Mid-Season Disease Mangement Adjustment

Good Day Everyone,

The rain continues to fall in South Carolina. A majority of the peanut producing counties have received more than 6 inches of rain over the last two weeks with more in the forecast for today. The good news, after today, is rain chances for the next seven days are minimal. This is great news if the predictions hold true.   The question is “what kind of impact will the excessive moisture received over the last few weeks along with hotter conditions in the coming week have on disease development?”  To be blunt, we could see high levels of disease start to develop and spread in the month of July.  For this reason, growers will need to adjust their fungicide programs to remain ahead of any potential disease problems.  These changes in the recommendations pertain to all peanut varieties.

 

Things to consider over the few weeks:

1.)  Disease Management

Resistant Varieties (Bailey and Sugg) –  

For peanuts currently at or before 45 Days After Planting (DAP) –

  • Apply a leaf spot fungicide like Headline (6 oz/ac) with tebuconazole (7.2 oz/ac)
  • I would assess conditions at 60 DAP before deciding on what fungicide to apply — you may only need Bravo + Tebuconazole for the 60, 75, and 90 DAP applications.

For peanuts currently at 60 Days After Planting (DAP)–

  • Apply leaf spot fungicide plus a soilborne fungicide – see examples below
    • Headline (6 oz/ac)+ Convoy (13 oz/ac)
    • Abound (18.5 oz/ac) + Alto (5.5 oz/ac)
    • Fontelis (16 oz/ac)
    • Provost (10.7 oz/ac)

I would assess conditions at 75 DAP before deciding on what fungicide to apply — you may only need Bravo + Tebuconazole for the 75, 90, and 105 DAP applications.

 

Susceptible Varieties (runners and Virginias) –  

The fungicide recommendations for the more susceptible varieties like Champs, Spain, and all runners are similar to the recommendations above.

For peanuts at or before 45 Days After Planting (DAP) –

  • Apply a leaf spot fungicide like Headline (9 oz/ac) with tebuconazole (7.2 oz/ac)

For peanuts at 60 Days After Planting (DAP) –

  • Apply a highly effective leaf spot fungicide plus a soilborne fungicide – see examples below
    • Headline (9 oz/ac)+ Convoy (16 oz/ac)
    • Abound (18.5 oz/ac) + Alto (5.5 oz/ac)
    • Fontelis (16 oz/ac)
    • Provost (10.7 oz/ac)

Growers need to choose a fungicide program that has proven to be highly effective on soilborne and foliar diseases and remain timely on your applications for the entire growing season.  Please see the 2013 Peanut Money Maker for fungicide program examples.  http://www.clemson.edu/extension/rowcrops/peanuts/peanut_guide/peanutguide2013.pdf/diseases13.pdf —- page 44 and 45

 

2.)  What can I do for a gypsum alternative for calcium?

The excessive rains have inhibited gypsum applications throughout much of the state.  Even if the rain stopped today, it will likely be next week or longer before growers can resume gypsum application. With some peanuts 50 to 60 days old, growers are getting worried that they have missed the optimal timing for gypsum application to have adequate available calcium during pod formation.   Unfortunately there is little we can do but try to apply the gypsum as soon as we can and hope for the best.  The biggest risk is for the Virginia type peanut varieties.  One potential option for growers with irrigation is applying liquid calcium chloride (“HI-CAL” from Tetra Technologies, Inc.) through the pivot at 20 gal per acre at 60 to 75 DAP.   Twenty gallons of HI-CAL provides roughly 27.36 lbs of available or soluble calcium per acre.  Although HI-CAL has not been tested in South Carolina, results from states have been promising as a calcium supplement for peanut.  Please contact me if you need further information.

 

Please let me know if I can help in any way.

 

Scott

Cell phone: 803-335-8531

 

 

Leave a Reply

  

  

  

You can use these HTML tags

<a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>