Flea beetles, leafminers, and cabbage maggot can be controlled in spring crops with spunbonded row covers. Cover at seeding and seal the edges with soil. Rotate fields so that flies do not emerge under row covers. Row covers are most effective for spring crops. Use a non-heating row cover, such as Proteknet, to protect fall turnips and rutabagas from cabbage maggot during August and early September, as spunbonded row covers can trap too much heat and cause reduced yield and root quality. Aphids are generally kept below damaging levels by natural enemies. If using row cover, do not place over crops with aphids present, as the cover will exclude natural enemies and cause outbreaks of aphids under the cover.
Aphid, primarily Cabbage Aphid (Brevicoryne brassicae)
See the Cabbage, Broccoli, Cauliflower, and Other Brassica Crops insect control section for information on cabbage aphid. Green peach aphid is an occasional pest of rutabaga and turnip; see the Pepper insect control section for more information on green peach aphid.
IRAC Group 1:
- dimethoate (Dimethoate 4EC): 0.5 pt/A; PHI 14d, REI 48h, Bee: H, Group 1B. Turnip only.
- malathion (Malathion 57EC): 1 to 1.6 pt/A for rutabaga, 1 to 2 pt/A for turnip; PHI 7d rutabaga, 1d turnip, REI 12h, Bee: H, Group 1B.
IRAC Group 3:
- alpha-cypermethrin (Fastac* CS): 3.2 to 3.8 oz/A; PHI 1d, REI 12h, Bee: H. See resistance statement on label. Aphid control may be variable depending on species present and host-plant relationships. Aids in control.
- bifenthrin (Brigade* 2EC): 5.12 to 6.4 oz/A; PHI 21d, REI 12h, Bee: H.
- pyrethrin (PyGanic EC5.0OG): 4.5 to 15.61 oz/A, or 0.25 to 0.50 oz/gal and 3 gal/1000 sq ft in greenhouse for backpack sprayers; PHI 0d, REI 12h, Bee: M.
IRAC Group 4:
- dinotefuran (Venom): 2 to 3 oz/A; PHI 1d, REI 12h, Bee: H, Group 4A. Turnip greens only. Do not apply to vegetables grown for seed.
- flupyradifurone (Sivanto): 7 to 14 oz/A foliar, 21 to 28 oz/A soil turnip greens only; PHI 7d foliar (1d turnip greens), 21d soil, REI 4h, Bee: L, Group 4D.
- imidacloprid (Admire Pro): 4.4 to 10.5 oz/A soil, 1.2 oz/A foliar; PHI 21d soil, 7d foliar, REI 12h, Bee: H, Group 4A.
- sulfoxaflor (Transform WG): 0.75 to 1.5 oz/A; PHI 7d, REI 24h, Bees: H, Group 4C.
- thiamethoxam (Actara): 1.5 to 3 oz/A; PHI 7d, REI 12h, Bee: H, Group 4A.
- thiamethoxam (Platinum 75SG): 1.7 to 4.01 oz/A; REI 12h, Bee: H, Group 4A. Systemic insecticide used at planting.
IRAC Group 9:
- pymetrozine (Fulfill): 2.75 oz/A; PHI 7d, REI 12h, Bee: L, Group 9B. Selective control of aphids. Translaminar. Turnip greens only.
IRAC Group 29:
- flonicamid (Beleaf 50SG): 2 to 2.8 oz/A; PHI 3d, REI 12h, Bee: L.
IRAC Group UN:
- azadirachtin (Azatin OOG): 4 to 16 oz/A, 4 to 16 oz/100 gal in greenhouses; PHI 0d, REI 4h, Bee: L. When using lower rates, combine with adjuvant for improved spray coverage and translaminar uptake.
- Chromobacterium subtsugae strain PRAA4-1 (GrandevoOG): 2 to 3 lb/A; PHI 0d, REI 4h, Bee: M.
Cabbage Maggot (Delia radicum)
See the Cabbage, Broccoli, Cauliflower, and Other Brassica Crops insect control section for more information on cabbage maggot. Both spring and fall crops are susceptible to maggot damage. Cooler soils in early fall allow survival of eggs from late-season flights. Use drop nozzles directed to the base of the plant. Use at least 100 gal water/A.
IRAC Group 1:
- diazinon (Diazinon* AG500): 2 to 4 qt/A; REI 4d, Bee: H, Group 1B. Broadcast and incorporate to a depth of 4" just before planting. Rutabaga only.
IRAC Group 3:
- alpha-cypermethrin (Fastac* CS): 3.2 to 3.8 oz/A; PHI 1d, REI 12h, Bee: H.