Simulated crop rotation systems control swede midge, Contarinia nasturtii (Diptera: Cecidomyiidae) Mao Chen & Anthony M. Shelton Department of Entomology, Cornell University/NYSAES
Contarinia nasturtii (Diptera: Cecidomydiiea)
Contarinia nasturtii (Diptera: Cecidomydiiea)
Host plants: Cabbage, broccoli, cauliflower, canola cruciferous weeds Distribution in NA: First discovery in Ontario Canada in 2000 Ontario: 32 counties, Quebec:33 counties, 1 location in Nova Scotia and 3 locations in Saskatchewan (http://www.inspection.gc.ca/english/ plaveg/protect/dir/smidgee.shtml updated on Sept 2008) US: first discovery, Sept 2004 in NY By the end of 2008, 25 counties in NY, one each in Massachusetts (Hampshire), New Jersey (Sussex),and Connecticut(New Haven County) Economic impact: >$90 million yield in cruciferous crops in NY; The main fresh market vegetable crucifers (broccoli, cabbage and cauliflower) ca. $1.23 billion in 2006 (USDA ERS, 2007).
Control methods Different control strategies have been tested in the US and Canada Chemical control, cultural control, host plant resistance Wu et al., 2006; Kikkert et al., 2006, Chen et al., 2007; Chen & Shelton, 2007; Shelton et al., 2007; Hallett et al., 2008 In EU Chemical control, excluding fences, emulsions, soil management Hornig, 1953; Readshaw 1961, 1966, 1968; Thygesen, 1966; Rygg & Braekke, 1980; Ouden et al., 1987; Theunissen et al., 1997; Wyss & Daniel, 2004
Crop rotation Control of swede midge using crop rotation has been suggested, however no data exists to confirm this Taylor, 1912; Rygg & Braekke, 1980; Theunissen et al., 1997; Kikkert et al., 2002; ISMTF, 2005
Questions: 1. Can swede midge emerge from soil planted to a non-host crop, as would occur in a rotation? 2. Will crop rotation be effective in reducing damage to a subsequent crop? 3. Can cruciferous weeds play a role in sustaining swede midge populations when cruciferous crops are not available?
Q1 Treatment: cauliflower, sweet corn, kidney beans, cruciferous weeds (shepherd s purse and wild mustard) and fallow 50 larvae/rep, 3 reps/trt Emergence time and rate (%) One-way ANOVA
Impact of host and non-host plants on C. nasturtii emergence pattern Plants Days to first emergence a Emergence rate (%) Cauliflower 11.8±0.8 a 30.8±4.7 a Sweet corn 12±1.2 a 30.4±5.5 a Kidney beans 11.6±1.1 a 32.8±4.9 a Cruciferous weeds 11.2±1.9 a 30±3.5 a Fallow 11.6±1.8 a 31.6±5.2 a 1
Summary for Q1 Plant type did not significantly affect swede midge emergence rate from previously infested soil. Emergence time of swede midge in the soil planted with the host plants (cauliflower or cruciferous weeds) and the non-host plants (sweet corn or kidney beans) was very similar to the fallow treatment.
Q 2&3 1 Simulated crop rotation systems tested in the laboratory for C. nasturtii control # Rotation system Simulated season 1 Simulated season 2 Simulated season 3 1 Cauliflower Cauliflower Cauliflower 2 Cauliflower Sweet corn Cauliflower 3 Cauliflower Kidney beans Cauliflower 4 Cauliflower Cruciferous weeds Cauliflower 5 Cauliflower Sweet corn + Cauliflower Cruciferous weeds 6 Cauliflower Kidney beans + Cauliflower Cruciferous weeds 7 Sweet corn Sweet corn Cauliflower 8 Kidney beans Kidney beans Cauliflower 9 Cruciferous weeds Cruciferous weeds Cauliflower 10 Sweet corn + Sweet corn + Cauliflower Cruciferous weeds 11 Kidney beans + Cruciferous weeds Cruciferous weeds Kidney beans + Cruciferous weeds Cauliflower
Q 2&3 Number of C. nasturtii larvae retrieved from cauliflower plants planted in simulated season 3 of a crop rotation system Rotation system C. nasturtii System Planting pattern larvae/plant 1 Cauliflower Cauliflower Cauliflower 1245.8±59.3 a 2 Cauliflower Sweet corn Cauliflower 0±0 c 1 3 Cauliflower Kidney beans Cauliflower 0±0 c 4 Cauliflower Cruciferous weeds Cauliflower 12.3±4.5 b 5 Cauliflower Sweet corn + Cruciferous weeds Cauliflower 18±13.1 b 6 Cauliflower Kidney beans + Cruciferous weeds Cauliflower 22.5±15.3 b 7 Sweet corn Sweet corn Cauliflower 0±0 c 8 Kidney beans Kidney beans Cauliflower 0±0 c 9 Cruciferous weeds Cruciferous weeds Cauliflower 0±0 c 10 Sweet corn + Cruciferous weeds Sweet corn + Cruciferous weeds Cauliflower 0±0 c 11 Kidney beans + Cruciferous weeds Kidney beans + Cruciferous weeds Cauliflower 0±0 c
Summary for Q2&3 No swede midge larvae or feeding damage were found on the non-host plants Without cruciferous weeds, one planting season with the non-host plants could eliminate swede midge population With weeds, the effectiveness of one cycle of non-host crop rotation was reduced Two consecutive cycles of non-host plant crop rotations provided full control of swede midge, regardless of the presence of the cruciferous weeds
Ongoing field work in CA 2008 Broccoli Beans without weed control Beans with weed control Beans with weed control Broccoli Beans without weed control Beans without weed control Beans with weed control Broccoli
Ongoing field work in CA Broccoli Broccoli Broccoli 2009 Broccoli Broccoli Broccoli Broccoli Broccoli Broccoli
Acknowledgements Cornell Cooperative Extension Julie R. Kikkert Christine A. Hoepting University of Guelph Rebecca Hallett Mark sears Cornell University Weiweil Li Hilda Collins Mei Cheung John Diaz Ping Wang Wendy Kain The New York Vegetable Research Association/Council