Cercospora Infection Values (2008 Crop)
Wahpeton Location
Date |
Infection Potential |
Aug 18 |
Slight |
Aug 17 |
Moderate |
Aug 16 |
Slight |
Aug 15 |
Slight |
Aug 14 |
Moderate |
Aug 13 |
Severe |
Aug 12 |
Severe |
Aug 11 |
Moderate |
Aug 10 |
Severe |
Aug 09 |
Moderate |
Aug 08 |
Slight |
Aug 07 |
Slight |
Aug 06 |
Slight |
Aug 05 |
Slight |
Aug 04 |
Moderate |
Aug 03 |
Slight |
Aug 02 |
Slight |
Aug 01 |
Slight |
July 31 |
Slight |
July 30 |
Slight |
July 29 |
Moderate |
July 28 |
Slight |
July 27 |
Slight |
July 26 |
Slight |
July 26 |
Slight |
July 25 |
Slight |
July 24 |
Slight |
July 23 |
Moderate |
July 22 |
Moderate |
July 21 |
Moderate |
July 20 |
Severe |
July 19 |
Moderate |
July 18 |
Moderate |
Information is for Cercospora infection potential is taken from the NDAWN web site; Wahpeton location. If you have not been to the NDAWN web site you should really take some time and look it over. Click on the link below to get there.
Cercospora leaf spot spraying is just around the corner with Triazoles back on the menu for the 2008 season. With resistance management in mind, the Ag Staff will be recommending a Triazole - Tin - Strobilurin application program for this year. Keep in mind that the RR varieites do not have as low of a CLS rating as many of the other varieites that you are used to dealing with. Keep in close contact with your Agriculturist for proper application timing and any additional questions that you may have.
Here is a good example of what you can expect for CLS management this season:
Spray Program |
Application #1 |
Application #2 |
Application #3 |
Application #4 |
One Spray |
Strobilurin |
--- |
--- |
--- |
Two Spray |
Triazole |
Strobilurin |
--- |
--- |
Three Spray |
Triazole |
Tin |
Strobilurin |
--- |
Four Spray |
Triazole |
Tin |
Strobilurin |
Tin |
Triazoles: Eminent - Enable - Proline - Inspire
Tins: AgriTin - SuperTin
Strobilurins: Headline - Gem - Quadris
Fungicides |
Re-Entry Interval (Hours) |
Pre Harvest Interval (Days) |
Ground Application Water Volume (Gallons) |
Rainfast (Hours) |
AgriTin 4L |
48 |
7 |
At least 15 |
*** |
AgriTin 80 WP |
48 |
21 in MN & 7 in ND |
At least 15 |
*** |
Quadris / Amistar |
4 |
0 |
Sufficient water to ensure thorough coverage |
*** |
Eminent |
12 |
14 |
5 or more |
*** |
Enable 2F |
12 |
14 |
20 |
1 |
Gem |
12 |
21 |
Min 10 |
*** |
Headline |
12 |
7 |
Sufficient water to ensure thorough coverage |
*** |
Inspire |
12 |
7 |
15 |
1 Hr or after it dries |
Proline |
48 |
7 |
Min 10 |
2 |
SuperTin 4L |
48 |
7 in MN & 21 in ND |
At Least 15 |
*** |
SuperTin 80 WP |
48 |
7 |
At Least 15 |
*** |
*** = Nothing is specified on the label.
General CLS Information:
- Inoculum spores have a 1 - 2 year survival in infected leaf debris in sugarbeet fields when left on the surface. When tillage buries the debris, most inoculum spores are destroyed in 10 months.
- Optimal sporulation, germination, and infection occur at 75 to 90 degrees with night temperatures above 61 degrees and high relative humidity.
- Other hosts for Cercospora are Red Beet, Swiss Chard, Spinach and several weed species - particularly Redroot Pigweed and Common Lambsquarter.
- Under natural infection conditions, a 3.5 KWS rating is reported to cause economic damage by reducing root yield and percent sugar (KWS scale of 1-9, with lower numbers indicationg less infection).