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Picking the Right Peanut Fungicide Program Bob Kemerait

Picking the Right Peanut Fungicide Program Bob Kemerait
Picking the “right” fungicide program is one of the most complicated (and confusing) decisions that our peanut growers
must make every season. I am often asked to share the “best” peanut program; this is an impossible request as there is
no “single-best” program. The “best” fungicide program varies from farmer to farmer, and from field to field. The
components of a “best” program include:

1. Timeliness of applications; it is critically important to stay AHEAD of disease.

2. Good coverage of the peanut plants; coverage is essential regardless of fungicide program.

3. Properly calibrated sprayers and a spray volume of not less than 10 gal/A.

4. Timely irrigation or rainfall to effectively redistribute the foliar-applied fungicide for control of white mold and
Rhizoctonia limb rot; irrigation is most effective if it occurs from approximately 8 to 24 hours after fungicide application.

5. Selection of specific fungicides which are active against the diseases that will occur in a field. (These diseases almost
always include leaf spot and white mold, but may also include Aspergillus crown rot, Rhizoctonia limb rot,
Cylindrocladium black rot, aka “CBR”, peanut rust, and Pythium pod rot).

6. Selection of specific fungicides with proven efficacy against specific diseases, e.g., CBR, that may be in a field and
better efficacy against diseases, e.g., leaf spot and white mold, in “higher risk” situations.

7. Selection of fungicide programs that add “convenience” to the grower. Examples include fungicides that may allow
the grower to combine or reduce the number of applications because of improved efficacy and/or a longer protective
window. For example, Priaxor allows a grower to combine the first two leaf spot sprays (30 and 45 days after planting)
into a single application at 45 days after planting. Use of Velum Total in-furrow for nematode control allows growers to
begin their leaf spot program at 45 days after planting. The Syngenta Miravis/Elatus program allows growers to switch
from a 7 to a 5 spray program.

8. Use of Peanut Rx disease risk index which allows growers to estimate the risk in their fields to leaf spot, white mold
and spotted wilt diseases. By determining their risk, growers can use more aggressive (and costly) programs in higherrisk fields and programs with fewer sprays (and lower costs) in lower-risk fields.

9. Growers who are highly risk-averse when it comes to fungicides and disease in their peanut crop can reduce their
worry by choosing more aggressive and higher input programs.

10. Lastly, in addition to points 1-9, cost is certainly an important consideration. In making a final decision on which
fungicides to include in a disease management program for peanuts, growers must weigh the initial cost of the program
to expected profitability of a program. Lowest price may not result in greatest profitability.