Cercospora Leafspot Control
2009 Edition
Wahpeton Location
Date |
Infection Potential |
September 17 |
Slight |
September 16 |
Slight |
September 15 |
Slight |
September 14 |
Slight |
September 13 |
Slight |
September 12 |
Moderate |
September 11 |
Moderate |
September 10 |
Moderate |
September 9 |
Moderate |
September 8 |
Slight |
September 7 |
Slight |
September 6 |
Slight |
September 5 |
Slight |
September 4 |
Slight |
September 3 |
Slight |
September 2 |
Slight |
September 1 |
Slight |
August 31 |
Slight |
August 30 |
Slight |
August 29 |
Slight |
August 28 |
Slight |
August 27 |
Slight |
August 26 |
Slight |
August 25 |
Moderate |
August 24 |
Slight |
August 23 |
Slight |
August 22 |
Moderate |
August 21 |
Moderate |
August 20 |
Slight |
August 19 |
Slight |
August 18 |
Slight |
August 17 |
Moderate |
August 16 |
Severe |
August 15 |
Severe |
August 14 |
Moderate |
August 13 |
Moderate |
August 12 |
Slight |
August 11 |
Slight |
August 10 |
Moderate
|
August 9 |
Severe |
August 8 |
Moderate |
| August 7 |
Slight |
| August 6 |
Slight |
| August 5 |
Slight |
August 4 |
Slight |
August 3 |
Slight |
August 2 |
Slight |
August 1 |
Slight |
July 31 |
Slight |
July 30 |
Slight |
July 29 |
Slight |
July 28 |
Slight |
July 27 |
Slight |
July 26 |
Slight |
July 25 |
Slight |
July 24 |
Slight |
July 23 |
Slight |
July 22 |
Moderate
|
July 21 |
Moderate |
July 20 |
Slight |
July 19 |
Slight |
July 18 |
Slight |
July 17 |
Slight |
July 16 |
Slight |
July 15 |
Slight |
July 14 |
Slight |
July 13 |
Slight |
| July 12 |
Slight |
July 11 |
Slight |
July 10 |
Slight |
July 9 |
Slight |
July 8 |
Slight |
July 7 |
Slight |
July 6 |
Slight |
July 5 |
Slight |
July 4 |
Slight |
July 3 |
Slight |
July 2 |
Slight |
July 1 |
Slight |
June 30 |
Slight |
June 29 |
Slight
|
June 28 |
Slight |
June 27 |
Slight |
June 26 |
Slight |
June 25 |
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.
General Recommendations 2009 Cercospora Leafspot Season
Cercospora leaf spot spraying is just around the corner for some of the healthier fields. Based on 2008 samples we have noticed a significant up tick in triazole tolerance. If possible we would like to limit the use of triazoles (Eminent-Proline-Inspire) this year. That should be possible in one and two spray programs. Three and four spray programs will likely need the use of trizoles.
Keep in mind that the RR varieties do not have as low of a CLS rating as many of the other varieties 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 are some examples of spray schedules for 2009:
Spray Program |
Application #1 |
Application #2 |
Application #3 |
Application #4 |
One Spray |
Strobilurin |
--- |
--- |
--- |
One Spray |
Tin |
--- |
--- |
--- |
. |
. | . | . | . |
Two Spray |
Tin |
Strobilurin |
--- |
--- |
Two Spray |
Strobilurin |
Tin |
--- |
--- |
| . | . | . | . | . |
Three Spray |
Triazole |
Tin |
Strobilurin |
--- |
| . | . | . | . | . |
Four Spray |
Triazole |
Tin |
Strobilurin |
Tin |
Triazoles: Eminent - Proline - Inspire XT-Inspire SB
Tins: AgriTin - SuperTin
Strobilurins: Headline - Gem
Fungicides |
Re-Entry Interval (Hours) |
Pre Harvest Interval (Days) |
Ground Application Water Volume (Gallons) * |
Rainfast (Hours) |
AgriTin |
48 |
21 |
At least 15 |
*** |
AgriTin Flowable |
48 |
7 |
At least 15 |
*** |
SuperTin 4L |
48 |
7 in MN & 21 in ND |
At Least 15 |
*** |
SuperTin 80 WP |
48 |
7 in MN & 21 in ND |
At Least 15 |
*** |
Eminent |
12 |
14 |
5 or more |
*** |
Gem |
12 |
21 |
Min 10 |
*** |
Headline |
12 |
7 |
Sufficient water to ensure thorough coverage |
*** |
Inspire SB |
12 |
7 |
15 |
1 hour or after it dries |
Inspire XT |
12 |
21 |
15 |
I hour or after it dries |
Proline |
48 |
7 |
Min 10 |
2 |
*Water by air is standard 5 gallons per acre for all fungicides.
*** = 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 indicating less infection).