Specialty Crop Report – Ginseng Edition

Preventing the Spread of Disease

Root and foliar diseases continue to be reported in ginseng gardens. Phytophthora and Pythium are the most common root diseases in gardens at this time. Symptoms are scattered throughout ginseng gardens and not just in low areas. These diseases have also been found in seedling gardens. Alternaria, Botrytis, and foliar Phytophthora are also present. While timely application of pesticides is important to reduce disease pressure, preventing the spread of disease is just as important. There are a number of things that can be done to prevent the spread of disease within and between gardens. While each practice will not have a large impact on its own, together they can substantially reduce disease problems.

1. When performing any garden maintenance, enter seedling gardens first and oldest gardens last.   
2. Avoid entering fields when the leaves are wet. Spores produced on leaf tissues can be picked up on machinery or field workers and spread down row.    
3. Sanitize boots and machinery after leaving a diseased garden or diseased area of an otherwise clean field. This is especially important when disease is present in seedling gardens.    
4. Pull the shades over areas with very high disease pressure to kill off infected leaf material and prevent further spread of the disease.    
5. Remove or kill off plants in diseased areas that appear to be spreading. Be sure to also remove apparently healthy plants immediately outside of the affected area, because they may already be infected but not show symptoms.    
6. Raise the side shades to allow more air flow through the gardens, especially when foliar disease is a concern.    
7. Do not apply extra nitrogen in diseased gardens, since nitrogen will promote more succulent growth that can be more susceptible to disease.    
8. Do not pick seed from diseased areas of gardens. Many ginseng diseases can be seed-borne and you may be collecting infected seeds that could initiate disease when those seeds are planted into the field the following summer.    
9. Avoid splashing water and soil onto the beds and leaves. Avoid entering gardens when there is water or mud in the trenches. Fill muddy trenches with wood chips or straw to prevent splashing. Also, add straw to areas of exposed soil.    
10. Follow recommended spray rotations for root and foliar diseases such as Alternaria, Botrytis and Phytophthora. This will prevent the development of resistance and ensure the products remain effective.    
11. Perform sprayer calibrations regularly to ensure even coverage of all plant material with the fungicide.    
12. Ensure that water can drain out of the field quickly after a heavy rainfall.

New Crops Workshop

New Crops, Old Challenges
Non-traditional crops integrated crop management workshop

Come out to the Simcoe Research Station to learn about:

- Non-traditional and specialty crops: demonstration plots of example crops
- Pest management and sprayer technology: discuss with provincial specialists
- Cover crops: opportunities to save your nitrogen dollars
- Current nitrogen research conducted by the University of Guelph
- Enjoy refreshments, meet with other producers and take the opportunity talk with University of Guelph staff and OMAFRA specialists

Date: Tuesday August 18, 2009
(Rain Date: Thursday August 20, 2009)
Time: 1:30 p.m.-5:00 p.m.
Place: Simcoe Research Station

PLEASE RSVP BY AUG. 14 BY CALLING 519-426-7127 ext. 323

NOTE: This will be the last weekly Ginseng Crop Report for this season. The report will be available biweekly for the remainder of the season unless important emerging issues develop.

Questions about ginseng can be directed to Sean Westerveld, OMAFRA’s Ginseng and Medicinal Herbs Specialist at 519-426-4323; E-mail: sean.westerveld@ontario.ca.