Acrolein as Potential Alternative to Methyl Bromide in California-Grown Calla Lilies Husein Ajwa University of California, Davis
Acrolein as Potential Alternative to Methyl Bromide in California-Grown Calla Lilies Researchers: Susanne Klose (PI) Husein Ajwa, UC-Davis Jim Gerik, USDA-ARS Ian Greene, Golden State Bulb Growers
MB Use in California in Ornamentals From US Nominations for CUE for Ornamentals, 2006 (US EPA) Year Total MB used Acre treated Rate (lbs) (lbs/acre) 1999 360,469 1,365 264 2000 347,010 1,424 244 2001 187,858 821 229 2002 143,474 900 159 2003 156,115 694 225 2004 not available 2008 MB nominations = 149,481 lbs
Acrylaldehyde Acrolein CAS number: 107-02-8 Molecular formula: C 3 H 4 O Properties: Molecular mass: 56.06 g/mol Appearance: colorless to yellow liquid, irritating odor Boiling point: 127 F (53 C) Vapor pressure: 286 mbar (20 C) Solubility in water: fair (< 10%)
Background Cut flower and ornamental bulb industries rely heavily on MB/Pic as a key pest management tool The loss of MB will require growers to use alternative fumigants MB alternative research for cut flowers and ornamental bulb crops received little attention relative to other crops Test of novel materials for management of a multi-pest complex as preplant treatments (drip applied) under plastic mulch in commercial Calla lily systems in Central Coastal California.
Experimental Design Control MeBr/Pic (67:33) Acrolein 400 lbs Acrolein 200 lbs Acrolein 100 lbs Acrolein 400 lbs Acrolein 200 lbs Acrolein 100 lbs Control MeBr/Pic (67:33) MeBr/Pic (67:33) Control Acrolein 400 lbs Acrolein 200 lbs Acrolein 100 lbs Acrolein 400 lbs Acrolein 200 lbs Acrolein 100 lbs MeBr/Pic (67:33) Control 50 ft 250 ft
Treatments Drip Injection Rate (lb/a) HDPE* Untreated 0 + MB/Pic (67/33) 350 + Acrolein 100 + Acrolein 200 + Acrolein 400 + * High density polyethylene film
Acrolein Drip Application Dolan Ranch, Moss Landing, CA, June 2006
Evaluations 1 Phytotoxicity test Five indicator Calla lily bulbs were buried in each plot at 2 soil depth at 1, 7, 14 and 21 d past Acrolein application, retrieved, transplanted in the greenhouse, and crop was evaluated at 21 d past emergence Viability of soil-borne plant pathogens Survival of Pythium spp. and Fusarium oxysporum was evaluated in soil samples from 0-6 depth 4 wks past application
Germination test on Calla bulbs after transplanting in the greenhouse
Evaluations 2 Weed density evaluated prior to each and weed removal practice Calla crop density evaluated every 8-10 wks after planting Plant growth and yield parameters Flower counts at peak flowering Bulb yield and quality (7 bulb grades (circumference, 1 1/4 to > 3, bulb disease symptoms) Bulb quality rated on transplanted bulbs after 3 months (number of flowers, plant and root appearance) Parameters currently evaluated
Germination of indicator Calla bulbs buried in Acrolein treated soils relative to an untreated control at 21 d past emergence Germination (%) Acrolein in lbs/acre Days past Application 100 200 400 1 54 47 54 7 62 69 69 14 100 100 97 21 100 100 100
Pathogen survival in Acrolein-treated soils (Error bars represent standard errors) (4 wks past application) Pathogen survival (PPG) 1400 1200 1000 800 600 400 200 Pythium Fusarium 0 Control MB/Pic 350 Acrolein 100 Acrolein 200 Treatment/Rate (lbs/acre) Acrolein 400
Calla lily stand density in Acrolein-treated soils (Error bars represent standard errors) Stand density (Thousand/acre) 9000 8000 7000 6000 5000 4000 3000 2000 UTC MB/Pic 350 Ac100 Ac200 Ac400 1000 0 8/06 10/06 11/06 4/07 Month/Year
Total Resident Weeds in Acrolein-treated soils (Error bars represent standard errors) 400 Total resident weeds (Thousands acre -1 ) 350 300 250 200 150 100 50 0 Untreated MB/CP 350 Acrolein 100 Acrolein 200 Acrolein 400 Treatment/Rate (lbs/acre)
Numbers of Malva in Acrolein-treated soils (Error bars represent standard errors) 400 Malva parviflora (Thousands acre -1 ) 350 300 250 200 150 100 50 0 Untreated MB/Pic 350 Acrolein 100 Acrolein 200 Acrolein 400 Treatment/Rate (lbs/acre)
Numbers of Calla Volunteers in Acrolein-treated soils (Error bars represent standard errors) 400 Zantedeschia spp. (Thousands acre -1 ) 350 300 250 200 150 100 50 0 Untreated MB/Pic 350 Acrolein 100 Acrolein 200 Acrolein 400 Treatment/Rate (lbs/acre)
Calla lily stand in Acrolein-treated soils relative to MB/Pic and an untreated soil (Control) 13 month after planting Ac 400 MB/Pic Ac 200 Control Ac 200 Control Ac 100 MB/Pic Ac 100
Calla lily stand 13 month after planting (July 2007) Acrolein 400 lbs/acre MB/Pic 350 lbs/acre Control 0 lbs/acre
Total Flower numbers (Calla lily) at peak flowing in Acrolein-treated soils (Error bars represent standard errors) 4,000 3,500 Flower counts (no acre -1 ) 3,000 2,500 2,000 1,500 1,000 500 0 Untreated MB/CP 350 Acrolein 100 Acrolein 200 Acrolein 400 Treatment/Rate (lbs/a)
Conclusions Acrolein at 400 lbs/acre provided fair control of key pests in Calla lilies, with exception of volunteer crops, up to 4 months after planting Pathogen control efficacy decreased markedly afterwards (lower stand densities, flower counts, bulb yield? than MB/Pic standard) Long-lasting pest control is crucial for this 18- month crop, therefore simultaneous or sequential application of Acrolein at 400 lbs/acre with other herbicide/ pesticide combinations or at low rates in-season need to be tested in the future
Acknowledgements Baker Petrolite Golden State Bulb Growers (Ian Greene) TriCal (Paul Niday, Mike Stanghellini, Bob Lino) Jonathan Hunzie, Ernie Leyva, Shachar Shem-Tov, Matthew Linder