Shank and Drip applied Soil Fumigants as Potential Alternative to Methyl Bromide in California-grown Cut Flowers Husein Ajwa University of California-Davis
Shank and Drip applied Soil Fumigants as Potential Alternative to Methyl Bromide in California-grown Cut Flowers Susanne Klose, H.A. Ajwa, S. Shem-Tov, S.A. Fennimore, K.V. Subbarao, J.D. Mac Donald, H. Ferris, F. Martin, J. Gerik, M.A. Mellano and I. Greene University of California-Davis, USDA-ARS Salinas and Parlier, Mellano & Co. Carlsbad, Golden State Bulb Growers, Moss Landing
Soil Fumigation for Calla Lily and Ranunculus Production
Key Diseases in selected Ornamentals controlled by MB/Pic From MB CUE Nominations for Ornamentals, 2008 Crop Key Pest Calla lily Gladiolus Ranunculus Erwinia soft rot (Erwinia carotovora) Pythium root rot (Pythium spp.) Fusarium wilt (Fusarium oxysporum fsp. gladioli) Stromatinia neck rot (Stromatinia gladioli) Pythium root rot (Pythium spp.) Xanthomonas leaf spot (Xanthomonas campestris)
Key pests in Calla lilies Root rot ( Water mold )
Key Weeds and Nematodes in Ornamentals controlled by MB/Pic From MB CUE Nominations for Ornamentals, 2008 Weeds Bulbs, tubers, cormlets from previous crop Yellow nutsedge, little mallow, common sow thistle, clover, others (?) Most soil nematodes (Meloidogyne spp.)
Yellow Nutsedge
Field Trials Comparison of pre-plant (1) shank and (2) drip-applied alternative fumigants under two mulch types (standard and ) in two model crops in California: Calla lily (Moss Landing) and Ranunculus (Carlsbad)
Field Trial 1 Shank applied fumigants & and standard () mulch Pre-plant shank rates ( and ): 350 lbs/acre MB/Pic (67/33) 300 lbs/acre Midas (50/50) Untreated Control
Field Trial 2 Drip applied alternative fumigants & and standard () mulch Treatment Rate (lbs/acre) 1,2) Untreated Check 0 MB/Pic (67/33) 200 Pic 200 InLine 300 Midas (33/67) 200 1) All fumigants were applied under and mulch. 2) Sequential metam-k or metam-na application of 37.5 or 50 gal/a to ½ of the plots of all treatments.
Tests Weed control efficacy Survival of six common weed seeds and of volunteers (bulbs and/or seeds) (sachet test) Numbers of native weeds and major weed species Weeding times Plant pathogen and nematode control efficacy Survival of five soil-borne pathogens and citrus nematode (sachet test) Presence of general soil fungi and Pythium spp. in soil
Tests - continued Plant growth and yield parameters Stand density Disease incidents Flower counts (Calla lily) Flower stem yield (Ranunculus) Bulb yield and quality (circumference, disease incidents)
Weed control by MB alternative fumigants
Weed seed survival in shank-fumigated soils Treatment Rate lbs/ac Plastic type Chickweed Seed viability (%) Knotweed Mallow Purslane Nutsedge MB/Pic (67/33) 350 0 0 37 0 0 0 0 26 0 0 Midas (50/50) 300 0 0 39 0 0 0 0 29 0 1 Control 0 none 71 97 50 73 42 Midas provided similar control of flower bulbs (Calla, Gladiolus, Ranunculus) and seeds (Ranunculus) as the standard MB/Pic mix
Native weed populations in shank-fumigated soils (Ranunculus system) Treatment MB/Pic (67/33) Rate lbs/ac 350 Plastic type Malva Weed density (No./acre) Clover Fescue Swine cress Cover % Weed biomass g/acre 4,901 a 170,701 0 0 18 4,525 6,534a 130,727 4,901 0 15 2,581 Midas (50/50) 300 817b 164,984 0 0 10 5,018 0b 151,916 0 0 13 3,734 Control 0 none 817b 178,052 0 1,634 13 4,515
Weed control with drip applied alternatives (standard mulch) Viability of weed seeds and flower bulbs (%) Fumigant Vapam Yellow Nutsedge Chickweed Knotweed Mallow Purslane Calla lily C. esculentus S. media P. arenastrum M. parviflora P. oleracea Zantedeschiaspp. Untreated - 60 62 98 70 86 53 + 39 32 49 54 48 44 MB/Pic - 10 0 8 53 1 13 + 0 0 5 46 0 25 Midas - 1 0 17 44 0 13 + 6 0 11 45 12 6 InLine - 26 0 31 53 10 31 + 21 0 22 44 0 28 CP - 33 0 43 50 1 16 + 23 0 25 45 3 19 Similar weak control of bulbs of Gladiolus and Iris by all drip applied fumigants; control of volunteer bulbs by Midas and MB/Pic under
Pathogen control by MB alternative fumigants Burial, fumigation and retrieval of nylon bags with soil-borne pathogens and nematodes
Verticillium dahliae survival in shank-fumigated soils (Error bars represent standard errors) Verticillium dahliae (microclerotia g -1 ) 160 140 120 100 80 60 40 20 0 MB/Pic shank standard Std Std Std Std Std Untreated MB/CP Midas Telone C35 CP Fumigant Treatment/Plastic
