 9/7/13 9/14/13 9/21/13 9/28/13

21 Oct Sugarcane Molasses Injection (1:1 to 1:3 dilution with H 2 O)

22 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

23 Spence Field - Salinas Fall 2012 Eh mv st molasses injection 2nd molasses injection (10/23/12 3 ton/ac) Changes in Soil Eh (6" depth) (Spence, Salinas. 2012) Aerobic Anaerobic /13 10/20 10/27 11/3 11/10 11/17

24 C- Source efficacy? Differential effects of Molasses versus Rice Bran ASD on fungal communities 9.00E E E+06 cfu g -1 soil 6.00E E E E E E E+00 UTC Mol 6 Mol 9 RB 6 RB 9 RBMol PicChlor MBPic M. Mazzola 2013

25 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

26 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

27 Porous soil structure in heavy soil (large clods) prevented good ASD conditions Macrophomina and other pathogens not controlled

28 When Verticillium levels in soil very high (30+ microsclerotia/g soil), ASD may not completely eliminate disease Watsonville field Cumulative marketable fruit yield (lbs/acre) Marketable Fruit Yield Proprietary variety. 8/17/13. Mean ± SEM D CD BC AB A 0 UTC ASD molasses 9 tons/ac ASD rice bran 9 tons/ac Steam Steam + MSM

29 Alternatives to rice bran as C source? Bed application costs with 9 ton/ac rice bran typically around $ 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

30 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 N 2 O 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?

31 Questions?