Appling County Crop E News

Pecan Fungicide Program

The optimum temperature range for scab infection is 59-77 degrees F and a leaf wetness of about 12 hours.

Dr. Lenny Wells provided the following recommended spray guide.

DMI/Stobilurin mixes include Absolute, Brixen, Custodia, Quilt, Top Gard EQ, and Amistar Top (used to be called Quadris Top). Use Amistar Top only during extreme pressure. You could also make your own DMI/Strobi mix, sometimes cheaper than you can buy a pre-mixed product. Just be certain you have the correct amount of active ingredients in the mix. There is no one program suited to every grower and every cultivar but the following provides a few options:

8 spray program for moderately susceptible cultivars or those under less scab pressure

1. DMI/Strobi mix

2. Phosphite–2 qt/acre rate*

3. DMI/Strobi mix

4. Elast/Tin

5. DMI/Strobi mix +Phosphite

6. Elast/Tin

7. Elast/Tin

8. Tin

*Check mixing compatibility of your phosphite and foliar zinc (or other foliar nutrient) choices prior to application. Some phosphite and zinc products do not mix well.

Heavy Scab Pressure (Desirable, Pawnee)

1. DMI/Strobi mix

2. Phosphite–-2 qts/acre

3. DMI Fungicide or Strobilurin + Phosphite (2 qts/acre)

4. DMI/Strobi Mix

5. Elast/Tin

6. Elast/Tin

7. Amistar Top

8. Elast/Tin

9. Elast/Tin

10. DMI/Strobi Mix + Phosphite

11. Elast/Tin

12. Elast/Tin

Continue to rotate Elast/Tin and the DMI strobi Mix if you need to go beyond 12 sprays

OFF Crop or Low Scab Risk Cultivar 8 spray Program

1. DMI or Strobi plus Phosphite @ 1 qt/acre

2. Phosphite–2 qt/acre rate*

3. DMI/Strobi mix

4. Tin

5. DMI/Strobi mix

6. Tin

7. DMI + Phosphite @ 2 qt rate

8. Tin