1. Borges, © 2002-2005 University of Wisconsin – Agronomy This presentation is available at http://soybean.uwex.edu/

2. Borges, © 2002-2005 University of Wisconsin – Agronomy This presentation is available at http://soybean.uwex.edu/ Pathogen: Fusarium spp. Mostly Fusarium graminearum Symptoms: Usually first detected soon after flowering White head, while leaves and stems may remain green Often, only part of the head is attacked Bleached Spikelets often with a salmon-pink tint Stem directly below the head may turn to chocolate brown color Kernels above the infected spikelets may be shriveled Kernels are shrunken and chalky or pink in color Tombstone or light weight kernels Barren spikelets Mycotoxin SCAB (HEAD BLIGHT)

3. Borges, © 2002-2005 University of Wisconsin – Agronomy This presentation is available at http://soybean.uwex.edu/ Very erratic Depends on wet weather conditions at flowering Happened once every six or seven years in Wisconsin SCAB SEVERITY AND FREQUENCY

4. Borges, © 2002-2005 University of Wisconsin – Agronomy This presentation is available at http://soybean.uwex.edu/ Corn, oats, barley, sorghum, and other grasses On corn, it causes root, stalk, and ear rot (giberela) On sorghum, it causes stalk rot May cause root rot in small grains ALTERNATIVE HOSTS

5. Borges, © 2002-2005 University of Wisconsin – Agronomy This presentation is available at http://soybean.uwex.edu/ Mainly crop residue of small grains and corn During moist weather, spores of the fungi are windblown or splashed onto the heads Seed borne Fusarium spp may cause seedling blight ALTERNATIVE HOSTS

6. Borges, © 2002-2005 University of Wisconsin – Agronomy This presentation is available at http://soybean.uwex.edu/ From flowering to soft dough stage. Mainly through anthers (flowers). Then grow into the kernels, glumes, or other parts of the head. Favored by prolonged periods (48- 72 hs) of high humidity and warm temperatures of 75-85 0 F. INFECTION

7. Borges, © 2002-2005 University of Wisconsin – Agronomy This presentation is available at http://soybean.uwex.edu/ HEAD EMERGENCE

8. Borges, © 2002-2005 University of Wisconsin – Agronomy This presentation is available at http://soybean.uwex.edu/

9. Borges, © 2002-2005 University of Wisconsin – Agronomy This presentation is available at http://soybean.uwex.edu/ Spikelets, row, or mesh Flower

10. Borges, © 2002-2005 University of Wisconsin – Agronomy This presentation is available at http://soybean.uwex.edu/

11. Borges, © 2002-2005 University of Wisconsin – Agronomy This presentation is available at http://soybean.uwex.edu/

12. Borges, © 2002-2005 University of Wisconsin – Agronomy This presentation is available at http://soybean.uwex.edu/

13. Borges, © 2002-2005 University of Wisconsin – Agronomy This presentation is available at http://soybean.uwex.edu/

14. Borges, © 2002-2005 University of Wisconsin – Agronomy This presentation is available at http://soybean.uwex.edu/

15. Borges, © 2002-2005 University of Wisconsin – Agronomy This presentation is available at http://soybean.uwex.edu/ Variety selection: Some varieties are extremely susceptible No variety is considered highly resistant Choose varieties based on scab ratings from multi-location! Spread risk by choosing varieties with different maturities. Crop rotation with non-host crops (i.e. soybeans) Chop, bury, or remove crop residue SCAB MANAGEMENT

16. Borges, © 2002-2005 University of Wisconsin – Agronomy This presentation is available at http://soybean.uwex.edu/ Seed treatments: Help raise seed germination May prevent or reduce seedling blight DO NOT CONTROL HEAD BLIGHT Seed cleaning Set combine fans higher during harvest Foliar fungicides Not cost effective in Wisconsin SCAB MANAGEMENT

17. Borges, © 2002-2005 University of Wisconsin – Agronomy This presentation is available at http://soybean.uwex.edu/