Verticillium dahliae survival in drip-fumigated soils (Error bars represent standard errors) 180 160 Verticillium dahliae (microclerotia g -1 ) 140 120 100 80 60 40 MB/Pic shank standard 20 0 Untreated Untreated + Kpam MB/Pic MB/Pic + Kpam Pic Pic + Kpam Fumigant Treatment/Plastic InLine InLine + Kpam Midas Midas + Kpam
Fusarium oxysporum survival in shankfumigated soils (Error bars represent standard errors) 500,000 Fusarium oxysporum (CFU g -1 ) 400,000 300,000 200,000 100,000 0 Untreated MB/CP Midas Telone C35 CP Fumigant Treatment/Plastic
Fusarium oxysporum survival in drip-fumigated soils (Error bars represent standard errors) Fusarium oxysporum (CUF g -1 ) 80 60 40 20 0 Untreated = 443,333 CUF g -1 = 557,500 CUF g -1 100% control in MB/Pic shank standard Untreated + Kpam MB/Pic MB/Pic + Kpam Pic Pic + Kpam InLine InLine + Kpam Fumigant Treatment/Plastic Midas Midas + Kpam
Pathogen survival in shank fumigated soils Complete control of Fusarium, Phytophthora and nematodes 30 Pathogen survival (%) rel. to untreated soil 25 20 15 10 5 0 Pythium Verticillium MB/CP Midas Telone C35 CP Fumigant Treatment/Plastic
Pathogen survival in drip fumigated soils Complete control of Fusarium, Phytophthora, Pythium spp. and nematodes Pathogen survival (%) relative to untreated soil 100 80 60 40 20 Rhizoctonia Verticillium 0 MB/Pic MB/Pic + Kpam Pic Pic + Kpam InLine InLine + Kpam Midas Midas + Kpam Fumigant Treatment/Plastic
Yield data 1. Flower stems Calla lily stem harvest
Yield data 2. Flower bulbs Ranuncula bulb harvest
Flower Stem yield in shank-fumigated soils (relative to MB/Pic standard mix) Ranunculus stem yield (% to MB/Pic ) 140 120 100 80 60 40 20 0 MB/Pic standard none Untreated MB/CP 350 Midas 300 Fumigant Treatment/Plastic
Flower bulb yield in shank-fumigated soils (Ranunculus system) Bulb yield per size (per acre) 8+ 7-8 Total Treatment Plastic No kg No kg No kg UTC none 36,777 151 44,802 134 305,168 537 MB/Pic 51,966 245 37,542 119 198,484 503 39,548 178 42,548 107 201,293 442 Midas 46,865 220 35,727 92 182,245 436 44,133 205 36,109 90 210,731 409 ANOVA n.s. n.s. n.s. n.s. n.s. n.s. No significant differences in all other bulb sizes
Flower Stem yield in drip-fumigated soils (relative to MB/Pic standard mix) 140 Ranunculus stem yield (% to MB/Pic shank) 120 100 80 60 40 20 0 MB/Pic standard - + - + - + - + - + UTC MB/Pic Pic Midas InLine Treatment/Sequential Kpam (+/-) mulch
Flower bulb yield in drip-fumigated soils (Ranunculus system) Fumigant Vapam Bulb yield per size (per acre) 8+ 7-8 Total No kg No kg No kg UTC - 8,981 a 32 a 17,209 a 30 a 97,365 a 135 a + 14,574 a 54 a 25,652 a 46 a 107,125 a 164 a MB/Pic - 26,486 b 105 b 29,901 ab 70 b 132,025 b 256 b + 25,679 b 105 b 31,594 b 70 b 141,893 b 269 b Pic - 37,510 bc 118 b 27,666 ab 76 b 142,619 b 285 b + 27,642 b 116 b 35,843 b 81 b 140,495 b 280 b Inline - 27,992 b 121 b 33,047 b 76 b 142,135 b 288 b + 33,746 bc 143 c 29,040 ab 73 b 143,829 b 301 b Midas - 36,193 bc 132 bc 44,609 c 100 c 194,918 c 352 c + 36,515 bc 142 c 36,784 b 78 b 161,898 bc 309 b ANOVA (P -value) 0.000 0.000 0.005 0.003 0.032 0.000 No significant differences in all other bulb sizes
Conclusions Ranunculus production Shank-applied Midas (once registered in CA) at 300 lbs/acre was equally effective in providing weed and pathogen control. Drip-applied alternatives at 200 lbs/ acre were not consistently effective as the MB/Pic shank standard at 350 lbs/acre Bulb quality seemed to be better under drip fumigation than shank injection
Conclusions Calla lily production Drip fumigation resulted in better pest control and bulb yield and quality than shank fumigation Drip-applied Midas at 200 lbs/ acre and InLine at 300 lbs/acre are currently the best alternative treatments for multi-pest complex control in the absence of MB/Pic Advantage of over mulch and of sequential application of Kpam or Vapam to improve fumigant efficacy in floricultural production could not consistently proven in these two systems
Acknowledgements USDA-CSREES California Cut Flower Commission USDA-IR4 program Golden State Bulb Growers (Ian Greene) Mellano & Co. (Mike A. Mellano, Mike Muehe) TriCal (Paul Niday, Mike Stanghellini, Bob Lino, Mark Lauman) Arysta LifeSciences Bruno Rimini Ltd & PolyPak Cheryl Wilen, UCCE San Diego Jonathan Hunzie, Matthew Linder, Ernie Leyva, Patricia Martinez, Wonsook Ha, Stella Lee